Pollution Characteristics And Risk Assessment Of Indoor Volatile Organic Compounds In Buildings

In winter,the indoor air of buildings in severe cold regions accumulates the concentration of indoor pollutants due to insufficient ventilation.Volatile organic compounds(VOCs)are one of the main pollutants in the air.The harm of VOCs to the human body has been widely concerned,but most researches aim The number of pollutants is single,and it is impossible to comprehensively assess the indoor pollution situation.Therefore,through the long-term detection of VOCs in the indoor air of colleges and universities in severe cold areas,this study analyzes the types and concentration characteristics of indoor air VOCs in classrooms and dormitories,and studies the variation law of TVOC concentration;principal component analysis method is used to analyze the source of VOCs;The health risk assessment model recommended by the US Environmental Protection Agency(USEPA)is used to assess the health risk of indoor exposure populations.This study tested the types and concentrations of VOCs in the indoor air of 5classrooms and 7 student dormitories.The results showed that 20 VOCs were detected in the classroom air samples,with an average concentration of 22.39μg/m~3.The TVOC concentration in classrooms with teaching activities exceeds the standard,and the TVOC concentration is positively correlated with the teaching activity time and the number of personnel.22 kinds of VOCs were detected in the air samples at21:00 in the bedroom at night,with an average concentration of 23.93μg/m~3;18kinds of VOCs were detected in the bedroom samples at 6:00 in the morning,with an average concentration of 10.60μg/m~3,which was 13.33μg/m~3lower than that at night.The results of health risk assessment are:(1)VOCs in classroom air will not cause obvious non-carcinogenic health risks to exposed people,the total carcinogenic risk value is greater than the acceptable carcinogenic risk value,and indoor exposure populations have carcinogenic risk.(2)There is no obvious non-carcinogenic health risk in the exposed population in the dormitory.The carcinogenic risk values of1,4-dichlorobenzene,benzene,1,2-dichloropropane and 1,2-dichloroethane in the samples and The total risk value exceeds the acceptable carcinogenic risk value,indicating that the indoor exposure population has a certain carcinogenic health risk.Through principal component analysis,the main sources of VOCs in classroom air are:solvents,paints and inks,with a contribution rate of 58.13%;coal combustion and biomass combustion,with a contribution rate of 26.85%;deodorants,disinfectants,dyes and adhesives The contribution rate is 10.13%.The main sources of VOCs in bedroom air are:vehicle exhaust emissions,industrial emissions and biomass combustion,with a contribution rate of 44.08%;use of indoor solvents,with a contribution rate of 25.86%;pesticides,medicines,dyes,wallpaper glue,contribution rate 10.81%;synthetic resins,pesticides,etc.,the contribution rate is9.23%;dry cleaning fluids,solvents,etc.,the contribution rate is 7.39%.