Indoor/outdoor Characterization And Sources Of PAHs,NPAHs And OPAHs In Atmosphere Of Urban Areas

Polycyclic aromatic hydrocarbons(PAHs)are a type of persistent organic pollutants widely present in the atmosphere,accounting for more than 1/3 of the total carcinogenic substances in nature.The concentration of polycyclic aromatic hydrocarbon derivatives(NPAHs and OPAHs)is low,but their carcinogenic Sexuality and teratogenicity are much higher than PAHs.Polycyclic aromatic hydrocarbons and their derivatives can exist in the gas phase and particulate phase.Low molecular weight PAHs are volatile and exist in the gas phase;high molecular weight polycyclic aromatic hydrocarbons are not easy to evaporate and mainly exist in the particulate phase.Dust is an important part of atmospheric aerosols,and it will have a series of important effects on the atmospheric environment,ecosystems,and earth surface-atmosphere exchange.In order to control PAHs pollution effectively and protect people's health,it is very important to study PAHs and their derivatives in the air and dust,and grasp the pollution status,main sources and destination of PAHs and their derivatives accurately.To study the pollution characteristics of PAHs,NPAHs and OPAHs in indo or and outdoor air and dust in households in two urban areas of Shandong,bas ed on passive atmospheric sampling technology,2018.9-11(non-heating period),2018.11-2019.1(heating period),indoor and outdoor atmospheric and dust samples were collected simultaneously in the urban areas of Weihai and Heze.19 PAH s,17 NPAHs and 6 OPAHs were analyzed by gas chromatography and mass s pectrometry(GC/MS-MS).The concentration of PAHs,NPAHs and OPAHs in i ndoor and outdoor atmospheric air and dust in Weihai and Heze,indoor and o utdoor relationships,sources and health exposure risks were studied.The concentrations of PAHs,NPAHs and OPAHs in indoor and outdoor air and dust in Weihai and Heze were obtained.The concentrations of PAHs,NPAHs and OPAHs in Heze were higher than those in Weihai.The concentrations of PAHs,NPAHs and OPAHs in outdoor air are generally higher than those in kitchen and bedroom.Different from the distribution of PAHs and their derivatives in the air,the average concentration of PAHs and OPAHs in indoor dust samples is higher than that in outdoor environment,and the average concentration of outdoor NPAHs is higher than that in indoor environment.PAHs and their derivatives in the air and dust are obviously different.PAHs in the air are mainly composed of 2-3-ring PAHs,NPAHs are mainly composed of 1N-NAP and 2N-NAP,and OPAHs are mainly composed of NAP-1-ALD,9-FO and ATQ.PAHs in the dust are mainly composed of middle ring PAHs and heavy ring PAHs,NPAHs are mainly composed of 9-ANT,2N-FLT,3N-FLT and 1N-PYR,and OPAHs are mainly composed of 9-FO and ATQ.By calculating the indoor and outdoor concentration ratio I/O of PAHs,NPAHs and OPAHs in the indoor and outdoor air and dust,we found that the I/O of PAHs in the air were less than 1,indicating that PAHs in the air of the study area mainly comes from the outdoor emission source;in the non heating period,the I/O of PAHs in the dust is more than 1,and the PAHs in the dust mainly comes from the indoor,while in the heating period,the PAHs in Heze dust mainly comes from the indoor PAHs in Weihai dust mainly come from indoor.The I/O values of NPAHs and OPAHs in the air of Heze and Weihai are mostly less than 1,which indicates that NPAHs mainly come from the outside of the room and are more obvious in the heating period;the I/O values of NPAHs in the dust of Heze and Weihai have no obvious distribution and OPAHs are mainly from the indoor sources.The source ratio analysis of PAHs,NPAHs and OPAHs in the indoor and outdoor atmospheres of Heze and Weihai was carried out by the characteristic ratio method.PAHs and NPAHs in the air of kitchens and bedrooms come from primary emission sources generated by indoor activities such as heating and cooking.PAHs and NPAHs in outdoor mainly come from secondary generation sources.PAHs in indoor and outdoor dustfall mainly come from coal and biomass combustion and petroleum combustion.Low-temperature petroleum sources also contribute partly.NPAHs mainly come from primary emission sources.By calculating the lifetime carcinogenic risk(ILCR),the health exposure risks of children and adults to the indoor and outdoor atmospheres,dust,PAHs and NPAHs in Weihai and Heze were evaluated.For dermal contact and ingestion,the risk of carcinogenesis for adults is greater than children,and the risk of carcinogenesis for children when swallowing dust is greater than that for adults.The total ILCR value of outdoor PAHs is higher than that of kitchens and bedrooms.The ILCR value of PAHs by inhalation is significantly lower than that of ingestion and dermal contact.The overall ILCR value of NPAHs is lower than that of PAHs.The ILCR value of NPAHs by inhalation is higher than that of ingestion and skin contact.The total ILCR value of NPAHs in the bedroom is the highest.This paper provides a theoretical basis for the control of indoor pops,and it is of great significance to protect human health and improve the living environment.