evaluation of relation between air pollution and ibd flare

background: to evaluate relation between air pollution and rate of flare and   hospital admission among ibd patients. methods: during a 10 months period, the number and average duration of hospitalization of patients admitted in gi ward due to ibd flare were recorded in an industrial capital city. concomitantly the level of 4 major air pollutants including so2, co, no2 and o3 measured and the correlation between severity of ibd flare and air pollution determined by pearson correlation coefficient. results: average number of admission was 7 patients per month (1-12). this figure for crohn's disease (cd) was 2.9 and 3.7 for ulcerative colitis (uc). the average duration of hospitalization for uc and cd were 2.8 days (1 – 13) and 2.9 days (1 – 22) respectively. after comparison of average concentration of 4 major air pollutants with rate of ibd flare, , there was a relation, although non-meaningful, between co concentration and number and duration of admissions due to uc flare (p= 0.135 & 0.08, correlation coefficient 0.196 & 0.251 respectively). data analysis did not reveal any significant relation between so2 and no2 and the rate of admission due to ibd flare (p > 0.05) and interestingly there were a reverse meaningful correlation between concentration of o3 and number and duration of admissions due to crohn’s disease flare (p= 0.016 and 0.006, correlation coefficient -0.338 & -0.413 respectively). conclusion: it seems that co as one of the major air pollutants can aggravates course of ulcerative colitis and on the other hand o3 could have a potential protective effect on crohn’s disease. this issue should further be clarified in future studies.