Assessment of bioavailability in aquatic(sediment) for metalsKey words : sediment ; heavy metal ;transformation ; bioavailability
the assessment system and existing forms in sediments for metals;influence of metal Toxicity in sediments;the biological toxicity of metals in sediments;the principle of metal detoxification for aquatic animalsConclusion and prospect
The assessment system and existing forms in sediments for metalsthe assessing methods raised from the perspective of sedimentation;metal Forms in Sediment and influence to aquatic organisms;
沉积物中重金属形态及对水生生物的影响metal Forms in Sediment and influence to aquatic organisms① 水溶性和可交换态； water-extractable phase and exchangeable forms② 碳酸盐结合态； Carbonate combination state③ 铁锰氧化物结合态； Iron manganese oxide combination patterns④ 有机质、硫化物结合态； Organic and Sulfide combination state⑤ 残余态 ; residual forms
influence extent ： Ion exchange state> Carbonate combination state>Ironmanganese oxide combination patterns> Organic and Sulfide combination state
The influence factors of metal Toxicity in sediments metal forms influence on the biological toxicity ; the relationship between Gap water ligand and metal toxicity; the relationship between Surface oxidation of the sediments and metal toxicity;
the biological toxicity of metals in sediments (a) Effects Range Low (ERL) and Effects Range Median (ERM) Screening Levels for Marine Sediments and Acute/Chronic Marine Water Quality Criteria are Included (b) Marine water quality values are for inorganic mercury. The chronic value of methylmercury is 0.025μg/L.
the principle of metal detoxification for aquatic animals 4.1 超氧化物歧化酶 (SOD) 4.1 谷胱甘肽（ GSH ） 4.2 过氧化氢酶 4.3 金属硫蛋白 (MT)
Conclusion and prospect 1. Based on the Researches on the total amount of metals in sediments, themetal forms’ analysis is very important. 2. The development of advanced analysis methods and testing instrument,accurate determination of trace elements’ chemical forms in the environment willbe the main development direction. 3. Strengthening the bioaccessibility researches on metal, set up a assessmentstandard.