| Perfluoroalkyl acids?PFAAs?are an emerging class of persistent organic pollutants?POPs?.The hydrogen atom in the organic carbon chains are completely replaced by the fluorine atom.Due to their high thermal stability,surface activity,and water-,oil-repellent properties,they have been employed in a variety of industrial and commercial products.PFAAs have the characteristics of high toxicity,biological accumulation and biological magnification,which made them transfer and accumulate along with the food chain,thus the human at the top of the food chain will be seriously threatened.Many studies have showed that PFAAs exposure in animal derived foods were much higher than those in other foods.At present,the researches of PFAAs was mainly focused on water,air and human blood in China.However,the exposure values of PFAAs in meat samples was lacking.Especially in Xinjiang,the pollution level and health risk assessment of PFAAs in meat products were rarely reported.In this study,the method of solid phase extraction?SPE?combined with high performance liquid chromatography tandem mass spectrometry?SPE-HPLC-MS/MS?was used to analyze the concentrations of PFAAs in meat samples.A total of 541 muscle and liver samples?cattle and sheep?were collected from22 cities of Xinjiang from August 2015 to December 2016,and then the occurrence,distribution,sources analysis,and risk assessment of PFAAs in the samples of cattle and sheep were carried out.The main results are as follows:?1?All 13 target compounds were detected in Xinjiang,and mean concentration of the total PFAAs was 0.043 ng/g?detection rate:53%?in muscle and 1.994 ng/g?96%?in liver.Overall,the average levels for PFAAs were comparative or lower than that reported in previous studies.The concentrations of PFAAs in liver were higher than those in muscle;in addition,the exposure levels of PFAAs from sheep samples were significantly higher than those in the samples form cattle.Medium-chain PFAAs were the dominant,and perfluorooctanoic acid?PFOA?,perfluorooctane sulfonate?PFOS?and perfluoroundecanoic acid?PFUdA?were considered to be the major pollutants with the detection frequency of higher than 70%.Interestingly,the levels of PFPeA?detection rate:83%;the highest concentration:1.273 ng/g?and PFHpA?78%;2.626 ng/g?in liver samples from sheep was significantly higher than that in beff liver?PFPeA:3%,0.734 ng/g;PFHpA:39%,0.803 ng/g?.Among the three regions of Xinjiang,the differences of PFAA profiles do exist,and the northern Xinjiang showed the highest levels than the southern and eastern Xinjiang.The regional distribution differences were related to many factors,such as industrial/agricultural level and environmental climate characteristics in each region.?2?Samples from Urumqi showed the highest mean levels of total PFAAs?13.103 ng/g?,which was over 10-fold higher than that in Toksun?1.213 ng/g,the least polluted city?.When comparing the 22 cities of Xinjiang,the top 5 cities in the PFAA pollution level were:Urumqi>Karamay>Changji>Korla>Shihezi;the 5 cities with the lowest pollution levels were Tacheng,Turpan,Hotan,Aletai,and Toksun.Among the samples from different cities,there were significant differences in the detection type,detection rate and concentration of PFAAs.The relationship between the concentration of PFAAs and the GDP vulue was studied in each city,and the results showed that there was a significant positive correlation between these two factors especially in the samples from eastern Xinjiang.?3?Direct sources of PFAAs pollution in muscle and liver samples from Xinjiang included drinking water,food intake,air breathing,and inhaling dust of the cattle and sheep;industrial production?such as petroleum industry,textile industry?,the release of agricultural production?such as pesticide and fertilizer?,and the long distance of PFAAs with atmospheric currents to Xinjiang were the indirect PFAAs sources.In addition,feed intake aggravated the pollution level of PFAAs in muscle and liver.Furthermore,the average daily intake and hazard ratios?HR?of PFOS,PFOA,and PFAAs were calculated in different groups?region,urban/rural,gender,ethnicity and age?basing on the PFAA concentration.The highest HRPFAAsFAAs value obtained was 2.203×10-3,which is far less than 1,indicating that muscle and liver consumption posed no immediate harm to local residents.The results in this study can contribute to China's relevant departments and researchers to understand the concentration and pollution status of PFAAs in the sale of beef and mutton from Xinjiang.In addition,it also can provide data support for the source analysis and risk assessment,and provide a scientific basis for PFAAs pollution sources control. |
PDF Full Text Request