Distribution,Sources And Risk Assessment Of Polycyclic Aromatic Hydrocarbons (PAHs)in Water,Sediment And Soil In Different Seasons Of The Yellow River Basin

With the development of the economy along the Yellow River,more and more attention has been paid to the Persistent Organic Pollutants.This paper aimed at 23 kinds of polycyclic aromatic hydrocarbons(PAHs)pollutants from water,sediments and soil of the Yellow River.The pollution status of PAHs in the Yellow River River was revealed.In order to effectively control the input of PAHs from the source,it is necessary to analyze the sources and risks of highly carcinogenic PAHs.The results are as follows:(1)PAHs were detected in the 39 water,sediment and soil samples of the Yellow River.The concentration of ?23PAHs(?6carPAHs)in the water samples of spring and autumn were range of 51.84?1941.29 ng/L(8.17?1122.83ng/L)and 1.20?802.13 ng/L(0?575.17 ng/L);The concentration of ?23PAHs(?6carPAHs)in the sediment samples of spring and autumn were range of 14.09?1004.08ng/g(1.39?134.05ng/g)and 10.01?2429.70 ng/g(16.93?171.92ng/g);The concentration of ?23PAHs(?6carPAHs)in the soil samples of spring and autumn were range of 18.22-867.55ng/g(24.73-370.54ng/g)and 3.53?1097.23 ng/g(53.6?582.01ng/g).In different season,the concentration of total PAHs and carcinogenic PAHs had high distribution correlation in the Yellow River.The PAHs concentration of Gansu and Henan province content is much higher than the average PAHs concentrations of the Yellow River.Compared with different rivers,the concentration of PAHs in water,sediment and soil in the medium to low levels,but high pollution risk areas should be controled to prevent deterioration.(2)Using the ratio method,principal component analysis(PCA)and PMF model method to analysis the input source.The results showed that:the main sources in the water samples of spring and autumn were oil,coal and wood burning;The main sources in the sediment samples of spring and autumn were the burning of coal,timber and oil,coal and incomplete combustion of wood;The main sources in the soil samples of spring and autumn was the coal combustion.The sources of PAHs in the Yellow River were different between different media and different season,it is mainly decided by the physical and chemical properties of PAHs.(3)Using TEQ toxicity equivalent method,the RQ and health risk assessment method in the Yellow River to assess the ecological risk.The results show that:high carcinogenic risk of sampling points were Guide,Sanmenxia,Xishi and Minhe Shizuishan,Gaocun in spring and autumn,respectively.There were 12.5%and 15%sampling points of Benzene[a]pyrene higher than surface water standard limit value in spring and autumn,respectively.Sediment sampling points of high carcinogenic risk were Xishi,Heishiguan.Soil sampling points risk of High carcinogenic were Heishiguan and Qingtongxia.The risk of Henan section was higher than other regions,Henan province as a big province in agriculture and industry,more profligate emissions caused the PAHs high residue and high risk.Health risk assessment analysis indicated that the risk of exposure were eating>skin contact>respiration.53%and 55%of the sample points can cause high risk by eating via the children along the river in spring and autumn,respectively.17.5%and 25%of the sampling points caused a risk of cancer by skin exposure for the children along the river.Therefore,we should reduce the high risk sample point source emission and to strengthen the protection of children along river.