Air Pollution Linked to Irregular Heartbeat, Blood Clots

New research published in the journal Heart cites evidence that air pollution is linked to irregular heartbeat and lung blood clots, while also suggesting an effect on other cardiovascular diseases.

High levels of certain air pollutants can cause such cardiovascular concerns, but exactly how this association works has not been clarified.

Researchers set out to explore this idea using data from three national collections in England and Wales from 2003 to 2009: the Myocardial Ischaemia National Audit Project (MINAP), which tracks hospital admissions for heart attack/stroke; hospital episode statistics (HES) on emergency admissions; and figures from the Office of National Statistics (ONS) on recorded deaths.

According to MINAP data, there were 400,000 heart attacks during this time period, 2 million emergency admissions for cardiovascular problems, and 600,000 heart attack and stroke deaths were related to average levels of air pollutants over a 5-day period.

Air pollutants investigated included carbon monoxide, nitrogen dioxide, particulate matter (PM10 and PM2.5), sulfur dioxide and ozone.

The study showed that PM2.5 is clearly linked to a heightened risk of irregular heart rhythms, irregular heartbeat (atrial fibrillation) and blood clots in the lungs (pulmonary embolism). And only nitrogen dioxide was linked to more hospitalizations for cardiovascular problems, including heart failure, and an increased risk of a particular type of heart attack referred to as non-ST elevation.

Aside from these two findings, researchers revealed that there is no clear evidence implicating short term exposure to air pollution in boosting the risk of heart attacks and stroke.

An accompanying editorial, written by cardiologists from the University of Edinburgh, points out that particulate matter is thought to be responsible for more than 3 million deaths worldwide, primarily as a result of heart attacks and stroke.

Nevertheless, the relationship between the two is still hazy.

"The current lack of consistent associations with contemporary UK data may suggest that as the fog begins to clear, the adverse health effects of air pollution are starting to have less of an impact and are more difficult to delineate," authors concluded in a statement.