Could Appendicitis be Caused by Air Pollution?

A Canadian study reported at the American College of Gastroenterology Annual Meeting has caused a stir. Appendicitis was first fully described in 1886 by an American surgeon; its occurrence increased over the years in industrialized countries like Canada, the US, and England, but it has tapered off after 1970; this happens to be the year the USA passed the Clean Air Act, and air pollution was reduced throughout the country.

The possible relationship between air pollution and appendicitis has been explored by Canadian scientists. They identified more than 5,000 patients over 18 admitted to Calgary hospitals for appendicitis between 1999 and 2006. Data on air pollution over the study time was obtained from the Environment Canada’s National Air Pollution Surveillance, which monitors levels of ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and particulate matter.

The 5-day average of ozone concentrations leading up to admission of the patient for appendectomy was compared with the averages on other 5-day periods. Patients were 15% more likely to be admitted for appendicitis on days of highest ozone concentrations compared to days of lowest concentrations. Results for the other pollutants were similar. The effect of air pollution was more pronounced in summer months (when subjects were more likely to spend time out-of-doors).

This study is more interesting for the method used than for the findings. After all, we know that appendicitis involves inflammatory changes, and air pollution is a accepted cause of inflammatory changes in the body, including coronary heart disease. But the results here represent a neat way of showing how reduction in air pollution might prevent the occurrence of appendicitis in some people. . .