A Study published in the journal Circulation shows Ozone pollution having a marked effect on those at high risk for heart attack. The World Health organization estimated that some 2 million people die annually due to a combination of heart problems increased by Ozone.

Whilst Ozone at high altitude helps to shield the planet from radiation, at ground level it is considered a pollutant, a nuisance and a health risk, it is created when pollutants from vehicles, power plants, industry, and other sources react in the sunlight.

Until the new study, most research had focused on lung problems and associated respiratory issues, however Robert B. Devlin, PhD, a senior scientist at the U.S. Environmental Protection Agency’s (EPA) National Health and Environmental Effects Research Laboratory in Research Triangle Park, N.C. took a new approach, looking at changes to heart and cardiovascular function in healthy individuals exposed to Ozone, as they might be in city situations where air pollution and ozone levels spike.

23 healthy adults, aged 19 to 33, where exposed to ozone polluted air for a two hour period, twice in two weeks. During the two hours they alternated between resting and 15 minutes of cycling. The level of Ozone was 0.3ppm, with a datum established by also running tests on the subjects using clean air.

The results show significant changes in heart function both the same day of the exposure and the morning after. Problems picked up on included:

  • Increases in an indicator of inflammation known as interleukin-1-beta, which researchers say is a key player in heart disease.
  • Decreases in components that play an important role in dissolving blood clots that may form along arterial walls (plasminogen activator inhibitor 1 and plasminogen).
  • Changes in heart rhythm, an indication of an alternation in the nervous system’s control of the heart rate.

The test subjects were all young and healthy, so the changes were not particularly problematic or permanent, however in elderly people, those on medication, with weight or heart issues, especially those with heart risk and other factors involved, the stress placed on the cardiovascular system could be enough to bring on major symptoms or even a heart attack.

Devlin advises people who have known risks of heart disease to limit their exposure to time outdoors, especially on hot sunny days, when ozone reaches its peak levels. The EPA has more information on its website about local air quality. www. airnow.gov

Written by Rupert Shepherd