122 Human biomonitoring for firefighters after exposure to acrylonitrile

Abstract Human biomonitoring (HBM) can be used to investigate exposure to hazardous substances after short-term exposure or accidental events. The comparison with occupational and environmental medical assessment values allows an evaluation of hazardous substance intake and reliable risk communication. This presentation describes the results of a biomonitoring program after an operation of a professional fire brigade on a chemical site triggered by a container reaction with fire and leakage of acrylonitrile. After the operation and on the following day, urine samples of the firefighters were collected for HBM. The samples were analyzed for the acrylonitrile metabolite cyanoethyl mercapturic acid (CEMA, limit of determination: 1 µg/L). In total, 55 samples (urinary creatinine 0.3 – 3.0 g/L) were collected and categorized into “operation day” (n = 38) and “following day” (n = 17). Further subdivision was made into non-smokers’ and smokers’ samples. On operation day, CEMA concentrations above the reference value (15 µg/g creatinine, Biological Reference Value, MAK Commission) were found in 32 % of the non-smokers’ samples (max. 357 µg/g creatinine). The maximum CEMA concentration was 648 µg/g creatinine, found in a smoker’s sample. Highest CEMA concentrations occurred in connection with the post-operation “fire watch”. Following-day samples showed a decrease in acrylonitrile exposure in both non-smokers and smokers. Based on the HBM results, low to moderate exposure to acrylonitrile during the operation can be assumed. In non-smokers, CEMA concentrations at the level of typical acrylonitrile exposures of tobacco smokers were observed. Special attention should be paid to the exposure protection during fire watches.