Researchers armed with satellites and statistics have shown that long-term exposure to fine (PM2.5) particle air pollution increases hospital admissions for diabetes, respiratory illness, cardiovascular disease and strokes. The new research, conducted by the Harvard School of Public Health, was published this week in “PLoS One,” an online scientific journal.

The new study points to the potential benefits of air purifiers in improving health and reducing the severity of medical symptoms caused by particle air pollution. The study comes out just as the American Lung Association prepares to issue its State of the Air 2012 report next week. That annual report details particle and ozone pollution levels in cities and regions across the United States. The Harvard study offers additional perspective on the health consequences of air pollution.

The researchers found measurable, significant increases in hospitalizations related to each increase of 10 micrograms per cubic meter (mcg/m3) in long-term exposure to PM2.5 particle pollution. For each 10 mcg/m3 increase in long-term exposure, hospitalizations increased 6.33% for diabetes, 4.2% for respiratory illness, 3.49% for strokes and 3.12 % for cardiovascular disease. Let’s try to put that in perspective: Yesterday afternoon, a reasonably clean air day, the PM2.5 particle pollution level in Orange County, Calif., was 20 mcg/m3 lower than the level in nearby Los Angeles County.

In the “Discussion” section of the report, the authors took note of a 2008 study that showed the positive role a HEPA air purifier could play in reducing particle levels and improving cardiovascular function. That study focused on 21 couples who lived near roads with heavy traffic, and found that the use of a HEPA air purifier improved the inner lining of the blood vessels of the subjects. The couples in that study used a HEPA air purifier over a 48-hour period, and the researchers reported an improvement in microvascular function of 8.1%.

The Harvard research team noted that hospitalizations caused by long-term exposure to pollution are even greater than short-term, or acute, exposures. The U.S. Environmental Protection Agency reports air quality data for both short-term (24 hours) and long term (annual) concentrations, and both are included in the State of the Air reports. Check out the state of the air where you live or work usingIQAir’s “What’s the State of Your Air” widget.