Phthalate exposure in pregnant women and their children in central Taiwan

Abstract

Phthalate exposure was found to be associated with endocrine disruption, respiratory effects, reproductive and developmental toxicity. The intensive use of plastics may be increasing the exposure to phthalates in Taiwanese population, particularly for young children. We studied phthalate metabolites in pregnant women and their newborns in a prospective cohort from a medical center in Central Taiwan. One hundred maternal urine samples and 30 paired cord blood and milk samples were randomly selected from all of participants (430 pregnant women). Eleven phthalate metabolites (MEHP, 5OH-MEHP, 2cx-MEHP, 5cx-MEPP, 5oxo-MEHP, MiBP, MnBP, MBzP, OH-MiNP, oxo-MiNP, and cx-MiNP) representing the exposure to five commonly used phthalates (DEHP, di-isobutyl phthalate (DiBP), DnBP, BBP, DiNP) were measured in urine of pregnant women, cord serum and breast milk after delivery, and in urine of their children. Exposure was estimated with excretion factors and correlation among metabolites of the same parent compound. Thirty and 59 urinary samples from 2 and 5 years-old children were randomly selected from 185 children successfully followed. Total urinary phthalate metabolite concentration (geometric mean, μg L⁻¹) was found to be higher in 2-years-olds (398.6) and 5-years-olds (333.7) than pregnant women (205.2). Metabolites in urine are mainly from DEHP. The proportion of DiNP metabolites was higher in children urine (4.39 and 8.31%, ages 2 and 5) than in adults (0.83%) (p<0.01). Compared to urinary levels, phthalate metabolite levels are low in cord blood (37.45) and milk (14.90). DEHP metabolite levels in women's urine and their corresponding cord blood are significantly correlated. Compared to other populations in the world, DEHP derived metabolites in maternal urine were higher, while phthalate metabolite levels in milk and cord blood were similar. The level of phthalate metabolites in milk and cord blood were comparable to those found in other populations. Further studies of health effects related to DEHP and DiNP exposure are necessary for the children.