| Polycyclic Aromatic Hydrocarbons (PAHs) have been concerned because of high toxicity, non-biodegradable and biological accumulation and so on. PAHs not only can affect regional and even global air quality through long distance migration, but also can threaten human health through breathing and food chain. In this paper, fine particulate matter samples in atmospheric and cooking fumes were collected and PAHs in fine particulate matter were analyzed by GC-MS. To investigate the pollution characteristics and influence factors of PAHs in atmospheric fine particulate, and conduct health risk assessment for PAHs in different fine particulates in Lanzhou. The results were reached as follows:(1) PAHs in the atmospheric fine particulate had obviously pollution characteristics in Lanzhou. The concentration of EPAHs changed in "U" curve, ranging from 9.39 to 202.78ng/m3, and the average concentration was 54.19ng/m3. The pollution level of ΣPAHs in winter and autumn was higher than spring and summer significantly, besides the highest and lowest were in winter and summer respectively. The concentration of ΣPAHs in heating period was much higher than in non-heating period, there were 102.43ng/m3 and 19.74ng/m3 respectively. PAHs in fine atmospheric particulate were dominated by 4 to 6 ring PAHs in different seasons. In spring, autumn and winter, BbF was higher than other monomer PAHs as well as BkF in summer.(2) The sources of PAHs in atmospheric fine particulate in different seasons were not the same in Lanzhou. The sources of PAHs in atmospheric fine particulate mainly originated from coal-fired and vehicle exhaust, petroleum and coal-fired in spring and summer, straw burning in summer, coal-fired, petroleum and straw burning in autumn, coal-fired in winter.(3) The proportion of the medium and small-sized restaurants was 80% in all restaurants with various different management types. The proportion of using clean energy was 63.11%, and 36.42% of restaurants was installed fume-decontaminating device. The concentration of PM2.5 in cooking fumes was much higher than that in atmospheric environment, and the average concentrations of PM2.5 from kitchen operation and cooking fumes discharging outlet were 2044.75μg/m3 and 5644.62μg/m3 respectively.(4) The concentrations of ΣPAHs in fine particulate of kitchen operation and cooking fumes discharging outlet were ranging from 170.58 to 499.71ng/m3 and 219.76 to 836.14ng/m3, and were dominated by 4 to 5 ring PAHs which reached 61.36% and 62.29% respectively. Pyr was higher than other monomer PAHs and the average concentration from kitchen operation and cooking fumes discharging outlet was 38.57ng/m3 and 61.91ng/m3 respectively.(5) The pollution levels of ΣPAHs in fine particulate from kitchen operation and cooking fumes discharging outlet of restaurant and rotisserie were higher than other cooking categories, the concentrations were 499.71ng/m3 and 616.71ng/m3 respectively. The lowest was 170.58ng/m3 by Hunan cuisine. And that the concentration of ΣPAHs was gradually increased with increase of the stove number, and it was higher in salad oil and coal-fired than other cooking oil and fuel.(6) The incremental lifetime cancer risks by breath exposure among adults and children were 1.25×10-5 and 8.73×10-6, and the losses of life expectancy were 77.86 min and 54.26 min respectively. The incremental lifetime cancer risks of restaurant workers were ranging from 4.40×10-6 to 2.61×10-5, the average was 1.15×10-5. The losses of life expectancy of restaurant workers were ranging from 27.33 to 162.02 min and the average was 71.21 min.In summary, the concentrations of PAHs in atmospheric and cooking fumes fine particulate were at higher pollution level. The incremental lifetime cancer risks by breath exposure of different people (adults, children and restaurant workers) were higher than the acceptable level 1×10-6 which was recommended by WHO. |
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