Examining the Impact of Inter-provincial Migration on Environmental Health in China

Abstract Background China has a large volume of inter-provincial migrants, accounting for more than 11% of the total population. The economic benefits of inter-provincial migration have been well studied, whereas the health impacts related to environmental factors are generally ignored. Methods In this study, we use 1% national population sampling survey data from 2015 and daily PM2.5 (particles ≤ 2.5 µm in aerodynamic diameter) concentration data from 360 cities to analyze the health benefits associated with air pollution due to inter-provincial migration. The exposure-response function was used to estimate the economic value of these health benefits via the adjusted-human-capital and cost-of-illness methods. Results Considering a full-exposure scenario, inter-provincial migration resulted in a reduction in the PM2.5 exposure concentration of 3.94 µg/m3 in 2015, corresponding to a reduction of 6114 premature deaths, 233.4 thousand hospitalization cases, and 1.5 million asthma attacks. The corresponding economic value of these health benefits was about 10.44 billion yuan (0.02% of the national GDP in 2015). A protection scenario, assuming that the migrants protected themselves from air pollution, showed very similar results to the full-exposure scenario (PM2.5 exposure reduced by 3.60 µg/m3); hence, personal protection does not reduce significantly the health risks of air pollution. Conclusions At the national level, the labor force obtains both economic and health benefits. However, a high number of migrants flow out of the central region of China result in a labor deficiency and social imbalance. Migration to large cities provides economic benefits at the expense of health. Environmental migration becomes an increasingly important motivation for inter-provincial migration, which places new pressure on policy makers to consider social welfare and environmental protection in the provinces.