Di-n-butylphthalate and butylbenzylphthalate — urinary metabolite levels and estimated daily intakes: pilot study for the German Environmental Survey on children

Abstract

We analysed urine samples from the 2001/2002 pilot study of the German Environmental Survey on Children (GerES IV) for the concentrations of the di-n-butylphthalate (DnBP) metabolite mono-n-butylphthalate (MnBP) and the butlybenzylphthalate (BBzP) metabolite mono-benzyl-phthalate (MBzP). The study population consisted of 239 children (106 boys, 133 girls) aged between 2 and 14 years (median 8.5 years). We applied two calculation models to estimate the daily intake for the two parent phthalates from metabolite excretion. One was based on the creatinine-related metabolite concentrations; the other was based on the volume-related metabolite concentrations. Median urinary metabolite concentrations were 174 mg/l (136 mg/g creatinine) for MnBP and 19.7 mg/l (15.3 mg/g creatinine) for MBzP. Such levels have been determined in German children before. Compared to the USA, German median MnBP levels were about 3-10 times higher, whereas MBzP levels were in the same range. Median daily intakes calculated with the creatinine-based model were 4.07 (range: 0.66-76.4; 95th percentile: 14.9) mg/kg body weight (bw)/day for DnBP and 0.42 (range: 0.06-13.9; 95th percentile: 2.57) mg/kg bw/day for BBzP. Daily intakes calculated with the volume-based model were approximately two times higher with a median of 7.61 (range: 0.91-110; 95th percentile: 30.5) mg/kg bw/day for DnBP and a median of 0.77 (range: 0.05-31.3; 95th percentile: 4.48) mg/kg bw/day for BBzP. Using the creatinine model, 28 (11.7%) of the 239 children exceeded the TDI for DnBP of 10 mg/kg bw/day defined by the European Union. Employing the volume model, 89 (37.2%) children exceeded the TDI. For BBzP, no preventive limit values (TDI or RfD) were exceeded. For both phthalates and independent of the model, we found increasing daily intakes with decreasing age. Between 25% (creatinine model) and 50% (volume model) of the 2-4-year old children had daily intakes for DnBP above the TDI.

Creatinine corrections for estimating children's and adult's pesticide intake doses in equilibrium with urinary pesticide and creatinine concentrations

“…These equations give results that are similar to a previously reported ecologic equation (Institute of Algorithmic Medicine, 2006, based on the data of Viteri and Alvarado (1970)) for both male and female daily CE (mg/day) ¼ (252/ Ht)À8.01 þ 0.0817 Ht, with height in cm, age from birth to 8.5 years. This similarity supports the use of creatinine correction as being more stable than a volume correction (estimated daily volume of urine to scale up a single void sample) that may lead to a higher estimate (Koch et al, 2006). …”

“…Koch et al (2006) have also used these same CE data to estimate average daily intake of di-n-butylphthalate and butylbenzylphthalate in German children based on their urine analyses.…”

Estimated daily intake of phthalates in occupationally exposed groups

“…Biomarker-based estimates of phthalate daily intake are available for adults and children in the United States, Germany, Korea, Japan, and Taiwan (David, 2000;Kohn et al, 2000;Koo et al, 2002;Clark et al, 2003;Itoh et al, 2005;Koo and Lee 2005;Itoh et al, 2007;Koch et al, 2007Koch et al, , 2006Koch et al, , 2003bWittassek et al, 2007;Chen et al, 2008;Wittassek and Angerer, 2008), for pregnant women (Marsee et al, 2006) and for infants in neonatal intensive care units (Calafat and McKee, 2006;Weuve et al, 2006); however, phthalate daily intake estimates for occupationally exposed groups are lacking. In 2003-2005, the National Institute for Occupational Safety and Health (NIOSH) conducted a preliminary study of phthalate exposures among 156 workers in eight industry sectors where materials containing diethyl phthalate (DEP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) were manufactured or used as part of the workers' regular job duties.…”

DEHP, DEP and DBP Exposure Analysis using Urinary Metabolites of Gyonggi Province University Students

“…35) The daily DBP intake of university students were similar to children in median, but higher in 95th percentile. These finding indicated that children had the highest DEHP and DBP daily intakes, follow by university students.…”