Biological, Environmental & Occupational Health Sciences, School of Public Health, College of Health Sciences, University of Ghana, Legon, Accra, Ghana; Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana.
Respiratory Intervention Group, Institute of Applied Health Science, University of Aberdeen, Aberdeen, Scotland.
Environ Int. 2017 Jun;103:73-90. doi: 10.1016/j.envint.2017.03.010. Epub 2017 Mar 22.
Cookstove intervention programs have been increasing over the past two (2) decades in Low and Middle Income Countries (LMICs) across the globe. However, there remains uncertainty regarding the effects of these interventions on household air pollution concentrations, personal exposure concentrations and health outcomes.
The primary objective was to determine if household air pollution (HAP) interventions were associated with improved indoor air quality (IAQ) in households in LMICs. Given the potential impact of HAP interventions on health, a secondary objective was to evaluate the effectiveness of HAP interventions to improve health in populations receiving these interventions.
OVID Medline, Ovid Embase, SCOPUS and PubMED were searched from their inception until December 2015 with no restrictions on study design. The WHO Global database of household air pollution measurements and Members' archives were also reviewed together with the reference lists of identified reviews and relevant articles.
STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTION: We considered randomized controlled trials, or non-randomized control trials, or before-and-after studies; original studies; studies conducted in a LMIC (based on the United Nations Human Development Report released in March 2013 (World Bank, 2013); interventions that were explicitly aimed at improving IAQ and/or health from solid fuel use; studies published in a peer-reviewed journal or student theses or reports; studies that reported on outcomes which was indicative of IAQ or/and health. There was no restriction on the type of comparator (e.g. household receiving plancha vs. household using traditional cookstove) used in the intervention study.
Five review authors independently used pre-designed data collection forms to extract information from the original studies and assessed risk of bias using the Effective Public Health Practice Project (EPHPP). We computed standardized weighted mean difference (SMD) using random-effects models. Heterogeneity was computed using the Q and I2-statistics. We examined the influence of various characteristics on the study-specific effect estimates by stratifying the analysis by population type, study design, intervention type, and duration of exposure monitoring. The trim and fill method was used to assess the potential impact of missing studies.
Fifty-five studies met our a priori inclusion criteria and were included in the systematic review. Fifteen studies provided 43 effect estimates for our meta-analysis. The largest improvement in HAP was observed for average particulate matter (PM) (SMD=1.57) concentrations in household kitchens (1.03), followed by daily personal average concentrations of PM (1.18), and carbon monoxide (CO) concentrations in kitchens. With respect to personal PM, significant improvement was observed in studies of children (1.26) and studies monitoring PM for ≥24h (1.32). This observation was also noted in terms of studies of kitchen concentrations of CO. A significant improvement was also observed for kitchen levels of PM in both adult populations (1.56) and in RCT/cohort designs (1.59) involving replacing cookstoves without chimneys. Our findings on health outcomes were inconclusive.
LIMITATIONS, CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: We observed high statistical between study variability in the study-specific estimate. Thus, care should be taken in concluding that HAP interventions - as currently designed and implemented - support reductions in the average kitchen and personal levels of PM and CO. Further, there is limited evidence that current stand-alone HAP interventions yield any health benefits. Post-intervention levels of pollutants were generally still greatly in excess of the relevant WHO guideline and thus a need to promote cleaner fuels in LMICs to reduce HAP levels below the WHO guidelines.
The review has been registered with PROSPERO (registration number CRD42014009768).
在过去的二十年中，在全球范围内的低收入和中等收入国家（LMICs）中，炊具干预计划一直在增加。然而，对于这些干预措施对家庭空气污染浓度、个人暴露浓度和健康结果的影响仍然存在不确定性。
主要目的是确定家庭空气污染（HAP）干预措施是否与改善 LMIC 家庭的室内空气质量（IAQ）相关。鉴于 HAP 干预措施对健康的潜在影响，次要目的是评估 HAP 干预措施改善接受这些干预措施的人群健康的有效性。
OVID Medline、Ovid Embase、SCOPUS 和 PubMED 从成立开始进行搜索，直到 2015 年 12 月，对研究设计没有任何限制。还审查了世界卫生组织家庭空气污染测量全球数据库和成员档案，以及确定的综述和相关文章的参考文献列表。
研究资格标准、参与者和干预措施：我们考虑了随机对照试验，或非随机对照试验，或前后对照研究；原始研究；在一个 LMIC 进行的研究（基于 2013 年 3 月发布的联合国人类发展报告（世界银行，2013 年）；明确旨在改善使用固体燃料产生的室内空气质量和/或健康的干预措施；发表在同行评议期刊或学生论文或报告中的研究；报告的结果表明室内空气质量或/和健康。干预研究中使用的比较器类型（例如，使用 plancha 的家庭与使用传统炉灶的家庭）没有限制。
五名审查作者独立使用预先设计的数据收集表格从原始研究中提取信息，并使用有效公共卫生实践项目（EPHPP）评估偏倚风险。我们使用随机效应模型计算标准化加权均数差（SMD）。使用 Q 和 I2 统计量计算异质性。我们通过按人群类型、研究设计、干预类型和暴露监测持续时间对分析进行分层，研究各种特征对研究特定效应估计的影响。使用修剪和填充方法评估缺失研究的潜在影响。
有 55 项研究符合我们预先确定的纳入标准，并包含在系统评价中。15 项研究为我们的荟萃分析提供了 43 项效应估计。在家庭厨房中观察到最大的 HAP 改善是平均颗粒物（PM）浓度（SMD=1.57），其次是每日个人平均 PM 浓度（1.18）和厨房中一氧化碳（CO）浓度。就个人 PM 而言，在监测 PM 时间≥24h 的研究中（1.32）和在监测 PM 时间≥24h 的研究中（1.26）观察到显著改善。在研究厨房 CO 浓度时也观察到了这一观察结果。还观察到在成人人群（1.56）和涉及更换无烟囱炉灶的 RCT/队列设计（1.59）中厨房水平 PM 也有显著改善。我们关于健康结果的发现没有定论。
局限性、结论和关键发现的影响：我们观察到研究内估计值的统计间变异性很大。因此，在得出 HAP 干预措施 - 如目前设计和实施的那样 - 支持降低平均厨房和个人 PM 和 CO 水平的结论时，应谨慎行事。此外，目前独立的 HAP 干预措施产生任何健康益处的证据有限。干预后污染物水平通常仍大大超过相关的世卫组织指南，因此需要在 LMIC 推广清洁燃料，以将 HAP 水平降低到世卫组织指南以下。
该综述已在 PROSPERO（注册号 CRD42014009768）中进行了登记。
