南寧市場及邕江魚類Hg含量研究
發(fā)布時間：2018-07-25 12:29
【摘要】：汞作為重金屬元素對生物具有危害性,甲基汞對生物危害性更大,水環(huán)境中的汞通過生物富集和逐級放大,在魚體內大量富集。魚類則是人的食物來源之一,過高的魚汞含量可使人體造成汞暴露,危害人體健康。民以食為天,隨著社會的進步和經濟的發(fā)展,食品安全問題越來越引起人們的高度關注。南寧作為南方城市,魚類消費量較大,因此對于市售及邕江魚類進行汞含量水平進行調查并對通過食用途徑汞暴露的安全進行評價有重要的價值。本文以南寧市邕江及各大農貿市場作為研究區(qū)域,采用實地調查與實驗室分析相結合的方法,運用U.S.EPA 7473 Method并結合DMA-80直接測汞儀,對南寧市10個大型農貿市場的6種淡水魚類、邕江7個采樣點的12種魚類及11個沿江地點的沉積物中的總汞進行含量測定,完善了實驗過程及質量控制,并對魚類食用風險安全及沉積物潛在生態(tài)風險進行了評價。結果表明:1.市場魚類肌肉總汞含量范圍在3.15ng/g~79.71ng/g之間,平均值為19.35ng/g,中值為11.64ng/g。邕江魚類肌肉總汞含量范圍在2.10ng/g~330.56ng/g之間,平均值為44.18ng/g,中值為29.53ng/g。邕江魚類總汞含量略高于市場魚類,兩者汞含量中值都低于平均值,表明大部分魚類汞含量水平較低,且兩者含量都低于國家規(guī)定的食品安全限量中淡水魚類總汞含量500ng/g,魚肉總汞含量處于安全范圍內。2.邕江水環(huán)境中不同營養(yǎng)層級魚類汞含量排序為:草食性雜食性濾食性魚類。3.根據體長、重量和含量的相關性分析表明大部分魚類無顯著性相關,市場魚類只有羅非魚體長與魚汞含量呈負相關;邕江魚類禾花鯉體長與體重與魚汞含量呈正相關,羅非魚體重與魚汞含量呈負相關。4.根據單因子指數法、WHO和FAO每日可接受攝入量PTDIs對魚肉食用安全進行評價,表明市場及邕江大部分魚類對人體潛在危害很小,而敏感人群應盡量避免過多攝入鳙魚、鰱魚及藍刀魚。5.邕江河流沉積物汞含量空間分布特征為東西低,中間高,中游河段流經城區(qū),各類污染物由支流匯入邕江,汞含量以水塘江及八尺江匯入邕江處較高。運用潛在生態(tài)指數法,以珠江流域沉積物汞含量平均值作為依據,表明汞在邕江沉積物中的潛在生態(tài)風險較小,但水塘江入邕江口沉積物中的汞負荷需要引起足夠的重視�？傮w來說,市售魚類及邕江水環(huán)境中的汞負荷較小,魚體內汞含量低于國家限定標準,在可食用安全范圍內。通過對魚類產地來源探討,可否在食品安全方面建立一種產地回溯的機制,當食品質量安全出現問題時,可以通過實驗分析手段并結合其它方法來確定受污染食品的來源。
[Abstract]:Mercury, as a heavy metal element, is harmful to organisms, and methylmercury is more harmful to organisms. Mercury in water environment is enriched in large quantities in fish by bioenrichment and step by step amplification. Fish is one of the sources of human food, too high content of fish mercury can cause mercury exposure to human health. With the development of society and economy, people pay more and more attention to food safety. As a southern city, Nanning has a large consumption of fish, so it is of great value to investigate the mercury content of fish sold on the market and Yongjiang River and to evaluate the safety of mercury exposure through food route. In this paper, using Yongjiang River and major farmers' markets in Nanning as the research area, using the method of field investigation and laboratory analysis, using U.S.EPA 7473 Method and DMA-80 direct mercury analyzer, 6 kinds of freshwater fish in 10 large-scale farmers' markets in Nanning were studied. The contents of total mercury in the sediments of 12 species of fish and 11 sites along the Yongjiang River were determined, the experimental process and quality control were improved, and the safety of fish edible risks and potential ecological risks of sediments were evaluated. The result shows that 1: 1. The total mercury content in fish muscle is in the range of 3.15ng/g~79.71ng/g, with an average of 19.35 ng / g and a median value of 11.64 ng / g. The total mercury content in the muscle of Yongjiang fish was in the range of 2.10ng/g~330.56ng/g, with an average of 44.18 ng / g and a median value of 29.53 ng / g. The total mercury content of the fish in Yongjiang River was slightly higher than that of the market fish, and the median mercury content of both fish was lower than the average value, which indicated that the mercury content of most fish was low. Both contents are lower than the total mercury content of freshwater fish (500ng / g), and the total mercury content of fish meat is within the safe range of .2.The total mercury content of freshwater fish is lower than the national food safety limit of 500ng / g. The order of mercury content in different trophic levels of fish in Yongjiang River was: herbivorous, omnivorous, filter feeding fish. According to the correlation analysis of body length, weight and content, there was no significant correlation between body length and mercury content in most fishes, only tilapia had a negative correlation with mercury content in fish in the market, and there was a positive correlation between body length and body weight and mercury content in fish in Yongjiang River. There was a negative correlation between body weight and mercury content in tilapia. According to the single factor index method and the daily acceptable intake of FAO and PTDIs, the food safety of fish was evaluated. The results showed that most of the fish in the market and the Yongjiang River had little potential harm to human body, and the sensitive population should avoid excessive intake of bighead carp as far as possible. Silver carp and blue saber. The spatial distribution of mercury content in the sediments of the Yongjiang River is low in the east and west, high in the middle. The middle reaches of the river flow through the urban area, and all kinds of pollutants flow from the tributaries to the Yongjiang River. The mercury content in the Yongjiang River is higher in the reservoirs and the Bazhijiang rivers. Based on the average mercury content in sediments of the Pearl River basin, the potential ecological risk of mercury in the sediments of Yongjiang River is relatively small, but the mercury load in the sediments from the Yongjiang River estuary should be paid more attention to. In general, the mercury load in the market fish and Yongjiang river water environment is relatively small, and the mercury content in fish is lower than the national standard, which is within the safe range of edible. By discussing the origin of fish, we can establish a kind of backtracking mechanism in food safety. When food quality and safety problems occur, we can determine the source of contaminated food by means of experimental analysis and other methods.
【學位授予單位】：廣西師范學院
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TS254.7;X56
本文編號：2143827
[Abstract]:Mercury, as a heavy metal element, is harmful to organisms, and methylmercury is more harmful to organisms. Mercury in water environment is enriched in large quantities in fish by bioenrichment and step by step amplification. Fish is one of the sources of human food, too high content of fish mercury can cause mercury exposure to human health. With the development of society and economy, people pay more and more attention to food safety. As a southern city, Nanning has a large consumption of fish, so it is of great value to investigate the mercury content of fish sold on the market and Yongjiang River and to evaluate the safety of mercury exposure through food route. In this paper, using Yongjiang River and major farmers' markets in Nanning as the research area, using the method of field investigation and laboratory analysis, using U.S.EPA 7473 Method and DMA-80 direct mercury analyzer, 6 kinds of freshwater fish in 10 large-scale farmers' markets in Nanning were studied. The contents of total mercury in the sediments of 12 species of fish and 11 sites along the Yongjiang River were determined, the experimental process and quality control were improved, and the safety of fish edible risks and potential ecological risks of sediments were evaluated. The result shows that 1: 1. The total mercury content in fish muscle is in the range of 3.15ng/g~79.71ng/g, with an average of 19.35 ng / g and a median value of 11.64 ng / g. The total mercury content in the muscle of Yongjiang fish was in the range of 2.10ng/g~330.56ng/g, with an average of 44.18 ng / g and a median value of 29.53 ng / g. The total mercury content of the fish in Yongjiang River was slightly higher than that of the market fish, and the median mercury content of both fish was lower than the average value, which indicated that the mercury content of most fish was low. Both contents are lower than the total mercury content of freshwater fish (500ng / g), and the total mercury content of fish meat is within the safe range of .2.The total mercury content of freshwater fish is lower than the national food safety limit of 500ng / g. The order of mercury content in different trophic levels of fish in Yongjiang River was: herbivorous, omnivorous, filter feeding fish. According to the correlation analysis of body length, weight and content, there was no significant correlation between body length and mercury content in most fishes, only tilapia had a negative correlation with mercury content in fish in the market, and there was a positive correlation between body length and body weight and mercury content in fish in Yongjiang River. There was a negative correlation between body weight and mercury content in tilapia. According to the single factor index method and the daily acceptable intake of FAO and PTDIs, the food safety of fish was evaluated. The results showed that most of the fish in the market and the Yongjiang River had little potential harm to human body, and the sensitive population should avoid excessive intake of bighead carp as far as possible. Silver carp and blue saber. The spatial distribution of mercury content in the sediments of the Yongjiang River is low in the east and west, high in the middle. The middle reaches of the river flow through the urban area, and all kinds of pollutants flow from the tributaries to the Yongjiang River. The mercury content in the Yongjiang River is higher in the reservoirs and the Bazhijiang rivers. Based on the average mercury content in sediments of the Pearl River basin, the potential ecological risk of mercury in the sediments of Yongjiang River is relatively small, but the mercury load in the sediments from the Yongjiang River estuary should be paid more attention to. In general, the mercury load in the market fish and Yongjiang river water environment is relatively small, and the mercury content in fish is lower than the national standard, which is within the safe range of edible. By discussing the origin of fish, we can establish a kind of backtracking mechanism in food safety. When food quality and safety problems occur, we can determine the source of contaminated food by means of experimental analysis and other methods.
【學位授予單位】：廣西師范學院
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TS254.7;X56
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