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空气污染对登革热的影响
空气污染对登革热的影响是一个复杂且多方面的研究领域,现有证据表明空气污染物可能通过多种机制影响登革热的传播和发病率,包括直接影响蚊媒生物学、改变人类免疫反应以及与气候因素相互作用。
1. 颗粒物 (PM) 对登革热的影响
颗粒物,特别是直径小于或等于2.5微米 (PM2.5) 和10微米 (PM10) 的颗粒,是空气污染的重要组成部分,与登革热发病率之间存在复杂的关联。
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负面关联与保护性效果:
- 在泰国76个省份进行的一项2003-2021年综合分析显示,较高的SO2和PM2.5地表浓度与登革热病例数呈负相关 。这意味着在某些情况下,这些空气污染物可能具有保护性效果,导致登革热病例减少。
- 台湾两南部城市的研究也发现,PM2.5的最低值与每月登革热发病率呈负相关 。这进一步支持了PM2.5可能降低登革热风险的观点。
- 一项对埃及伊蚊(Aedes aegypti)蚊子血粉活动和卵巢变化的剂量依赖性研究发现,细颗粒物(PM)浓度与蚊子的血粉活动呈显著强负相关(r = -0.85; p ≤ 0.00001)。PM浓度越高,蚊子的血粉活动越低,并且卵巢出现剂量依赖性空泡变性。这表明高PM水平可能通过影响蚊子的行为和生理来减少疾病传播。
- 在危地马拉圣罗莎进行的一项病例对照研究(2011-2018年)发现,使用柴火在家中做饭(主要的室内空气污染源)与登革热、基孔肯雅热和寨卡病毒感染呈负相关。具体来说,在主屋中使用柴火做饭(AOR: 0.22; 95% CI: 0.08-0.57)、在开放式炉灶上使用柴火做饭(AOR: 0.50; 95% CI: 0.33-0.78)以及每周使用柴火做饭≥5次(AOR: 0.54; 95% CI: 0.36-0.81)都与较低的蚊媒病毒感染风险相关 。这表明室内空气污染,特别是柴火燃烧产生的颗粒物,可能通过某种机制减少蚊媒疾病的传播风险,例如作为驱蚊剂。
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正面关联与风险增加:
- 然而,也有研究表明PM与登革热风险增加相关。一项针对巴西全国范围的研究发现,野火特异性PM(颗粒物)暴露与登革热相关的住院风险增加有关。野火特异性PM每增加5 μg/m3(滞后0-7天),登革热相关的住院人数增加10.5% (相对风险 [RR]: 1.105, 95% 置信区间 [CI]: 1.060-1.152),其中对典型登革热的影响强于登革出血热(DHF)。这种关联在旱季和人口密度较低的地区更为显著,估计每年有28,994例登革热相关的住院可归因于野火特异性PM暴露 。
- 中国一项针对507个城市儿童和青少年感染性疾病的全国性时间分层病例交叉研究显示,PM2.5的成分与感染性疾病发病率显著相关。其中,硫酸盐导致所有感染性疾病风险增加2.72%(每增加一个四分位距),其次是黑碳(增加2.04%)、有机物(增加1.70%)、无机硝酸盐(增加1.67%)和铵(增加0.79%)。具体而言,硫酸盐对登革热等蚊媒疾病的风险增加了7.46% 。这表明PM2.5的不同化学成分对登革热等传染病有不同的影响,并强调了空气质量标准和有针对性的疾病预防的重要性 。
- 《柳叶刀倒计时》2024年报告指出,沙尘暴的增加导致暴露于危险高浓度颗粒物的人数在2003-2007年到2018-2022年间增加了31% 。虽然没有直接指出登革热,但颗粒物浓度的增加可能通过影响蚊媒活动或人体免疫系统间接影响登革热传播。
- 《柳叶刀倒计时》2019年报告也指出,全球归因于环境细颗粒物(PM)的死亡人数在2016年仍为290万人,而总空气污染死亡人数达到700万人 。虽然这些是呼吸道疾病的主要原因,但环境污染对登革热等传染病的影响也值得关注。
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机制的复杂性:
- 颗粒物可能通过多种途径影响蚊媒疾病。例如,PM可能影响蚊子的生命周期、行为和病毒传播能力 。一项研究显示,制动粉尘(PM的主要成分)对白纹伊蚊(Aedes albopictus)有多种毒性作用,包括降低成虫羽化率、延迟幼虫生长、改变雄性翅膀形状,并在高浓度下增加幼虫的自相残杀行为 。幼虫还会生物积累制动粉尘中的元素,并表现出氧化应激反应 。这表明城市环境中的颗粒物污染可能对蚊媒的生存和繁殖产生负面影响。
- 另一方面,颗粒物也可能通过影响人类免疫系统,使人体更容易感染疾病 。空气污染通常会引起炎症反应并破坏免疫防御系统 。
- 有研究指出,城市环境中人工容器内的碎屑和养分受到细尺度环境变化的影响,进而影响伊蚊幼虫的表型性状和营养组成 。较高不透水覆盖区域的容器中,埃及伊蚊幼虫体型更小、氮富集度较低 。这些微环境变化可能与城市地区的空气污染程度相关联,从而间接影响蚊媒的健康状况和疾病传播潜力。
2. 其他空气污染物对登革热的影响
除了颗粒物,其他空气污染物如SO2、NO2、O3和CO也可能对登革热产生影响。
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二氧化硫 (SO2):
- 泰国研究发现,较高的SO2地表浓度与登革热病例数呈负相关 。
- 然而,台湾研究中SO2的最低值与每月登革热发病率呈正相关 。这表明SO2的影响方向可能因地理位置和具体研究条件而异。
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二氧化氮 (NO2):
- 一项综述发现,NO2的长期暴露与COVID-19发病率增加相关 。尽管没有直接提及登革热,但NO2作为一种常见空气污染物,可能对呼吸道健康和免疫系统产生影响,进而间接影响对其他传染病的易感性。
- 台湾研究并未直接提及NO2与登革热的明确关系,但其与PM一同被认为是潜在影响因素 。
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臭氧 (O3) 和 一氧化碳 (CO):
- 泰国研究发现,登革热与非极端温度和CO地表浓度之间的关系更为复杂,关联方向在不同疾病之间有所变化 。
- 台湾研究发现,O3的最大值和CO的最小值被保留在模型中,与PM一同作为预测登革热发病率的因素 。这表明这些污染物可能在蚊媒生命周期、登革病毒或人类免疫状况中发挥生物学作用 。
3. 空气污染与气候因素的相互作用
登革热的传播强度受多种因素影响,包括气象因素和空气污染物,它们之间可能存在复杂的非线性关联 。
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温度:
- 极高温度与登革热病例数呈负相关 。这可能是因为极端高温对蚊子的生存和繁殖不利。
- 然而,每增加1°C,登革热发病风险增加13% (RR = 1.130 per 1 °C, 95% CI: 1.120-1.150) 。《柳叶刀倒计时》2023年报告指出,气候变化导致全球气温升高,使得登革热传播潜力增加了13%(通过埃及伊蚊传播)和7%(通过白纹伊蚊传播),相对于1950年代的基线 。2023年报告还预测,到本世纪中叶,登革热的传播潜力将增加36-37% 。2016年,全球登革热病毒传播的媒介容量达到历史最高水平,比1950年代基线高出9.1%(埃及伊蚊)和11.1%(白纹伊蚊)。2019年报告也指出,有记录以来登革热传播最适宜的十年中有九年发生在2000年之后 。这些数据强调了温度升高在全球范围内对登革热传播的促进作用。
- 虽然一项研究发现温度与登革热病例没有统计学关联,但温度高峰与登革热暴发高峰相吻合 。
- 《柳叶刀倒计时》2024年报告指出,气温升高和降水模式变化正在促进登革热等致命传染病的传播,使以前未受影响的地区面临传播风险 。
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湿度与降水:
- 高于平均值的绝对湿度(AH)与疾病病例数呈正相关 。
- 高于平均值的总降水量与疾病病例数呈正相关 。
- 降水日与登革热发病率也存在关联 。
- 一项对大圣保罗地区的研究发现,湿度与登革热报告病例存在统计学关联 。
- 《柳叶刀倒计时》2024年报告指出,1961-1990年至2014-2023年间,全球61%的陆地面积极端降水日数增加,这反过来又增加了洪水、传染病传播和水污染的风险 。
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环境异质性:
- 城市梯度上的环境异质性影响人工容器内的碎屑和养分,进而影响伊蚊幼虫 。这提示了城市规划和环境管理在登革热控制中的作用。例如,在老挝,埃及伊蚊蛹最常见于储水罐和轮胎中,而白纹伊蚊蛹与轮胎、水桶和罐子有关 。清除这些积水容器是有效的蚊媒控制措施 。
4. 研究质量与未来方向
- 一项针对空气污染物和温度对传染病暴露风险的系统综述发现,纳入的23篇文章中,只有3篇(13%)为“低”质量,20篇(87%)为“极低”质量 。这表明现有研究的质量参差不齐,需要更高质量的研究来更准确地评估这些风险。
- 研究气候变化与人类健康,尤其是传染病的研究活动正在增加,感染相关研究占了很大一部分 。疟疾和登革热是感染相关文献中最常遇到的病原体/传染病 。然而,国际研究合作不足,未来研究需要关注气候变化对心理社会、精神健康、创新、政策和卫生系统准备的影响 。
- 未来登革热预防应关注空气污染对经典气候因素的贡献 。此外,还需要进一步研究环境污染及其对埃及伊蚊整个生命周期发展的影响,并制定更好的监测策略,包括宣传和监测活动 。
- 加强地方监测系统识别有利城市虫媒病毒传播的变量的能力,有助于优化病媒控制策略。例如,哥伦比亚的VECTOS综合信息系统通过整合流行病学、昆虫学和社区知识、态度和实践(KAP)调查数据,并进行地理空间分析,提供了识别不同社区风险因素异质性的更好见解,从而支持基于证据的决策 。
总结:
空气污染对登革热的影响复杂且具有两面性。一方面,一些研究指出高PM2.5和SO2浓度可能与登革热病例数呈负相关,甚至有证据表明高PM水平会抑制蚊媒的血粉活动和卵巢发育,柴火烟雾可能作为驱蚊剂降低蚊媒感染风险 。这可能通过直接影响蚊媒的生理和行为,使其不利于病毒传播。
另一方面,野火产生的PM暴露以及PM2.5的某些化学成分(如硫酸盐)被发现与登革热住院和发病风险增加相关 。这可能通过影响人类免疫系统,使个体对病毒更易感,或通过其他尚不明确的机制促进疾病传播。
此外,空气污染与气候因素(如温度、湿度和降水)的相互作用也极为重要。全球气温升高明确促进了登革热的传播潜力 ,而极端降水也增加了传染病传播的风险 。因此,在评估空气污染对登革热的影响时,必须将这些复杂的相互作用纳入考量。未来的研究需要更高质量、更全面的数据和更深入的机制探索,以制定更有效的登革热预防和控制策略。
References
1Non-linear associations between meteorological factors, ambient air pollutants and major mosquito-borne diseases in Thailand.PubMed
Pranav Tewari, Pei Ma, Gregory Gan, et al.
PLoS Negl Trop Dis. 2023 Dec 27;17(12):e0011763. doi: 10.1371/journal.pntd.0011763. eCollection 2023 Dec.
BACKGROUND: Transmission intensity for mosquito-borne diseases are highly heterogenous and multi-factorial. Understanding risk factors associated to disease transmission allow the optimization of vector control. This study sets out to understand and compare the combined anthropogenic and environmental risk factors of four major mosquito-borne diseases, dengue, malaria, chikungunya and Japanese encephalitis in Thailand. METHODS: An integrated analysis of mosquito-borne diseases, meteorological and ambient air pollutants of 76 provinces of Thailand was conducted over 2003-2021. We explored the use of generalized linear models and generalized additive models to consider both linear and non-linear associations between meteorological factors, ambient air pollutants and mosquito-borne disease incidence. Different assumptions on spatio-temporal dependence and nonlinearity were considered through province-specific and panel models, as well as different spline functions. Disease-specific model evidence was assessed to select best-fit models for epidemiological inference downstream. RESULTS: Analyses indicated several findings which can be generally applied to all diseases explored: (1) higher AH above mean values was positively associated with disease case counts (2) higher total precipitation above mean values was positively associated with disease case counts (3) extremely high temperatures were negatively associated with disease case counts (4) higher SO2 and PM2.5 surface concentrations were negatively associated with disease case counts. However, the relationships between disease and RH, non-extreme temperatures and CO surface concentration were more mixed, with directions of associations changing across the different diseases considered. CONCLUSIONS: This study found protective and enhancing effects of meteorological and ambient air pollutant factors on mosquito-borne diseases burdens in Thailand. Further studies should employ these factors to understand and predict risk factors associated with mosquito-borne disease transmission.
2Human exposure risk assessment for infectious diseases due to temperature and air pollution: an overview of reviews.PubMed
Xuping Song, Xinye Guo, Xiaopeng Hu, et al.
Environ Sci Pollut Res Int. 2023 Aug;30(38):88272-88280. doi: 10.1007/s11356-023-28453-5. Epub 2023 Jul 13.
Air pollution and global temperature change are expected to affect infectious diseases. Air pollution usually causes inflammatory response and disrupts immune defense system, while temperature mainly exacerbates the effect of vectors on humans. Yet to date overview of systematic reviews assessing the exposure risk of air pollutants and temperature on infectious diseases is unavailable. This article aims to fill this research gap. PubMed, Embase, the Cochrane Library, Web of Science, and the Cumulative Index to Nursing and Allied Health Literature were searched. Systematic reviews and meta-analyses investigated the exposure risk of pollutants or temperature on infectious diseases were included. Two investigators screened literature, extracted data and performed the risk of bias assessments independently. A total of 23 articles met the inclusion criteria, which 3 (13%) were "low" quality and 20 (87%) were "critically low" quality. COVID-19 morbidity was associated with long-term exposure PM (RR = 1.056 per 1 [Formula: see text], 95% CI: 1.039-1.072) and NO (RR = 1.042 per 1 [Formula: see text], 95% CI: 1.017-1.068). In addition, for each 1 °C increase in temperature, the morbidity risk of dengue increased 13% (RR = 1.130 per 1 °C, 95% CI: 1.120-1.150), infectious diarrhea increased 8% (RR = 1.080 per 1 °C, 95% CI: 1.050-1.200), and hand, foot and mouth disease (HFMD) increased 5% (RR = 1.050 per 1 °C, 95% CI: 1.020-1.080). In conclusion, PM and NO increased the risk of COVID-19 and temperatures were associated with dengue, infectious diarrhoea and HFMD morbidity. Moreover, the exposure risk of temperature on COVID-19 was recommended to be further explored.
3Dose-Dependent Blood-Feeding Activity and Ovarian Alterations to PM in .PubMed
Thipruethai Phanitchat, Sumate Ampawong, Artit Yawootti, et al.
Insects. 2021 Oct 18;12(10):948. doi: 10.3390/insects12100948.
High levels of fine particulate matter (PM) air pollution are a concern for human health. Several studies have examined the effects of air pollution on human and animal health. However, there is a lack of knowledge about its effects on arbovirus vectors. Thus, we investigated whether PM concentration alters the blood-feeding activity of mosquitoes. We investigated the effect on the females' propensity to blood feed at eight concentrations of PM ranging from 100 to 1000 μg/m. Correlation analysis showed blood-feeding activity had a significant strong negative correlation with concentration of PM ( = -0.85; ≤ 0.00001). Exploratory linear and non-linear models showed an exponential decay relationship was the best fitting model (corrected Akaike's information criterion, 193.0; Akaike's weight, 0.766; adjusted R, 0.780). Ultrastructural study demonstrated PM did not obstruct the respiratory system, but some fine particles were present on the antenna and abdominal body parts. Ovaries showed a dose-response relationship between PM level and vacuolated degeneration. In conclusion, the blood-feeding behavior of females may have an exponential decay relationship with PM level, and their ovaries may demonstrate dose-dependent degeneration. These findings may be important in understanding the vector's biology and disease transmission in settings with high PM levels. These results are important to understand blood-feeding and feeding pattern of mosquitoes during PM pollution, which is important for disease transmission and vector control.
4The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms.PubMed
Marina Romanello, Claudia di Napoli, Carole Green, et al.
Lancet. 2023 Dec 16;402(10419):2346-2394. doi: 10.1016/S0140-6736(23)01859-7. Epub 2023 Nov 14.
UNLABELLED: The Countdown is an international research collaboration that independently monitors the evolving impacts of climate change on health, and the emerging health opportunities of climate action. In its eighth iteration, this 2023 report draws on the expertise of 114 scientists and health practitioners from 52 research institutions and UN agencies worldwide to provide its most comprehensive assessment yet. In 2022, the Countdown warned that people’s health is at the mercy of fossil fuels and stressed the transformative opportunity of jointly tackling the concurrent climate change, energy, cost-of-living, and health crises for human health and wellbeing. This year’s report finds few signs of such progress. At the current 10-year mean heating of 1·14°C above pre-industrial levels, climate change is increasingly impacting the health and survival of people worldwide, and projections show these risks could worsen steeply with further inaction. However, with health matters gaining prominence in climate change negotiations, this report highlights new opportunities to deliver health-promoting climate change action and a safe and thriving future for all. THE RISING HEALTH TOLL OF A CHANGING CLIMATE: In 2023, the world saw the highest global temperatures in over 100 000 years, and heat records were broken in all continents through 2022. Adults older than 65 years and infants younger than 1 year, for whom extreme heat can be particularly life-threatening, are now exposed to twice as many heatwave days as they would have experienced in 1986–2005 (indicator 1.1.2). Harnessing the rapidly advancing science of detection and attribution, new analysis shows that over 60% of the days that reached health-threatening high temperatures in 2020 were made more than twice as likely to occur due to anthropogenic climate change (indicator 1.1.5); and heat-related deaths of people older than 65 years increased by 85% compared with 1990–2000, substantially higher than the 38% increase that would have been expected had temperatures not changed (indicator 1.1.5). Simultaneously, climate change is damaging the natural and human systems on which people rely for good health. The global land area affected by extreme drought increased from 18% in 1951–60 to 47% in 2013–22 (indicator 1.2.2), jeopardising water security, sanitation, and food production. A higher frequency of heatwaves and droughts in 2021 was associated with 127 million more people experiencing moderate or severe food insecurity compared with 1981–2010 (indicator 1.4), putting millions of people at risk of malnutrition and potentially irreversible health effects. The changing climatic conditions are also putting more populations at risk of life-threatening infectious diseases, such as dengue, malaria, vibriosis, and West Nile virus (indicator 1.3). Compounding these direct health impacts, the economic losses associated with global heating increasingly harm livelihoods, limit resilience, and restrict the funds available to tackle climate change. Economic losses from extreme weather events increased by 23% between 2010–14 and 2018–22, amounting to US$264 billion in 2022 alone (indicator 4.1.1), whereas heat exposure led to global potential income losses worth $863 billion (indicators 1.1.4 and 4.1.3). Labour capacity loss resulting from heat exposure affected low and medium Human Development Index (HDI) countries the most, exacerbating global inequities, with potential income losses equivalent to 6·1% and 3·8% of their gross domestic product (GDP), respectively (indicator 4.1.3). The multiple and simultaneously rising risks of climate change are amplifying global health inequities and threatening the very foundations of human health. Health systems are increasingly strained, and 27% of surveyed cities declared concerns over their health systems being overwhelmed by the impacts of climate change (indicator 2.1.3). Often due to scarce financial resources and low technical and human capacity, the countries most vulnerable to climate impacts also face the most challenges in achieving adaptation progress, reflecting the human risks of an unjust transition. Only 44% of low HDI countries and 54% of medium HDI countries reported high implementation of health emergency management capacities in 2022, compared with 85% of very high HDI countries (indicator 2.2.5). Additionally, low and medium HDI countries had the highest proportion of cities not intending to undertake a climate change risk assessment in 2021 (12%; indicator 2.1.3). These inequalities are aggravated by the persistent failure of the wealthiest countries to deliver the promised modest annual sum of $100 billion to support climate action in those countries defined as developing within the UN Framework Convention on Climate Change. Consequently, those countries that have historically contributed the least to climate change are bearing the brunt of its health impacts—both a reflection and a direct consequence of the structural inequities that lie within the root causes of climate change. THE HUMAN COSTS OF PERSISTENT INACTION: The growing threats experienced to date are early signs and symptoms of what a rapidly changing climate could mean for the health of the world’s populations. With 1337 tonnes of CO emitted each second, each moment of delay worsens the risks to people’s health and survival. In this year’s report, new projections reveal the dangers of further delays in action, with every tracked health dimension worsening as the climate changes. If global mean temperature continues to rise to just under 2°C, annual heat-related deaths are projected to increase by 370% by midcentury, assuming no substantial progress on adaptation (indicator 1.1.5). Under such a scenario, heat-related labour loss is projected to increase by 50% (indicator 1.1.4), and heatwaves alone could lead to 524·9 million additional people experiencing moderate-to-severe food insecurity by 2041–60, aggravating the global risk of malnutrition. Life-threatening infectious diseases are also projected to spread further, with the length of coastline suitable for pathogens expanding by 17–25%, and the transmission potential for dengue increasing by 36–37% by midcentury. As risks rise, so will the costs and challenges of adaptation. These estimates provide some indication of what the future could hold. However, poor accounting for non-linear responses, tipping points, and cascading and synergistic interactions could render these projections conservative, disproportionately increasing the threat to the health of populations worldwide. A WORLD ACCELERATING IN THE WRONG DIRECTION: The health risks of a 2°C hotter world underscore the health imperative of accelerating climate change action. With limits to adaptation drawing closer, ambitious mitigation is paramount to keep the magnitude of health hazards within the limits of the capacity of health systems to adapt. Yet years of scientific warnings of the threat to people’s lives have been met with grossly insufficient action, and policies to date have put the world on track to almost 3°C of heating. The 2022 Countdown report highlighted the opportunity to accelerate the transition away from health-harming fossil fuels in response to the global energy crisis. However, data this year show a world that is often moving in the wrong direction. Energy-related CO emissions increased by 0·9% to a record 36·8 Gt in 2022 (indicator 3.1.1), and still only 9·5% of global electricity comes from modern renewables (mainly solar and wind energy), despite their costs falling below that of fossil fuels. Concerningly, driven partly by record profits, oil and gas companies are further reducing their compliance with the Paris Agreement: the strategies of the world’s 20 largest oil and gas companies as of early 2023 will result in emissions surpassing levels consistent with the Paris Agreement goals by 173% in 2040—an increase of 61% from 2022 (indicator 4.2.6). Rather than pursuing accelerated development of renewable energy, fossil fuel companies allocated only 4% of their capital investment to renewables in 2022. Meanwhile, global fossil fuel investment increased by 10% in 2022, reaching over $1 trillion (indicator 4.2.1). The expansion of oil and gas extractive activities has been supported through both private and public financial flows. Across 2017–21, the 40 banks that lend most to the fossil fuel sector collectively invested $489 billion annually in fossil fuels (annual average), with 52% increasing their lending from 2010–16. Simultaneously, in 2020, 78% of the countries assessed, responsible for 93% of all global CO emissions, still provided net direct fossil fuels subsidies totalling $305 billion, further hindering fossil fuel phase-out (indicator 4.2.4). Without a rapid response to course correct, the persistent use and expansion of fossil fuels will ensure an increasingly inequitable future that threatens the lives of billions of people alive today. THE OPPORTUNITY TO DELIVER A HEALTHY FUTURE FOR ALL: Despite the challenges, data also expose the transformative health benefits that could come from the transition to a zero-carbon future, with health professionals playing a crucial role in ensuring these gains are maximised. Globally, 775 million people still live without electricity, and close to 1 billion people are still served by health-care facilities without reliable energy. With structural global inequities in the development of, access to, and use of clean energy, only 2·3% of electricity in low HDI countries comes from modern renewables (against 11% in very high HDI countries), and 92% of households in low HDI countries still rely on biomass fuels to meet their energy needs (against 7·5% in very high HDI countries; indicators 3.1.1 and 3.1.2). In this context, the transition to renewables can enable access to decentralised clean energy and, coupled with interventions to increase energy efficiency, can reduce energy poverty and power high quality health-supportive services. By reducing the burning of dirty fuels (including fossil fuels and biomass), such interventions could help avoid a large proportion of the 1·9 million deaths that occur annually from dirty-fuel-derived, outdoor, airborne, fine particulate matter pollution (PM; indicator 3.2.1), and a large proportion of the 78 deaths per 100 000 people associated with exposure to indoor air pollution (indicator 3.2.2). Additionally, the just development of renewable energy markets can generate net employment opportunities with safer, more locally available jobs. Ensuring countries, particularly those facing high levels of energy poverty, are supported in the safe development, deployment, and adoption of renewable energy is key to maximising health gains and preventing unjust extractive industrial practices that can harm the health and livelihoods of local populations and widen health inequities. With fossil fuels accounting for 95% of road transport energy (indicator 3.1.3), interventions to enable and promote safe active travel and zero-emission public transport can further deliver emissions reduction, promote health through physical activity, and avert many of the 460 000 deaths caused annually by transport-derived PM pollution (indicator 3.2.1), and some of the 3·2 million annual deaths related to physical inactivity. People-centred, climate-resilient urban redesign to improve building energy efficiency, increase green and blue spaces, and promote sustainable cooling, can additionally prevent heat-related health harms, avoid air-conditioning-derived emissions (indicator 2.2.2), and provide direct physical and mental health benefits. Additionally, food systems are responsible for 30% of global greenhouse gas (GHG) emissions, with 57% of agricultural emissions in 2020 being derived from the production of red meat and milk (indicator 3.3.1). Promoting and enabling equitable access to affordable, healthy, low-carbon diets that meet local nutritional and cultural requirements can contribute to mitigation, while preventing many of the 12·2 million deaths attributable to suboptimal diets (indicator 3.3.2). The health community could play a central role in securing these benefits, by delivering public health interventions to reduce air pollution, enabling and supporting active travel and healthier diets, and promoting improvements in the environmental conditions and commercial activities that define health outcomes. Importantly, the health sector can lead by example and transition to sustainable, resource-efficient, net-zero emission health systems, thereby preventing its 4·6% contribution to global GHG emissions, with cascading impacts ultimately affecting the broader economy (indicator 3.4). Some encouraging signs of progress offer a glimpse of the enormous human benefits that health-centred action could render. Deaths attributable to fossil-fuel-derived air pollution have decreased by 15·7% since 2005, with 80% of this reduction being the result of reduced coal-derived pollution. Meanwhile the renewable energy sector expanded to a historical high of 12·7 million employees in 2021 (indicator 4.2.2); and renewable energy accounted for 90% of the growth in electricity capacity in 2022 (indicator 3.1.1). Supporting this, global clean energy investment increased by 15% in 2022, to $1·6 trillion, exceeding fossil fuel investment by 61% (indicator 4.2.1); and lending to the green energy sector rose to $498 billion in 2021, approaching fossil fuel lending (indicator 4.2.7). Scientific understanding of the links between health and climate change is rapidly growing, and although coverage lags in some of the most affected regions, over 3000 scientific articles covered this topic in 2022 (indicators 5.3.1 and 5.3.2). Meanwhile, the health dimensions of climate change are increasingly acknowledged in the public discourse, with 24% of all climate change newspaper articles in 2022 referring to health, just short of the 26% in 2020 (indicator 5.1). Importantly, international organisations are increasingly engaging with the health co-benefits of climate change mitigation (indicator 5.4.2), and governments increasingly acknowledge this link, with 95% of updated Nationally Determined Contributions (NDCs) under the Paris Agreement now referring to health—up from 73% in 2020 (indicator 5.4.1). These trends signal what could be the start of a life-saving transition. A PEOPLE-CENTRED TRANSFORMATION: PUTTING HEALTH AT THE HEART OF CLIMATE ACTION: With the world currently heading towards 3°C of heating, any further delays in climate change action will increasingly threaten the health and survival of billions of people alive today. If meaningful, the prioritisation of health in upcoming international climate change negotiations could offer an unprecedented opportunity to deliver health-promoting climate action and pave the way to a thriving future. However, delivering such an ambition will require confronting the economic interests of the fossil fuel and other health-harming industries, and delivering science-grounded, steadfast, meaningful, and sustained progress to shift away from fossil fuels, accelerate mitigation, and deliver adaptation for health. Unless such progress materialises, the growing emphasis on health within climate change negotiations risks being mere healthwashing; increasing the acceptability of initiatives that minimally advance action, and which ultimately undermine—rather than protect—the future of people alive today and generations to come. Safeguarding people’s health in climate policies will require the leadership, integrity, and commitment of the health community. With its science-driven approach, this community is uniquely positioned to ensure that decision makers are held accountable, and foster human-centred climate action that safeguards human health above all else. The ambitions of the Paris Agreement are still achievable, and a prosperous and healthy future still lies within reach. But the concerted efforts and commitments of health professionals, policy makers, corporations, and financial institutions will be needed to ensure the promise of health-centred climate action becomes a reality that delivers a thriving future for all.
5Sri Lanka: report on its children's environmental health.PubMed
Himan Galappaththi
Rev Environ Health. 2020 Mar 26;35(1):65-70. doi: 10.1515/reveh-2019-0091.
Sri Lanka is an island country located in the Indian Ocean, characterized by tropical weather, with an estimated population of 21.4 million in 2017, one third of them being children. Advancing and rapidly changing technology, novel industries, consumer goods and equipment have introduced new health hazards of a chemical, biological and physical nature to future generations. The infant mortality rate has declined to around 8-9 per 100,000 since 2015. Congenital malformations were the most significant cause of neonatal death. Thus, there might be unproven environmental factors which affect infant mortality rates despite robust field and hospital services. Air pollution is a major environmental health hazard to children, largely due to hazardous industries, vehicular emissions and traditional cooking stoves. The health of children living in urban households and attending schools in cities is adversely affected by air pollution. Usage of polythene and plastic for toys, utensils, bags, lunch sheets and other daily essentials leads to overusage and improper waste management and open burning. This emits dioxins, which are carcinogens, hormone disruptors, and which can be transferred to the fetus via the placenta. In rural areas, the burning of agricultural waste and certain agro-forestry activities have also led to air pollution. Indoor air pollution (IAP) remains a large threat as 66% of the population use biomass for cooking. Use of inefficient stoves and biomass, poor ventilation and absence of chimneys, contribute to IAP. Other indoor air pollutants such as tobacco smoke, volatile organic compounds, asbestos, pesticides, kerosene, mercury, mosquito coils and biological pollutants also prevail. Biological pollutants, such as dust mites, droppings and urine from pets, insects and rodents, pollen from indoor plants and outdoor air, and fungi, including moulds in poorly maintained buildings, can trigger asthma or cause allergic reactions and infections among children inhabiting these environments. In rural areas, chemicals were accountable for 30.2% of acute poisonings, with kerosene oil being the most common cause, followed by paracetamol. More than 80% of agricultural workers in the country work in the informal sector with limited personal protective equipment use, while pesticide usage is increasing. Children who engage in agriculture-related work and hazardous industries are at risk of developing health consequences at early stages. Dengue remains a major environmental health problem as the reduction of mosquito breeding sites has been a challenging task for many years. It is essential to gain more evidence of existing environmental risk factors and their associations with the health of children. Information dissemination among local and international experts on Children's Environmental Health (CEH) issues needs to be enhanced and properly established. Training programs should be conducted for healthcare workers to update their knowledge. Pediatricians are needed for remote hospitals and primary healthcare centers. Environmental parameters and biological parameters are not routinely monitored in most of the hazardous environments.
6Role of air pollutants in dengue fever incidence: evidence from two southern cities in Taiwan.PubMed
Hao-Chun Lu, Fang-Yu Lin, Yao-Huei Huang, et al.
Pathog Glob Health. 2023 Sep;117(6):596-604. doi: 10.1080/20477724.2022.2135711. Epub 2022 Oct 19.
Air pollution may be involved in spreading dengue fever (DF) besides rainfalls and warmer temperatures. While particulate matter (PM), especially those with diameter of 10 μm (PM10) or 2.5 μm or less (PM25), and NO2 increase the risk of coronavirus 2 infection, their roles in triggering DF remain unclear. We explored if air pollution factors predict DF incidence in addition to the classic climate factors. Public databases and DF records of two southern cities in Taiwan were used in regression analyses. Month order, PM10 minimum, PM2.5 minimum, and precipitation days were retained in the enter mode model, and SO2 minimum, O3 maximum, and CO minimum were retained in the stepwise forward mode model in addition to month order, PM10 minimum, PM2.5 minimum, and precipitation days. While PM2.5 minimum showed a negative contribution to the monthly DF incidence, other variables showed the opposite effects. The sustain of month order, PM10 minimum, PM2.5 minimum, and precipitation days in both regression models confirms the role of classic climate factors and illustrates a potential biological role of the air pollutants in the life cycle of mosquito vectors and dengue virus and possibly human immune status. Future DF prevention should concern the contribution of air pollution besides the classic climate factors.
7Bibliometric analysis of peer-reviewed literature on climate change and human health with an emphasis on infectious diseases.PubMed
Waleed M Sweileh
Global Health. 2020 May 8;16(1):44. doi: 10.1186/s12992-020-00576-1.
BACKGROUND: Assessing research activity is important for planning future protective and adaptive policies. The objective of the current study was to assess research activity on climate change and health with an emphasis on infectious diseases. METHOD: A bibliometric method was applied using SciVerse Scopus. Documents on climate change and human health were called "health-related literature" while documents on climate change and infectious diseases were called "infection-related literature". The study period was from 1980 to 2019. RESULTS: The search query found 4247 documents in the health-related literature and 1207 in the infection-related literature. The growth of publications showed a steep increase after 2007. There were four research themes in the health-related literature: (1) climate change and infectious diseases; (2) climate change, public health and food security; (3) heat waves, mortality, and non-communicable diseases; and (4) climate change, air pollution, allergy, and respiratory health. The most frequently encountered pathogens/infectious diseases in the infection-related literature were malaria and dengue. Documents in infection-related literature had a higher h-index than documents in the health-related literature. The top-cited documents in the health-related literature focused on food security, public health, and infectious diseases while those in infection-related literature focused on water-, vector-, and mosquito-borne diseases. The European region had the highest contribution in health-related literature (n = 1626; 38.3%) and infection-related literature (n = 497; 41.2%). The USA led with 1235 (29.1%) documents in health-related literature and 365 (30.2%) documents in infection-related literature. The Australian National University ranked first in the health-related literature while the London School of Hygiene & Tropical Medicine ranked first in the infection-related literature. International research collaboration was inadequate. Documents published in the Environmental Health Perspectives journal received the highest citations per document. A total of 1416 (33.3%) documents in the health-related literature were funded while 419 (34.7%) documents in the infection-related literature were funded. CONCLUSION: Research on climate change and human health is on the rise with research on infection-related issues making a good share. International research collaboration should be funded and supported. Future research needs to focus on the impact of climate change on psychosocial, mental, innovations, policies, and preparedness of health systems.
8Wildfire smoke and dengue burden in Brazil: Evidence from a nationwide study.PubMed
Rahini Mahendran, Lei Zhang, Rongbin Xu, et al.
Environ Pollut. 2026 Feb 1;390:127505. doi: 10.1016/j.envpol.2025.127505. Epub 2025 Dec 6.
Wildfire fine particulate matter (PM) is an emerging health concern, yet its effects on mosquito-borne diseases, particularly dengue, remain unclear. Brazil faces one of the world's highest dengue burdens alongside frequent wildfires. We examined the association between short-term wildfire-specific PM exposure and dengue-related hospitalizations across Brazil. We conducted a nationwide two-stage time-series analysis using daily dengue-related hospitalizations and daily wildfire-specific PM concentrations across all Brazilian immediate-regions from 2008 to 2019. The wildfire-specific PM estimates were derived from a chemical transport model and machine-learning calibration. Immediate region-specific associations between wildfire-specific PM with dengue hospitalization risks were estimated using quasi-Poisson regression with distributed lag models and pooled using random-effects meta-analysis. Effect modification by socio-demographic factors, season, and forest cover was examined and attributable dengue hospitalizations were estimated. A 5 μg/m increase in wildfire-specific PM (lag 0-7 days) was associated with a 10.5 % increase in dengue-related hospitalizations (Relative risk [RR]: 1.105 (95 % Confidence Interval [CI]: 1.060-1.152), stronger for dengue fever (RR: 1.094, 95 %CI: 1.049-1.141) than for Dengue Hemorrhagic Fever (DHF) (1.174, 0.754-1.831). Associations were consistent across sex, age groups, and regions, with higher risks in the elderly for DHF. Risks were greater during the dry season and in less densely populated areas. An estimated 28,994 dengue-related hospitalizations (95 % CI: 16,737-40,867) were attributable to wildfire-specific PM exposure in Brazil, averaging 17.3 per 100,000 population annually. The Northeast region had the highest number of attributable dengue-related hospitalizations, while the Southeast region had higher population-level impact. No association was found with non-wildfire PM. Wildfire-specific PM exposure increases dengue-related hospitalization risk in Brazil, underscoring the need to integrate wildfire smoke into dengue and vector surveillance and to target high-risk areas to reduce disease burden.
9Environmental factors can influence dengue reported cases.PubMed
Marco Antonio F Carneiro, Beatriz da C A Alves, Flávia de Sousa Gehrke, et al.
Rev Assoc Med Bras (1992). 2017 Nov;63(11):957-961. doi: 10.1590/1806-9282.63.11.957.
INTRODUCTION: Global climate changes directly affect the natural environment and contribute to an increase in the transmission of diseases by vectors. Among these diseases, dengue is at the top of the list. The aim of our study was to understand the consequences of temporal variability of air temperature in the occurrence of dengue in an area comprising seven municipalities of the Greater São Paulo. METHOD: Characterization of a temporal trend of the disease in the region between 2010 and 2013 was performed through analysis of the notified number of dengue cases over this period. Our analysis was complemented with meteorological (temperature) and pollutant concentration data (PM10). RESULTS: We observed that the months of January, February, March, April and May (from 2010 to 2013) were the ones with the highest number of notified cases. We also found that there is a statistical association of moisture and PM10 with the reported cases of dengue. CONCLUSION: Although the temperature does not statistically display an association with recorded cases of dengue, we were able to verify that temperature peaks coincide with dengue outbreak peaks. Future studies on environmental pollution and its influence on the development of Aedes aegypti mosquito during all stages of its life cycle, and the definition of strategies for better monitoring, including campaigns and surveillance, would be compelling.
10Oil fly ash as a promise larvicide against the Aedes aegypti mosquitoes.PubMed
Hanan Abo El-Kassem Bosly, Numan Salah, Salama A Salama, et al.
Acta Trop. 2023 Jan;237:106735. doi: 10.1016/j.actatropica.2022.106735. Epub 2022 Oct 29.
Two environmental problems exist in some tropical and subtropical areas: the Aedes aegypti (L.) (Ae. aegypti) mosquito and thousands of tons of heavy oil fly ash (HOFA) from power plants. Herein, micro/nanoparticles of HOFA have been utilized as a larvicide against Ae. aegypti without any chemical or biological additive materials. We estimated the accumulative mortalities in the third instar after 24/48 h (h). We found that after 24 h of exposing the larvae to the HOFA microsized, the LC50 and LC90 were 0.55 and 4.87 mg/ml, respectively, while they were 0.10 and 0.36 mg/ml after 48 h. At the same time, the LC50 and LC90 were respectively 0.12 and 0.60 mg/ml after 24 h exposing the larvae to the HOFA nanosized, and they were 0.06 and 0.23 mg/ml after 48 h. These results showed that the HOFA nanoparticles as larvicides were more effective than HOFA microparticles. The microscopy images also revealed deformations such as pigmentations, segment shrinkage, larva swelling, segment body contraction, siphon swelling, intermediate stage, head deformations, and thorax swelling in the larvae exposed to the HOFA. These deformations could indicate alterations in the hormones that control the biochemistry of the larvae body. The findings of this study could suggest the possibility of using HOFA, particularly in nanosized, as a promising larvicide against the Ae. aegypti mosquito.
11The 2024 report of the Lancet Countdown on health and climate change: facing record-breaking threats from delayed action.PubMed
Marina Romanello, Maria Walawender, Shih-Che Hsu, et al.
Lancet. 2024 Nov 9;404(10465):1847-1896. doi: 10.1016/S0140-6736(24)01822-1. Epub 2024 Oct 30.
UNLABELLED: Despite the initial hope inspired by the 2015 Paris Agreement, the world is now dangerously close to breaching its target of limiting global multiyear mean heating to 1·5°C. Annual mean surface temperature reached a record high of 1·45°C above the pre-industrial baseline in 2023, and new temperature highs were recorded throughout 2024. The resulting climatic extremes are increasingly claiming lives and livelihoods worldwide. The Countdown: tracking progress on health and climate change was established the same year the Paris Agreement entered into force, to monitor the health impacts and opportunities of the world’s response to this landmark agreement. Supported through strategic core funding from Wellcome, the collaboration brings together over 300 multidisciplinary researchers and health professionals from around the world to take stock annually of the evolving links between health and climate change at global, regional, and national levels. The 2024 report of the Countdown, building on the expertise of 122 leading researchers from UN agencies and academic institutions worldwide, reveals the most concerning findings yet in the collaboration’s 8 years of monitoring. THE RECORD-BREAKING HUMAN COSTS OF CLIMATE CHANGE: Data in this year’s report show that people all around the world are facing record-breaking threats to their wellbeing, health, and survival from the rapidly changing climate. Of the 15 indicators monitoring climate change-related health hazards, exposures, and impacts, ten reached concerning new records in their most recent year of data. Heat-related mortality of people older than 65 years increased by a record-breaking 167%, compared with the 1990s, 102 percentage points higher than the 65% that would have been expected without temperature rise (indicator 1.1.5). Heat exposure is also increasingly affecting physical activity and sleep quality, in turn affecting physical and mental health. In 2023, heat exposure put people engaging in outdoor physical activity at risk of heat stress (moderate or higher) for a record high of 27·7% more hours than on average in the 1990s (indicator 1.1.2) and led to a record 6% more hours of sleep lost in 2023 than the average during 1986–2005 (indicator 1.1.4). People worldwide are also increasingly at risk from life-threatening extreme weather events. Between 1961–90 and 2014–23, 61% of the global land area saw an increase in the number of days of extreme precipitation (indicator 1.2.3), which in turn increases the risk of flooding, infectious disease spread, and water contamination. In parallel, 48% of the global land area was affected by at least 1 month of extreme drought in 2023, the second largest affected area since 1951 (indicator 1.2.2). The increase in drought and heatwave events since 1981–2010 was, in turn, associated with 151 million more people experiencing moderate or severe food insecurity across 124 countries assessed in 2022, the highest recorded value (indicator 1.4.2). The hotter and drier weather conditions are increasingly favouring the occurrence of sand and dust storms. This weather-environmental phenomenon contributed to a 31% increase in the number of people exposed to dangerously high particulate matter concentrations between 2003–07 and 2018–22 (indicator 1.2.4). Meanwhile, changing precipitation patterns and rising temperatures are favouring the transmission of deadly infectious diseases such as dengue, malaria, West Nile virus-related illness, and vibriosis, putting people at risk of transmission in previously unaffected locations (indicators 1.3.1–1.3.4). Compounding these impacts, climate change is affecting the social and economic conditions on which health and wellbeing depend. The average annual economic losses from weather-related extreme events increased by 23% from 2010–14 to 2019–23, to US$227 billion (a value exceeding the gross domestic product [GDP] of about 60% of the world’s economies; indicator 4.1.1). Although 60·5% of losses in very high Human Development Index (HDI) countries were covered by insurance, the vast majority of those in countries with lower HDI levels were uninsured, with local communities bearing the brunt of the physical and economic losses (indicator 4.1.1). Extreme weather and climate change-related health impacts are also affecting labour productivity, with heat exposure leading to a record high loss of 512 billion potential labour hours in 2023, worth $835 billion in potential income losses (indicators 1.1.3 and 4.1.3). Low and medium HDI countries were most affected by these losses, which amounted to 7·6% and 4·4% of their GDP, respectively (indicator 4.1.3). With the most underserved communities most affected, these economic impacts further reduce their capacity to cope with and recover from the growing impacts of climate change, thereby amplifying global inequities. Concerningly, multiple hazards revealed by individual indicators are likely to have simultaneous compounding and cascading impacts on the complex and inter-connected human systems that sustain good health, disproportionately threatening people’s health and survival with every fraction of a degree of increase in global mean temperature. Despite years of monitoring exposing the imminent health threats of climate inaction, the health risks people face have been exacerbated by years of delays in adaptation, which have left people ill-protected from the growing threats of climate change. Only 68% of countries reported high-to-very-high implementation of legally mandated health emergency management capacities in 2023, of which just 11% were low HDI countries (indicator 2.2.5). Moreover, only 35% of countries reported having health early warning systems for heat-related illness, whereas 10% did so for mental and psychosocial conditions (indicator 2.2.1). Scarcity of financial resources was identified as a key barrier to adaptation, including by 50% of the cities that reported they were not planning to undertake climate change and health risk assessments (indicator 2.1.3). Indeed, adaptation projects with potential health benefits represented just 27% of all the Green Climate Fund’s adaptation funding in 2023, despite a 137% increase since 2021 (indicator 2.2.4). With universal health coverage still unattained in most countries, financial support is needed to strengthen health systems and ensure that they can protect people from growing climate change-related health hazards. The unequal distribution of financial resources and technical capacity is leaving the most vulnerable populations further unprotected from the growing health risks. FUELLING THE FIRE: As well as exposing the inadequacy of adaptation efforts to date, this year’s report reveals a world veering away from the goal of limiting temperature rise to 1·5°C, with concerning new records broken across indicators monitoring greenhouse gas emissions and the conditions that enable them. Far from declining, global energy-related CO emissions reached an all-time high in 2023 (indicator 3.1.1). Oil and gas companies are reinforcing the global dependence on fossil fuels and—partly fuelled by the high energy prices and windfall profits of the global energy crisis—most are further expanding their fossil fuel production plans. As of March, 2024, the 114 largest oil and gas companies were on track to exceed emissions consistent with 1·5°C of heating by 189% in 2040, up from 173% 1 year before (indicator 4.2.2). As a result, their strategies are pushing the world further off track from meeting the goals of the Paris Agreement, further threatening people’s health and survival. Although renewable energy could provide power to remote locations, its adoption is lagging, particularly in the most vulnerable countries. The consequences of this delay reflect the human impacts of an unjust transition. Globally, 745 million people still lack access to electricity and are facing the harms of energy poverty on health and wellbeing. The burning of polluting biomass (eg, wood or dung) still accounts for 92% of the energy used in the home by people in low HDI countries (indicator 3.1.2), and only 2·3% of electricity in these countries comes from clean renewables, compared with 11·6% in very high HDI countries (indicators 3.1.1). This persistent burning of fossil fuel and biomass led to at least 3·33 million deaths from outdoor fine particulate matter (PM) air pollution globally in 2021 alone (indicator 3.2.1), and the domestic use of dirty solid fuels caused 2·3 million deaths from indoor air pollution in 2020 across 65 countries analysed (indicator 3.2.2). Compounding the growth in energy-related greenhouse gas emissions, almost 182 million hectares of forests were lost between 2016 and 2022 (indicator 3.4), reducing the world’s natural capacity to capture atmospheric CO. In parallel, the consumption of red meat and dairy products, which contributed to 11·2 million deaths attributable to unhealthy diets in 2021 (indicator 3.3.2), has led to a 2·9% increase in agricultural greenhouse gas emissions since 2016 (indicator 3.3.1). Health systems themselves, although essential to protect people’s health, are also increasingly contributing to the problem. Greenhouse gas emissions from health care have increased by 36% since 2016, making health systems increasingly unprepared to operate in a net zero emissions future and pushing health care further from its guiding principle of doing no harm (indicator 3.5). The growing accumulation of greenhouse gases in the atmosphere is pushing the world to a future of increasingly dangerous health hazards and reducing the chances of survival of vulnerable people all around the globe. HEALTH-THREATENING FINANCIAL FLOWS: With the availability of financial resources a key barrier to tackling climate change, a rapid growth in predictable and equitable investment is urgently needed to avoid the most dangerous impacts of climate change. A growing body of literature shows that the economic benefits of a transition to net zero greenhouse gas emissions will far exceed the costs of inaction. Healthier, more resilient populations will further support more prosperous and sustainable economies (indicators 4.1.2–4.1.4). However, although funding to enable potentially life-saving climate change adaptation and mitigation activities remains scarce, substantial financial resources are being allocated to activities that harm health and perpetuate a fossil fuel-based economy. The resulting reliance on fossil fuel energy has meant many countries faced sharp increases in energy prices following Russia’s invasion of Ukraine and the resulting disruption of fossil fuel supplies. To keep energy affordable to local populations, many governments resorted to increasing their explicit fossil fuel subsidies. Consequently, 84% of countries studied still operated net negative carbon prices (explicit net fossil fuel subsidies) in 2022, for a record high net total of $1·4 trillion (indicator 4.3.3), with the sums involved often comparable to countries’ total health budgets. In addition, although clean energy investment grew by 10% globally in 2023—exceeding fossil fuel investment by 73%—considerable regional disparities exist. Clean energy investment is 38% lower than fossil fuel spending in emerging market and developing economies outside China. Clean energy spending in these countries only accounted for 17·4% of the global total. Moreover, investment in energy efficiency and end use, essential for a just transition, decreased by 1·3% in 2023 (indicator 4.3.1). The resulting expansion of fossil fuel assets is increasingly jeopardising the economies on which people’s livelihoods depend. On the current trajectory, the world already faces potential global income losses ranging from 11% to 29% by 2050. The number of fossil fuel industry employees reached 11·8 million in 2022, increasing the size of a workforce whose employment cannot be sustained in a world that avoids the most catastrophic human impacts of climate change (indicator 4.2.1). Meanwhile, ongoing investments in coal power have pushed the value of coal-fired power generation assets that risk becoming stranded within 10 years (between 2025 and 2034) in a 1·5°C trajectory to a cumulative total of $164·5 billion—a value that will increase if coal investments persist (indicator 4.2.3). The prioritisation of fossil fuel-based systems means most countries remain ill-prepared for the vital transition to zero greenhouse gas emission economies. As a result of an unjust transition, the risk is unequally distributed: preparedness scores for the transition to a net zero greenhouse gas economy were below the global average in all countries with a low HDI, 96% of those with a medium HDI, and 84% of those with a high HDI, compared with just 7% of very high HDI countries (indicator 4.2.4). DEFINING THE HEALTH PROFILE OF PEOPLE WORLDWIDE: Following decades of delays in climate change action, avoiding the most severe health impacts of climate change now requires aligned, structural, and sustained changes across most human systems, including energy, transportation, agriculture, food, and health care. Importantly, a global transformation of financial systems is required, shifting resources away from the fossil fuel-based economy towards a zero emissions future. Putting people’s health at the centre of climate change policy making is key to ensuring this transition protects wellbeing, reduces health inequities, and maximises health gains. Some indicators reveal incipient progress and important opportunities for delivering this health-centred transformation. As of December, 2023, 50 countries reported having formally assessed their health vulnerabilities and adaptation needs, up from 11 the previous year, and the number of countries that reported having a Health National Adaptation Plan increased from four in 2022 to 43 in 2023 (indicators 2.1.1 and 2.1.2). Additionally, 70% of 279 public health education institutions worldwide reported providing education in climate and health in 2023, essential to build capacities for health professionals to help shape this transition (indicator 2.2.6). Regarding the energy sector, the global share of electricity from clean modern renewables reached a record high of 10·5% in 2021 (indicator 3.1.1); clean energy investment exceeded fossil fuel investment by 73% in 2023 (indicator 4.3.1); and renewable energy-related employment has grown 35·6% since 2016, providing healthier and more sustainable employment opportunities than those in the fossil fuel industry (indicator 4.2.1). Importantly, mostly as a result of coal phase-down in high and very high HDI countries, deaths attributable to outdoor PM from fossil fuel combustion decreased by 6·9% between 2016 and 2021 (indicator 3.2.1), showing the life-saving potential of coal phase-out. Important progress was made within international negotiations, which opened new opportunities to protect health in the face of climate change. After years of leadership from WHO on climate change and health, its Fourteenth General Programme of Work, adopted in May, 2024, made responding to climate change its first strategic priority. Within climate negotiations themselves, the 28th Conference of the Parties (COP28) of the United Nations Framework Convention on Climate Change (UNFCCC) featured the first health thematic day in 2023: 151 countries endorsed the COP28 United Arab Emirates Declaration on Climate and Health, and the Global Goal on Adaptation set a specific health target. The outcome of the first Global Stocktake of the Paris Agreement also recognised the right to health and a healthy environment, urging parties to take further health adaptation efforts, and opened a new opportunity for human survival, health, and wellbeing to be prioritised in the updated Nationally Determined Contributions (NDCs) due in 2025. The pending decision of how the Loss and Damage fund will be governed and the definition of the New Collective Quantified Goal on Climate Finance during COP29 provide further opportunities to secure the financial support crucial for a healthy net zero transition. Although still insufficient to protect people’s health from climate change, these emerging signs of progress help open new opportunities to deliver a healthy, prosperous future. However, much remains to be done. HANGING IN THE BALANCE: With climate change breaking dangerous new records and emissions persistently rising, preventing the most catastrophic consequences on human development, health, and survival now requires the support and will of all actors in society. However, data suggest that engagement with health and climate change could be declining across key sectors: the number of governments mentioning health and climate change in their annual UN General Debate statements fell from 50% in 2022 to 35% in 2023, and only 47% of the 58 NDCs updated as of February, 2024, referred to health (indicator 5.4.1). Media engagement also dropped, with the proportion of newspaper climate change articles mentioning health falling 10% between 2022 and 2023 (indicator 5.1). The powerful and trusted leadership of the health community could hold the key to reversing these concerning trends and making people’s wellbeing, health, and survival a central priority of political and financial agendas. The engagement of health professionals at all levels of climate change decision making will be pivotal in informing the redirection of efforts and financial resources away from activities that jeopardise people’s health towards supporting healthy populations, prosperous economies, and a safer future. As concerning records continue to be broken and people face unprecedented risks from climate change, the wellbeing, health, and survival of individuals in every country now hang in the balance.
12VECTOS: An Integrated System for Monitoring Risk Factors Associated With Urban Arbovirus Transmission.PubMed
Clara B Ocampo, Neila J Mina, Maria I Echavarria, et al.
Glob Health Sci Pract. 2019 Mar 29;7(1):128-137. doi: 10.9745/GHSP-D-18-00300. Print 2019 Mar 22.
In Colombia, as in many Latin American countries, decision making and development of effective strategies for vector control of urban diseases such as dengue, Zika, and chikungunya is challenging for local health authorities. The heterogeneity of transmission in urban areas requires an efficient risk-based allocation of resources to control measures. With the objective of strengthening the capacity of local surveillance systems to identify variables that favor urban arboviral transmission, a multidisciplinary research team collaborated with the local Secretary of Health officials of 3 municipalities in Colombia (Giron, Yopal, and Buga), in the design of an integrated information system called VECTOS from 2015 to 2018. Information and communication technologies were used to develop 2 mobile applications to capture entomological and social information, as well as a web-based system for the collection, geo-referencing, and integrated information analysis using free geospatial software. This system facilitates the capture and analysis of epidemiological information from the Colombian national surveillance system (SIVIGILA), periodic entomological surveys-mosquito larvae and pupae in premises and peridomestic breeding sites-and surveys of knowledge, attitudes, and practices (KAP) in a spatial and temporal context at the neighborhood level. The data collected in VECTOS are mapped and visualized in graphical reports. The system enables real-time monitoring of weekly epidemiological indicators, entomological indices, and social surveys. Additionally, the system enables risk stratification of neighborhoods, using selected epidemiological, entomological, demographic, and environmental variables. This article describes the VECTOS system and the lessons learned during its development and use. The joint analysis of epidemiological and entomological data within a geographic information system in VECTOS gives better insight to the routinely collected data and identifies the heterogeneity of risk factors between neighborhoods. We expect the system to continue to strengthen vector control programs in evidence-based decision making and in the design and enhanced follow-up of vector control strategies.
13Differentiated impacts of short-term exposure to fine particulate constituents on infectious diseases in 507 cities of Chinese children and adolescents: A nationwide time-stratified case-crossover study from 2008 to 2021.PubMed
Li Chen, Wen Yuan, Mengjie Geng, et al.
Sci Total Environ. 2024 Jun 10;928:172299. doi: 10.1016/j.scitotenv.2024.172299. Epub 2024 Apr 12.
This study assesses the association of short-term exposure to PM (particles ≤2.5 μm) on infectious diseases among Chinese children and adolescents. Analyzing data from 507 cities (2008-2021) on 42 diseases, it focuses on PM components (black carbon (BC), ammonium (NH), inorganic nitrate (NO), organic matter (OM), and sulfate (SO)). PM constituents significantly associated with incidence. Sulfate showed the most substantial effect, increasing all-cause infectious disease risk by 2.72 % per interquartile range (IQR) increase. It was followed by BC (2.04 % increase), OM (1.70 %), NO (1.67 %), and NH (0.79 %). Specifically, sulfate and BC had pronounced impacts on respiratory diseases, with sulfate linked to a 10.73 % increase in seasonal influenza risk and NO to a 16.39 % rise in tuberculosis. Exposure to PM also marginally increased risks for gastrointestinal, enterovirus, and vectorborne diseases like dengue (7.46 % increase with SO). Sexually transmitted and bloodborne diseases saw an approximate 6.26 % increase in incidence, with specific constituents linked to diseases like hepatitis C and syphilis. The study concludes that managing PM levels could substantially reduce infectious disease incidence, particularly in China's middle-northern regions. It highlights the necessity of stringent air quality standards and targeted disease prevention, aligning PM management with international guidelines for public health protection.
14Inverse association between dengue, chikungunya, and Zika virus infection and indicators of household air pollution in Santa Rosa, Guatemala: A case-control study, 2011-2018.PubMed
Zachary J Madewell, María Reneé López, Andrés Espinosa-Bode, et al.
PLoS One. 2020 Jun 19;15(6):e0234399. doi: 10.1371/journal.pone.0234399. eCollection 2020.
BACKGROUND: Dengue, chikungunya, and Zika viruses are increasingly important public health problems. Burning vegetation, leaves, and other plant products have been shown to be effective mosquito repellents for their vector, Aedes spp., but there has been scant research on whether firewood cooking smoke in households influences mosquito populations or mosquito-borne diseases. About 2.9 billion people worldwide use biomass fuel for household cooking and heating, resulting in an estimated 1.6 million deaths annually from household air pollution (HAP)-related diseases. Global health agencies now encourage households to transition from biomass to clean fuels, but it is unclear whether such interventions may actually increase risk for mosquito-borne diseases. This retrospective case-control study evaluated associations between arboviral infections and cooking with firewood in Santa Rosa, Guatemala. METHOD: Vigilancia Integrada Comunitaria (VICo) was a prospective public health surveillance system for bacterial, parasitic, and viral causes of diarrheal, neurological, respiratory, and febrile illnesses in hospitals and clinics in the department of Santa Rosa, Guatemala. Enrolled VICo in-patients and out-patients during 2011-2018 were interviewed using standardized questionnaires on demographics and household characteristics. Blood and stool specimens were collected and tested to identify the etiologies presenting symptoms. Cases were defined as laboratory-positive for dengue, chikungunya, or Zika virus infections. Controls were laboratory-positive for bacterial and viral diarrheal illnesses (e.g., Salmonella, Shigella, Campylobacter, Escherichia coli, rotavirus, norovirus, sapovirus, or astrovirus). Cooking with firewood, kitchen location, stove type, and firewood cooking frequency were the independent exposure variables. Logistic regression models were used to analyze unadjusted and adjusted associations between arboviral infections and exposures of interest. RESULT: There were 311 arboviral cases and 1,239 diarrheal controls. Arboviral infections were inversely associated with cooking with firewood in the main house (AOR: 0.22; 95% CI: 0.08-0.57), cooking with firewood on an open hearth (AOR: 0.50; 95% CI: 0.33-0.78), and cooking with firewood ≥5 times per week (AOR: 0.54; 95% CI: 0.36-0.81), adjusting for age, sex, ethnicity, socioeconomic status index, number of people per household, community population density, community elevation, recruitment location, season, and admission year. CONCLUSION: Several primary determinants of HAP exposure were inversely associated with arboviral infections. Additional studies are needed to understand whether interventions to reduce HAP might actually increase risk for mosquito-borne infectious diseases, which would warrant improved education and mosquito control efforts in conjunction with fuel interventions.
15The 2021 report of the Lancet Countdown on health and climate change: code red for a healthy future.PubMed
Marina Romanello, Alice McGushin, Claudia Di Napoli, et al.
Lancet. 2021 Oct 30;398(10311):1619-1662. doi: 10.1016/S0140-6736(21)01787-6. Epub 2021 Oct 20.
UNLABELLED: The Countdown is an international collaboration that independently monitors the health consequences of a changing climate. Publishing updated, new, and improved indicators each year, the Countdown represents the consensus of leading researchers from 43 academic institutions and UN agencies. The 44 indicators of this report expose an unabated rise in the health impacts of climate change and the current health consequences of the delayed and inconsistent response of countries around the globe—providing a clear imperative for accelerated action that puts the health of people and planet above all else. The 2021 report coincides with the UN Framework Convention on Climate Change 26th Conference of the Parties (COP26), at which countries are facing pressure to realise the ambition of the Paris Agreement to keep the global average temperature rise to 1·5°C and to mobilise the financial resources required for all countries to have an effective climate response. These negotiations unfold in the context of the COVID-19 pandemic—a global health crisis that has claimed millions of lives, affected livelihoods and communities around the globe, and exposed deep fissures and inequities in the world’s capacity to cope with, and respond to, health emergencies. Yet, in its response to both crises, the world is faced with an unprecedented opportunity to ensure a healthy future for all. DEEPENING INEQUITIES IN A WARMING WORLD: Record temperatures in 2020 resulted in a new high of 3·1 billion more person-days of heatwave exposure among people older than 65 years and 626 million more person-days affecting children younger than 1 year, compared with the annual average for the 1986–2005 baseline (indicator 1.1.2). Looking to 2021, people older than 65 years or younger than 1 year, along with people facing social disadvantages, were the most affected by the record-breaking temperatures of over 40°C in the Pacific Northwest areas of the USA and Canada in June, 2021—an event that would have been almost impossible without human-caused climate change. Although the exact number will not be known for several months, hundreds of people have died prematurely from the heat. Furthermore, populations in countries with low and medium levels of UN-defined human development index (HDI) have had the biggest increase in heat vulnerability during the past 30 years, with risks to their health further exacerbated by the low availability of cooling mechanisms and urban green space (indicators 1.1.1, 2.3.2, and 2.3.3). Agricultural workers in countries with low and medium HDI were among the worst affected by exposure to extreme temperatures, bearing almost half of the 295 billion potential work hours lost due to heat in 2020 (indicator 1.1.4). These lost work hours could have devastating economic consequences to these already vulnerable workers—data in this year’s report shows that the average potential earnings lost in countries in the low HDI group were equivalent to 4–8% of the national gross domestic product (indicator 4.1.3). Through these effects, rising average temperatures, and altered rainfall patterns, climate change is beginning to reverse years of progress in tackling the food and water insecurity that still affects the most underserved populations around the world, denying them an essential aspect of good health. During any given month in 2020, up to 19% of the global land surface was affected by extreme drought; a value that had not exceeded 13% between 1950 and 1999 (indicator 1.2.2). In parallel with drought, warm temperatures are affecting the yield potential of the world’s major staple crops—a 6·0% reduction for maize; 3·0% for winter wheat; 5·4% for soybean; and 1·8% for rice in 2020, relative to 1981–2010 (indicator 1.4.1)—exposing the rising risk of food insecurity. Adding to these health hazards, the changing environmental conditions are also increasing the suitability for the transmission of many water-borne, air-borne, food-borne, and vector-borne pathogens. Although socioeconomic development, public health interventions, and advances in medicine have reduced the global burden of infectious disease transmission, climate change could undermine eradication efforts. The number of months with environmentally suitable conditions for the transmission of malaria () rose by 39% from 1950–59 to 2010–19 in densely populated highland areas in the low HDI group, threatening highly disadvantaged populations who were comparatively safer from this disease than those in the lowland areas (indicator 1.3.1). The epidemic potential for dengue virus, Zika virus, and chikungunya virus, which currently primarily affect populations in central America, South America, the Caribbean, Africa, and south Asia, increased globally, with a basic reproductive rate increase of 13% for transmission by and 7% for transmission by compared with the 1950s. The biggest relative increase in basic reproductive rate of these arboviruses was seen in countries in the very high HDI group (indicator 1.3.1); however, people in the low HDI group are confronted with the highest vulnerability to these arboviruses (indicator 1.3.2). Similar findings are observed in the environmental suitability for , a pathogen estimated to cause almost 100 000 deaths annually, particularly among populations with poor access to safe water and sanitation. Between 2003 and 2019, the coastal areas suitable for transmission increased substantially across all HDI country groups—although, with 98% of their coastline suitable to the transmission of in 2020, it is people in the low HDI country group that have the highest environmental suitability for this disease (indicator 1.3.1). The concurrent and interconnecting risks posed by extreme weather events, infectious disease transmission, and food, water, and financial insecurity are over-burdening the most vulnerable populations. Through multiple simultaneous and interacting health risks, climate change is threatening to reverse years of progress in public health and sustainable development. Even with overwhelming evidence on the health impacts of climate change, countries are not delivering an adaptation response proportionate to the rising risks their populations face. In 2020, 104 (63%) of 166 countries did not have a high level of implementation of national health emergency frameworks, leaving them unprepared to respond to pandemics and climate-related health emergencies (indicator 2.3.1). Importantly, only 18 (55%) of 33 countries with a low HDI had reported at least a medium level of implementation of national health emergency frameworks, compared with 47 (89%) of 53 countries with a very high HDI. In addition, only 47 (52%) of 91 countries reported having a national adaptation plan for health, with insufficient human and financial resources identified as the main barrier for their implementation (indicator 2.1.1). With a world facing an unavoidable temperature rise, even with the most ambitious climate change mitigation, accelerated adaptation is essential to reduce the vulnerabilities of populations to climate change and protect the health of people around the world. AN INEQUITABLE RESPONSE FAILS EVERYONE: 10 months into 2021, global and equitable access to the COVID-19 vaccine had not been delivered—more than 60% of people in high-income countries have received at least one dose of a COVID-19 vaccine compared with just 3·5% of people in low-income countries. Data in this report exposes similar inequities in the global climate change mitigation response. To meet the Paris Agreement goals and prevent catastrophic levels of global warming, global greenhouse gas emissions must reduce by half within a decade. However, at the current pace of reduction, it would take more than 150 years for the energy system to fully decarbonise (indicator 3.1), and the unequal response between countries is resulting in an uneven realisation of the health benefits of a low-carbon transition. The use of public funds to subsidise fossil fuels is partly responsible for the slow decarbonisation rate. Of the 84 countries reviewed, 65 were still providing an overall subsidy to fossil fuels in 2018 and, in many cases, subsidies were equivalent to substantial proportions of the national health budget and could have been redirected to deliver net benefits to health and wellbeing. Furthermore, all the 19 countries whose carbon pricing policies outweighed the effect of any fossil fuels subsidies came from the very high HDI group (indicator 4.2.4). Although countries in the very high HDI group have collectively made the most progress in the decarbonisation of the energy system, they are still the main contributors to CO emissions through the local production of goods and services, accounting for 45% of the global total (indicator 4.2.5). With a slower pace of decarbonisation and poorer air quality regulations than countries in the very high HDI group, the medium and high HDI country groups produce the most fine particle matter (PM) emissions and have the highest rates of air pollution-related deaths, which are about 50% higher than the total deaths in the very high HDI group (indicator 3.3). The low HDI group, with comparatively lower amounts of industrial activity than in the other groups, has a local production that contributes to only 0·7% of global CO emissions, and has the lowest mortality rate from ambient air pollution. However, with only 12% of its inhabitants relying on clean fuels and technologies for cooking, the health of these populations is still at risk from dangerously high concentrations of household air pollution (indicator 3.2). Even in the most affluent countries, people in the most deprived areas over-whelmingly bear the burden of health effects from exposure to air pollution. These findings expose the health costs of the delayed and unequal mitigation response and underscore the millions of deaths to be prevented annually through a low-carbon transition that prioritises the health of all populations. However, the world is not on track to realising the health gains of the transition to a low-carbon economy. Current global decarbonisation commitments are insufficient to meet Paris Agreement ambitions and would lead to a roughly 2·4°C average global temperature increase by the end of the century. The current direction of post-COVID-19 spending is threatening to make this situation worse, with just 18% of all the funds committed for economic recovery from the COVID-19 pandemic by the end of 2020 expected to lead to a reduction of greenhouse gas emissions. Indeed, the economic recovery from the pandemic is already predicted to lead to an unprecedented 5% increase in greenhouse gas emissions in 2021, which will bring global anthropogenic emissions back to their peak amounts. In addition, the current economic recession is threatening to undermine the target of mobilising US$100 billion per year from 2020 onwards to promote low-carbon shifts and adaptation responses in the most underserved countries, even though this quantity is minute compared with the trillions allocated to COVID-19 recovery. The high amounts of borrowing that countries have had to resort to during the pandemic could erase their ability to deliver a green recovery and maximise the health gains to their population of a low-carbon transition. AN UNPRECEDENTED OPPORTUNITY TO ENSURE A HEALTHY FUTURE FOR ALL: The overshoot in emissions resulting from a carbon-intensive COVID-19 recovery would irreversibly prevent the world from meeting climate commitments and the Sustainable Development Goals and lock humanity into an increasingly extreme and unpredictable environment. Data in this report expose the health impacts and health inequities of the current world at 1·2°C of warming above pre-industrial levels and supports that, on the current trajectory, climate change will become the defining narrative of human health. However, by directing the trillions of dollars that will be committed to COVID-19 recovery towards the WHO’s prescriptions for a healthy, green recovery, the world could meet the Paris Agreement goals, protect the natural systems that support wellbeing, and minimise inequities through reduced health effects and maximised co-benefits of a universal low-carbon transition. Promoting equitable climate change mitigation and universal access to clean energies could prevent millions of deaths annually from reduced exposure to air pollution, healthier diets, and more active lifestyles, and contribute to reducing health inequities globally. This pivotal moment of economic stimulus represents a historical opportunity to secure the health of present and future generations. There is a glimpse of positive change through several promising trends in this year’s data: electricity generation from renewable wind and solar energy increased by an annual average of 17% between 2013 and 2018 (indicator 3.1); investment in new coal capacity decreased by 10% in 2020 (indicator 4.2.1); and the global number of electric vehicles reached 7·2 million in 2019 (indicator 3.4). Additionally, the global pandemic has driven increased engagement in health and climate change across multiple domains in society, with 91 heads of state making the connection in the 2020 UN General Debate and newly widespread engagement among countries in the very high HDI group (indicator 5.4). Whether COVID-19 recovery supports, or reverses these trends, is yet to be seen. Neither COVID-19 nor climate change respect national borders. Without widespread, accessible vaccination across all countries and societies, SARS-CoV-2 and its new variants will continue to put the health of everybody at risk. Likewise, tackling climate change requires all countries to deliver an urgent and coordinated response, with COVID-19 recovery funds allocated to support and ensure a just transition to a low-carbon future and climate change adaptation across the globe. Leaders of the world have an unprecedented opportunity to deliver a future of improved health, reduced inequity, and economic and environmental sustainability. However, this will only be possible if the world acts together to ensure that no person is left behind.
16Risk factors for the presence of Aedes aegypti and Aedes albopictus in domestic water-holding containers in areas impacted by the Nam Theun 2 hydroelectric project, Laos.PubMed
Alexandra Hiscox, Angela Kaye, Khamsing Vongphayloth, et al.
Am J Trop Med Hyg. 2013 Jun;88(6):1070-8. doi: 10.4269/ajtmh.12-0623. Epub 2013 Mar 4.
We assessed risk factors for vectors of dengue and chikungunya viruses near a new hydroelectric project, Nam Theun 2, in Laos. Immature stages of Aedes aegypti were found only in sites within 40 km of the urban provincial capital, but Aedes albopictus was found throughout. Aedes aegypti pupae were most common in water storage jars (odds ratio [OR] = 4.72) and tires (OR = 2.99), and Ae. albopictus pupae were associated with tires in 2009 (OR = 10.87) and drums, tires, and jars in 2010 (drums OR = 3.05; tires OR = 3.45, jars OR = 6.59). Compared with water storage vessels, containers used for hygiene, cooking, and drinking were 80% less likely to harbor Ae. albopictus pupae in 2010 (OR = 0.20), and discarded waste was associated with a 3.64 increased odds of infestation. Vector control efforts should focus on source reduction of water storage containers, particularly concrete jars and tires.
17Environmental heterogeneity across an urban gradient influences detritus and nutrients within artificial containers and their associated vector Aedes sp. larvae in San Juan, Puerto Rico.PubMed
Limarie J Reyes-Torres, Rebeca de Jesús Crespo, Autumn J Oczkowski, et al.
J Med Entomol. 2025 Jul 17;62(4):816-827. doi: 10.1093/jme/tjaf058.
Detrital inputs from the surrounding terrestrial environment provide essential nutrients that sustain mosquito populations in aquatic containers. The larvae of Aedes aegypti (L.), an anthropophilic invasive vector species, often develop in artificial habitats in urban areas but little is known about how that environment shapes their life history or phenotypic traits. We hypothesized that container detritus, nutrients, and larval interspecific competition with the endemic mosquito, Aedes mediovittatus (Coquillett), would vary along an urban gradient in the San Juan Metropolitan Area in Puerto Rico. We also hypothesized that fine-scale variations within a 200 m buffer of the container environment would alter Ae. aegypti larval nutrients, density, and biomass. We sampled mosquito larvae, container detritus, and suspended particulate organic matter in 44 locations and characterized the surrounding environment in terms of land cover, land use, and vegetation α diversity. We show that container detritus and nutrients are influenced by fine-scale environmental variations environment, affecting Ae. aegypti and Ae. mediovittatus larvae phenotypic traits and nutrient composition. Aedes aegypti was the dominant species in all samples across the urban gradient. We found a negative relationship between Ae. mediovittatus larval % carbon and vegetation cover in the surrounding environment, and a negative correlation between this species' larval C:N and suspended particulate organic matter C:N. These findings suggest a potential disadvantage in nutrient allocation that could affect its competitive ability in urban areas. We found smaller and less nitrogen enriched (δ¹⁵N) Ae. aegypti in containers surrounded by higher impervious cover. The implications of these findings on potential vector disease risk across urban gradients are discussed.
18An in vivo assessment revealed multiple toxic effects of brake dust on the urban mosquito Aedes albopictus.PubMed
Emanuele Vaccarella, Valentina Lucchesi, Silvia Canepari, et al.
Sci Total Environ. 2025 Aug 20;991:179937. doi: 10.1016/j.scitotenv.2025.179937. Epub 2025 Jun 21.
Brake dust is a major component of particulate matter (PM) and enriched in potentially toxic elements (PTEs), posing a significant threat to both the environment and health especially in densely populated areas. In this context, an in vivo approach is essential to understand its potential negative effects. Here, we investigated the toxicity of brake dust on Aedes albopictus, a common mosquito species in urban environments. We exposed larvae to increasing concentrations of brake dust in the water (10-500 mg L) to evaluate: (i) effects on developmental, behavioural and morphological traits; (ii) element bioaccumulation; (iii) oxidative stress. We found a significant reduction in adult emergence rate, delayed larval growth, and morphological changes in male wing shape. At high brake dust concentrations, an increase in cannibalistic interactions among larvae was also observed. Furthermore, we demonstrated that larvae bioaccumulate elements from brake dust in different ways, with Cu, La, Ce, and Ba which were progressively bioaccumulated as brake dust concentration increased, while most other PTEs showed bioaccumulation up to 50 mg L, followed by a decrease at higher concentrations. The overexpression of superoxide dismutase (SOD) and catalase genes at concentrations above 50 mg L indicated induction of oxidative stress response. We conclude that the toxic effects of brake dust on Ae. albopictus occurred at multiple levels, with important biological and ecological relevance. Moreover, our findings identify Ae. albopictus as a valuable model for in vivo studies on PM toxicity.
19The 2018 report of the Lancet Countdown on health and climate change: shaping the health of nations for centuries to come.PubMed
Nick Watts, Markus Amann, Nigel Arnell, et al.
Lancet. 2018 Dec 8;392(10163):2479-2514. doi: 10.1016/S0140-6736(18)32594-7. Epub 2018 Nov 28.
UNLABELLED: The Lancet Countdown: tracking progress on health and climate change was established to provide an independent, global monitoring system dedicated to tracking the health dimensions of the impacts of, and the response to, climate change. The Countdown tracks 41 indicators across five domains: climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; finance and economics; and public and political engagement. This report is the product of a collaboration of 27 leading academic institutions, the UN, and intergovernmental agencies from every continent. The report draws on world-class expertise from climate scientists, ecologists, mathematicians, geographers, engineers, energy, food, livestock, and transport experts, economists, social and political scientists, public health professionals, and doctors. The Countdown’s work builds on decades of research in this field, and was first proposed in the 2015 Commission on health and climate change, which documented the human impacts of climate change and provided ten global recommendations to respond to this public health emergency and secure the public health benefits available (panel 1). THE FOLLOWING FOUR KEY MESSAGES DERIVE FROM THE LANCET COUNTDOWN’S 2018 REPORT: 1.. Present day changes in heat waves, labour capacity, vector-borne disease, and food security provide early warning of the compounded and overwhelming impact on public health that are expected if temperatures continue to rise. Trends in climate change impacts, exposures, and vulnerabilities show an unacceptably high level of risk for the current and future health of populations across the world. 2.. A lack of progress in reducing emissions and building adaptive capacity threatens both human lives and the viability of the national health systems they depend on, with the potential to disrupt core public health infrastructure and overwhelm health services. 3.. Despite these delays, a number of sectors have seen the beginning of a low-carbon transition, and it is clear that the nature and scale of the response to climate change will be the determining factor in shaping the health of nations for centuries to come. 4.. Ensuring a widespread understanding of climate change as a central public health issue will be crucial in delivering an accelerated response, with the health profession beginning to rise to this challenge. CLIMATE CHANGE IMPACTS, EXPOSURES, AND VULNERABILITY: Vulnerability to extremes of heat has steadily risen since 1990 in every region, with 157 million more people exposed to heatwave events in 2017, compared with 2000, and with the average person experiencing an additional 1·4 days of heatwaves per year over the same period (indicators 1.1 and 1.3). For national economies and household budgets, 153 billion hours of labour were lost in 2017 because of heat, an increase of more than 62 billion hours (3·2 billion weeks of work) since 2000 (indicator 1.4). The direct effects of climate change extend beyond heat to include extremes of weather. In 2017, a total of 712 extreme weather events resulted in US$326 billion in economic losses, almost triple the total losses of 2016 (indicator 4.1). Small changes in temperature and precipitation can result in large changes in the suitability for transmission of important vector-borne and water-borne diseases. In 2016, global vectorial capacity for the transmission of the dengue fever virus was the highest on record, rising to 9·1% for and 11·1% for above the 1950s baseline. Focusing on high-risk areas and diseases, the Baltic region has had a 24% increase in the coastline area suitable for epidemics of , and in 2016, the highlands of sub-Saharan Africa saw a 27·6% rise in the vectorial capacity for the transmission of malaria from the 1950 baseline (indicator 1.8). A proxy of agricultural yield potential shows declines in every region, with 30 countries having downward trends in yields, reversing a decades-long trend of improvement (indicator 1.9.1). Decreasing labour productivity, increased capacity for the transmission of diseases such as dengue fever, malaria, and cholera, and threats to food security provide early warning of compounding negative health and nutrition effects if temperatures continue to rise. ADAPTATION, PLANNING, AND RESILIENCE FOR HEALTH: Global inertia in adapting to climate change persists, with a mixed response from national governments since the signing of the Paris Agreement in 2015. More than half of global cities surveyed expect climate change to seriously compromise public health infrastructure, either directly, with extremes of weather disrupting crucial services, or indirectly, through the overwhelming of existing services with increased burdens of disease (indicator 2.2). Globally, spending for climate change adaptation remains well below the $100 billion per year commitment made under the Paris Agreement. Within this annual spending, only 3·8% of total development spending committed through formal UN Framework Convention on Climate Change (UNFCCC) mechanisms is dedicated to human health (indicator 2.8). This low investment in adaptive capacity is magnified in specific regions around the world, with only 55% of African countries meeting International Health Regulation core requirements for preparedness for a multihazard public health emergency (indicator 2.3). MITIGATION ACTIONS AND HEALTH CO-BENEFITS: Multiple examples of stagnated mitigation efforts exist, with a crucial marker of decarbonisation—the carbon intensity of total primary energy supply—remaining unchanged since 1990 (indicator 3.1). A third of the global population, 2·8 billion people, live without access to healthy, clean, and sustainable cooking fuel or technologies, which is the same number of people as in 2000 (indicator 3.4). In the transport sector, per-capita global road-transport fuel use increased by 2% from 2013 to 2015, and cycling comprises less than 10% of total journeys taken in three quarters of a global sample of cities (indicators 3.6 and 3.7). The health burden of such inaction has been immense, with people in more than 90% of cities breathing polluted air that is toxic to their cardiovascular and respiratory health. Indeed, between 2010, and 2016, air pollution concentrations worsened in almost 70% of cities around the globe, particularly in low-income and middle-income countries (LMICs; indicator 3.5.1). In 2015 alone, fine particulate matter (ie, atmospheric particulate matter with a diameter of less than 2·5 μm [PM]) was responsible for 2·9 million premature deaths, with coal being responsible for more than 460 000 (16%) of these deaths, and with the total death toll (from other causes including particulates and emissions such as nitrogen oxide) being substantially higher (indicator 3.5.2). Of concern, global employment in fossil-fuel extractive industries actually increased by 8% between 2016, and 2017, reversing the strong decline seen since 2011 (indicator 4.4). At a time when national health budgets and health services face a growing epidemic of lifestyle diseases, continued delay in unlocking the potential health co-benefits of climate change mitigation is short-sighted and damaging for human health. Despite this stagnation, progress in the power generation and transport sectors provide some cause for optimism, with many positive trends being observed in the 2017 report, and which continue in the present 2018 report. Notably, coal use continues to decline (indicator 3.2) and more renewable energy was installed in 2017 than energy from fossil fuels (indicator 3.3). However, maintaining the global average temperature rise to well below 2°C necessitates wide-reaching transformations across all sectors of society, including power generation, transport, spatial infrastructure, food and agriculture, and the design of health systems. These transformations, in turn, offer levers to help tackle the root causes of the world’s greatest public health challenges. FINANCE AND ECONOMICS: About 712 climate-related extreme events were responsible for US$326 billion of losses in 2017, almost triple the losses of 2016 (indicator 4.1). Crucially, 99% of the losses in low-income countries remained uninsured. Indicators of investment in the low-carbon economy show that the transition is already underway, with continued growth in investment in zero-carbon energy, and growing numbers of people employed in renewable energy sectors (indicators 4.2 and 4.4). Furthermore, investment in new coal capacity in 2017, was at its lowest in at least 10 years, with 2015 potentially marking a peak in coal investment. Correspondingly, global subsidies for fossil fuels continued to decrease, and carbon pricing only covers 13·1% of global greenhouse-gas emissions, a number that is expected to increase to more than 20% when planned legislation in China is implemented in late 2018 (indicators 4.6 and 4.7). However, the rise of employment in fossil fuel industries in 2017 reversed a 5 year downward trend, and will be a key indicator to follow closely. PUBLIC AND POLITICAL ENGAGEMENT: A better understanding of the health dimensions of climate change allows for advanced preparedness, increased resilience and adaptation, and a prioritisation of mitigation interventions that protect and promote human wellbeing. To this end, coverage of health and climate change in the media has increased substantially between 2007, and 2017 (indicator 5.1). Following this trend, the number of academic journal articles published on health and climate change has almost tripled over the same period (indicator 5.2). These figures often follow internationally important events, such as the UNFCCC’s Conference of the Parties (COP), along with temporary rises in mentions of health and climate change within the UN General Debate (UNGD; indicator 5.3). The extended heatwaves across the northern hemisphere in the summer of 2018, might prove to be a turning point in public awareness of the seriousness of climate change. 2017 saw a substantial rise in the number of medical and health professional associations actively responding to climate change. In the USA, the US Medical Society Consortium on Health and Climate represents 500 000 physicians. This organisation follows the formation of the UK Health Alliance on Climate Change, which brings together many of the UK’s royal medical and nursing colleges and major health institutions. Organisations like the European Renal Association–European Dialysis and Transplant Association and the UK’s National Health Service (NHS) are committing to reducing the contributions of their clinical practice emissions. The NHS achieved an 11% reduction in emissions between 2007, and 2015. Several health organisations have divested, or are committing to divest, their holdings in fossil fuel companies, including the Royal Australasian College of Physicians, the Canadian Medical Association, the American Public Health Association, and the World Medical Association (indicator 4.5). Given that climate change is the biggest global health threat of the 21st century, responding to this threat, and ensuring this response delivers the health benefits available, is the responsibility of the health profession; indeed, such a transformation will not be possible without it. PROGRESS ON THE RECOMMENDATIONS OF THE 2015 LANCET COMMISSION: The 2015 Commission made ten global recommendations to accelerate the response to climate change and deliver the health benefits this response could offer. A summary of the progress made against these recommendations using the 2018 Countdown’s indicators is presented in panel 1. Here, global leadership is increasingly provided by China, the EU, and many of the countries that are most vulnerable to climate change.
20The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate.PubMed
Nick Watts, Markus Amann, Nigel Arnell, et al.
Lancet. 2019 Nov 16;394(10211):1836-1878. doi: 10.1016/S0140-6736(19)32596-6.
UNLABELLED: The Countdown is an international, multidisciplinary collaboration, dedicated to monitoring the evolving health profile of climate change, and providing an independent assessment of the delivery of commitments made by governments worldwide under the Paris Agreement. The 2019 report presents an annual update of 41 indicators across five key domains: climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement. The report represents the findings and consensus of 35 leading academic institutions and UN agencies from every continent. Each year, the methods and data that underpin the Countdown’s indicators are further developed and improved, with updates described at each stage of this report. The collaboration draws on the world-class expertise of climate scientists; ecologists; mathematicians; engineers; energy, food, and transport experts; economists; social and political scientists; public health professionals; and doctors, to generate the quality and diversity of data required. The science of climate change describes a range of possible futures, which are largely dependent on the degree of action or inaction in the face of a warming world. The policies implemented will have far-reaching effects in determining these eventualities, with the indicators tracked here monitoring both the present-day effects of climate change, as well as the worldwide response. Understanding these decisions as a choice between one of two pathways—one that continues with the business as usual response and one that redirects to a future that remains “well below 2°C”—helps to bring the importance of recognising the effects of climate change and the necessary response to the forefront. Evidence provided by the Intergovernmental Panel on Climate Change, the International Energy Agency, and the US National Aeronautics and Space Administration clarifies the degree and magnitude of climate change experienced today and contextualises these two pathways. THE IMPACTS OF CLIMATE CHANGE ON HUMAN HEALTH: The world has observed a 1°C temperature rise above pre-industrial levels, with feedback cycles and polar amplification resulting in a rise as high as 3°C in north western Canada. Eight of the ten hottest years on record have occurred in the past decade. Such rapid change is primarily driven by the combustion of fossil fuels, consumed at a rate of 171 000 kg of coal, 116 000 000 L of gas, and 186 000 L of oil per s. Progress in mitigating this threat is intermittent at best, with carbon dioxide emissions continuing to rise in 2018. Importantly, many of the indicators contained in this report suggest the world is following this “business as usual” pathway. The carbon intensity of the energy system has remained unchanged since 1990 (indicator 3.1.1), and from 2016 to 2018, total primary energy supply from coal increased by 1·7%, reversing a previously recorded downward trend (indicator 3.1.2). Correspondingly, the health-care sector is responsible for about 4·6% of global emissions, a value which is steadily rising across most major economies (indicator 3.6). Global fossil fuel consumption subsidies increased by 50% over the past 3 years, reaching a peak of almost US$430 billion in 2018 (indicator 4.4.1). A child born today will experience a world that is more than four degrees warmer than the pre-industrial average, with climate change impacting human health from infancy and adolescence to adulthood and old age. Across the world, children are among the worst affected by climate change. Downward trends in global yield potential for all major crops tracked since 1960 threaten food production and food security, with infants often the worst affected by the potentially permanent effects of undernutrition (indicator 1.5.1). Children are among the most susceptible to diarrhoeal disease and experience the most severe effects of dengue fever. Trends in climate suitability for disease transmission are particularly concerning, with nine of the ten most suitable years for the transmission of dengue fever on record occurring since 2000 (indicator 1.4.1). Similarly, since an early 1980s baseline, the number of days suitable for (a pathogen responsible for part of the burden of diarrhoeal disease) has doubled, and global suitability for coastal has increased by 9·9% indicator 1.4.1). Through adolescence and beyond, air pollution—principally driven by fossil fuels, and exacerbated by climate change—damages the heart, lungs, and every other vital organ. These effects accumulate over time, and into adulthood, with global deaths attributable to ambient fine particulate matter (PM) remaining at 2·9 million in 2016 (indicator 3.3.2) and total global air pollution deaths reaching 7 million. Later in life, families and livelihoods are put at risk from increases in the frequency and severity of extreme weather conditions, with women among the most vulnerable across a range of social and cultural contexts. Globally, 77% of countries experienced an increase in daily population exposure to wildfires from 2001–14 to 2015–18 (indicator 1.2.1). India and China sustained the largest increases, with an increase of over 21 million exposures in India and 17 million exposures in China over this time period. In low-income countries, almost all economic losses from extreme weather events are uninsured, placing a particularly high burden on individuals and households (indicator 4.1). Temperature rise and heatwaves are increasingly limiting the labour capacity of various populations. In 2018, 133·6 billion potential work hours were lost globally, 45 billion more than the 2000 baseline, and southern areas of the USA lost 15–20% of potential daylight work hours during the hottest month of 2018 (indicator 1.1.4). Populations aged 65 years and older are particularly vulnerable to the health effects of climate change, and especially to extremes of heat. From 1990 to 2018, populations in every region have become more vulnerable to heat and heatwaves, with Europe and the Eastern Mediterranean remaining the most vulnerable (indicator 1.1.1). In 2018, these vulnerable populations experienced 220 million heatwave exposures globally, breaking the previous record of 209 million set in 2015 (indicator 1.1.3). Already faced with the challenge of an ageing population, Japan had 32 million heatwave exposures affecting people aged 65 years and older in 2018, the equivalent of almost every person in this age group experiencing a heatwave. Finally, although difficult to quantify, the downstream risks of climate change, such as migration, poverty exacerbation, violent conflict, and mental illness, affect people of all ages and all nationalities. A business as usual trajectory will result in a fundamentally altered world, with the indicators described providing a glimpse of the implications of this pathway. The life of every child born today will be profoundly affected by climate change. Without accelerated intervention, this new era will come to define the health of people at every stage of their lives. RESPONDING TO CLIMATE CHANGE FOR HEALTH: The Paris Agreement has set a target of “holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1·5°C.” In a world that matches this ambition, a child born today would see the phase-out of all coal in the UK and Canada by their sixth and 11th birthday; they would see France ban the sale of petrol and diesel cars by their 21st birthday; and they would be 31 years old by the time the world reaches net-zero in 2050, with the UK’s recent commitment to reach this goal one of many to come. The changes seen in this alternate pathway could result in cleaner air, safer cities, and more nutritious food, coupled with renewed investment in health systems and vital infrastructure. This second path—which limits the global average temperature rise to “well below 2°C”—is possible, and would transform the health of a child born today for the better, right the way through their life. Considering the evidence available in the 2019 indicators, such a transition could be beginning to unfold. Despite a small increase in coal use in 2018, in key countries such as China, it continued to decrease as a share of electricity generation (indicator 3.1.2). Correspondingly, renewables accounted for 45% of global growth in power generation capacity that year, and low-carbon electricity reached a high of 32% of global electricity in 2016 (indicator 3.1.3). Global per capita use of electric vehicles increased by 20·6% between 2015 and 2016, and now represents 1·8% of China’s total transportation fuel use (indicator 3.4). Improvements in air pollution seen in Europe from 2015 to 2016, could result in a reduction of Years of Life Lost (YLL) worth €5·2 billion annually, if this reduction remained constant across a lifetime (indicator 4.2). In several cases, the economic savings from a healthier and more productive workforce, with fewer health-care expenses, will cover the initial investment costs of these interventions. Similarly, cities and health systems are becoming more resilient to the effects of climate change; about 50% of countries and 69% of cities surveyed reported efforts to conduct national health adaptation plans or climate change risk assessments (indicators 2.1.1, 2.1.2, and 2.1.3). These plans are now being implemented, with the number of countries providing climate services to the health sector increasing from 55 in 2018 to 70 in 2019 (indicator 2.2) and 109 countries reporting medium to high implementation of a national health emergency framework (indicator 2.3.1). Growing demand is coupled with a steady increase in health adaptation spending, which represents 5% (£13 billion) of total adaptation funding in 2018 and has increased by 11·8% over the past 12 months (indicator 2.4). This increase is in part funded by growing revenues from carbon pricing mechanisms, with a 30% increase to US$43 billion in funds raised between 2017 and 2018 (indicator 4.4.3). However, current progress is inadequate, and despite the beginnings of the transition described, the indicators published in the Countdown’s 2019 report are suggestive of a world struggling to cope with warming that is occurring faster than governments are able, or willing to respond. Opportunities are being missed, with the Green Climate Fund yet to receive projects specifically focused on improving climate-related public health, despite the fact that in other forums, leaders of small island developing states are recognising the links between health and climate change (indicator 5.3). In response, the generation that will be most affected by climate change has led a wave of school strikes across the world. Bold new approaches to policy making, research, and business are needed in order to change course. An unprecedented challenge demands an unprecedented response, and it will take the work of the 7·5 billion people currently alive to ensure that the health of a child born today is not defined by a changing climate.