Biomonitoring of the di(2-ethylhexyl) phthalate metabolites mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethyl-5-oxohexyl) phthalate in children and adults during the course of time and seasons

Abstract

Di(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with ubiquitous spread. Its metabolites are suspected to impair endocrine functions and fertility in man. This study is aimed to assess the DEHP exposure in children and adults, to evaluate the intraindividual variability, the influence of seasons and to identify potential routes of intake. Urine samples were collected from 6 people (age 4-58) over 7 consecutive days 4-times during a year to test for seasonal factors. 5-OH-MEHP and 5-oxo-MEHP were quantified by GC-MS. Urine concentrations of both metabolites were highly correlated with each other. Both female subjects showed remarkably low and stable 5-OH-MEHP concentrations throughout the year (median <or=64.1 and <or=78.5microg/l). Also both male adults exhibited a low burden during most measurements (median <or=50.0 and <or=52.5microg/l) except in January for the 19 year old (median: 141.4microg/l) and two single high events for the 58 year old male. In contrast, both examined boys reached weekly median concentrations as high as 171.0microg/l accompanied by a high degree of variability. Five peak events were identified, 3 of which are suspected to be caused by particular meals. During the 28 days of monitoring one adult male and two male children exceeded the tolerable metabolite concentration for the sum of 5-oxo-MEHP and 5-OH-MEHP (HBM I value) 4 times. Two of the children contributed one transgression event each, exceeding the HBM I value by a factor of 2-4. Across the 6 studied individuals we found a weak seasonal trend towards higher levels of exposure during the winter.