Urinary excretion of phthalate metabolites in 129 healthy Danish children and adolescents: Estimation of daily phthalate intake

Phthalates are a group of chemicals with widespread use in the industrial production of numerous consumer products. They are suspected to be involved in male reproductive health problems and have also been associated with several other health problems in children including obesity and asthma. This study examined the urinary excretion of phthalate metabolites in Danish children recruited from the general population and to estimate the daily intake of phthalates in this segment of the population. One 24 h urine sample and to consecutive first morning urine samples were collected from 129 healthy Danish children and adolescents (range 6-21 yrs). The concentrations of 11 phthalate metabolites of 5 different phthalate diesters were analysed by liquid chromatography-tandem mass spectrometry. The analysed metabolites were detectable in almost all 24 h urine samples. The median concentrations of monoethyl phthalate (MEP), monobenzyl phthalate (MBzP) and the sums of the two monobutyl phthalate isoforms (MBP(i+n)), metabolites of di-(2-ethylhexyl) phthalate (DEHPm) and of diisononyl phthalate (DiNPm) were 29, 17, 111, 107 and 31 ng/mL, respectively. The younger children were generally more exposed to phthalates than older children and adolescents (except di-Et phthalate (DEP)). Boys were more exposed than girls. The median estimated daily intake of phthalate diesters was: 4.29 (di-Bu phthalate isoforms (DBP(i+n))), 4.04 (DEHP), 1.70 (DiNP), 1.09 (DEP) and 0.62 (butylbenzyl phthalate (BBzP)), all calculated as íg/kg body weight/24 h. Between 40% and 48% of the absolute amount of phthalate metabolites excreted over 24 h were excreted in first morning urine voids. The authors concluded that Danish children are exposed simultaneously to multiple phthalates. The highest exposure levels were found for DBP(i+n) and DEHP, which in animal models are the known most potent anti-androgenic phthalates. The combined exposure to the two isoforms of DBP, which have similar endocrine-disrupting potencies in animal models, exceeded the TDI for di-Bu phthalate (DnBP) in several of the younger children.

Authors: Frederiksen, Hanne; Aksglaede, Lise; Sorensen, Kaspar; Skakkebaek, Niels E.; Juul, Anders; Andersson, Anna-Maria ;Full Source: Environmental Research 2011, 111(5), 656-663 (Eng) ;