High levels of air pollution may increase the risk of appendicitis in adults, according to the results of a study conducted in Canada and reported this week at the 73rd annual scientific meeting of the American College of Gastroenterology in Orlando, Florida.
This study "provides epidemiologic evidence that some cases of appendicitis may be triggered by exposures to air pollutants," principle investigator Dr Gilaad G. Kaplan from the University of Calgary notes in a university-issued statement. This relationship may explain the drop in appendicitis rates "in North America and Europe in the latter part of the twentieth century."
The researchers identified more than 5 000 patients older than age 18 years who were admitted to Calgary hospitals for appendicitis between 1999 and 2006. They determined exposures to air pollution prior to admission using data from Environment Canada's National Air Surveillance programme, which uses monitoring stations to collect hourly levels of ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide and particulate matter of varying sizes.
Kaplan reported that in the summer months - when people were more likely to be outdoors and when more than half of the appendicitis cases occurred - "there was a modest increased risk for being admitted for appendicitis when the concentrations of ozone and nitrogen dioxide were elevated in the atmosphere."
"This is really the first time that we've made an association between the air that we breathe and the occurrence of appendicitis," said Kaplan.
What the study found
He also noted that appendicitis was first recognized in 1886 by an American surgeon and the rates increased significantly around this time in industrialised countries such as Canada, the US and England. The incidence of appendicitis tapered off after 1970, when the U.S. passed the Clean Air Act, which reduced air pollution exposure throughout the country.
"In developing countries, rates of appendicitis are actually quite low, but as these countries become more industrialised, we start to see the disease emerge," Kaplan added. He also noted that the pathogenesis of appendicitis is still unclear.
If confirmed by other studies, the current findings "may provide insight into the pathogenesis of appendicitis and offer the potential for prevention through air quality control," the researchers write in a meeting abstract. – (Reuters Health, October 2008)
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