A new study a link between air pollution levels and risk of experiencing kidney function decline and of developing kidney disease or kidney failure. The study, which appears in an upcoming issue of the Journal of the American Society of Nephrology (JASN), reveals that the effects on the kidneys are seen at low levels of particulate matter and increase linearly with rising levels of pollution.

A team led by Ziyad Al-Aly, MD, Director of Clinical Epidemiology at the VA Saint Louis Health Care System, linked the Environmental Protection Agency and the Department of Veterans Affairs databases to examine information on 2,482,737 U.S. veterans who were followed for a median of 8.5 years. Air pollution levels were also assessed using space-borne sensors from NASA satellites.

The researchers found a linear relationship between air pollution levels and risk of experiencing kidney function decline and of developing kidney disease or kidney failure. The results suggest that each year in the United States, 44,793 new cases of CKD and 2438 new cases of kidney failure are attributed to particulate matter air pollution exceeding the EPA’s recommended limit of 12 μg/m3.

“Even levels below the limit set by the EPA were harmful to the kidneys,” noted Dr. Al-Aly. “This suggests that there is no safe level of air pollution.” He noted that the burden is not evenly distributed geographically: the highest toll seems to be in southern California and in large swaths of the Midwest, the Northeast, and the South.