Institute of Occupational Medicine, Edinburgh, EH14 4AP, UK.
Australian National University, Canberra, Australia.
Environ Health. 2020 Jul 3;19(1):77. doi: 10.1186/s12940-020-00629-3.
Exposure to particulate matter (PM) emitted from biomass burning is an increasing concern, particularly in Southeast Asia. It is not yet clear how the source of PM influences the risk of an adverse health outcome. The objective of this study was to quantify and compare health risks of PM from biomass burning and non-biomass burning sources in northern Thailand.
We collected ambient air pollutant data (PM with a diameter of < 10 μm [PM], PM, Carbon Monoxide [CO], Ozone [O], and Nitrogen Dioxide [NO]) from ground-based monitors and daily outpatient hospital visits in Thailand during 2014-2017. Outpatient data included chronic lower respiratory disease (CLRD), ischaemic heart disease (IHD), and cerebrovascular disease (CBVD). We performed an ecological time series analysis to evaluate the association between daily air pollutants and outpatient visits. We used the 90th and 95th percentiles of PM concentrations to determine days of exposure to PM predominantly from biomass burning.
There was significant intra annual variation in PM levels, with the highest concentrations occurring during March, coinciding with peak biomass burning. Incidence Rate Ratios (IRRs) between daily PM and outpatient visits were elevated most on the same day as exposure for CLRD = 1.020 (95% CI: 1.012 to 1.028) and CBVD = 1.020 (95% CI: 1.004 to 1.035), with no association with IHD = 0.994 (95% CI: 0.974 to 1.014). Adjusting for CO tended to increase effect estimates. We did not find evidence of an exposure response relationship with levels of PM on days of biomass burning.
We found same-day exposures of PM to be associated with certain respiratory and cardiovascular outpatient visits. We advise implementing measures to reduce population exposures to PM wherever possible, and to improve understanding of health effects associated with burning specific types of biomass in areas where such large-scale activities occur.
生物质燃烧产生的颗粒物（PM）的暴露问题日益受到关注，尤其是在东南亚地区。目前尚不清楚 PM 的来源如何影响不良健康后果的风险。本研究的目的是量化和比较泰国北部生物质燃烧和非生物质燃烧源 PM 对健康的影响。
我们收集了 2014-2017 年泰国地面监测站和每日门诊就诊的环境空气污染物数据（直径<10μm 的颗粒物[PM]、PM、一氧化碳[CO]、臭氧[O]和二氧化氮[NO]）。门诊数据包括慢性下呼吸道疾病（CLRD）、缺血性心脏病（IHD）和脑血管疾病（CBVD）。我们进行了生态时间序列分析，以评估每日空气污染物与门诊就诊之间的关联。我们使用 PM 浓度的第 90 和 95 百分位数来确定主要由生物质燃烧引起的 PM 暴露天数。
PM 浓度存在显著的年内变化，最高浓度出现在 3 月，与生物质燃烧高峰期相吻合。CLRD 的每日 PM 与门诊就诊之间的发病率比值（IRR）在暴露当天最高为 1.020（95%置信区间：1.012 至 1.028），而 CBVD 为 1.020（95%置信区间：1.004 至 1.035），与 IHD 无关联为 0.994（95%置信区间：0.974 至 1.014）。调整 CO 后，估计值有所增加。我们没有发现生物质燃烧日 PM 水平与暴露量之间存在暴露反应关系的证据。
我们发现 PM 的当日暴露与某些呼吸道和心血管门诊就诊有关。我们建议尽可能采取措施减少人群对 PM 的暴露，并改善对在发生此类大规模活动的地区燃烧特定类型生物质相关健康影响的理解。
