Contamination Status And Risk Assessment Of N-Nitrosamines In Qingdao Dried Aquatic Products

Objectives: To establish a method with high sensitivity,accuracy and precision to determine the content of 9 N-nitrosamines(NAs)in dried aquatic products,analyze their contamination characteristics,and on this basis,combined with dietary consumption data to assess the health risks caused by the ingestion of nitrosamines in dried aquatic products among residents in Qingdao.This study aims to enrich the dietary exposure data of nitrosamines,and provide scientific basis and reasonable suggestions for consumers’ purchase and contamination supervision of relevant administrative departments.Method:1.Sample collection and processing: A total of 300 dried aquatic products,including 97 fish products,50 squid products,123 shrimp products and 30 sea cucumber products,were collected offline and online by random sampling method from November 2021 to June 2022.The 100 grams of edible portion was taken from the whole sample and pulverized,numbered and stored at minus 20 degrees Celsius.2.Method of determination: The samples were extracted by steam distillation and detected by gas chromatography-tandem mass spectrometry(GC-MS/MS).The retention time was qualitative and the internal standard method was quantitative.3.Method evaluation: The linearity,accuracy and precision of the method were verified,the linear range,correlation coefficient,the limit of detection and the limit of quantitative were determined,and the recoveries and relative standard deviation were calculated to carry out method evaluation.4.Data processing and statistical analysis: The Microsoft Excel 2019 was used for data collation,and SPSS26.0 was used for statistical analysis,by using the Chi-square test and Kruskal-Wallis test to compare the groups.5.The method of health risk assessment: The model of cancer risk assessment recommended by the USEPA and margin of exposure(MOE)were used to assess the health risks of nitrosamines from ingestion of dried aquatic products.Meanwhile,the changes in health risks with the application of different recommended limits were calculated.Results:1.Method evaluation: Nine nitrosamines were completely separated in GC-MS/MS with detection limits of 0.20–0.30μg/kg and quantitation limits of 0.72-0.90μg/kg.The correlation coefficients were in the range of 0.9991–0.9999.The recoveries at low,middle and high spiked levels were 85.3%–100.6%,88.8%–107.4% and 87.6%–101.4%,respectively.The range of relative standard deviation(RSD)at three levels was 1.0–2.7%.The method showed good linearity,accuracy and precision,and could be applied for analysis.2.Content of nitrosamines in dried aquatic products: Six nitrosamines were detected in dried aquatic products in Qingdao,including NDMA,NDEA,NDBA,NDPh A,NMor Ph and NPYR,whose content range was ND– 318、ND–81.1、ND–40.6、ND–6.52、ND–34.2、ND–7.61μg/kg(ND means not detected),respectively.The over-standard rate of NDMA reached 35%,and the highest content of NDMA was nearly 80 times higher than the limit.The contamination in NDEA and NDBA was also serious.The highest average content of nitrosamines was NDMA(9.21μg/kg),followed by NDBA,NDEA,NDPh A,NMor Ph and NPYR.The content of NDMA was 3 times that of NDBA and 1 order of magnitude higher than that of other nitrosamines.NDMA dominated the total nitrosamines.3.Contamination characteristics of nitrosamines in dried aquatic products: The detection rate of nitrosamines in squid products and shrimp products was the highest,reaching 100%.The detection rate of NDMA was the highest in squid and shrimp products,followed by sea cucumber and fish products.The detection rate of NDMA was identical with the total detection rate of nitrosamines.The detection rate of NDEA in squid,shrimp and sea cucumber products was above 90%,while the detection rate of NDEA in fish products was much lower.The detection rates of NDBA in shrimp and sea cucumber products were 94.3% and 93.3%,respectively,higher than those in fish and squid products.For NMor Ph,the detection rate of squid and shrimp products was the highest,both of which were over 70%,while the detection rate of fish and sea cucumber products was low.The order of detection rate of NDPh A in four kinds of dried aquatic products was shrimp>fish>squid>sea cucumbers.There was no significant difference in the detection rate of NPYR in the four dried aquatic products.The average content of nitrosamines in fish products was higher,followed by squid,shrimp and sea cucumber products.The content of NDMA was the highest in fish,squid and sea cucumber,and the content of NDBA in shrimp was slightly higher than that of NDMA.NDMA,NDBA and NDEA were the main nitrosamines in four kinds of dried aquatic products,while the content of the other three kinds of nitrosamines was at a very low level.4.Health risks of residents ingesting dried aquatic products in Qingdao: The average cancer risk of NAs in Qingdao dried aquatic products ranged from 2.91×10-10 to 3.53×10-5.NDMA had the highest risk,with the range of 9.54×10-6–1.22×10-3.The cancer risk of NDEA were similar to that of NDMA.For NDMA,NDEA and NDBA,the cancer risks estimated by the average,P95 and maximum were 3.53×10-5、1.17×10-5 and 1.22×10-6,higher than the safety acceptable level,especially the cancer risk correspond to the maximum content for NDMA was serious.NDMA,NDEA and NDBA were the most important ones among the nine NAs,which can be considered to pose a potential cancer risk to residents in Qingdao.The risks of NMor Ph,NDPh A and NPYR were only slightly higher in the high-exposure population,which can be considered to pose no risk to the residents in Qingdao.When ingesting high levels of NDMA,the MOE was less than 10000,which has public health significance and needs to be paid attention to by risk management departments.Conclusion:1.The method established in this study was used to detect nitrosamines in dried aquatic products in Qingdao.The nitrosamines detected were mainly NDMA,NDBA,NDEA,NDPh A,NMor Ph and NPYR,and NDMA exceeded the limit seriously.NDMA dominated the total nitrosamines,followed by NDBA and NDEA.Fish products showed the highest content of nitrosamines,and squid and shrimp products had the highest detection rate of nitrosamines.The content and detection of nitrosamines in different kinds of dried aquatic products were characteristic.2.The average cancer risk of N-nitrosamine in Qingdao dried aquatic products ranged from 2.91×10-10 to 3.53×10-5.NDMA,NDEA and NDBA were considered to pose potential cancer risk to the Qingdao residents.It is necessary to control the cancer risk of dried aquatic products.It is suggested to reduce the consumption of dried aquatic products by Qingdao residents,supervise and standardize the production to ensure product quality,improve the processing technology,and degrade or block the formation of nitrosamines.