Characteristics Of Phthalic Acid Esters In Household Dust And Health Risk Assessment For The Related Childhood Exposure

BackgroundAs an environmental endocrine disruptor,Phthalic acid esters（PAEs）are universal in urban household dust.Exposure to household dust PAEs may have detrimental effects on children’s health.Pre-school-aged children are a sensitive group of people to exposure to PAEs from household dust.To date,systematic and multicenter investigations of PAEs in household dust in China still need to improve.ObjectiveThis study aims to investigate the pollution level,seasonal and spatial pollution characteristics,potential family environmental factors,and possible sources of PAEs in daily life scenarios.Secondly,to evaluate the exposure level and health risks of PAEs in children aged 0-5 years.Thus providing a scientific basis for preventing and controlling PAEs pollution and protecting children’s health.（1）Considering various factors,such as climatic conditions,geographical location,air pollution level,and socioeconomic level,nine cities,namely Lanzhou,Luoyang,Mianyang,Panjin,Qingdao,Shenzhen,Shijiazhuang,Wuxi,and Xi’an,were selected for the survey.About 20-40surveyed households were selected in each city using stratified sampling method in combination with household inclusion and exclusion criteria.Dust samples were collected from households in the cold and warm seasons.Information on household environmental parameters（temperature and humidity,etc.）,household environment questionnaires（household information,housing status and living habits,etc.）,and health status questionnaires（demographic characteristics,behavioral activity patterns and disease history,etc.）were also collected.（2）246 collected dust samples were subjected to pre-treatment such as extraction and concentration,and analyzed by gas chromatography-mass spectrometry（GC-MS）for 10 PAE congeners,including DMP,DEP,DBP,DMEP,DPP,DNHP,BBP,DEHP,DCHP and DNOP.（3）Wilcoxon rank sum test is used to analyze the differences between cold and warm seasons and the upper and lower wind directions.The influencing factors of∑PAEs,DCHP,and DEHP were analyzed by univariate analysis and multivariate logistic regression（4）Based on the assumed typical indoor exposure scenarios,the health risks of 10 PAEs and 6 PAEs in 0-5 years old children were evaluated by using the model recommended by US EPA under the medium exposure level scenario(P₅₀)and high exposure level scenario(P₉₅).（5）Pearson correlation analysis and systematic cluster analysis were used to analyze the source of 10 PAEs.Result（1）Pollution status of PAEs in household dust:The total content of 10PAEs ranged from 0.921 to 29097.297μg/g（median:142.343μg/g）.DCHP and DEHP are the two PAEs with the highest content in household dust,accounting for 49.78%and 41.49%of∑PAEs on average.（2）Seasonal and wind direction differences of PAEs in households:There were significant differences in∑PAEs in Mianyang,Shenzhen,Luoyang,and Shijiazhuang between the warm and cold seasons（P<0.05）.The concentration of∑PAEs in the upwind area of Mianyang was significantly higher than that in the downwind area（P=0.018）.（3）Children’s exposure and health risk assessment:Oral intake was the primary exposure pathway of children to household dust PAEs.PAEs with high exposure in 9 cities were DCHP,DEHP,and DMP.The non-carcinogenic risks of six PAEs（DMP,DEP,DBP,BBP,DEHP,and DNOP）were all under an acceptable level.At medium and high exposure levels,the cumulative carcinogenic risk of DEHP in household dust from all three exposure pathways exceeded acceptable levels,with risk values of 6.32×10^-6and 1.95×10^-4,respectively.（4）Analysis of the influencing factors of giving priority to the control of PAEs:The wall topcoats used for decoration in recent five years were∑PAEs（OR=14.306,95%CI:2.939,69.636）,DCHP（OR=7.864,95%CI:1.744,35.463）and DEHP（OR=6.924,95%CI:1.726,27.779）.Using double-layer window glass was a risk factor for the increase of DCHP（OR=5.132,95%CI:1.033,25.504）and DEHP（OR=6.062,95%CI:1.365,26.921）.（5）Potential pollution sources of PAEs in household dust:polyvinyl chloride materials,household chemicals,adhesives for decoration,and rubber hoses,respectively.Conclusion（1）In real-life scenarios,there was widespread contamination of PAEs in household dust,of which DCHP and DEHP were the dominant congeners.（2）There were seasonal and up and downwind area differences in PAEs content in different cities,but no uniform trend of temporal and spatial characteristics has been observed.（3）For children aged 0-5 years,oral intake was the main pathway of exposure to PAEs.The carcinogenic risk of preschool children’s DEHP exposure exceeded the acceptable level,while all non-carcinogenic risks were acceptable.（4）The concentrations of PAEs in household dust may be related to influencing factors such as residential characteristics,decoration materials,living habits and disease history.To reduce children’s exposure to PAEs,effective measures should be taken according to family-related information,residential characteristics,decoration materials,and lifestyle to maintain a healthy and green family environment.（5）The sources of PAEs in household dust were complex,and four main sources were:PVC materials,household chemicals,decorative adhesives,and rubber hoses.