Comprehensive indoor phthalate risk assessment: A multimedia exposure framework for quantifying population health...

Phthalates (PAEs) represent ubiquitous indoor contaminants with widespread occurrence in residential environments, posing significant health risks through multiple simultaneous exposure pathways. This study developed a novel multimedia exposure assessment framework integrating settled dust, air, drinking water, and food matrices to quantify PAE exposure doses, health risks, and disease burden. Among the six target PAEs, DEHP dominated in settled dust (median: 183 μg/g), while lower molecular weight PAEs prevailed in indoor air, with DBP showing the highest concentration (1319 ng/m³), followed by DIBP (282 ng/m³) and DMP (124 ng/m³). Monte Carlo simulation revealed children experienced 1.4-2.2-fold higher total PAE exposure than adults. Source apportionment identified air as the dominant medium (children: 85.30 %; adults: 87.88 %) with dermal absorption as the primary pathway (children: 82.87 %; adults: 85.52 %). Health risk assessment demonstrated non-carcinogenic risks from DBP, DEHP, and DIBP affecting 8.12 %, 1.57 %, and 1.39 % of children, respectively, while DBP affected 2.93 % of adults. Butyl benzyl phthalate exhibited carcinogenic risks for 0.32 % of children and 0.02 % of adults. Disease burden analysis revealed PAE-associated asthma and dermatitis resulted in 1.45 million and 0.14 million disability-adjusted life years lost, respectively. This comprehensive multimedia assessment provides the quantitative framework for integrated PAE health risk evaluation, informing exposure mitigation strategies and regulatory policy development.