DEHP metabolites in urine of children and DEHP in house dust

Urine samples from the 2001/2002 pilot study for the German Environmental Survey on children (GerES IV) were analysed for concentrations of the primary DEHP metabolite MEHP (mono(2-ethylhexyl)phthalate) and two secondary DEHP metabolites 5OH-MEHP (2-ethyl-5-hydroxy-hexylphthalate) and 5oxo-MEHP (2-ethyl-5-oxo-hexylphthalate). Urine samples had been taken from 254 children aged 3 to 14. In addition, DEHP was analysed in house dust samples. These samples had been collected with vacuum cleaners in the homes of the children. The geometric mean (GM) was 7.9 μg/l for MEHP in urine, and the GMs for the secondary metabolites 5OH-MEHP and 5oxo-MEHP were 52.1 μg/l and 39.9 μg/l. 5OH-MEHP and 5oxo-MEHP concentrations were highly correlated (r=0.98). The correlations of 5OH-MEHP and 5oxo-MEHP with MEHP were also high (r=0.72 and r=0.70). The concentrations of 5OH-MEHP and 5oxo-MEHP were 8.0-fold and 6.2-fold higher than the concentrations of MEHP. The ratios 5OH-MEHP/5oxo-MEHP and 5oxo-MEHP/MEHP decreased with increasing age. Boys showed higher concentrations than girls for all three metabolites of DEHP in urine. Children aged 13 – 14 had the lowest mean concentrations of the secondary metabolites in urine. The house dust analyses revealed DEHP contamination of all samples. The GM was 508 mg/kg dust. No correlation could be observed between the levels of any of the urinary DEHP metabolites and those of DEHP in house dust.