Env_tox_lecture5_2010.pptVIP

Lined copper cooking utensils炊具 can safely be used for most foods. Speciation of Copper Copper complexes weakly with Chloride But strongly with humics腐殖质 High toxicity of Cu2+ seen in laboratory tests with aquatic animals may not apply equally in the natural environment Symptoms of Copper intoxication Chronic exposure to copper in dust, fumes Nasal ulceration and bleeding Various damage to lung Discoloration of the skin Oral ingestion Nausea, vomiting, diarrhea and intestinal cramps Disrupted liver and kidney functions ? jaundice黄疸 and cirrhosis肝硬变 Hemolytic anemia and death Nickel镍 Common element Resistant to corrosion腐蚀 ? industrial and consumer uses US and Canadian 5-cent pieces are 25% Ni and 75% Cu. Nickel compounds are unusually toxic and carcinogenic Inhalation of Ni 3S2 and NiO and Ni ? nasal and pulmonary cancer Contact dermatitis Contact the nickel coin ? rash in sensitive individual May be responsible for a decline in marine life Symptoms for Nickel intoxication Hypersensitivity过敏症 Nickel itch ? redness of hands ? eczema湿疹 ? lichenification苔癣样硬化 (scaling) Cancer ?mortality rates from cancers of the lungs and nasal cavities for Nickel refining workers Exposure to nickel sulfide and nickel oxide ? ?malignant tumors恶性肿瘤 in larynx, kidney, prostate前列腺 or stomach Respiratory disorders Exposure to nickel carbonyl ? interstitial pneumonitis Cadmium镉 (Cd) Toxic pollutants – used primarily for protective plating, in solder, in Ni-cad batteries Occurs closely associated with zinc Vehicle tires wear down ? major source of Cd pollution Occurs at relatively high levels in cigarette smoke Symptoms for Cd intoxication Acute toxicity Via respiratory route ? lung edema, fibrosis Dietary intake ? painful sites spread all over the body, difficulty in walking, bone fractures Chronic and low exposure Cd bound to metallothionein金属硫蛋白 released from the liver ? move to kidney via blood ? Cd-metallothionein accumulates in tubular cells ? affect proximal tubule’s reabsor