New evidence on the impact of sustained exposure to air pollution on life expectancy from China’s Huai River Policy

Summary:

• This study uses a novel analysis to determine the impact of air pollution on life expectancy in Northern China. The researchers conduct a quasiexperiment building on China’s Huai River policy, which provided free coal for heating in Northern China and restricted coal in the south. The analysis compares locations just to the north and south of the Huai River.
• The analysis was conducted with the most comprehensive data set ever compiled on health and pollution in a developing country. These conditions and data provided the researchers with the ability to measure the impact of high levels of particulate pollution over a long period of time, and isolate that impact from other factors that could affect health.
• The researchers found that particulate pollution was 46 percent higher north of the Huai River due to the winter heating policy and resulting coal combustion. The elevated levels of air pollution reduced average lifespans by 3.1 years. The researchers discovered that this was due to increased incidences of cardiorespiratory deaths among all age groups. There was no evidence of an increase in mortality rates due to non-cardiorespiratory causes of death.
• From the data in China, the researchers formed an important generalized metric that can apply to any country’s environment: Every additional 10 micrograms per cubic meter of sustained exposure to airborne particulate matter reduces life expectancy by 0.6 years.
• Using the metric, the researchers found that 3.7 billion life years would be saved if China met its own pollution standard (Class 1 PM10). The metric can be similarly used to discover life years saved if other countries met their own standards.
• This metric can be used to develop estimates of the benefits of clean air regulations that can be compared with their costs.