Nationwide Occurrence of Synthetic Antioxidants in Household Dust from Regions across China

Synthetic antioxidants (SAOs) are additive chemicals with diverse commercial applications, yet knowledge of the occurrence of these emerging contaminants in households on a large geographical scale is lacking. We thus explored the levels and regional patterns of 56 SAOs in 1407 household dust samples from 29 provincial administrative regions across China. Total SAO concentrations in province-based pooled samples ranged from 1810 to 18 280 ng/g (median of 4010 ng/g). Twenty-five SAOs were detected in >60% yield, including 15 novel SAOs. SAO concentrations and compositions varied significantly across China, with coastal regions such as Hong Kong and Shanghai showing higher levels and a greater prevalence of novel SAOs. Despite these differences, either 1,3-diphenylguanidine (DPG) or 2,6-di-tert-butyl-4-methylphenol (BHT) was the dominant SAO nationwide, indicating widespread usage. Results indicated that anthropogenic factors (e.g., GDP and population density) significantly influenced SAO levels and distributions in household dust across China (p < 0.001). Risk assessments showed low hazard quotients for SAOs, suggesting minimal risks overall. However, novel SAOs posed higher risks than traditional ones, particularly for toddlers. Our study highlights the need for further monitoring and improved understanding of the health consequences of SAOs to better inform future policies and raise public awareness.