On June 27th a new study from Harvard’s Chen Zengxi School of Public Health provided the most comprehensive evidence yet of a causal link between long-term exposure to fine particulate matter (PM2.5) air pollution and premature death,media reported. The new study is based on a 2017 study that found that long-term exposure to PM2.5 pollution and ozone, even below current U.S. air quality standards, increases the risk of premature death in older Americans.
In the new study, researchers looked at data from 68.5 million Medicare enrollees for 16 years, 97 percent of Americans over 65 adjusted for weight index, smoking, race, income and education. The participants’ postal codes were matched to air pollution data collected from across the United States.
In estimating the daily PM2.5 air pollution levels per zip code, the researchers also took into account satellite data, land-use information, weather variables and other factors. They used two traditional statistical methods, as well as three the latest methods to find a causal relationship.
All five different types of analysis were consistent, even if there was a causal relationship between exposure to PM2.5 and the mortality rate of Medicare enrollees, even if it was below the current U.S. air quality standard of 12 micrograms per cubic meter per year.
The researchers found that pm2.5 pollution by 10 micrograms per year reduced mortality by 6 to 7 percent. Based on the findings, they estimate that if the United States lowers its annual PM2.5 standard to 10 micrograms per cubic meter, it could save 143,257 lives within a decade.
Air pollution has become the world’s fifth leading cause of death, after dietary risk, high blood pressure, cigarettes and high blood sugar, according to previous reports. Air pollution levels in the United States increased by 5.5% between 2017 and 2018, killing 10,000 Americans. According to WHO, about 7 million people die each year from air pollution worldwide.