Next time you draw a breath downtown, know that it might cause one of your organs to burst.
A recent study led by University of Calgary researcher Gil Kaplan uncovered a link between the ozone found in smog and perforated appendicitis — the medical term used to describe a ruptured appendix. The study was done across 12 cities in Canada over four years and found that the risk of perforated appendicitis rose by up to 22 per cent with every 16 parts-per-billion rise of ozone in the air.
The appendix is a small appendage of the colon, which can burst when infected, releasing fecal matter into the abdomen. This bursting can cause abdominal infections, and in extreme cases, death.
Around one in 15 Canadians will get appendicitis in their lifetime. The only cure for the infection is to remove the appendix through surgery.
The study looked at the reported incidence of appendicitis in Canada’s 12 largest cities and compared this number with levels of ozone in these cities as measured by Environment Canada.
“That allowed us to look at an association of what happens when we see spikes in ozone, which is one of the air pollutants that we get exposed to through smog,” Kaplan said, disscussing his study. “What we consistently found is that there is an association between air quality and appendicitis, particularly between perforated appendicitis — the more serious form where the appendix bursts.”
Ozone is a pollutant that comes from burning gasoline and coal. At high levels, ozone is harmful to the respiratory system and can damage plant life.
The average ozone levels in Calgary range between 13–22 parts-per-billion, with the highest average levels in the northwest. These levels are moderate compared to the other Canadian cities examined.
The study found that short-term rises in ozone corresponded with rises in emergency room visits for appendicitis. The rate of emergency room visits for appendicitis increased at a faster rate during consecutive days with high levels of ozone.
He stressed that while interesting, the reasons behind the correlation between ozone and appendicitis are still unclear, as the study did not look at how smog might cause appendicitis. Kaplan said his colleagues are now looking to find the mechanism behind this apparent link.
Kaplan said he thought of the idea for the study after looking at historical incidences of perforated appendicitis in wealthy, industrialized societies.
“What’s interesting about perforated appendicitis is that it is a relatively modern disease,” Kaplan said. “If you go back in history, we really don’t see much in terms of records of it and it really began to emerge in post-industrial nations — countries like England, Canada and the United States after the industrial revolution.”
Looking at the historical rise of appendicitis in these countries, Kaplan said he noticed a drop in the number of reported cases during the 1960s.
“After the 1960s, you started to see a drop in the incidence of appendicitis for completely unexplained reasons.
No one really understood why that is,” he said. “One of the things that happened in these post-industrial societies after the 1960s is people started to create legislation to clean up the air and to create technologies that reduced emissions in cars. Looking at these measures, you actually begin to see an improvement in air quality in these industrialized nations.”
The study was funded through a grant from the Canadian Institute of Health Research.