土壤和烟叶中多环芳烃的暴露特征及健康风险评估

The exposure characteristic and health risk assessment of polycyclic aromatic hydrocarbons in soils and tobacco plants

【目的】揭示土壤和烟叶中多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的暴露特征及其对人体造成的健康风险。【方法】采集了贵州松桃县长坪(CP)、太平(TP)、平头(PT)、普觉(PJ)、盘信(PX)和孟溪(MX)6个烟区土壤和新鲜烟叶样品各40个,测定样品中16种PAHs含量,分析其经口(ingestion)、皮肤(dermal)和呼吸(inhalation)3种非饮食摄入途径的暴露特征,并评估了PAHs对烟农造成的致癌和非致癌健康风险。【结果】土壤和烟叶中7种致癌性的PAHs[䓛(Chr)、苯并(a)蒽(BaA)、苯并(b)荧蒽(BbF)、苯并(k)荧蒽(BkF)、二苯并(a,h)蒽(DahA)、苯并(a)芘(BaP)和茚并(1,2,3-cd)芘(IP)]的含量分别为70.97~365.71和293.53~1730.72μg/kg,平均含量分别为221.13和707.03μg/kg;土壤和烟叶中9种非致癌性PAHs[萘(Nap)、蒽(Ant)、菲(Phe)、芘(Pyr)、苊烯(Ane)、二氢苊(Any)、芴(Flu)、荧蒽(Fla)和苯并(g,h,i)芘(BghiP)]的总含量分别为65.6~647.6和108.9~606.1μg/kg,平均值分别为379.6和304.2μg/kg。PAHs暴露特征从大到小呈现为:经口摄入>皮肤摄入>呼吸摄入,土壤和烟叶中7种致癌性的PAHs对烟农总的平均每日暴露量分别为54.41~280.38和225.04~1326.87 pg/(kg·d),平均值分别为169.53和542.05 pg/(kg·d);非致癌性的9种PAHs对烟农总的平均每日暴露量分别为146.70~1448.19和243.41~1355.33 pg/(kg·d),平均值分别为848.91和680.22 pg/(kg·d);致癌性和非致癌性PAHs的平均每日摄入量最大值均出现在MX烟区。土壤和烟叶中PAHs对烟农产生的非致癌性总危险指数为1.02×10-5~4.31×10^(-4),平均值为1.92×10^(-4);PAHs对烟农产生的总致癌风险指数为8.39×10^(-7)~5.14×10^(-6),平均值为2.18×10^(-6)。其中,BaP的总致癌风险指数最大(3.69×10^(-7)~4.25×10^(-6),平均值为1.58×10^(-6));有26个点位的BaP超过美国环保署建议的临界值,超标率为65%,有90%的取样点7种致癌性PAHs的总量处于低风险水平。【结论】土壤和烟叶中PAHs对烟农的暴露方式主要为经口和皮肤途径,PAHs的非致癌风险值处于美国环保署建议的临界值之下,为可接受水平。绝大多数取样点的致癌性PAHs已经给烟农造成了低风险的健康影响,尤其是BaP应该受到重点关注。

【Objective】The aim of this research is to determine the exposure characteristic and health risk of polycyclic aromatic hydrocarbons(PAHs)in soils and tobacco plants.【Method】Forty samples of soil and fresh tobacco plants were collected from tobacco-growing areas in Changping(CP),Taiping(TP),Pingtou(PT),Pujue(PJ),Panxin(PX)and Mengxi(MX)in Songtao County of Guizhou Province.A total of 16 PAH species were isolated from the samples.The characteristics of PAHs exposure were analyzed after ingestion,dermal administration,and inhalation.The carcinogenic and non-carcinogenic health risks on farmers were assessed.【Result】The total contents of seven kinds of carcinogenic PAHs[perylene(Chr),benzo(a)anthracene(BaA),benzo(b)fluoranthene(BbF),benzo(k)fluoranthene(BkF),dibenzo(a,h)anthracene(DahA),benzo(a)pyrene(BaP),and indeno(1,2,3-cd)pyrene(IP)]in the soil and tobacco samples were 70.97-365.71 and 293.53-1730.72μg/kg,and the mean values were 221.13 and 707.03μg/kg,respectively.The total contents of nine non-carcinogenic PAHs[naphthalene(Nap),anthracene(Ant),phenanthrene(Phe),pyrene(Pyr),acenaphthylene(Ane),diacenaphthylene(Any),fluorene(Flu),fluoranthene(Fla),and benzo(g,h,i)pyrene(BghiP)]were 65.6-647.6 and 108.9-606.1μg/kg,and the mean values were 379.6 and 304.2μg/kg,respectively.Analysis of the exposure characteristics of the PAHs revealed that ingestion>dermal>inhalation in terms of the exposure risk.The total average daily exposure of the farmers to the seven carcinogenic PAHs in the soil and tobacco samples was 54.41-280.38 and 225.04-1326.87 pg/(kg·d),and the mean values were 169.53 and 542.05 pg/(kg·d),respectively.The total average daily exposure of the farmers to the nine non-carcinogenic PAHs in the soil and tobacco samples were 146.70-1448.19 and 243.41-1355.33 pg/(kg·d),and the mean values were 848.91 and 680.22 pg/(kg·d),respectively.The average daily intake(ADI)of the carcinogenic and non-carcinogenic PAHs was the highest in MX.The total non-carcinogenic risk index of the PAHs in the soil and tobacco samples to the farmers ranged from 8.39×10^(-7)to 5.14×10^(-6),with a mean value of 2.18×10^(-6).The total carcinogenic risk index of the PAHs to the farmers varied from 8.39×10^(-7)to 5.14×10^(-6),with a mean value of 2.18×10^(-6).The total carcinogenic risk index of BaP was the highest among the PAHs,being 3.69×10^(-7)to 4.25×10^(-6),with a mean value of 1.58×10^(-6).The levels of BaP exceeded the recommended threshold published by the United States Environmental Protection Agency(USEPA)at 26 sites(65%),and the total carcinogenic risk of the seven carcinogenic PAHs was low at 90%of the sampling sites.【Conclusion】Ingestion and dermal exposure were the main exposure routes of the PAHs in the soil and tobacco samples.The carcinogenic risk of the non-carcinogenic PAHs was below the critical value recommended by the USEPA,and their values were at acceptable range.The carcinogenic PAHs had a low health risk to farmers at the majority of sampling sites.However,the carcinogenic PAH,BaP,requires further attention.