Short-term exposure to air pollution could trigger appendicitis in adults, possibly because pollutants cause inflammatory responses, according to a Canadian study.
Researchers found that people exposed to nitrogen dioxide for a week during June, July and August -- when levels of the pollutant are at their highest -- were almost twice as likely to come down with the potentially deadly condition as those who had no exposure.
Those over 64 were more than four times more likely to develop appendicitis under the same conditions.
Nitrogen dioxide is most usually produced by traffic and causes most health problems during summer months.
How the study was done
The Canadian team -- led by Dr Gilaad Kaplan of the University of Calgary -- studied the cases of 5 191 people admitted with appendicitis at three adult hospitals in Calgary, Alberta, over a seven-year period.
Kaplan said 52.5% of overall admissions occurred between April and September, the warmest months of the year in Canada, when people are more likely to be outside.
Appendectomies are among the most common surgeries that are performed in United States and Canada, where one in 12 people have a chance of developing appendicitis.
"Even though the outcomes of the operations are actually really good, because it's such a serious condition if it's missed ... it actually is a significant burden to the healthcare system," Kaplan said.
"The one thing we know about air pollution is that it's modifiable and so if there is a potential link then maybe we could improve air quality and prevent some cases."
Appendicitis growing in industrialised countries
The link between air pollution and appendicitis was more marked in men, possibly because they worked more outdoors. Kaplan wants to study the phenomenon further in an attempt to confirm the initial findings.
Most medical specialists believe appendicitis is caused by obstruction of the appendix opening but Kaplan's team said this theory did not explain the trends of appendicitis in developed and developing countries.
Appendicitis cases increased dramatically in industrialised countries in the 19th and early 20th centuries. They then decreased in the middle and late 20th century, a period that coincided with legislation to boost air quality.
"That correlation between seeing the incidence of appendicitis decrease following improvement in air quality was one of the things that motivated me to do the study," Kaplan said.
The incidence of appendicitis has been growing in developing countries as they become more industrialised. The team said air pollution was a known risk factor for several medical conditions such as asthma, strokes and cancer.
The study -- conducted by researchers at the University of Calgary and the University of Toronto as well as the federal health ministry -- appeared in the latest edition of the Canadian Medical Association Journal. – (Reuters Health, October 2009)