Abstract

Background: Phthalates are found in products made of plastic. Because of concerns regarding the hazards of phthalate exposure, including endocrine disruption, many countries have regulations to restrict their use in products used by children. However, in Thailand, no such restrictions exist, and data relating to phthalate exposure are scarce. Objectives: To determine the level of exposure of Thai children and adolescents to phthalates, and study its associations with sociodemographic data and the exposure to potential sources of phthalates. Methods: Healthy children aged 2-18 y were enrolled into the present cross-sectional study between January 2016 and December 2016 inclusive. Their anthropometric indices and Tanner staging were determined. Urinary concentrations of the phthalate metabolites, monomethyl phthalate (MMP) and mono-n-butyl phthalate (MBP), were determined in spot samples by high-performance liquid chromatography to estimate the level of phthalate exposure. Associations between sociodemographic data, exposure to potential sources of phthalates, and phthalate metabolite concentrations were analyzed. Results: We included 103 boys and 118 girls with a mean age of 9.4 ± 3.64 (range 2.8-17.1) y and detected MMP in 28.5% and MBP in 88.6%. The geometric means (interquartile range) of urinary MMP and MBP were 3400 (2489, 4642) and 214.4 (164, 279) mg/g creatinine (Cr), respectively. Significant associations were found between exposure to floor cleaning products and Cr-adjusted urinary MMP level (P < 0.05), and paint and Cr-adjusted urinary MMP and MBP levels (P < 0.05). Prepuberty was significantly associated with urinary Cr-adjusted MMP level. Conclusion: Urinary phthalate metabolite levels were high in a proportion of Thai children and adolescents. Exposure to floor cleaning products and paint is associated with phthalate exposure, and advanced Tanner stage is negatively associated with urinary Cr-adjusted MBP.