Abstract:
Objective To evaluate exposure levels of phthalates and its influencing factors in infants at the age of 2 years old.
Methods Questionnaires and spot urine samples were collected from 344 2-year-old infants in a county of Jiangsu Province from June 2011 to January 2012. The survey content included infants' general information and their behaviors & habits with potential exposure to phthalates. Nine urinary phthalate metabolites were determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Non-parametric test and multiple linear regression analysis were used to identify the influencing factors of infant phthalates exposure.
Results The phthalate metabolites were identified in all urine samples of these infants. The median levels were as follows: monomethyl phthalate (MMP), 15.73 μg/L; monoethyl phthalate (MEP), 13.99 μg/L; monobutyl phthalate (MBP), 39.30 μg/L; monoisobutyl phthalate (MiBP), 29.23μg/L; mono-3-carboxypropyl phthalate (MCPP), 2.90 μg/L; mono-2-ethylhexyl phthalate (MEHP), 2.88 μg/L; mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), 11.93 μg/L; mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), 8.70 μg/L, and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), 50.10 μg/L. The positive rates were 100.00% for MMP, MEHHP, and MECPP, respectively; 89.80% for MEHP; and 96.80%-99.71% for the other 5 metabolites. The usage of plastic milk bottles or plastic tableware was found to have statistically significant effects on concentrations of some urinary phthalate metabolites in infants' urine samples (P < 0.05).
Conclusion The findings suggest that the infants are widely exposed to phthalates. The usage of plastic milk bottles or plastic tableware might increase infants' exposure to phthalates.