Pollution Characteristics And Integrative Assessment Of Health Risk Of Three Heavy Metals In Aquatic Products From One City

Objectives To detect the contents of Cadmium（Cd）,Lead（Pb）and Mercury（Hg）in aquatic products sold in one city,analyze their pollution status and assess their pollution levels.Comprehensively assessing consumers’health risks due to taking heavy metals through aquatic products,to provide scientific basis and reasonable suggestions for relevant regulatory departments and consumers.Methods Samples were collected from some aquatic products selling places in one city from January to December in 2019.After sample pretreatment,the contents of Cd,Pb and Hg in the samples were determined according to the test methods in national standard.The test database was established,the detection rate and the violation rate were calculated by Excel 2019.The contents of heavy metals were described,and the differences of the detection rate and the violation rate between aquatic products were compared through chi-square test by SPSS 23.0.The single pollution level of each heavy metal and the comprehensive pollution level of three heavy metals in aquatic products were evaluated respectively by Pollution index（P_i）and Nemerow pollution index(P_Nemerow).Risk classification,Target hazard quotient（THQ）and Food safety index（IFS）were used to assess consumers’health risks due to taking heavy metals through aquatic product.Taking the heavy metal pollution level and the human health risk into consideration,the Analytic Hierarchy Process（AHP）was used to calculate the risk weights of heavy metal pollution in each kind of aquatic products to make comprehensive decision on the risks,so as to make the health risk assessment results more comprehensive.Results 1 The average contents of Cd,Pb and T-Hg in aquatic products are 0.1145 mg/kg,0.0457 mg/kg and 0.0219 mg/kg respectively.The highest contents of Cd and Pb appear in shellfish,which are 0.3552 mg/kg and 0.1148 mg/kg respectively.The highest T-Hg content appears in crustaceans,which is 0.0265 mg/kg.2 The total detection rate of Cd was 47.67%（635/1332）,and the difference of Cd detection rates among three kinds of aquatic products was statistically significant（χ²=690.484,P<0.001）.The Cd detection rates of shellfish,crustaceans and fish were 95.40%,70.66%and 13.10%respectively.The total detection rate of Pb was 19.89%（265/1332）,and there was significant difference in the detection rates of Pb among the three kinds of aquatic products（χ²=544.327,P<0.001）.The detection rates of Pb in shellfish,fish and crustaceans were 64.72%,5.51%and 5.09%respectively.The total detection rate of T-Hg was 71.55%（953/1332）,and there was significant difference in the detection rate of T-Hg among the three kinds of aquatic products（χ²=61.935,P<0.001）.The detection rates of T-Hg in crustaceans,shellfish and fish were 81.44%,81.29%and 61.90%respectively.3 The total violation rate of Cd was 1.58%（21/1332）,and the difference of the violation rates of Cd in three kinds of aquatic products was statistically significant（χ²=6.358,P=0.042）.The violation rates of Cd in crustaceans,shellfish and fish were 2.99%,1.53%and 0.89%respectively.There was only one sample with Pb exceeding the national standard,the total violation rate of Pb was 0.08%（1/1332）,and that of fish was 0.15%（1/672）.According to the limit standard of Me-Hg,there was no sample with T-Hg exceeding the national standard.4 For single heavy metal pollution,the P_i values of Cd,Pb and Hg in three kinds of aquatic products were all less than 0.2,which was clean level,however,the P_i values of Cd in crustaceans was 0.1984,which were close to the boundary between clean level and light pollution level.For the comprehensive pollution of three heavy metals,the P_Nemerowvalues of fish,shellfish and crustaceans were 0.0481,0.1422 and 0.1568 respectively,indicating that the comprehensive pollution level was at a safe level.5 The result of Risk classification method showed that the health risk level of dietary exposure to Cd,Pb and Hg caused by eating aquatic products is low risk（3～4 points）.The result of THQ method showed that the THQ values of Cd,Pb and Hg in three kinds of aquatic products were all far less than 1,and the HI value was less than 1,too.The result of IFS method showed that the average IFS values of Cd,Pb and Hg in three kinds of aquatic products were all less than 1,but there was a fish sample whose IFS value was more than 1（1.3907）.The total IFS values of three kinds of aquatic products were all less than 1.According to the comprehensive evaluation results based on AHP,the order of risk weight was fish（0.5109）>crustaceans（0.3070）>shellfish（0.1820）.Conclusions 1 The pollution status of Cd,Pb and T-Hg of the three kinds of aquatic products is different.Shellfish are mainly polluted by Cd and Pb,crustaceans are mainly polluted by T-Hg,while fish are less polluted by heavy metals.2 The violation rates of Cd,Pb and T-Hg of the three kinds of aquatic products are different.There all have samples with Cd content exceeding the standard in three kinds of aquatic products,the violation rate of Cd is highest in crustaceans and lowest in fish.There is only one fish sample with Pb content exceeding the standard.According to the national limit standard of Me-Hg,the T-Hg content does not exceed.3 The comprehensive pollution level of the three heavy metals in the three kinds of aquatic products is safe level,which indicates that the pollution situation of heavy metals is generally light.Although the single heavy metal pollution levels of Cd,Pb and Hg are all on the clean level,the Cd pollution in crustaceans is close to the light pollution level.4 The food safety of aquatic products sold in the city is generally good,and the health risk of Cd,Pb and Hg pollution is relatively low.Consumers are less likely to have Cd,Pb and Hg exposure risk due to eating the three kinds of aquatic products in this study.5 The comprehensive assessment result shows that fish has the highest risk weight,followed by crustaceans,and shellfish’risk weight is lowest.Figure 9;Table 27;Reference 126...