A major study published Friday in The Lancet Planetary Health has confirmed a reported link between air pollution and diabetes in a big way, finding that particulate matter exposure can increase risk for the disease even at levels currently deemed safe by the U.S. Environmental Protection Agency (EPA) and the World Health Organization, CNN reported.

"This is important because many industry lobbying groups argue that current levels are too stringent and should be relaxed. Evidence shows that current levels are still not sufficiently safe and need to be tightened," study lead author and Washington University School of Medicine in Saint Louis assistant professor Dr. Ziyad Al-Aly said in a Washington University press release.

The study found that air pollution caused 3.2 million new diabetes cases globally in 2016, 14 percent of the year's total cases, and causes 150,000 new cases in the U.S. every year.

Pollution-linked diabetes was also the cause of 8.2 million years of healthy life lost globally in 2016, 14 percent of the total number of healthy years lost due to diabetes that year. In the U.S., 350,000 years of healthy life are lost a year.

"This is a very well-done report, very believable, and fits well with this emerging knowledge about the impacts of air pollution on a series of chronic diseases," said Dr. Philip Landrigan to CNN. The dean for Global Health at Icahn School of Medicine at Mount Sinai in New York was not part of the study. "I think you can very directly link relaxation of air pollution control standards with increased sickness and death."

The study builds on previous research linking diabetes to air pollution, as well as a growing awareness of the extent of the health risks associated with pollution exposure.

"Ten or 15 years ago, we thought that air pollution caused pneumonia, asthma and bronchitis and not much more than that," Landrigan told CNN. "We now know that air pollution is a very important cause of heart disease and stroke and contributes to chronic lung disease, lung cancer and chronic kidney disease."

Health experts believe pollution triggers diabetes by reducing insulin production and increasing inflammation, making it harder for the body to turn glucose into energy.

To reach their conclusions, researchers at Washington University and the Veterans Affairs' Clinical Epidemiology Center followed 1.7 million veterans with no prior history of diabetes for a median of 8.5 years. They then compared the patient data with particulate matter levels provided by EPA air quality monitors and National Aeronautics and Space Administration (NASA) satellites.

They then looked at previous air pollution studies to develop a model for risk at different pollution levels and used Global Burden of Disease data to determine yearly diabetes cases and years of life lost.

One key finding was that diabetes risk increases at particulate matter levels of 2.4 micrograms per cubic meter of air, while the current EPA safe limit is 12 micrograms per cubic meter of air. The researchers found that 21 percent of veterans developed diabetes when exposed to between 5 to 10 micrograms of particulate matter per cubic meter of air. That number rose to 24 percent among veterans exposed to 11.9 to 13.6 micrograms, an increase of 5,000 to 6,000 new diabetes cases per 100,000 people per year.

While even pollution levels considered safe in the U.S. can increase diabetes risk, the study did find that people in poorer countries that lack the resources to clean their air sufficiently, such as India, Afghanistan, Papua New Guinea and Guyana, faced the greatest risk from pollution-caused diabetes. People in wealthy countries like France, Finland and Iceland faced a lower risk, while people in the U.S. faced moderate risk, the study found.