More appendicitis hospitalizations on "high ozone" days

Could there be a link between high levels of air pollution and the risk of appendicitis? New research presented at the 73rd Annual Scientific Meeting of the American College of Gastroenterology in Orlando, suggests a novel connection.

"Adult onset appendicitis is a common condition whose cause is unclear and almost universally requires surgery," explained Dr. Gilaad G. Kaplan of the University of Calgary.

Dr. Kaplan and his colleagues identified more than 5,000 adults who were hospitalized for appendicitis in Calgary between 1999 and 2006. The team used data from Environment Canada's National Air Pollution Surveillance (NAPS) monitors that collect hourly levels of ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and particulate matter of varying sizes. Regression analysis was used to evaluate whether short-term daily changes in air pollution levels were related to the development of appendicitis.

When researchers compared the 5-day average of ozone concentrations prior to admission to the hospital, patients were approximately 15 percent more likely to be hospitalized for appendicitis on days of highest ozone concentrations compared to days of lowest ozone concentrations. Similar findings were seen for sulfur dioxide, nitrogen dioxide, and particulate matter, though with lower effect. Notably, the effect of air pollution was strongest during the summer months, when people were more likely to be outside.

Exposure to air pollutants, particularly ozone, was associated with a modest increased risk of developing appendicitis. Previous studies have shown that air pollution may promote other disease states through inflammation, and this may be the mechanism by which air pollution increases the risk of appendicitis.

"If the relationship between air pollution and appendicitis is confirmed, then improving air quality may prevent the occurrence of appendicitis in some individuals," said Dr. Kaplan.