| China is one of the most important aquaculture countries with abundant aquatic resources which are at the forefront of the world.As an important source of nutrition?protein,unsaturated fatty acids,vitamins and minerals?and energy for human beings,the consumption demand from the residents is increasing.Among them,seafoods is favored for its high quality and taste.However,the food safety of seafoods is also of great concern due to the bioaccumulation by exposing to the contaminated environmental media for their whole lifetimes,and eventually posing a potential health risk to consumers.Therefore,this investigation studied the residual levels of 16priority PAHs and 5 heavy metals in the seafood collected form the offshore areas?Changjiang Estuary,Wentai fishery?,open sea areas?fishing fishery?and oceanic areas?Pacific,Indian Ocean,Atlantic?.The 16 priority PAHs were specified by USEPA and the 5 heavy metals include copper?Cu?,lead?Pb?,cadmium?Cd?,chromium?Cr?,arsenic?As?.Based on the determination of the levels of heavy metals and PAHs in seafoods and trophic levels of different species,trophic transfer patterns were characterized.Finally,the risk via seafood consumption was assessed based on residual levels of the target analytes and daily average intake.The main conclusions are as follows:?1?The highest concentration of heavy metals in the marine products in the studied three regions is Cu.It should be noted that the heavy metals all exhibited higher concentrations except for Cu comparing with other sea areas in the world.Furthermore,Cu and As in the seafoods collected in the open sea waters were 15-20and 6-26 times higher than those collected in offshore areas and oceanic areas.According to the criteria for food safety of China,the concentrations of Pb in offshore areas and open sea areas exceeded the guidelines significantly,and the concentrations of Cd in oceanic areas exceeded the guidelines significantly.?2?The concentrations of?PAHs in the seafood in offshore areas,open sea areas and oceanic areas are 172602 ng?g-1 dw,176-418 ng?g-1 dw,100-322 ng?g-11 dw,respectively.Compared with the findings worldwide,only the level of?PAHs in offshore seafood is higher,the consumption of seafoods in this area may lead to possible health risks;the major components of PAHs in the three regional seafoods are 23 ring PAHs.High levels of low-molecular-weight PAHs in the marine products in these areas may be related to frequent sea transportation and ship fuel leakage.?3?The concentration of heavy metal Cd in offshore seafood decreased with increasing trophic level.The concentrations of heavy metals Cu and Cd in the offshore seafood decreased with increasing trophic level.Other heavy metals and?PAHs did not correlated to the trophic levels significantly.In organisms,the bioaccumulation and biomagnification of heavy metals and?PAHs are complex dynamic processes.Many parameters,including the trophic level,physical status of the organism and environmental factors may affect the bioaccumulation and biomagnification.Therefore,for heavy metals and?PAHs in seafood,the characteristics of trophic delivery are yet to be further studied.?4?According to the risk assessment,the health risk of heavy metals in seafood in open sea was the highest,and the lowest was offshore seafoods.Except for greenfin fish,the health risks of seafood in coastal sea,open sea and ocean were all less than the critical level recommended by the International Commission on Radiological Protection?ICRP?5.0×10-5?a?,and contributed by heavy metals Cu,As and Cu,respectively.Meanwhile,the life-long carcinogenic risk?ILCR?caused by?PAHs in seafoods in open sea was the highest,one order of magnitude higher than those in offshore and ocean.Notably,the ILCR values were all lower than the 1.0×10-6 which is the acceptable limit proposed by USEPA,indicating no significant carcinogenic risk.In general,the heavy metals and PAHs in the three regional seafoods would not lead to significant health risks. |
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