Biomonitoring of 2,4’–methylene diphenyldianiline for assessment of exposure to methylene diphenyl diisocyanate aerosol

摘要

The exposure to methylene diphenyl diisocyanate (MDI) aerosol was investigated by biomnitoring of 2,4’–methylene diphenyldianiline (MDA) in urines of exposed workers. Biological monitoring was done for its metabolite by the analysis of isocyanate–derived diamines released from protein adducts in urine or plasma by GC–MS. The urine samples, at the end of working shifts of polyurethane factory, were collected in polystyrene bottles containing 10 g citric acid, and stored at 4 °C until analysis. The mean concentration values of MDA in the five selected factories were in the range of 3.01 to 3.58 µmol/mol creatinine for all subjects and the highest mean value of MDI concentration was 99 µg/m³ from indoor air samples analysis. The results show a linear relationship between MDI and MDA concentrations with a value of R2=0.801 (P0.05). This study demonstrates that not only urinary MDA is detectable following diisocyanates aerosol exposure but also it is likely to be a useful practical biomarker to monitor diisocyanates exposure in the workplaces or for the epidemiologic studies.