Guo Huagui, Li Weifeng, Wu Jiansheng, Ho Hung Chak
School of Architecture and Urban-Rural Planning, Fuzhou University, Fuzhou, 350108, China.
Department of Urban Planning and Design, The University of Hong Kong, Hong Kong, China.
Environ Sci Pollut Res Int. 2022 Apr;29(16):23905-23918. doi: 10.1007/s11356-021-17406-5. Epub 2021 Nov 24.
It remains unknown whether exposure to ambient air pollution can be a mediator linking socioeconomic indicator to health outcome. The present study aims to examine the mediation effect of PM air pollution on the association between urban-rural division and the incidence (mortality) rate of male lung cancer. We performed a nationwide analysis in 353 counties (districts) of China between 2006 and 2015. A structural equation model was developed to determine the mediation effect of exposure to PM. We also tested whether the findings of the mediation effect of exposure to PM are sensitive to the controls of smoking factors and additional air pollutant, and PM exposures with different lag structures. According to the results, we found that exposure to PM significantly mediated the association between urban-rural division and the incidence rate of male lung cancer. Specifically, there were significant associations between urban-rural division, exposure to PM, and the incidence rate of male lung cancer, with PM exposure accounting for 29.80% of total urban-rural difference in incidence rates of male lung cancer. A similar pattern of results was observed for the mortality rate of male lung cancer. That is, there was a significant mediation effect by PM on the association of the mortality rate with urban-rural division. The findings of exposure to PM as a mediator were robust in the three sensitivity analyses. In conclusion, urban-rural difference in exposures to PM may be a potential factor that contributes to urban-rural disparity in male lung cancer diseases in China. The findings inform that air pollution management and control may be effective measures to alleviate the great difference in male lung cancer diseases between urban and rural areas in China.
暴露于环境空气污染是否能作为将社会经济指标与健康结果联系起来的中介尚不清楚。本研究旨在检验PM空气污染对城乡划分与男性肺癌发病率（死亡率）之间关联的中介作用。我们于2006年至2015年在中国353个县（区）进行了一项全国性分析。构建了一个结构方程模型来确定PM暴露的中介作用。我们还测试了PM暴露中介作用的结果对吸烟因素和其他空气污染物控制以及不同滞后结构的PM暴露是否敏感。根据结果，我们发现PM暴露显著中介了城乡划分与男性肺癌发病率之间的关联。具体而言，城乡划分、PM暴露与男性肺癌发病率之间存在显著关联，PM暴露占男性肺癌发病率城乡总差异的29.80%。男性肺癌死亡率也观察到类似的结果模式。也就是说，PM对死亡率与城乡划分之间的关联有显著的中介作用。在三项敏感性分析中，PM作为中介的暴露结果是稳健的。总之，PM暴露的城乡差异可能是导致中国男性肺癌疾病城乡差距的一个潜在因素。这些发现表明，空气污染管理和控制可能是缓解中国城乡男性肺癌疾病巨大差异的有效措施。
