The impact of fine particulate pollution (PM2.5) on hospitalization costs in China.

Introduction: Air pollution poses a threat to public health and socio-economic stability, significantly increasing the disease burden on the population and causing heavy economic impacts, especially in terms of medical expenses. Quantifying this economic impact is crucial for formulating effective public health strategies. This study aims to deeply explore the direct impact of air pollution on specific medical expenses. Methods: This study utilized the medical data of inpatients in a certain city in southwest China from 2014 to June 2019, the data of key air pollution indicators such as PM2.5 and AQI collected through local monitoring stations, and the data of land use types in this city. Results: (1) Air pollution has significantly increased the total hospitalization costs for patients and is a key factor leading to the rise in their medical expenses.Taking the 7-day moving average as an example, a 10 μg/m³ increase in PM2.5 led to a 0.5% rise in total hospitalization costs, equivalent to about 42 yuan per individual. (2) Air pollution has significantly increased the amount of medical insurance reimbursement for patients rather than their out-of-pocket expenses, suggesting that patients tend to mitigate related expenses through insurance reimbursement. (3) Green space area can effectively alleviate the increasing effect of air pollution on hospitalization costs, while industrial land has the opposite effect.The mitigating effect of green spaces on air pollution is most prominent among middle-aged and older adults groups and is more significant under conditions of low wind speed and precipitation. Discussion: Air pollution has exerted economic pressure on both individual patients and the medical security system. The research results can provide important references for optimizing the allocation of medical resources and strengthening health protection to reduce the health and economic burden of air pollution.