Evidence on the impact of sustained exposure to air pollution on life expectancy from China’s Huai River policy

TLDR

The study uses a regression‑discontinuity design exploiting the Huai River policy that provided free coal heating north of the river but not south, comparing TSP concentrations and life expectancy across the boundary. The analysis shows that the policy raises TSPs by about 184 µg/m³, leading to a 5.5‑year drop in life expectancy and an estimated loss of over 2.5 billion life years for 500 million residents, with each 100 µg/m³ increase in TSPs associated with a 3‑year reduction in life expectancy at birth.

Abstract

This paper's findings suggest that an arbitrary Chinese policy that greatly increases total suspended particulates (TSPs) air pollution is causing the 500 million residents of Northern China to lose more than 2.5 billion life years of life expectancy. The quasi-experimental empirical approach is based on China’s Huai River policy, which provided free winter heating via the provision of coal for boilers in cities north of the Huai River but denied heat to the south. Using a regression discontinuity design based on distance from the Huai River, we find that ambient concentrations of TSPs are about 184 μg/m 3 [95% confidence interval (CI): 61, 307] or 55% higher in the north. Further, the results indicate that life expectancies are about 5.5 y (95% CI: 0.8, 10.2) lower in the north owing to an increased incidence of cardiorespiratory mortality. More generally, the analysis suggests that long-term exposure to an additional 100 μg/m 3 of TSPs is associated with a reduction in life expectancy at birth of about 3.0 y (95% CI: 0.4, 5.6).