Daily Intake of DEHP and Other Phthalates by Korean—-Estimated by Determination of Urinary Concentration of Phthalate Metabolites

PP-30-109 Background/Aims: 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. Methods: 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. Results: 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. Conclusion: Determination of urinary metabolites of phthalates enabled to estimate internal exposure to phthalate diesters, such as DEHP, DBP, and DEP.