Phthalate Pollution Characteristics In Dust In University Dormitory Of Beijing And Exposure Assessment

Currently,the pollution of phthalates（PAEs）has become a research hotspot.As a type of endocrine disruptors,they are widely present in the environment and can enter the human body through oral,skin contact and inhalation,thereby causing health to the human body.harm.The dormitory is the main place of stay for college students,and the environment in the dormitory is related to the physical and mental health of college students.There are more than90 universities in Beijing,ranking first in the number of urban universities in the country.The analysis of pollution characteristics and exposure evaluation of PAEs in university dormitories in Beijing is also particularly important.This study takes dust fall in 122 dormitories of 14 universities in Beijing as the research object.Brushes are used to collect dust in the dormitories in autumn and winter.The collected dust is sieved,weighed,ultrasonically extracted,rotary evaporation,and nitrogen blown.The volume was adjusted to 1 m L and analyzed by GC-MS.Discuss the concentration characteristics of PAEs in the dormitory dust fall between different genders,different orientations,different campuses and different seasons;organize the questionnaires during the sampling process to perform chi-square test;establish a binary logistic regression model for the chi-square test results to analyze the possible influence on dormitory dust fall Factors in the concentration of PAEs;Monte-Carlo（Monte-Carlo）simulation is used to determine the gas and particle concentration;to estimate the oral,inhalation and skin contact exposure and total exposure of indoor people to PAEs,and to assess the carcinogenic risk of DEHP.The main conclusions drawn from this research are:（1）The detection rate of PAEs in 244 dust fall samples was 100%,and a total of 14 PAEs were detected in the tested samples,of which DCHP,DEHP,DNOP,DNP,DIBP,DBP,and DEEP were detected in 100%.The proportions of DCHP,DEHP,DBP and DIBP among different campuses are relatively high,accounting for about 30%～42%,35%～46%,12%～21%and 8%～10%of∑PAEs respectively.DMPP,DNP,and DNOP account for less than 10%of the total.（2）DMEP,DEP,DPP,DNHP and DMP are the main detected substances in male and female dormitories.The detection rate of DMPP in male dormitories in autumn is only 1.6%,but the detection rate in female dormitories is as high as 49.1%.Except for DMPP and BBP in autumn,the concentration of PAEs is slightly lower than that of female dormitory in male dormitory.The concentration trend of PAEs in winter samples is basically similar to that in autumn.The mean concentration of∑PAEs in the shaded dormitory was 1.1 times that of the Xiangyang dormitory,and the concentrations were 1996.21μg/g and 1729.08μg/g respectively.The median concentration of PAEs in the shaded dormitory was slightly lower than that in the shaded dormitory.For between different campuses.The highest concentrations of PAEs in autumn and winter are DEHP and DCHP are 1416.81μg/g and 1318.86μg/g,respectively.Some campuses are located in geographic locations,dormitory environments and personal living habits lead to significant differences in PAEs concentrations in dormitories.The median and average concentrations of PAEs in the dormitory dust were slightly higher in winter than in autumn.Using SPSS for data analysis,the results show that PAEs are significantly different in different genders,different orientations,different campuses,and different seasons.（3）Combining the questionnaire survey to perform a contingency table chi-square test to obtain 15 possible influencing factors,and further establish a binary logistic regression model.The results show that:geographic location,window orientation and light,indoor temperature,PM₁₀ concentration,floor material,polyester fiber and other materials,gender,indoor ventilation time,floor cleaning frequency,indoor spray cosmetics may affect the concentration of PAEs in the dormitory dust Level.（4）Based on the concentration of PAEs in dust fall,use Oracle Crystal Ball 11.1.2.4 to estimate the concentration of phthalates in the gas phase and the particle phase.The results showed that the median concentration of DMP（1.41μg/m³ in autumn and 0.56μg/m³ in winter）in gas phase PAEs was the highest,followed by DEP,DIBP and DBP.The concentration of DMPP,DCHP,DEHP,DNOP and DNP in the gas phase are all less than 0.001μg/m³.The median concentrations of DCHP and DEHP in the two seasons of the granular phase were higher,and both were 0.12μg/m³ and 0.11μg/m³,followed by DBP,DIBP,DIBP,DNOP,DEP,DNOP,DMP.（5）The median exposure of DEP（7.01μg/（kg·d）in autumn and 10.7μg/（kg·d）in winter）was the highest in the two seasons,followed by DIBP and DBP.DEEP（0.042μg/（kg·d）in autumn and 0.053μg/（kg·d））in winter)had the lowest total exposure.Small molecular weight PAEs such as DEP,DIBP and DBP all use skin contact as the main exposure route,accounting for 53%,62%and 55%of the total exposure in autumn,and 46%,72%and 67%in winter.DEHP was almost entirely oral exposure in the two seasons.