2. Relevance to Public Health 2.1 Background and Environmental Exposures to Cadmium in the United States
ثبت نشده
چکیده
Cadmium occurs in the earth’s crust at a concentration of 0.1–0.5 ppm and is commonly associated with zinc, lead, and copper ores. It is also a natural constituent of ocean water with average levels between <5 and 110 ng/L, with higher levels reported near coastal areas and in marine phosphates and phosphorites. The cadmium concentration of natural surface water and groundwater is usually <1 μg/L. Surface soil concentrations will depend on several factors such as its mobility, natural geochemistry, and magnitude of contamination from sources such as fertilizers and atmospheric deposition. Natural emissions of cadmium to the environment can result from volcanic eruptions, forest fires, generation of sea salt aerosols, or other natural phenomena.
منابع مشابه
2. Relevance to Public Health 2.1 Background and Environmental Exposures to Cadmium in the United States
Cadmium occurs in the earth’s crust at a concentration of 0.1–0.5 ppm and is commonly associated with zinc, lead, and copper ores. It is also a natural constituent of ocean water with average levels between <5 and 110 ng/L, with higher levels reported near coastal areas and in marine phosphates and phosphorites. The cadmium concentration of natural surface water and groundwater is usually <1 μg...
متن کامل2. Relevance to Public Health 2.1 Background and Environmental Exposures to Zinc in the United States
Zinc is ubiquitous in the environment, constituting 20–200 ppm (by weight) of the Earth's crust. It is not found as elemental zinc in nature, instead being found mainly as zinc oxide or sphalerite (ZnS). Zinc is released into the environment as the result of mining, smelting of zinc, lead, and cadmium ores, steel production, coal burning, and burning of wastes. Ambient background air concentrat...
متن کامل2. RELEVANCE TO PUBLIC HEALTH 2.1 BACKGROUND AND ENVIRONMENTAL EXPOSURES TO TOXAPHENE IN THE UNITED STATES Toxaphene is a manufactured pesticide comprising a complex mixture of hundreds of chlorinated
Toxaphene is a manufactured pesticide comprising a complex mixture of hundreds of chlorinated terpenes. After DDT was banned from use in the United States in 1972, toxaphene became the most popular substitute. Control of pests on cotton crops was the principal use of toxaphene in the United States, although the pesticide was used to control a variety of insects on a range of crops and to eradic...
متن کامل2. Relevance to Public Health 2.1 Background and Environmental Exposures to Perfluoroalkyls in the United States
Perfluoroalkyls constitute a class of compounds that have been used extensively in surface coating and protectant formulations due to their unique surfactant properties. Major applications have included protectants for paper and cardboard packaging products, carpets, leather products, and textiles that enhance water, grease, and soil repellency. Perfluoroalkyls have also been used as processing...
متن کامل2. RELEVANCE TO PUBLIC HEALTH 2.1 BACKGROUND AND ENVIRONMENTAL EXPOSURES TO TRICHLOROETHYLENE IN THE UNITED STATES Trichloroethylene is a major nonflammable industrial solvent. In 2011, the estimated capacity of the commercial production of trichloroethylene in the United States
Trichloroethylene is a major nonflammable industrial solvent. In 2011, the estimated capacity of the commercial production of trichloroethylene in the United States was 270 million pounds. Historically, the most important use of trichloroethylene has been vapor degreasing of metal parts. This use has declined over the past decade due to increased environmental regulations governing trichloroeth...
متن کامل