Children's phthalate intakes and resultant cumulative exposures estimated from urine compared with estimates from dust ingestion, inhalation and dermal absorption in their homes and daycare centers.

Gabriel Bekö,Jørn Toftum,Geo Clausen,Sarka Langer,Michael Callesen,Charles J Weschler,Jaymie Meliker

doi:10.1371/journal.pone.0062442

Abstract

Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of age. For each child the intake attributable to exposures in the indoor environment via dust ingestion, inhalation and dermal absorption were estimated from the phthalate levels in the dust collected from the child’s home and daycare center. Based on the urine samples, DEHP had the highest total daily intake (median: 4.42 µg/d/kg-bw) and BBzP the lowest (median: 0.49 µg/d/kg-bw). For DEP, DnBP and DiBP, exposures to air and dust in the indoor environment accounted for approximately 100%, 15% and 50% of the total intake, respectively, with dermal absorption from the gas-phase being the major exposure pathway. More than 90% of the total intake of BBzP and DEHP came from sources other than indoor air and dust. Daily intake of DnBP and DiBP from all exposure pathways, based on levels of metabolites in urine samples, exceeded the Tolerable Daily Intake (TDI) for 22 and 23 children, respectively. Indoor exposures resulted in an average daily DiBP intake that exceeded the TDI for 14 children. Using the concept of relative cumulative Tolerable Daily Intake (TDIcum), which is applicable for phthalates that have established TDIs based on the same health endpoint, we examined the cumulative total exposure to DnBP, DiBP and DEHP from all pathways; it exceeded the tolerable levels for 30% of the children. From the three indoor pathways alone, several children had a cumulative intake that exceeded TDIcum. Exposures to phthalates present in the air and dust indoors meaningfully contribute to a child’s total intake of certain phthalates. Such exposures, by themselves, may lead to intakes exceeding current limit values.

Highlights

Phthalates are a group of ubiquitous chemicals present in many consumer products, including building materials, furnishings, clothing, paints, food packaging, toys, personal care products and pharmaceuticals
The only exceptions were the slopes of the daily intakes for diethyl phthalate (DEP) from the three indoor exposure pathways, which were larger than the slope of the intake calculated from urine
Distributions without skewed tails were obtained for the average daily intakes estimated from a weeklong exposure (WIindoors/7), which were determined based on exposure in both environments for all children, regardless of the day of urine sampling (Figure S1)

Summary

Introduction

Phthalates are a group of ubiquitous chemicals present in many consumer products, including building materials, furnishings, clothing, paints, food packaging, toys, personal care products and pharmaceuticals. Phthalates can be released into the environment by leaching, evaporation, migration, abrasion or application of phthalate-containing personal care products Due to their widespread use, the general population is continuously exposed to phthalates. A large number of human and animal studies have focused on possible health effects of phthalate exposure. Phthalates are known to be developmental and reproductive toxicants Indications exist that they may impact genital development, semen quality, children’s neurodevelopment, thyroid function, onset of puberty in females and that they may possibly cause respiratory problems [1],[2],[3],[4],[5],[6],[7],[8],[9]. There is some evidence that the secondary oxidized metabolites of DEHP may themselves be developmental toxicants [24],[25]

Methods

Results

Discussion

Conclusion