Cadmium Compounds

Abstract

Cadmium (Cd) is a soft, malleable, silvery bluish‐gray, relatively rare metal, occurs mainly with Zn, Pb, and Cu. Cadmium is used in nickel–cadmium batteries; pigments, protective plating on steel, ceramics, and glass; stabilizers for PVC; and as a component in various alloys. Production of Cd was ∼20 tons in 1920 and is well over 25,000 tons now. Cadmium is released into the atmosphere from both natural and anthropogenic sources. In workplace, Cd dust and fume arise from smelting nonferrous metals and in the production of Cd‐containing materials. Cadmium in air range 0.1–5 ng/m 3 in rural, 1–20 ng/m 3 in urban, and 15–150 ng/m 3 in industrialized areas. Little or no differences are noted in Cd levels between indoor and outdoor air; however, smoking substantially increases indoor air Cd concentrations as it is present in tobacco. Cadmium can cause severe acute or chronic toxicity; although, acute toxicity is less common. Most cases are from chronic exposure; even low‐level chronic exposure can affect many organs with the kidneys and bones being the principal targets. OSHA has three occupational exposure limits for Cd: AL of 2.5 μg/m 3 (8‐h TWA), PEL of 5 μg/m 3 , and SECAL of 15 or 50 μg/m 3 , depending on the processes involved. SECAL requires that the levels are achieved by combination of engineering and work practice control methods and respirators to the extent feasible to protect workers from exposures above PEL. This chapter covers toxicity of a number of Cd compounds along with regulations based on the available data.