| hazards summary | Cadmium is a natural element in the earth's crust. It is usually found as a mineral combined with other elements such as oxygen (cadmium oxide), chlorine (cadmium chloride), or sulfur (cadmium sulfate, cadmium sulfide). All soils and rocks, including coal and mineral fertilizers, contain some cadmium. Most cadmium used in the United States is extracted during the production of other metals like zinc, lead, and copper. Cadmium does not corrode easily and has many uses, including batteries, pigments, metal coatings, and plastics.The main sources of cadmium in the air are the burning of fossil fuels such as coal or oil and the incineration of municipal waste. The acute (short-term) effects of cadmium in humans through inhalation exposure consist mainly of effects on the lung, such as pulmonary irritation. Chronic (long-term) inhalation or oral exposure to cadmium leads to a build-up of cadmium in the kidneys that can cause kidney disease. Cadmium has been shown to be a developmental toxicant in animals, resulting in fetal malformations and other effects, but no conclusive evidence exists in humans. An association between cadmium exposure and an increased risk of lung cancer has been reported from human studies, but these studies are inconclusive due to confounding factors. Animal studies have demonstrated an increase in lung cancer from long-term inhalation exposure to cadmium. EPA has classified cadmium as a Group B1, probable human carcinogen.Inhaling high concentrations of cadmium fume can cause acute pneumonitis. At levels common in factories in the past, cadmium accumulated in the kidneys of workers and caused chronic renal injury with elevated urine cadmium and protein levels. Cadmium levels in adult nonsmokers, not occupationally exposed are <0.5 ug/100 ml whole blood and <2 ug/g creatinine in urine. In animal studies, high doses increase fetal loss and birth defects. Cadmium fume is associated with airway obstruction and emphysema. The proximal tubule is the primary target of cadmium-induced kidney injury, but at higher exposures, the glomeruli can also be affected. . . . Measurement of cadmium in urine is the most widely used biological measure of chronic exposure to cadmium. However, it may provide no information on integrated exposure during the first year of exposure. See Cadmium oxide.The major hazards encountered in the use and handling of cadmium stem from its toxicologic properties. Toxic primarily by inhalation and ingestion, exposure to cadmium (salts, dust, or fumes) may occur from the smelting and refining of ore, and from its use in metal plating and coating, production of batteries, synthesis and use of cadmium-containing pigments, soldering, and in plastics, ceramic glazes, alloys, and amalgams. Effects from exposure may include headache, nausea, shortness of breath, chest pain, weakness, fever, kidney damage, liver damage, chronic bronchitis, emphysema, and pulmonary edema (possibly resulting in death). NIOSH has recommended that cadmium (dust and fumes) be treated as a potential human carcinogen. The OSHA PEL for cadmium fume is 0.1 mg/cu m, and for cadmium dust is 0.2 mg Cd/cu m. Neither odor, nor irritation potential serves as an adequate warning of over-exposure. Processes and operations which may release cadmium fumes or dust should be enclosed and fitted with exhaust ventilation if practicable. Workers should wear a high efficiency particulate filter respirator or self-contained breathing apparatus in activities where over-exposure is possible. Protective clothing and gloves also should be worn, and these should be removed before leaving work. If contact should occur, immediately wash contaminated skin with large amounts of water. Do not eat, smoke, or drink in work areas. Cadmium dust or powder is a moderate firehazard when exposed to heat (autoignition temperature: 250 °C) or flame, or by chemical reaction with oxidizing agents, metals, hydrogen azide, zinc, selenium, or tellurium. Wear a self-contained breathing apparatus when fighting such fires. Cadmium should be stored in closed containers, away from sources of physical damage. Consult the regulatory requirements of the U.S. Department of Transportation before shipping cadmium, and with environmental regulatory agencies before implementing land disposal of cadmium wastes. |