Associations of long-term fine particulate matter exposure with all-cause and cause-specific mortality: results from the ChinaHEART project.

Background: The chronic effects of fine particulate matter (PM) at high concentrations remains uncertain. We aimed to examine the relationship of long-term PM exposure with all-cause and the top three causes of death (cardiovascular disease [CVD], cancer, and respiratory disease), and to analyze their concentration-response functions over a wide range of concentrations.

Methods: We enrolled community residents aged 35-75 years from 2014 to 2017 from all 31 provinces of the Chinese Mainland, and followed them up until 2021. We used a long-term estimation dataset for both PM and O concentrations with a high spatiotemporal resolution to assess the individual exposure, and used Cox proportional hazards models to estimate the associations between PM and mortalities.

Findings: We included 1,910,923 participants, whose mean age was 55.6 ± 9.8 years and 59.4% were female. A 10 μg/m increment in PM exposure was associated with increased risk for all-cause death (hazard ratio 1.02 [95% confidence interval 1.012-1.028]), CVD death (1.024 [1.011-1.037]), cancer death (1.037 [1.023-1.052]), and respiratory disease death (1.083 [1.049-1.117]), respectively. Long-term PM exposure nonlinearly related with all-cause, CVD, and cancer mortalities, while linearly related with respiratory disease mortality.

Interpretation: The overall effects of long-term PM exposure on mortality in the high concentration settings are weaker than previous reports from settings of PM concentrations < 35 μg/m³. The distinct concentration-response relationships of CVD, cancer, and respiratory disease mortalities could facilitate targeted public health efforts to prevent death caused by air pollution.

Funding: The Chinese Academy of Medical Sciences Innovation Fund for Medical Science, the National High Level Hospital Clinical Research Funding, the Ministry of Finance of China and National Health Commission of China, the 111 Project from the Ministry of Education of China.