Exposure and Health Risk Assessment of Phthalates in House Dust among Schoolchildren in Phatthalung, Thailand

Abstract

Phthalates are widely used chemicals that are not chemically bonded to materials. Therefore, they can be readily released into house dust. Children are at high risk of phthalate exposure through dust ingestion due to inadequate hygiene practices, which may adversely affect their health. Settled house dust samples were collected from 310 households of elementary school children in Phatthalung, Thailand, using a vacuum cleaner. Ten phthalates were then analyzed by gas chromatography-mass spectrometry. A quantitative health risk assessment for children via ingestion was conducted using the United States Environmental Protection Agency (US EPA) methodology. Di-2-ethylhexyl phthalate (DEHP) was the most abundantly detected compound, followed by di-n-octyl phthalate (DnOP) and dibutyl phthalate (DBP) (detection rates > 60%), with median concentrations ranging from 6.90 to 150.91 µg/g. The median concentration of total phthalates (Σ10PAEs) was 190.71 µg/g. The median estimated daily intakes (EDIs) of DEHP, DnOP, DBP, and Σ10PAEs ranged from 3.95 to 112.56 ng/kg bw/day and 13.18 to 375.22 ng/kg bw/day under central-tendency and upper-percentile scenarios, respectively. The EDIs of DEHP, DnOP, and Σ10PAEs in children aged ≥ 9 years were significantly higher than those in younger children. The hazard quotient (HQ) and hazard index (HI) values for the three phthalates were less than 1. The CR for DEHP was below 1×10^-4; however, one child exceeded this threshold under the upper-percentile scenario (1.001×10^-4). These findings suggest that DEHP exposure warrants attention given its potential carcinogenic risk, highlighting the need for appropriate risk management strategies to reduce phthalate exposure in indoor environments.