New research suggests that exposure to air pollution, even at levels that are below the currently acceptable limits, may increase the risk of diabetes among area residents.
In a study published in the July 2018 issue of the journal the Lancet Planetary Health, researchers warn that air pollution may cause more than 3.2 million new cases of diabetes each year worldwide.
Researchers from the Washington University School of Medicine in St. Louis studied 1.7 million U.S. veterans with no previous history of diabetes. They used data from various databases and followed participants for an average of 8.5 years. They examined the association between particulate matter 2.5 (PM 2.5) and the risk of diabetes.
The data indicated every 10 microgram per cubic meter (μg/m3) increase in PM 2.5 was associated with an increased risk of diabetes. According to the findings, 21% more veterans developed diabetes due to air pollution exposure.
The levels seen in the study are below the current safe levels of air pollution set by the Environmental Protection agency (EPA) and the World Health Organization (WHO).
When exposed to higher levels of PM 2.5, between 11.9 and 13.9 μg/m3, 24% of veterans developed diabetes. That 3% increase translates to an additional 5,000 to 6,000 new cases of diabetes per 100,000 people every year.
Another study published in 2017 indicated a link between air pollution and diabetes among Latino children. The new study seems to support those findings.
PM 2.5 is a mix of dust, dirt, smoke, soot, and liquid particles smaller than 2.5 micrometers. By comparison, one strand of human hair is 70 micrometers, which is 30 times larger than these particles.
Particles smaller than 10 micrometers can enter the lungs, leading to the cardiovascular system, and cause heart disease, those particles can also pass into the bloodstream where it is carried to other organs, further leading to disease.
Researchers estimate that PM 2.5 air pollution contributed to 3.2 million cases of diabetes, or roughly 14%, of the total cases around the world. In the United States, this leads to 150,000 new cases per year.
Air pollution exposure is also linked to 8.2 million disability-adjusted life years caused by diabetes. The incidence of diabetes was varied among geographical locations, but was more heavily skewed toward low-income and lower-to-middle-income countries.
More than 30 million Americans have diabetes. In 2014, 422 million adults globally were diagnosed with diabetes compared to 108 million in 1980.
Researchers of the new study noted air pollution exposure was also associated with an increased risk of death; more than 200,000 each year from diabetes. These findings also emphasize the findings of prior studies indicating air pollution kills more than 7 million people each year.