Estimation of intake level of di (2-ethyhexyl) phthalate (DEHP) in Japanese pregnant women based on measurement of concentrations of three urinary metabolites

OBJECTIVES: [corrected] The daily intake level of di (2-ethyhexyl) phthalate (DEHP) of Japanese pregnant women was estimated on the basis of the measurement of the urinary concentrations of three DEHP metabolites. METHODS: Spot urine samples were collected from 42 pregnant women who visited the gynecology division of a hospital for routine health check between June and October, 2003. The urinary concentrations of three DEHP metabolites, namely, mono (2-ethyhexyl) phthalate (MEHP), mono (2-ethy-5-hydroxyhexyl) phthalate (MEHHP), and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) were measured by HPLC/MS/MS. RESULTS: The concentrations of urinary MEHP, MEOHP and MEHHP (n=40) were 3.27-39.5 (median 9.83), 1.51-41.0 (median 10.4) and 4.6-26.6 (median 10.9) microg/g cre, respectively. The ranges of the estimated daily intake of DEHP per body weight based on the MEHP, MEOHP and MEHHP concentrations (n=40) were 3.45-41.6 (median 10.4), 0.66-17.9 (median 4.55) and 1.47-8.57 (median 3.51) microg/kg/day, respectively. The maximum estimated intake level per body weight (41.6 microg/kg/day) reached the Tolerable Daily Intake (TDI) level of 40-140 microg/kg/day set by the Ministry of Health and Welfare (now the Ministry of Health, Labour and Welfare). CONCLUSIONS: The health risk of DEHP exposure of our study subjects was found to be minimum from the viewpoint of the current knowledge of its risk level, although the human health effects of low-level DEHP exposure have to be studied further.