Occurrence And Health Risk Of Semi-volatile Organic Compounds In Indoor Air And Dust

Most people spend about 80%-90%of theirtime indoors,and exposure to semi-volatile organic compounds(SVOCs)which are widespread in indoor environment will cause adverse health effects in humans.Most previous studies focused on a few classes of SVOCs,while overall pollution profiles and corresponding health risks via multiple exposure pathways are still unknown.Furthermore,prior studies on indoor SVOCs pollutions were primarily crosssectional,and there is a dearth of knowledge about seasonal differences in indoor SVOCs pollutions.To clarify the overall pollution status and identify predominant pollutants,this study conducted high-throughput screening of 895 SVOCs in the indoor air and dust samples from Chinese homes in winter and summer.Indoor pollution levels were compared in the winter and summer.Daily intakes for infants and adults,via inhalation,ingestion and dermal contact with air and dust,were assessed and related to the health-based reference doses.Potential high-risk pollutants were identified to provide a theoretical basis for the prevention and control of health risks in indoor environment.A total of 97 SVOCs,including phthalate(PAEs),alcohols,fatty acids,esters,polycyclic aromatic hydrocarbons(PAHs),pesticides,organophosphate esters(OPEs),phenols,and substituted benzenes,were detected in indoor air and dust samples in winter.Among them,PAEs were the most abundant SVOCs,accounting for 55.3±28.6%and 43.4±16.9%of the total SVOCs concentrations in air and dust samples,respectively.Human exposure and health risks caused by 34 SVOCs with detection frequencies>10%were assessed.For indoor SVOCs with log Koa<9,inhalation and dermal contact with air were the predominant exposure pathways for adults and infants.For SVOCs with log Koa>9,which are more easily enriched by dust,dust ingestion is the main pathway.The following five SVOCs in air samples posed high non-carcinogenic risks to infants and adults,and are listed based on their decreasing risk level:dibutyl phthalate>phenanthrene>stearic acid>methyl palmitate>lauryl alcohol.Four PAHs with 2-4 rings posed potential carcinogenic risks.Phenanthrene posed the highest carcinogenic risk which exceeded the acceptable level of 10-4.The high risks were mainly from inhalation exposure.A total of 97 SVOCs were detected in indoor air and dust samples in summer.PAEs were also the most abundant SVOCs,accounting for 62.3±16.9%and 40.9±11.7%of the total SVOCs concentrations in air and dust samples,respectively.Human exposure and health risks caused by 44 SVOCs with detection frequencies>10%were assessed.Inhalation and dermal contact with air were also the main pathways to indoor SVOCs(log Koa<9)in summer.The following six SVOCs in air samples posed high non-carcinogenic risks to infants,and are listed based on their decreasing risk level:myristic acid>phenanthrene>dibutyl phthalate>dimethyl phthalate>lauryl alcohol>methyl palmitate.Top five SVOCs also posed high risks to adults.In addition,the carcinogenic risks of phenanthrene,fluorene,fluoranthene,acenaphthene,biphenyl and butylated hydroxytoluene exceeded the level of 10-4.The high risks were also mainly from inhalation exposure.There was no significant difference in the total SVOC as well as PAE concentrations between winter and summer dust samples.However,the total concentrations of SVOCs and PAEs concentrations in the summer air samples were significantly higher than those in winter samples.And there were more classes of SVOCs detected in summer,indicating that indoor air pollution in summer was more complicated than that in winter.The seasonal differences may be due to variances in temperature and living habits.For example,high temperature in summer can accelerate the emissions of SVOCs from the products,and is conducive to their migration to the gas phase.This is the first study to conduct a comprehensive screening of a wide range of SVOCs in Chinese homes.The occurrence and health risks of 895 SVOCs in indoor air and dust were investigated which provided basic data for prevention and management of SVOCs risk in indoor environment.