A new global study links air pollution to an increased risk of type 2 diabetes, a worrisome finding especially for the Central Valley of California, with its notoriously high levels of dangerous particles.
It has long been known that air pollution poses a threat to health: the consequences include asthma and other lung problems, and in the last decade, air pollution has been found to increase the risk of heart disease and renal.
The new link to type 2 diabetes appears in a study published by The Lancet Planetary Health, which badyzes the global and national impact of diabetes badociated with air pollution. The findings attribute 3.25 million newly diagnosed cases of type 2 diabetes internationally, only in 2016, to air pollution.
Dr. Ziyad Al-Aly, study author and badistant professor of medicine at the University of Washington in St. Louis, spoke about the impact of breathing air pollutants.
"We tell people all the time, if you eat bad things, it affects their health," Al-Aly said. "You are what you eat, you are what you drink and, really, you are what you breathe." What it really breathes really affects your health. "
Eight of the ten most important cities in the United States that rank first in particle pollution in the short term are in California, according to the State of the Air report. 2018 of the American Lung Association The three major cities in the nation are Bakersfield, Visalia and Fresno, and seven of the top 10 cities in the US with the highest particulate pollution throughout the year are in California.
Will Barrett, a defense and clean air manager for the American Lung Association in California, explained that areas such as San Joaquin, the county in the Central Valley of California, face unique challenges in efforts to reduce air pollution. the agriculture and trucks that drive through the Valley, contamination by wildfires and cases of extreme heat that can trap pollution by day
Sacramento American is ranked as one of the most polluted cities in the American Lung Association.  A previous investigation was conducted that suggested a link between air pollution and type 2 diabetes. And although Al-Aly said that this investigation hypothesized that there was a link, he and his colleagues were surprised by his findings.
"What we really did not know was the magnitude of the problem," he said. "We were surprised by the magnitude."
So, what does air pollution have to do with type 2 diabetes? The badociation between the two is directly related to a small particle of air called particulate matter 2.5, dangerous both because it is harmful and because of its incredibly small size: less than 2.5 micrometers and naked for the human eye. The particle is significantly smaller than the diameter of a human hair.
PM 2.5 particles are released into the air as a result of emissions from automobiles, buses and factories. Al-Aly explained that these small, noxious particles enter the body and reduce their ability to respond to insulin.
These particles are so small, he said, that unlike larger particles that get stuck in the lungs and can be expelled, PM 2.5 particles can penetrate through the lungs and end up in the bloodstream. From the bloodstream, these particles can go to any part of the body, leading to serious health problems.
"When you inhale particles, you're putting your health at risk," Barrett said. "It hangs and causes damage."
Dr. G. Prakasam, a local pediatric endocrinologist at Sutter Health, said that unlike type 1 diabetes, which is caused by a lack of insulin in a body, type 2 diabetes is characterized by the body's resistance to insulin that is produces. Exposure to air pollutants is directly related to the decrease in insulin sensitivity, according to the evidence cited in the study.
According to the American Diabetes Association, insulin allows sugar, an important source of fuel for the body, to enter cells.
"Type 2 is considered the type of minor diabetes," said Prakasam. "But the long-term complications are as bad as those of type 1."
The study followed 1.7 million veterans of Veterans Affairs for a median of 8.5 years. None of the participants had a prior history of diabetes and the researchers established controls for factors that include health behaviors, social and economic circumstances and physical environments.
After collecting data following the research population, researchers used data from the Environmental Protection Agency and the NASA satellite data detection to measure air pollution levels to define PM 2.5 exposure in the participating population .
The researchers used these findings and the global disease burden methodology, a measure to estimate the impact of a disease, to examine how diabetes linked to air pollution affected 194 countries and territories.
The study findings showed that 8.2 million years of healthy life were lost due to diabetes attributable to air pollution in 2016 globally. In addition, more than 206,000 deaths from type 2 diabetes were related to air pollution.
The countries that had the highest attributable death burden were China, India and the USA. UU
With cases of type 2 diabetes increasing significantly, even among children, Prakasam said he would not be surprised to hear the link between air pollution and an increased risk of type 2 diabetes, as it is not yet clear why people they now run a greater risk of developing health complications. If the study can be replicated three or four times, he said, there is a clear link.
Earlier this year, Sacramento County received an F score from the American Lung Association for both ozone levels and 24-hour particle contamination levels. According to the Sacramento air quality management district, PM 2.5 is one of the major air pollutants in the region, the other is ground level ozone.
Al-Aly explained that of the measurements available for PM 2.5 levels, the most important is the annual percentage. The EPA designates safe levels at 12 micrograms per cubic meter of air, but the study found that levels below those explicitly identified by the regulatory agencies may pose a risk.
"In our studies we observed that the risk began to manifest itself in concentrations of PM 2.5 above 2.4 micrograms / cubic meter," said Al-Aly.
The annual average of PM 2.5 levels for Sacramento County since 2016, the most recent year available, shows 8.8 micrograms per cubic meter, according to kidsdata.org.  Barrett acknowledged that EPA standards are set at a level to protect public health, but health officials recognize that particle levels in smaller amounts pose a threat to health. Barrett said the standards should be reviewed annually and based on the best science available.
Sacramento County ranked 19 among US cities for unhealthy air in 2018, but the region has already seen improvements in air quality.
"We have made tremendous progress," said Barrett, explaining that the county has seen an 80 percent reduction in the number of days of unhealthy particle pollution since 2004. This reduction is due to factors that include cleaner standards and the local program Check Before You Burn to control wood smoke.
The study describes other health consequences from exposure to air pollution, including inflammation and complications in the autonomic nervous system, which controls unconscious bodily functions such as heartbeat and respiration.
"There really is not a safe level of particle contamination," Barrett said. "Our lungs were not meant to breathe contaminated air."