Assessing human exposure to phthalates using monoesters and their oxidized metabolites as biomarkers

Barr, DB; Silva, MJ; Kato, K; Reidy, JA; Malek, NA; Hurtz, D; Sadowski, M; Needham, LL; Calafat, AM

HERO ID

673408

Reference Type

Journal Article

Year

2003

Language

English

PMID

12842765

HERO ID 673408
In Press No
Year 2003
Title Assessing human exposure to phthalates using monoesters and their oxidized metabolites as biomarkers
Authors Barr, DB; Silva, MJ; Kato, K; Reidy, JA; Malek, NA; Hurtz, D; Sadowski, M; Needham, LL; Calafat, AM
Journal Environmental Health Perspectives
Volume 111
Issue 9
Page Numbers 1148-1151
Abstract Phthalates are a group of industrial chemicals with many commercial uses, such as solvents, additives, and plasticizers. For example, di-(2-ethylhexyl) phthalate (DEHP) is added in varying amounts to certain plastics, such as polyvinyl chloride, to increase their flexibility. In humans, phthalates are metabolized to their respective monoesters, conjugated, and eliminated. However, despite the high production and use of DEHP, we have recently found that the urinary levels of the DEHP metabolite mono-(2-ethylhexyl) phthalate (MEHP) in 2,541 persons in the United States were lower than we anticipated, especially when compared with urinary metabolite levels of other commonly used phthalates. This finding raised questions about the sensitivity of this biomarker for assessing DEHP exposure. We explored the utility of two other DEHP metabolites, mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), as additional DEHP biomarkers. These metabolites are formed by oxidative metabolism of MEHP. In urine from 62 people, both the range and the mean urinary levels of MEOHP and MEHHP were on average 4-fold higher than those of MEHP; the mean of the individual ratios of MEHHP/MEOHP, MEHHP/MEHP, and MEOHP/MEHP were 1.4, 8.2, and 5.9, respectively. These data suggest that MEOHP and MEHHP are more sensitive biomarkers of exposure to DEHP than is MEHP. These findings also suggest a predominant human metabolic route for DEHP hydrolysis to MEHP followed by oxidation of MEHP; they also imply that a similar mechanism may be relevant for other high-molecular-weight phthalates, such as di-n-octyl, di-isononyl, and di-isodecyl phthalates.
Doi 10.1289/ehp.6074
Pmid 12842765
Wosid WOS:000184992700022
Url https://search.proquest.com/docview/18886786?accountid=171501
Is Certified Translation No
Dupe Override No
Comments |WOS:000184992700022
Is Public Yes
Language Text English
Keyword Biological Markers/*analysis; Diethylhexyl Phthalate/*analogs & derivatives/metabolism/urine; *Environmental Exposure; Esters/analysis; Humans; Hydrolysis; Phthalic Acids/*analysis/*metabolism/poisoning/*therapeutic use/*urine; Sensitivity and Specificity
Is Qa No