New research suggests young people living in areas with high air pollution could be more likely to have inflammatory bowel disease compared to those living under clearer skies.

The study reported in the American Journal of Gastroenterology suggests that people aged 23 or less are more than twice as likely to be diagnosed with Crohn's disease if they were living in a plance that had relatively higher levels of nitrogen dioxide.

Though the findings do not link air pollution directly to inflammatory bowel disease (IBD), there is enough evidence to suggest that environmental factors could play a vital role in the development of the syndrome among the youth.

The United States has reported more than one in 600 cases of Crohn's disease while ulcerative colitis affects one in 400, according to data provided by the National Institute of Diabetes and Digestive and Kidney Diseases.

The disease results in the inflammation of the intestines leading to symptoms like abdominal pain and diarrhea. While the precise reasons for the disease are not known, they are thought to involve immune system overreaction that injures the intestinal tissues.

As part of the study, Dr. Gilaad G. Kaplan, gastroenterologist and assistant professor at the university of Calgary in Alberta, Canada, used British medical records to identify 367 children and adults diagnosed with the disease.

In addition, they identified 591 more patients of ulcerative colitis between 2005 and 1008. Then they matched each of them to five IBD-free individuals of the same age and sex. Thereafter, they used air-quality data from government monitors to assess annual pollution levels in the areas where the patients lived.

Through this study they observed that people who were 23 or younger were twice as likely to have Crohn's disease if they lived in an area that had higher nitrogen dioxide levels. They also observed that people aged 25 or less were twice as likely to have ulcerative colitis if they stayed in areas with higher sulfur dioxide levels.