Environmental Background Values And Contamination Assessment Of Heavy Metals In Sediments Of Jiaozhou Bay Catchment

Jiaozhou Bay,the“mother bay”of Qingdao,is located on the southern coast of Shandong Peninsula.With the development and construction of Qingdao and the Blue Economic Zone of Shandong Peninsula,the industry,agriculture and transportation in Jiaozhou Bay have got the fast developed quickly.To investigate the pollution characteristics of heavy metals in sediments of the Jiaozhou Bay,The current study investigated the grain size,the trace metals?As,Cr,Zn,Cu,Cd,Pb?and the Al₂O₃ in sediments of the Jiaozhou Bay using 76 surface sediments,and discussed the distribution,the environment background values and the pollution extent of heavy metals.The surface sediments of the study area was mainly composed clayey silt,silty clay.The range?average concentrations?of As,Cr,Zn,Cu,Cd and Pb were 0.96²0.57?8.28?,7.14¹85.53?69.51?,8.18³47.08?80.91?,4.46¹78.73?29.40?,0.01².36?0.26?,8.21³25.36?33.51?mg/kg,respectively.The eastern part of Jiaozhou Bay was the high value area of heavy metal elements.Transportation,industrial,and natural origin pollution were the main sources of heavy metals.The environment background values of As,Cr,Zn,Cu,Cd and Pb were 8.28,67.96,56.80,19.13,0.10 and 17.97 mg/kg,respectively.The background value of Cu was overestimated in previous studies.The background values were used to evaluate the pollution of the Jiaozhou Bay catchment,the results showed that the level of Enrichment Factor,Contamination Factor and Geoaccumulation Index followed the order:Cd>Pb>Cu>Zn>Cr>As,and the eastern of the studied area were seriously polluted by heavy metals.The range of pollution load index and the regional pollution load index were reflected that the study area was moderate pollution.The monomial potential ecological risk index were in the following order:Cd>As>Pb>Cu>Cr>Zn,the range of the potential ecological risk index was reflected that the study area was the low pollution,and the Cd is the primary potential ecological risk factor,Therefore,emergent strategies and artificial regulations should be used to control the sources of heavy metals?especially the Cd?in Jiaozhou Bay catchment.