Urine Metabolites of Phthalate Esters in 434 Shanghai Children and Their Associations with Ventilation Habits

Abstract

Phthalate have been reported to be associated with various adverse health effects in many countries or regions. In this paper, we assessed the urine levels of phthalate metabolites (PMs) in children and investigated their associations with various ventilation habits. During March 2013 to December 2014, we conducted an on-site inspection in 454 residences of 5-10 year-old children in Shanghai, China. The first morning urine samples of these children were took by cryogenic vials. We collected information with respect to ventilation habits by questionnaire. We analyzed ten PMs [Mono-methyl phthalate (MMP), Mono-ethyl phthalate (MEP), Mono-isobutyl phthalate (MiBP), Mono-n-butyl phthalate (MBP), Mono-benzyl phthalate (MBzP), Mono-cyclohexyl phthalate (MCHP), Mono-2-ethylhexyl phthalate (MEHP), Mono-2-ethyl-5-carboxypentyl phthalate (MECPP), Mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), Mono-2-ethyl-5-oxohexyl (MEOHP)] by High performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS). Mann-Whitney U test was applied to compare concentrations of urinary PMs among children with different ventilation habits. A total of 434 children had valid urine samples. The detection rates of PMs were >90% except for MBzP (51.2%) and MCHP (9.9%). The overall mean concentrations (standard deviation) of these metabolites were as follows: MnBP, 126.4 (205.9) μg/L; MiBP, 83.1 (119.2) μg/L; MECPP, 61.6 (111.1) μg/L; MEHHP, 42.9 (92.6) μg/L; MEP, 25.3 (51.5) μg/L; MEOHP, 23.9 (45.1) μg/L; MMP, 16.8 (21.5) μg/L; MEHP, 7.6 (19.0) μg/L; MBzP, 1.2 (4.3) μg/L; MCHP, 0.1 (0.2) μg/L. In general, averaged concentrations of PMs among children who opened the windows or doors were higher than among those who closed. Our results indicate that individual differences in PMs are obvious among Shanghai children. Natural ventilation without any mechanical ventilation or air purification is likely increase phthalate exposure in children. To reduce indoor phthalate concentrations, we suggested using mechanical ventilation or ‘natural ventilation and air cleaner’ in home.