By: By Lindsey Konkel, Contributing writer
Published: 07/18/2013 10:09 AM EDT on LiveScience
High levels of ozone -- a major component of smog -- may increase the risk of a burst appendix, according to a new study from Canada.
Researchers found that people's risk of a burst appendix rose by 22 percent with every 16-part-per-billion increase in ozone levels over the previous seven days. Ozone levels typically ranges between 0 ppb on good air quality days, to more than 300 ppb on days considered to have a "very unhealthy" air quality index.
The finding means the increased risk is significant but modest, said study researcher Dr. Gilaad Kaplan, a gastroenterologist at the University of Calgary. "The effect size suggests that air pollution isn't the only factor, though it may be one piece of the puzzle."
About one in 15 people will develop appendicitis over the course of their lifetime, according to the researchers. Patients with appendicitis can experience an inflamed appendix or a burst one, which doctors refer to as a perforated appendix.
The same researchers reported an association between air pollution and appendicitis in a 2009 study of about 5,000 people in Calgary[S2] .
In the new study, researchers looked at more than 35,000 people hospitalized for appendicitis across 12 Canadian cities between 2004 and 2008. On average, the patients were 30 years old at diagnosis. The researchers calculated average concentrations of ozone for each city during the week before each patient was hospitalized with appendicitis.
A number of ozone sources, including fossil fuel combustion, electricity generation and industrial activity, can contribute to levels of the air pollutant. Because it is created when pollutants from these sources interact with sunlight in the atmosphere, ozone levels in many regions tend to be higher in the summer months.
The study found no significant association between ozone levels and risk of inflamed (but not perforated) appendix.
"This study highlights a previously unrecognized association between air pollution and an increased risk of perforated appendicitis," said Dr. Robert Glatter, emergency physician at Lenox Hill Hospital in New York. Glatter was not involved in the current study.
While the researchers accounted for known appendicitis risk factors, such as age and sex (appendicitis is most commonly diagnosed in younger people and men), they cannot say whether some other factor for which they did not account may have influenced the results.
For instance, ozone was measured only at a regional level. People could have been exposed to more or less pollution depending on their habits, travel patterns and the amount of time spent outdoors each day.
While the study presents "an interesting association, more research is needed before recommendations can be made," Glatter said.
The researchers said it isn't clear exactly how air pollution may increase the risk of a burst appendix. It is possible that exposure to air pollution could increase inflammation in people already starting to develop appendicitis. One study in mice suggested that exposure to air pollutants may alter levels of intestinal microbes that help maintain a healthy gut, which could leave the digestive tract more prone to infection.
The major risk factor for a burst appendix is a delay in diagnosis. Most cases present as abdominal pain that worsens over 24 to 36 hours, though some cases of ruptured appendix happen very quickly with little warning.
A burst appendix is a medical emergency requiring immediate abdominal surgery, Kaplan said.
Follow LiveScience @livescience, Facebook &Google+. Original article on LiveScience.com.
Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. ]]>
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.