P.1.01 A nationwide, longitudinal study of crohn’s disease among korean workers exposed to toluene

The pathogenesis of inflammatory bowel diseases (IBD) probably involves an interaction between genetic and environmental factors. Recent studies have shown that air pollution and PFOA (perfluorooctanoic acid) are associated with IBD. It is presumed to be related to inflammatory response. Immunoreactivity and inflammatory response are known to be major important mechanisms that causes toluene induced toxicity. So we evaluated the Crohn’s disease morbidity among Korean workers exposed to toluene. Methods Data were collected from toluene-associated specialized medical check-up 2000 and 2004 in Korea. The number of workers admitted to hospital because of clinically diagnosed Crohn’s disease was analyzed in male workers exposed to toluene (n=149,183). As a control reference population, 2% of Korean men were randomly selected and their hospital admission data were analyzed. For toluene exposed workers, Standardized admission ratios (SARs) for Crohn’s disease, as determined by ICD-10 classifications, were estimated in reference to the control population. Results During follow up, 46 workers admitted because of Crohn’s diseases. Occupational exposure to toluene (5 63 852 person-years) was significantly associated with the SAR of Crohn’s disease (SAR: 1.60, 95% CI: 1.17–2.13), in particular, SARs of workers with 3rd quartile hippuric acid level was significantly increased (SAR: 1.95, 95% CI: 1.21–2.99). Conclusion In conclusion, toluene-exposed workers exhibited significantly elevated SARs for Crohn’s disease, especially workers with high level of hippuric acid, compared to the age-matched reference population, suggesting a relatedness with toluene exposure. This work was supported by Korea Environmental Industry and Technology Institute (KEITI) through ‘The Chemical Accident Prevention Technology Development Project’ funded by Korea Ministry of Environment (MOE) (2017001970001).