Residual Level And Safety Assessment For Petroleum Hydrocarbon And Organochlorine Pesticide In The Mudflat Shellfish In Ningbo

Seafood safety has been the main concern of people. Therefore, we sampled four species ofmudflat shellfishes （Moerella iridescens, Ostera cucullata, Sinonovacula constricta andTegillarca granosa） in21mudflat shellfish culturing areas. Water and sediments were alsocollected. HCHs, DDTs, PCBs and four kinds of Ops were determined. The residual level,component feature，accumulation patterns and sources were studied. And finally weassessed the health risk and estimated the safe amount of shellfish consumption.The main conclusions in this study were as the following:Concentration range of TPHs in shellfish were5.53-52.40mg kg^-1, and average of20.99mg kg^-1, beyond the standards critically. Concentration range of TPHs in water were0.015-0.188mg L^-1, and average of0.036mg L^-1. Andong, Longshan, Shuangpantu were beyondthe standard according to the first grade of sea water standards. Concentration range ofTPHs in the sediments were0.967-528.64mg kg^-1, and average of92.57mg kg^-1. Sediments inMinggang and Gaotang were beyond the standard at a little margin. Concentrations of TPHs inwater of Hangzhou Bay were higher than the other seas. The concentrations of TPHs in Osteracucullata were higher than the other species.Concentration range of OCPs in shellfish were1.94-48.92ng g^-1, and average of16.72ng g-1, DDTs concentrations in some species were beyong the standards. Concentration range of OCPsin water were2.57-15.20ng L^-1, and average of8.82ng L^-1. Concentration range of OCPs in thesediments were0.80-32.40ng g^-1, and average of8.30ng g^-1, DDTs concentrations in Qiangtouwere beyond the standards. The main components of DDTs and HCHs in each sample weredifferent, as they had different chemical properties and transportations in different types of samples.Component analysis of OCPs showed that, α-HCH in both3types of samples were atdegraded status. The detection rate of β-HCH was low in water and in the sedimentsthey were mostly at accumulated status. In most samples, γ-HCH and δ-HCH were ataccumulated status. In all samples, o,p’-DDT and p,p’-DDT were at degraded status. There were new inputs of some samples, the possible sources were Lindane andDicofol.Concentration range of PCBs in shellfish were2.03-31.81ng g^-1, and average of10.90ng g-1, the concentrations of PCBs of shellfish in Hangzhou Bay were significantly higher than the otherseas and PCBs concentrations in Moerella iridescens were higher than other species. Concentrationrange of PCBs in water were1.10-40.04ng L^-1, and average of20.86ng L^-1, the concentration ofthe seas were close to each other, and some samples were beyond the standards. Concentrationrange of PCBs in the sediments were3.20-33.33ng g^-1, and average of11.58ng g^-1, somesamples were beyond the standards. The order of concentration was Sammen Bay> XiangshanBay> Hangzhou Bay.According to the results, the concentration range of OPs in shellfish were nd-132.87ng g^-1,some samples were beyond the standards. The residual level in water was at a low level. In thesediments, the detection rate was different, but no standards to refer.According to the results of health risk assessment, there were no risks to people if taken lessthan the average amount. According to the acceptable cancer risk index and exposure risk index,the consumption of edible parts of shellfish were60and140grams per body weight per day percapita.