Distribution And Health Risk Assessment Of Heavy Metals In Fish Of Taiyuan Segment Of Fenhe River

In order to understand the status of fish resources,distribution of heavy metals in fish and pollution levels in the Taiyuan Segment of Fenhe River,in this study,fish samples were collected from three sampling points in the upstream,middle reaches and downstream of the Taiyuan Segment of Fenhe River.The indexes of species composition,quantity,length,body weight,fatness and dominance of the catches were analyzed.The heavy metals contents in different tissues and water of six main fishes in Taiyuan Segment of Fenhe River were detected,Pollution level in different tissues of six main fishes were evaluated by single factor pollution index(Pi)and comprehensive pollution index(MPI).The health risk in edible muscle tissue of 6 species of fishes were assessed by the target hazard quotient method(THQ).The results were as follows:(1)In this study,fish samples,belonging to 2 orders and 3 famili es10 genera,were collected at nine sampling points,354 in total.The largest number of fishes is in the Cypriniformes,9 species accounting f or 90% of the total species.The smallest number of fishes is in the P erciformes,accounting for 10% of the total species.By analyzing the d ominance(IRI)of these catches,the results showed that there were six main species and four common species.The main species includes: Pse udorasbora fowleri,Pseudoperilampus lighti,Hemiculter leucisculus,Cte nopharyngodon idellus,Abbottina rivularis and Misgurnus anguillicauda tus;the common species includes: Carassius auratus,Chinese hooksnou t,Eucyclogous newberryi,Cyprinus carpio.(2)In this study,the length and weight of all the catches were analyzed,and it was found that the largest length and body weight of individual were Ctenopharyngodon idellus,and the smallest length and body weight of individual were Pseudoperilampus lighti.The relationship between length and weight of four species of fish with large sample volume,includingPseudorasbora fowleri,Pseudoperilampus lighti,Hemiculter leucisculus,and Abbottina rivularis,was analyzed,which showed that Pseudorasbora fowleri and Hemiculter leucisculus were in isometric growth,Pseudoperilampus lighti and Abbottina rivularis negative allometric.The analysis of the correlation between length,body weight and fatness of the above four fishes suggested that there wasn't correlation between body length and fatness,but there was a significant correlation between body weight and fatness of the Pseudorasbora fowleri and Abbottina rivularis,a significant positive correlation between length,body weight and fatness of the Hemiculter leucisculus,and a significant negative correlation between length,body weight and fatness of the Pseudoperilampus lighti.The results showed that two species of fishes grew well.(3)In this study,the water samples of heavy metals in Taiyuan Segment of Fenhe River were detected by inductively coupled plasma mass spectrometry(ICP-MS).The results showed that Cd,As and Pb were all detected in the upstream,middle and downstream water samples,and only Hg was detected in the middle water samples.Through statistical analyzed,it is found that the contents of Hg,Cd,As and Pb in the middle reaches of Taiyuan Segment of Fenhe River are higher than those in the downstream and upstream.By comparing the contents of different heavy metals in the same reach,it is found that the upstream and downstream are As > Cd > Pb,and the middle reaches are As >Cd > Pb > Hg.(4)In this study,the heavy metals contents in the muscles,gills and liver tissues of 6 main species of fishes(Pseudorasbora fowleri,Pseudoperilampus lighti,Hemiculter leucisculus,Ctenopharyngodon idellus,Abbottina rivularis and Misgurnus anguillicaudatus)in Taiyuan Segment of Fenhe River were detected by inductively coupled plasma mass spectrometry(ICP-MS).The results showed that the content over standard of As in the gill of Misgurnus anguillicaudatus was higher than the China's national tolerance limit,and the content of Hg,Cd,As and Pb in the gill of other fish was lower than the China's national tolerance limit.In addition,the heavy metals in the abovetissues of 6 species were different,and there were also differences in the distribution of heavy metals in different tissues and organs of the same species.The accumulations of four heavy metals in different tissues of the 6species of fishes were generally the highest in the liver and the lowest in the muscles.(5)Through the analysis of the index Piof the muscle tissue,gill and liver of the 6 main species of fishes in the Taiyuan Segment of Fenhe River,the results showed that different tissues of the 6 species of fishes were polluted with Hg,Cd,As and Pb heavy metals to different degrees,among which As was the main pollution element in different tissues of the 6 species of fishes.The comparison and analysis of the index MPI of heavy metals in different tissues of the above 6 kinds of fishes showed that the muscle tissues of the other 5 kinds of fishes didn't exist pollution except for the Misgurnus anguillicaudatus.The gills and livers of 6 kinds of fishes were pollution-free.Among them,the index MPI in the above different tissues of Misgurnus anguillicaudatus were higher than those of other fish,indicating that Misgurnus anguillicaudatus was seriously polluted by heavy metals.By evaluating the potential health risks of heavy metals in edible muscle tissues of 6 kinds of fishes,the results showed that the THQ value of 6 kinds of fishes was all less than 1,it indicated that the above 6 kinds of fishes are safe to eat and have no obvious risk to human health.