Occurrence Characteristics and Ecological Risks of PAHs in Atmospheric Particles and Soil from Traffic Sources
To explore the impact of traffic sources on polycyclic aromatic hydrocarbons(PAHs)in the atmosphere and soil along roads,atmospheric particulate matter(TSP)and soil samples were collected at different distance gradients of 0/20/50/100/200 m along the road.The content,composition and spatial distribution characteristics of PAHs in TSP and soil were analyzed.Ecological risk impact of PAHs in soil was estimated using RQ-TEQ model and soil phase fate model.The results showed that the concentration of ∑16PAHs in TSP ranged from 2.66 to 16.31 ng/m3,with an average value of(8.17±3.51)ng/m3.With distance increase,the concentration of PAHs was decreased,then increased and then decreased in autumn,in spring it was increased and then decreased,both with significant changes within the range of 0～50 m.The content of ∑16PAHs in soil ranged from 0.05 to 2.43 mg/kg,with an average value of(0.70±0.57)mg/kg.The spatial variation trend is basically consistent with the PAHs in autumn TSP.The PAHs content in soil is the lowest at 20 meters,which is related to the shading effect of roadside trees.High-ring PAHs such as benzo[b]fluoranthene,benzo[k]fluoranthene,indene benzene[1,2,3-cd]pyrene and benzo[ghi]perylene were dominant components in TSP,while medium and high ring PAHs such as fluoranthene,pyrene,benzo[b]fluoranthene,benzo[k]pyrene were dominant in soil.The ecological risk of PAHs in the soil within 200 m along road can be ignored.The cumulative increment of PAHs in soil at different distances over time was 50 m＞0 m≈20 m＞100 mben＞200 m,and 10 years later,PAHs in soil increases by 0.11～0.15 mg/kg,and RQ increases by 10％.The cumulative effect of PAHs in soil increases soil ecological risk.
万方数据
维普
