When high-efficiency particle air (HEPA) filters were used for just 48 hours to clean the air in the apartments of 21 older couples, their blood vessel function improved by about 8 percent, Danish researchers have shown.

While the couples were all non-smokers, the improvement seen in the study was "in the same ballpark" as would be seen after a person quits smoking, Dr. Steffen Loft of the Institute of Public Health in Copenhagen, the study's lead author, told Reuters Health.

There is a wealth of data on how breathing minute particles carried in the air, known as particulate matter, can worsen heart and lung disease and even increase mortality rates, Loft and his team note in the American Journal of Respiratory and Critical Care Medicine.

To better understand how particulate matter in indoor air affects health, the researchers used a battery of tests to assess microvascular function and inflammation in 21 couples 60 to 75 years old after breathing nonfiltered air, and then after breathing filtered air for 48 hours. - See Home air filters may improve elders' heart health for the complete article.