Air pollution and diabetes have a link. The more pollution in the air, the higher the number of reported cases of adult diabetes a study has found.

A new epidemiological study by researchers at Children’s Hospital Boston has connected air pollution to an increase in insulin resistance which gives rise to diabetes.

Researchers used health, economic, geographical and other data from the Centers for Disease Control and the U.S. Census to adjust for diabetes risk factors, including obesity, exercise, ethnicity and population density.

The study focused on tiny airborne particles arising primarily by traffic, coal-fired power plants and industrial boilers.

They still found a 1 percent increase in diabetes rates for every 10 microgram per cubic meter rise in fine particulate matter.

“We didn’t have data on individual exposure, so we can’t prove causality, and we can’t know exactly the mechanism of these peoples’ diabetes,” said the study’s co-author John Brownstein, an assistant professor of epidemiology at Children’s Hospital Boston.

According to Brownstein, “pollution came across as a significant predictor in all models.”

An estimate of 23.5 million Americans suffer from diabetes according to 2007 statistics from the Centers on Disease Control and Prevention.

The study appears in the October issue of Diabetes Care.