Exposure Evaluation And Risk Assessment Of VOCs In Indoor Air Of Residential Buildings In Baotou City

With the development of our society,the interior decoration becomes more gorgeous.Abundant consumer goods lead to more and more indoor environmental problems.As we all know,volatile organic compounds?VOCs?are common indoor pollutants.According to IARC and USEPA,VOCs are harmful to human nervous system,development system,respiratory system and so on.The most time of our life is spent in indoor environment.So it is of great significance for human health risk assessments to conduct exposure assessments of indoor VOCs.Children is one of the most vulnerable groups,who also are more susceptible to external environment.However,the present researches on exposure evaluation of children are limited in our country.Therefore,this paper conducted relevant research,and the conclusions were as follows:?1?This paper randomly selected 123 families with children in Baotou main city.From August 2014 to August 2015,the households were tested,and there were 22 kinds of target VOCs detected.The results showed that the detection rates of toluene,styrene,sec-butylbenzene,p-isopropyltoluene,n-propylbenzene,2-chlorotoluene,1,4-dichlorobenzene,and dichloropropane all reached 100%,and the others also reached 95%.The higher concentration of VOCs were D-limonene?median:2.53?g/m³?,?-pinene?median:2.13?g/m³?and toluene?median:5.19?.The concentration of VOCs in the families of Baotou City is at the national average.?2?Based on the exposure parameters of children aged 0⁶ years and adults in Inner Mongolia,China in Exposure Factors Handbook of Chinese Population,this paper estimated VOCs exposure doses by Monte Carlo simulation among all age groups in Baotou City.The results showed that the VOCs exposure doses increased with age,and the VOCs exposure doses of infants aged less than 1 year old was the highest?benzene:0.23¹2.61?g/kg/day,toluene:0.11⁶2.12?g/kg/day,ethylbenzene:0.01¹6.37?g/kg/day,?-pinene:0.01⁸8.33?g/kg/day and D-limonene:0.04⁶3.12?g/kg/day?,the VOCs exposure doses of adults was minimal?benzene:0.02¹.25?g/kg/day,toluene:0.01⁶.10?g/kg/day,ethylbenzene:0.00¹.37?g/kg/day,?-pinene:0.00⁹.02?g/kg/day,and D-limonene:0.00⁶.18?g/kg/day?.For different age groups,the exposure doses of?-pinene,D-limonene,toluene and ethylbenzene were relatively higher among the 22 VOCs,which were4.7⁴6.7?g/kg/day and 1.94²0.0?g/kg/day,1.7¹6.72?g/kg/day and 0.79¹0.57?g/kg/day,respectively.This paper used the actual individual exposure parameters of children to calculate the exposure doses of children aged 3⁶ and compared these directly with the results calculating based on Exposure Factors Handbook of Chinese Population,showing that some simulation results were overestimated or underestimated.?3?This paper indicated that the carcinogenic risks of benzene,ethylbenzene,styrene,1,4-dichlorobenzene,trichloroethylene and tetrachloroethylene increased with age.Among all six estimated VOCs,the highest carcinogenic risk is benzene,followed by 1,4-dichlorobenzene,ethylbenzene,styrene,tetrachloroethylene and trichloroethylene.The carcinogenic risk of benzene is about1-3 higher than other VOCs.The carcinogenic risk of benzene for adult was4?10^-5.The carcinogenic risks of the above 6 VOCs in different ages children have exceeded1?10^-4.The study also evaluated the non-carcinogenic risks of 16 VOCs such as benzene,toluene,ethylbenzene,naphthalene and so on.The non-carcinogenic risk?mean?of naphthalene is the largest and is the only VOC with an HQ value?1.5?exceeding 1,Therefore,indoor naphthalene pollution should be taken seriously.