| Polychlorinated biphenyl (PCBs) and Organochlorine pesticides (OCPs) are one ubiquitous class of persistent organic pollutants(POPs), which are of great concern due to the characteristics of high toxicity, long-range transport and persistent in the environment for long period time. In the aquatic environment, fish was chosen as biological indicator for water contaminants due to their relatively high position in the food chain and consequently elevated exposure levels in the aquatic environment. The primary way of human exposure to these persistent pollutants are through diets, of which accounted for a higher proportion by fish consumption. However, fish were significant sources of proteins, polyunsaturated fatty acids, vitamins, and minerals, which were beneficial for human health. Therefore, this study aimed to determine the levels and distributions of PCBs and OCPs in Chinese coastal fisheries, assessing the potential human health risks by fish consumption, providing advisories on consumption of fish from coastal fisheries. Moreover, the tissue-specific levels and distribution characteristic of PCBs, OCPs in fish bought from Shanghai aquatic market and the relationship between the related factors were comprehensively studied, and evaluate the tissue-specific risk-benefit estimation via jointly ingestion of fatty acids and contaminants from fish consumption in Shanghai. This study could provide data and theoretical support for environmental monitoring, environmental manage and food safety supervision, and to provide citizens with the reference suggestion for proper amount of fish intake.In this study, the concentrations of PCBs and OCPs were determined in fish body collected from thirteen coastal fisheries. The results showed that PCBs, DDTs, and HCHs were detected in all samples indicating the widespread of these persistent pollutants contamination in coastal fisheries, but were all below the MLs value of aquatic products set by Chinese rule. The concentration of PCBs ranged from 20.01ng/g 1w to 294.489ng/g 1w with a median of 37.69ng/g lw and a mean of 147.97ng/g lw. The highest and lowest concentrations were observed in Shenzhen and Sanjiang, respectively. The concentration of DDTs ranged from 80.62ng/g lw to 9505.93 ng/g lw with a median of 1701.27ng/g lw and a mean of 2289.99ng/g lw. The highest and lowest concentrations were observed in Qingdao and Sanjiang, respectively. The concentration of HCHs ranged from 9 ng/g lw to 117.46 ng/g lw with a median of 64.55ng/g lw and a mean of 68.17ng/g lw. The highest and lowest concentrations were observed in Quanzhou and Sanjiang, respectively. The concentrations of target compounds in fish among coastal fisheries displayed a noted difference. The concentration gradient of persistent target pollutants in different fish tissues were as follows:liver>gill> muscle. Compared with other related domestic research, PCBs, HCHs and DDTs concentration of this study are in accordant with the existing research. Compared with previous research from other countries, concentration of PCBs in fish from coastal fisheries were in comparably lower level, but DDTs were in higher level, HCHs were in accordant with previous research from other countries.Penta-CBs and Hexa-CBs are dominant PCBs congeners in coastal fisheries. As for the composition of DDTs, o,p’-DDE and o,p’-DDD constitute a small proportion, which revealed that the influence of dicofol is limited. Source analysis found that the main source of DDTs in Lianyungang, Ningbo, Wenling, Quanzhou, Shenzhen, Sanjiang, and Wanning are mainly derived from the historical usage. The ratio of a-HCH and β-HCH in Tianjin, Qingdao, Zhoushan, Ningbo, Ningde, Quanzhou, Shantou, Shenzhen, Sanjiang, and Wanning are less than 1, indicating the continuous use of lindane in these coastal environment.Risk assessment of human exposure to coastal edible fish was conducted based on ADI and TDI. The results showed that HR value of fish were all less than 1 indicating consumption of those fish won’t cause harm to human health. Take the joint carcinogenic risk of PCBs, DDTs, and HCHs into account, the maximum consumption dosage of fish muscle were 1.5～16.61g/d (without the absorption rate), which were all below the average consumption dosage of mega cities residents in our country (62.3g/d). While with the absorption rate, the maximum consumption dosage of fish was 4.11～94.66g/d,which were below 62.3g/d except for that of Quanzhou. The maximum consume frequency with absorption rate and without absorption rate were 0.2～2.23 and 0.55～12.69 times per month, respectively, which were all less than 16 times per month, suggesting that citizens should control those fish consumption in order to avoid the joint carcinogenic risk brought by these persistent pollutants. When not considering the absorption rate, PCBs and DDTs were dominant in carcinogenic and carcinogenic effects. When considering the absorption rate, DDTs. contribute the most to non-carcinogenic and carcinogenic risk and PCBs contribute the least to carcinogenic risk, but HCHs contribute the least to non-carcinogenic risk.Investigation of concentration levels and distribution characteristics of PCBs, OCPs in fish bought from shanghai market showed that PCBs, OCPs were commonly detected in fish tissues, but that of concentration was far less than its MLs. The concentrations of PCBs, HCHs and DDTs in different tissues ranged from 0.09～57.58 ng/g ww,0.29～172.03 ng/g ww and 0～36.43 ng/g ww, respectively. And the concentration in muscles tissues were 0.09～2.25ng/g ww,0.29～87.35ng/g ww,0～1.25 ng/g ww, respectively. Compared with the domestic and abroad research, the concentration of PCBs were in lower level, while HCHs and DDTs concentration were in the medium level.The concentrations of PCBs, HCHs and DDTs were higher in carnivorous fish than that of omnivorous and herbivorous fish. Moreover, marine fish contain more PCBs and HCHs than that of fresh water fish in the same food habit group, the feature of HCHs were on the contrary. In the mean time, PCBs and DDTs concentration have significantly positive correlated with n-3PUFA, DHA+EPA, which indicated that the concentration of PCBs will increase with the increase of fatty acids concentration. HCHs concentration showed a positively relationship with n-6 PUFA. PCBs, HCHs and DDTs concentration in fish muscle tissues were higher in winter than that of summer, and higher in liver and abdominal fat tissue than in fish muscle tissues.Tri-CBs, Tetra-CBs, Penta-CBs, and Hexa-CBs are dominantly composed of PCBs congeners in fish collected from Shanghai aquatic markets, which was consistent with the previous research. Meanwhile, the PCBs profiles exhibited a markedly difference among different sampling areas, species, seasons and fish tissues. Regarding DDTs, p,p’-DDE was the dominant DDTs congeners in the range of 18.7%～64.56%. The source analysis showed that the DDTs contaminants were mainly derived from the historical usage without new pollution source input. α-HCH and β-HCH predominantly comprise HCHs congeners, with the both ratio of α-HCH and β-HCH greater than 1, indicating that HCHs contaminants major came from degradation of historical source.The distribution characteristics of nutrient substances in fish from Shanghai market found that the concentration of lipid, protein, PUFA, MUFA, and SFA in fish tissues were in the range of 1.03～75.2g/100g,6.06～20.22g/100g, 196.6～18201.29mg/100g,252.11～35389.43 mg/100g, and 422.3～26073.38 mg/100g, respectively. PUFA, MUFA, and SFA concentration were significantly correlated with lipid content, food habit, and fish species.The ratio of PUFA/SFA was from 0.03 to 1.08 with a median of 0.51, which were mostly higher than the lowest value recommended by FAO and WHO (0.4～0.5). The ratio of n-6/n-3 was from 0.1 to 11.1 with a median of 1.1, which the majority of that lower than the highest value recommended by FAO and WHO (4). The ratio were higher in marine fish than in freshwater fish.EPA+DHA concentration ranged from 19.3 mg/100g ww to 4280.2mg/100g ww, which significantly correlated with lipid content, food habits, and fish species. Fish consumption amount to meet the EPA+DHA recommended intake (250mg/day) revealed marine carnivorous fish, especially the abdominal muscle is the efficient source of EPA+DHA.Risk assessment of human exposure to fish collected from Shanghai market was conducted based on ADI and TDI. The results showed that HR value of three target pollutants were all less than 1, indicating these species of fish from Shanghai markets were relatively safe and the current fish consumption levels generally are unlikely to cause health risk to urban residents. In present study, we have also used benefit-risk quotient (BRQ) to assess the balance of benefits and risks of the co-ingestion of EPA+DHA and contaminants. According to the present study, when not considering absorption rate, the consumption amount of fish fillets needed to achieve the recommended EPA+DHA intake of 250 mg/d would not exert non-carcinogenic effects. However, this amount would bring carcinogenic risks in dorsal muscle of large yellow croaker in winter (DDTs-caused), dorsal and abdominal muscles of grass carp in winter (HCHs-caused), respectively. Although the muscles of freshwater fish had higher BRQ values in HCHs-caused carcinogenic risks, the actual daily consumption amounts needed to achieve BRQ limitation was much more than the average daily aquatic product consumption of in big Chinese cities, suggesting normal consumption of grass carp would be unlikely to cause carcinogenic risks. When not considering the absorption rate, PCBs were dominant in carcinogenic and carcinogenic effects; While considering the absorption rate, DDTs contribute most to carcinogenic risk and PCBs contribute the most to non-carcinogenic risk.Under the joint carcinogenic risk of PCBs, DDTs, and HCHs, when not considering the absorption rate, the maximum consumption dosage of fish muscle from Shanghai markets were 1.85～160.91g/d in winter and 1.9～163.83g/d in summer. The maximum consumption frequency were all below 16 times per month except tilapia dorsal muscle in winter and tail muscle in summer;While when considering absorption rate, the maximum consumption dosage of fish muscle were 4.05～714.56g/d in winter and 4～869.79g/d in summer. The monthly maximum consumption times were 0.54～95.82 times in winter and 0.54～116.64 times in summer. The maximum consumption frequency of river eel, large yellow croaker, grass carp dorsal and abdominal muscle in winter also below 16 times per month. Based on these valuable data, citizens should control the consumption of fish which consume frequency were below 16 times per month in order to avoid the joint carcinogenic risk caused by these target pollutants. |
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