Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, 20850, USA.
Institute for Risk Assessment Sciences, Division of Environmental Epidemiology, Utrecht University, Utrecht, 3508 TD, The Netherlands.
Sci Rep. 2020 Jul 9;10(1):11335. doi: 10.1038/s41598-020-68229-2.
Outdoor air pollution is a growing public health concern, particularly in urban settings. However, there are limited epidemiological data on outdoor air pollution in rural areas with substantial levels of air pollution attributed to solid fuel burning for household cooking and heating. Xuanwei and Fuyuan are rural counties in China where the domestic combustion of locally sourced bituminous ("smoky") coal has been associated with the highest lung cancer rates in China. We previously assessed indoor and personal air pollution exposures in this area; however, the influence of indoor coal combustion and household ventilation on outdoor air pollution has not been assessed. Therefore, we measured outdoor fine particulate matter (PM), species of polycyclic aromatic hydrocarbons (PAHs) including naphthalene (NAP) and the known carcinogen benzo(a)pyrene (BaP), sulfur dioxide (SO), and nitrogen dioxide (NO) over two consecutive 24-h sampling periods in 29 villages. Just over half of the villages were revisited two to nine months after the initial sampling period to repeat all measurements. The overall geometric mean (GM) of outdoor PM, BaP, NAP, and NO were 45.3 µg/m, 9.7 ng/m, 707.7 ng/m, and 91.5 µg/m, respectively. Using linear mixed effects models, we found that burning smoky coal was associated with higher outdoor BaP concentrations [GM ratio (GMR) = 2.79] and lower outdoor SO detection rates (GMR = 0.43), compared to areas burning smokeless coal. Areas with predominantly ventilated stoves (> 50% of stoves) had higher outdoor BaP (GMR = 1.49) compared to areas with fewer ventilated stoves. These results show that outdoor air pollution in a rural region of China was associated with the type of coal used for cooking and heating indoors and the presence of stove ventilation. Our findings suggest that efforts of household stove improvement to reduce indoor air pollution have resulted in higher outdoor air pollution levels. Further reducing adverse health effects in rural villages from household coal combustion will require the use of cleaner fuel types.
室外空气污染是一个日益严重的公共卫生问题，尤其是在城市环境中。然而，对于那些由于家庭烹饪和取暖而大量燃烧固体燃料导致空气污染的农村地区，有关室外空气污染的流行病学数据有限。宣威和富源是中国的农村县，当地采购的烟煤（“多烟”煤）用于家庭烹饪和取暖，与中国最高的肺癌发病率有关。我们之前评估了该地区的室内和个人空气污染暴露情况；然而，室内煤燃烧和家庭通风对室外空气污染的影响尚未得到评估。因此，我们在 29 个村庄连续进行了两次 24 小时采样，测量了室外细颗粒物（PM）、多环芳烃（PAHs）的种类，包括萘（NAP）和已知的致癌物质苯并（a）芘（BaP）、二氧化硫（SO）和二氧化氮（NO）。在最初采样期后，超过一半的村庄在两到九个月后再次进行了所有测量。室外 PM、BaP、NAP 和 NO 的总几何平均值（GM）分别为 45.3μg/m、9.7ng/m、707.7ng/m 和 91.5μg/m。使用线性混合效应模型，我们发现与燃烧无烟煤相比，燃烧烟煤与较高的室外 BaP 浓度有关[GM 比（GMR）=2.79]，与较低的室外 SO 检测率有关（GMR=0.43）。与通风炉具（>50%的炉具）为主的地区相比，通风炉具较少的地区室外 BaP 浓度更高（GMR=1.49）。这些结果表明，中国农村地区的室外空气污染与室内烹饪和取暖用煤的类型以及炉具通风的存在有关。我们的研究结果表明，为减少室内空气污染而进行的家庭炉具改进工作导致了更高的室外空气污染水平。要进一步减少农村地区家庭燃煤对健康的不利影响，需要使用更清洁的燃料类型。
