Occurrence, Characteristics, and Mixed Reproductive Exposure Risk Assessment of Traditional Phthalates and Their Novel Alternatives in Campus Indoor Dust

Phthalates (PAEs) constitute the primary components of
indoor dust
pollutants and significantly impact human reproductive health. However,
research on novel alternatives to PAEs and the risk assessment of
mixed exposure has remained relatively sparse. In this study, 193
indoor dust samples were collected in 2022 from various campus locations,
including classrooms, canteens, dormitories, offices, and laboratories.
Forty-four traditional PAEs and their alternatives were identified,
with concentrations ranging from 0.44 to 91.5 μg/g. Di(2-ethylhexyl)
phthalate (DEHP) and dioctyl terephthalate (DEHTH) were the predominant
compounds, with mean concentrations of 86.3 and 59.2 μg/g, respectively.
The ingestion pathway was the principal route of exposure, with dormitories
identified as the primary exposure sites. The mixed reproductive toxicity
equivalent factor (TEFmix) of PAEs and their alternatives
was developed using a quantitative structure–activity relationship
(QSAR) model in conjunction with machine learning algorithms. The
TEFmix was found to be lower than the sum of individual
PAEs, potentially due to the antagonistic effects of PAE monomers
on reproductive health. Under high-exposure scenarios, the TEFmix of PAEs in canteen dust was determined to be 0.245, surpassing
values observed in other environments. Females exhibited a higher
risk, with dormitories presenting a greater exposure risk than those
in other indoor locations. This study provided essential data to inform
regulatory measures aimed at mitigating the impact of PAEs and their
alternatives in indoor dust on human reproductive health.