Synthetic phenolic antioxidants in indoor dust across China:contamination characteristics and human exposure risk
In this study,we investigated the contamination characteristics of 13 synthetic phenolic antioxidants(SPAs)and their four transformation products in indoor dust collected from 17 provinces across China.The results revealed that the predominant SPAs in indoor dust from China were the traditional SPA,2,6-di-tert-butyl-4-methylphenol(BHT),and the novel SPA antioxidant 1010.Notably,these two SPAs exhibited comparable contamination levels(BHT:165~1.10 x 103ng/g;antioxidant 1010:62.0~2.37 x 103ng/g),accounting for 37.4%and 36.0%of the total SPA concentration,respectively.Additionally,the presence of antioxidant 330has been detected in indoor dust for the first time,with a concentration of up to 12.7ng/g.Furthermore,considerable concentrations of SPA transformation products,such as quinone/aldehyde products and aldehydes products,were found in the dust,constituting a relatively large proportion of the total SPA concentration(35.8%and 56.9%).This suggests the potential transformation of SPAs within indoor dust.The concentration of SPAs in indoor dust might be associated with the level of economic development in the sampling sites,with higher levels observed in southeastern and coastal cities.Moreover,the concentrations and compositions of SPAs displayed notable spatial variations,which might be influenced by climatic and geographical conditions in different regions.Daily intake assessments revealed that,under high exposure scenarios,the estimated daily intake of SPAs for adults ranged from 1.01x10 3 to 0.54ng/(kg bw·d),while for children,it ranged from 4.52x10 3 to 2.39ng/(kg bw·d).Although current human exposure levels through dust ingestion are relatively low,considering the rapid substitution of SPA contaminants and their increasing concentrations in the environment,continued attention must be given to their environmental risks.