Air pollution in the Twin Cities contributes to about 2,000 premature deaths every year, and sends 1,000 people to the hospital for asthma, lung and heart disease treatments.

It is particularly bad for the elderly, people of color and those living in poverty because they are more likely to suffer from the health conditions aggravated by air pollution, according to a joint analysis released Monday by the Minnesota Health Department and the Minnesota Pollution Control Agency.

It is the first time the state has conducted such a detailed study of the metro-wide health impacts from two kinds of pollution — ozone, which causes smog, and microscopic particles produced by combustion in everything from industry to backyard fires. In all, 6 to 13 percent of deaths in the metropolitan area were partly caused by one or both of those pollutants, similar to death rates from accidents and Alzheimer's disease.

"This report helps us see much more clearly than we could before just who is affected by air pollution, how serious the effects are and where we have health disparities that need to be addressed," said Ed Ehlinger, commissioner of the Minnesota Department of Health.

It also starts to make a case in Minnesota for what could be tough new federal standards for ground level ozone that are expected to be released in October. Right now, Minnesota's air almost always meets clean air standards, but that could change when the EPA updates them.

If the ozone levels are too high, then the state will be required to come up with a plan to reduce them; that could include the imposition of new regulations and laws that could be a burden to businesses and consumers.

"If we can do emissions reductions now, it's cheaper, easier and a whole lot less cumbersome and bureaucratic," said Julian Marshall, an environmental engineer at the University of Minnesota who studies air pollution.

New ozone limits loom

Ozone, the primary ingredient in smog, is created when pollutants from cars, factories and burning fuels mix in the presence of sunlight and heat. The Obama administration is considering limiting ozone to 65 to 70 parts per billion, below the existing standard of 75 set in 2008. The reduction would cost an estimated $3.9 billion in 2025, according to the EPA, which business groups say would be one of the costliest regulations in history.

But the health impact in the Twin Cities would be considerable. According to the computer analysis, which used 2008 data to create a computer model of health effects, each year in the Twin Cities, smog contributes to 23 deaths, plus 47 hospitalizations, and 185 emergency room visits for asthma.

The health impact of small particle pollution is much greater.

The small particle pollution created by small engines like lawn mowers and leaf blowers, diesel engines, industry and backyard fires causes 2,100 premature deaths each year, plus 291 hospitalizations for respiratory and cardiovascular problems, and 400 emergency room visits for asthma.

The air pollution from Canadian forest fires that blanketed the state last week was an extreme example of small particle pollution. Levels reached nearly three times the usual 35 micrograms per cubic meter that the Twin Cities gets on a normal day.

"That was a surreal sort of event," said Frank Kohlasch, air quality expert for the PCA.

No good particle threshold

But the latest research is finding that unlike other kinds of pollution limits, there is no good health threshold for small particles, Marshall said. Even though the levels in the Twin Cities are well below the national standard, "people are still getting sick and dying," he said. The most significant problem is that small particles contribute to heart disease and strokes, he said.

The state report estimated that a 10 percent reduction would save 247 lives.

Those who live in poverty would likely benefit from that the most. The analysis found that people who live in low-income ZIP codes, or in areas with high concentrations of people of color suffered higher rates of death and hospitalization from small particle pollution. That's not because the air pollution in those communities is worse, state officials said. It's because those groups are more likely to have the heart and lung diseases that make them more vulnerable to its effects.

Josephine Marcotty • 612-673-7394