Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August-1 September 2010: Exposure Assessment by Various Media and Pathways
It is very difficult to exactly estimate the dose of dialkylated phthalates taken up by the general population because of environmental contamination, especially in the case of di-(2-ethylhexyl) phthalate (DEHP). We performed this study to estimate daily intake of DEHP, diethyl phthalate (DEP), and dibutyl phthalate (DBP) by urinary metabolites.
We used LC/MS/MS with on-line enrichment and column-switching techniques for the biological monitoring. Metabolites determined were 4 primary metabolites: mono(2-ethylhexyl)phthalate (MEHP), mono(n-butyl)phthalate (MnBP), mono(iso-butyl)phthalate (MiBP), mono-ethylphthalate (MEP); and 2 secondary metabolites of DEHP: mono(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP) and mono(2-ethyl-5-oxo-hexyl)phthalate (5oxo-MEHP). The subjects of the study (n = 332) were divided into 60 children, 62 middle and high school student, 139 adults, and 61 elderly man in Korea. The subjects were not occupationally exposed to phthalates.
Determined median daily DEHP, DBP, and DEP intake was 8.3, 7.9, and 5.8 μg/kg body weight (bw)/d, respectively. For DEHP, 5 people (1.5%) exceeded the value of the tolerable daily intake of the European Food Safety authority of 50 μg/kg bw/d, whereas 7.2% exceeded the reference dose of 20 μg/kg bw/d of the US Environmental Protection Agency.
Determination of urinary metabolites of phthalates enabled to estimate internal exposure to phthalate diesters, such as DEHP, DBP, and DEP.