5790

5405

كارشناسي ارشد

آلودگي هاي محيط زيست

اصفهان: دانشگاه صنعتي اصفهان، دانشكده منابع طبيعي

1389

دوازده،79ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

نوراله مير غفاري، نصراله محبوبي صوفياني

ولي حسيني

3/2/89

مجيد افيوني، حسين مرادي

مهندسي منابع طبيعي

ID5405

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Assessment of the Mercury Contamination in the Southern Coastal Waters of the Caspian Sea Mazandaran Iran Using Golden Mullet Liza auratus and Kutum Rutilus frisii kutum as a Bioandicator Index Seyed Mehdi Hosseini s m hosseini@na iut ac ir Date of submission November 15 2010 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree MSc Language Persian Abstract Mercury is the most toxic heavy metal in the aquatic ecosystems which originates both from natural and industrial resources and is ultimately deposited in sediments as methyl mercury Due to its high dependence on protein sulfhydryl groups this metal is quickly transferred through the food chain and accumulated in organisms The high toxicity of mercury and its biomagnification characteristic necessitates the temporal and spatial environmental monitoring of mercury Mullet Liza auratus and kutum Rutillus frisii kutum are two species that their habitat and feeding habits cause them to accumulate significant amounts of heavy metals in their tissues and this not only affects fish health but also human health as the main consumer To determine the concentration of mercury contamination in the sediments and its accumulation in the muscle and liver of mullet and kutum 12 stations were randomly assigned in the central coasts of southern Caspian Sea and the samples were obtained from sediment and fish species Standard analytical methods used to determine mercury concentration in both sediments and fish Results showed that in sediments the average concentration of mercury is below the standard level at all stations 0 15 $g of sediment which represents the low levels of mercury contamination in the coastal province of Mazandaran The average concentration of mercury in kutum muscle and liver was respectively 0 112 and 0 123 $ 0 382 and 0 395 $ ght and for mullet was 0 137and 0 162 $ $ respectively The difference in mercury concentrations observed in the two species could possibly be attributed to the differences in ecological requirements nutrition metabolism and different habitats In both species mercury concentration was less than the allowable amount for human consumption 0 3 0 5 0 5 and 1 g of wet weight determined by USEPA WHO FAO and the FDA respectively The comparison between the different stations showed that fishes of west coast of province had higher concentration of mercury than the east coast In order to assessing the human health risks of kutum and mullet consumption the allowable level the daily intake of mercury by humans and also HQ Hazard Quotient index were obtained HQ Index for both species was about 0 4 and 0 5 respectively According to the results of our study consumption of 51g of mullet and 62 g of kutum per day consumption permitted rate is safe The daily and weekly mercury uptake for Iranian consumers according to FAO the amount consumed per capita is lower than the guide values PTWI and PTDI provided by WHO USEPA and JECFA Therefore the consumption of the studied fish muscle is not a serious threat to the consumer health Key Words Mercury Caspian Sea Sediment Organic matter Liza auratus Rutillus frisii kutum Risk assessment

نوراله مير غفاري، نصراله محبوبي صوفياني

ولي حسيني

مجيد افيوني، حسين مرادي