Prevalence of phthalate alternatives and monoesters alongside traditional phthalates in indoor dust from a typical e-waste recycling area: Source elucidation and co-exposure risk

Highlights: • High-molecular-weight phthalate diesters prevail in e-waste dust. • Phthalate alternatives and phthalate monoesters prevail in e-waste dust as well. • Biodegradation of diesters was recognized as the main source of monoesters in dust. • Phthalates and phthalate alternatives are being simultaneously used in e-products. • Occupational workers suffer from serious combined exposure to phthalate chemicals. This study first discovered the prevalence of phthalate (PAE) alternatives and PAE monoesters alongside traditional PAEs with elevated concentrations in indoor dust from typical e-waste recycling industrial park and adjacent communities. Among nine PAEs, high-molecular-weight (HMW) PAEs dominated over low-molecular-weight (LMW) PAEs in e-waste dust, with total concentrations (∑₉PAEs) ranging from 170 to 5300 μg g⁻¹. The diisononyl phthalate (DiNP) was identified as the most abundant PAE in e-waste dust, with over 10 times higher median concentration than that measured in home dust. Total concentrations of three PAE alternatives ranged from 20 to 1600 μg g⁻¹ in e-waste dust, which were 3–10 times higher than the measured levels in home dust. A total of 13 monoesters were all identified in all samples with total concentrations of 4.7–59 μg g⁻¹, and biodegradation of diesters was recognized as the major source of monoesters present in indoor dust. Significant correlations between the concentrations of PAE alternatives and the HMW PAEs were observed (p < 0.05), indicating that they are being simultaneously used in electronic and electrical products. The occupationally high co-exposure of e-waste dismantling workers to multiple PAEs and PAE alternatives as well as their monoesters should be of concern.