Biological monitoring of occupational exposure to di(2-ethylhexyl) phthalate:: survey of workers exposed to plastisols

Objective The aim of this study was to perform a biological monitoring survey of workers exposed to di(2-ethylhexyl)phthalate (DEHP) in a factory using polyvinyl chloride plastisols and to contribute additional occupational data of exposure particularly sparse in the industrial sectors where this plasticizer is used. Method Three urinary metabolites of DEHP, mono(2-ethylhexyl)phthalate (MEHP), mono(5-carboxy-2-ethylpentyl)phthalate (MCEPP) and 2-ethylhexanoic acid (2-EHA) were quantified in five workers using a plastisol (containing 33% of DEHP) and in five unexposed workers (controls), during 5 days with pre- and post-shift sampling. Analyses were performed by high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) with on-line extraction. Results Median concentrations of pre- and post-shift urinary samples in the exposed workers (n = 25) were 16.1 and 55.9 mu g/l for MEHP, 37.6 and 103.7 mu g/l for MCEPP and 46.3 and 72.1 mu g/l for 2-EHA, respectively. In the controls (n = 19), the corresponding values were 12.0 and 10.4 mu g/l for MEHP, 38.1 and 11.4 mu g/l for MCEPP and 31.9 and 46.0 mu g/l for 2-EHA, respectively. There is a significant increase (Mann-Whitney U-test, P < 0.05) of post-shift excretion in the exposed workers versus unexposed controls and in post-shift versus pre-shift concentrations only in the exposed workers. Conclusion MEHP and MCEPP are shown to be suitable biomarkers to assess DEHP exposure while 2-EHA, less specific but classified in the category 3 of the European Union (EU) reproductive toxicants, is also an interesting biomarker. There is clear evidence of occupational exposure of workers in this factory.