A new study from researchers in Canada has identified more than 5,000 adults hospitalized with appendicitis and linked these events with air pollution levels. Patients were more likely to develop appendicitis on days when ozone concentration was highest, they found. This adds to the catalog of health conditions known to be linked with environmental pollution.

Introduction

Appendicitis is an acute or chronic of the appendix, which is a worm-like structure - with no obvious function - attached to the beginning of the large intestine. The condition can cause severe abdominal pain. Rupture of an inflamed appendix can cause peritonitis, an inflammatory condition of the abdominal cavity which may be life-threatening. Treatment usually requires removal of the appendix. The causes of appendicitis remain unclear.

What was done

Researchers at the University of Calgary, Canada, studied more than 5,000 adults admitted to hospital for appendicitis between 1999 and 2006. They used data from Environment Canada's National Air Pollution Surveillance monitors. These collect hourly levels of ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide and particular matter - all of which forms of air pollution have been linked to health problems. The researchers carried out an analysis to determine whether or not short-term daily changes in pollutant levels could be linked to the development of appendicitis.

What was found

When the researchers compared the five day average of ozone concentrations before hospital admission, they found that patients were 15 percent more likely to be admitted for appendicitis on the days of highest, compared to lowest, ozone levels. Similar, but smaller, effects, were found for sulfur dioxide, nitrogen dioxide and particulate matter. The impact was greatest during summer months, when people were more likely to be outdoors.

What this study means

Previous studies have shown that air pollutants, including ozone, can promote inflammation. This is the first time this effect has been shown in the lower part of the digestive system, although the impact of this kind of inflammation on heart and lungs is well documented. Therefore, for the sake of the whole body, it seems prudent to improve air quality.