title: Seasonal variation of metals in seawater, sediment, and Manila clam Ruditapes philippinarum from China.
abstract: Concentrations of trace metals (Cu, Pb, Zn, Cd, Cr, Hg, and As) were determined for the first time in seawater, sediment, and Manila clam from Deer Island, Liaoning Province, China. The seawater, sediment, and clam samples were collected seasonally at three clam farming sites around Deer Island during 2010-2011. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the seawater samples were 4.16, 0.72, 5.88, 0.45, 2.51, 0.03, and 1.02 μg/l, respectively. The seasonal variations of trace metals in seawater showed a significant difference in the concentrations of Cu, Pb, Zn, Hg, and As among seasons. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the sediment samples were 6.43, 13.80, 53.08, 1.10, 36.40, 0.05, and 4.78 mg/kg dry weight, respectively. Trace metal concentrations in sediment seasonally varied significantly except for Cd and Hg. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the clam samples were 11.28, 0.61, 92.50, 0.58, 3.98, 0.03, and 1.98 mg/kg dry weight, respectively. Concentrations of Cu, Zn, Cd, Cr, and As in Manila clam showed marked seasonal fluctuations with significant difference. Cu and Zn were the metals with the highest mean biosediment accumulation factor values in Manila clam. Besides, significant correlations for the concentrations of Cu and Zn relative to their concentrations in sediment were also found. Such differences in regression analyzes may be explained by differential bioaccumulation of essential and xenobiotic metals. Concentrations of trace metals in Manila clam did not exceed the maximum established regulatory concentrations for human consumption. Moreover, the calculations revealed that the estimated daily intake values for the examined clam samples were below the internationally accepted dietary guidelines and the calculated hazard quotient values were well less than 1, thus strongly indicating that health risk associated with the intake studied metals through the consumption of Manila clam from Deer Island was absent.
authors: College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, People's Republic of China.
authors: Liqiang
authors: L
authors: Zhao
authors: Feng
authors: F
authors: Yang
authors: Yuan
authors: Y
authors: Wang
authors: Zhongming
authors: Z
authors: Huo
authors: Xiwu
authors: X
authors: Yan
mesh_terms: D000818:Animals; D001151:Arsenic / Q000032:analysis / Q000493:pharmacokinetics; D049872:Bivalvia / Q000737:chemistry* / Q000378:metabolism; D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis* / Q000493:pharmacokinetics; D012621:Seasons; D012623:Seawater / Q000737:chemistry*; D013054:Spectrophotometry, Atomic; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000493:pharmacokinetics
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D001151:Arsenic