| Aromatic hydrocarbons (AHC), a kind of VOCs, are ubiquitous in air, with the sourceof paint and solvent using, building materials emissions, environmental tobacco smoke,fuel-burning, cooking, oil-fumes, traffic emissions, and so on. The air pollution of AHCposes a grove threat to humanity. The understanding of occurrence, sources and risks forAHC in environment is the basis of controlling AHC pollution efficiently, thus reducingpersonal intake and protecting human health.In China, rapid economic development has lead to heavy air pollution, especially inmajor cities, although with the government effective measures.Hangzhou is taken as a case in this paper. The AHC pollution in the air of differentmicroenvironments in this city, including homes, offices, public places, buses and busstations, has been synthetically investigated. The potential sources of AHC in differentmicroenvironments were identified with different methods. The emission characteristics ofAHC in different tobacco smoke were also investigated. The lifetime risks for differentpersons exposed to AHC in Hangzhou were also assessed. The main conclusions were asfollows:(1) Average AHC levels in different microments in Hangzhou were between 29.90μg/m3 and 196.75μg/m3, while the benzene concentration were from 5.52μg/m3 to15.17μg/m3, which was much higher than that in America and Europe. Shopping centershas the highest level of AHC compared to other microenvironments. The highestconcentration of AHC was found in the working room in homes while it was measured inshoe counters in the shopping centers and supper markets. The concentration of AHCtended to be higher in summer than in winter in homes.(2) The extracted pollution sources included house fitment, human activity, printing,cooking, smoking, commodity-emissions and traffic-emrnisons. The results of APCSreceptor model indicated that 54.30% of the total AHC mass concentrations measured inhomes were originated from house fitment, 25.60% were emitted from human activitiessuch as smoking and cooking and 20.24% were apportioned to the traffic-emissions. Printing and traffic-emissions were the main source of AHC in offices which apportioned46.37% and 53.63% respectively. In shopping centers and supper markets, the mainsource of AHC was commodity-emissions which apportioned 74.32% followed by humanactivity for about 25.68%.(3) The concentration of AHC in our study was 63% lower than that in 2000, with theconcentration of benzene was 62% lower and toluene 67% lower. The AHC pollution wascontrolled effectively during this years. But the situation was still serious and need morework.(4) The contents of AHC in different cigarette smogs were between 603μg/cig and1449μg/cig, with the benzene of 164～239μg/cig. AHC in tobacco smoke were in goodrelation to tar content, having nothing to do with nicotin content.(5) The lifetime cancer risk for different people exposed to benzene in Hangzhouranged from 9.43×10-6 to 1.31×10-5, which were ten times higher than 1×10-6. The waitersin shopping centers and supper markets had the highest cancer risks followed by busdrivers and office clerk.
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