Cadmium in the Environment Emphasis on Water Gloria

Cadmium in the Environment: Emphasis on Water Gloria Benzakarya, Delia Ponce and Antonio F. Machado Department of Environmental & Occupational Health, CSUN Abstract: Cadmium, a heavy metal that is naturally present in the environment is also used in various industrial processes. This metal is an occupational and environmental concern. Cadmium depending on the route and the level of exposure may cause detrimental health effects that are irreversible. There are many different sources that can pollute the environment. Based on our findings we conclude that monitoring of Cd levels need not be only in water, but also in the cultivation on soil , the emissions that go into the air. etc. The current literature review is to evaluate cadmium toxicity to humans from water. Introduction What is Cadmium? § Cadmium (Cd) is a metal that is found naturally in the earth’s crust but is also derived from industrial processes. § Most commonly found in the environment in combination with other elements such as oxygen, chlorine, and sulfur. What is Cadmium used for? § Cd is used in metal plating and coating for the manufacture of pigments, batteries, & plastics. § In the US, Cd exists mainly as a byproduct of such practices. How are humans exposed to it? § Exposure can happen through inhalation of Cd from the burning of fossil fuel, eating Cd contaminated foods, drinking Cd containing water, and cigarette smoking. § Corrosion of galvanized pipes, runoff from waste batteries and paint & discharges from metal refineries lead to the contamination which can get into our water system. Why is Cadmium a concern? § Cd can cause health effects to humans such as kidney , liver and lung damage. The kidneys & liver contain about 50% of total Cd accumulation in the body. 1 § Growing concern is associated with long term exposure at low doses due to its long biological half life. The half life can be anywhere between 4 -38 years. 1 http: //en. wikipedia. org/wiki/Cadmium in the Environment Naturally Occurring Levels Earth’s crust 0. 1 -. 5 ppm 1 Ocean <5 and 110 ng/L 1 Surface/groundwater <1µg/L 1 Remediation Methods used to remove Cd from water 4: § Coagulation/Filtration § Salts (aluminum or iron) are added to the water which then bind with Cd to form larger particles that can more easily settle out of the water and/or filtered out more effectively. § Ion exchange § Works by replacing the Cd(II) ion by another ion which is considered less harmful. 2 § This method is considered to be highly efficient. Studies performed on industrial wastewater have resulted in 99. 9% extraction. 3 § Lime softening § Helps to settle out the contaminated water by the addition of calcium hydroxide. § Reverse osmosis. § Water is put through a semipermeable membrane. § Efficiency is dependent on solute concentration, Water pressure, and water flux rate. § Cd is leaked into the water from the leaching of landfills, sewage discharge, and the piping in the distribution system. § Higher levels of Cd are found in coastal areas. § Largest source of Cd emissions to water from man : made practices are from the smelting of nonferrous Drinking Water • The EPA has determined that exposure to Cd in drinking metal ores 1 water at a concentration of 0. 04 mg/L for up to 10 days is § Agricultural run-off is of major concern in areas that not expected to cause any adverse effects in a child. are in close proximity to farming because of the types • The EPA has determined that lifetime exposure to. 005 mg/L of fertilizers being used to grow crops. cadmium in drinking water is not expected to cause any § Amongst the food that have a high Cd content is adverse health effects. shellfish, oysters, and scallops. This is attributed to the Cd levels that contaminate the waters they live in Bottled Water • The FDA has determined that cadmium levels in bottled as well as the bioaccumulation factors of these fish. 4 water should not exceed. 005 mg/L. Soil § Cd concentrations vary depending on how the soil is Workplace Air • OSHA set a legal limit of 5µg/m 3 cadmium in air averaged being cultivated and the location of the land. over an 8 hour work day. § Phosphate fertilizers added to soil can contain up to http: //www. atsdr. cdc. gov/phs. asp? id=46&tid=151 300 mg Cd/kg. 1 In California, § Atmospheric deposition and sewage sludge disposal are additional ways Cd infiltrates the soil. Air Contaminant in Water MCL PHG § Cd is found at different concentrations in ambient air, occupational environments, and from Tobacco smoke. mg/L 1 § Concentrations vary from 0. 1 -5 ng/m 3 Cadmium 0. 005 0. 00004 § 1 cigarette contains. 5 -2μg of Cd; 10% is inhaled 1. 5 § Aside from industrial practices, Cd is released in the http: //cdph. ca. gov/certlic/drinkingwater/Pages/MCLReview 2011. aspx air through volcanic eruptions, forest fires, and may also be released from sea salt aerosols. Regulations Origin of cadmium: Cadmium is naturally occurring in the Earth’s crust from underlying bedrock. Sedimentary rocks have the highest cadmium levels; levels have been reported to be up to 25 ppm. However, most cadmium in the environment is a byproduct of industrial practices some of which are listed below. 6 Source Fertilizers Fossil Fuels Natural Sources Iron and Steel Production Cement and Others Nonferrous Metals Production Cadmium Products Waste Incineration Levels 33% 21% 20% 12% 7% 4% 2% 1% www. cadmium. org Significance given to Cd: Fate and Transport: Water: About 2, 346 pounds of cadmium compounds are released to surface water, the ocean has about 110 ng of cadmium. When cadmium is released into the water, it effects the ecosystem. The heavy metal is easily absorbed by fish and other aquatic organisms. Thus the cadmium bio-accumulates in fish and the levels increase as the trophic level increases and humans that consume fish become exposed to significant levels of cadmium, which in turn becomes a human exposure if the fish are consumed. 8 Aqueous cadmium is not influenced in water, and the potency stays the same. However, under reducing conditions, cadmium may form cadmium sulfide, which is not soluble and usually precipitates. Ionic cadmium seems to be the toxic form and becomes more predominant at low levels of salt. Air: Small particles of cadmium are transported from a hundred kilometers and have a typical atmospheric residence time of about 1 -10 days before it deposits again. This process complicates cadmium pollution. 7 Soil: When the soil is contaminated with cadmium, the plants ingest the cadmium and other animals eat it which also causes bioaccumulation. 9 The Cd accumulation of the plants occurs mostly in the leaves. Which can be further damaging to humans who consume leafy vegetables. 1 References: § The EPA has classified Cd as a probable human carcinogen (Group B 1). 4 Disposition and Metabolism: The metabolism of cadmium involves: Cd being transported to the liver inducing the creation of metallothionein, a low molecular weight metal-binding protein. Cadmium becomes bound to this protein, forming a metal-protein complex which is then released back to the blood and transported to the kidney. 10 The excretion of Cadmium: Cd is excreted from the human body by going through the kidneys and liver, which accumulates for many years. A small portion of cadmium is excreted through urine and feces over a long period of time. 11 § Cd ranks #7 on the ATSDR 2013 Substance Priority List with a score of 1318. 71 In conclusion… The regulations for Cd levels in drinking water are sufficient to maintain human intake at low levels. The problem associated with this contaminant, as with many others, is a dynamic issue. Contamination is not merely associated with one source. Levels of contamination depend on the many variables unique to a particular area. Cd emissions that affect the air, soil, water, food, and atmosphere all will interact and accumulate differently based on factors such as location, temperatures, and p. H levels of different media. The highest Cd exposure to humans are known to come from Cd Health Effects: contaminated food, not the drinking water (1). Therefore, a closer look This depends on the route of exposure and the dose, but since the main should be taken at the way crops are being grown. For example, more concern is through oral exposure from drinking water, then chronic stringent regulations need to be established for the types of fertilizers exposure would be the main concern and cause the following: that are being used. Location of where the crops are being grown need to • Itai-Itai is a disease that is coined in Japan that literally mean “ouch- also be considered to determine if waste sludge, runoff or any other near ouch, ” and it consists of severe pain in the bone, joint, and muscle. by industrial processes are adding to the Cd concentration of plants. This disease is also coupled with eventually having loss of kidney will avoid not only the crops from accumulating high levels of Cd, but the function animals who are perhaps feeding on these plants (which humans may • Hematuria is a condition in which red blood cells are present in urine. eventually eat) will also benefit from lower Cd exposures. This is an indicator of kidney damage and results in anemia. To avoid further contamination of ground water, alternatives to Cd • Cancer of the breast, kidney and pancreas, and urinary bladder is containing batteries, for example, should also be sought. This will avoid caused by long-term exposure to cadmium. 12 the leaching of Cd from landfills into the ground. 1. Agency for Toxic Substances & Disease registry. Cadmium Profile. http: //www. atsdr. cdc. gov/toxprofiles/TP. asp? id=48&tid=15 2. Da browski, A, Z Hubicki, P Podkościelny, and E Robens. "Selective Removal of the Heavy Metal Ions from Waters and Industrial Wastewaters by Ion-exchange Method. " Chemosphere, 56. 2 (2004): 91 -106. 3. Al-Enezi, G, MF Hamoda, and N Fawzi. "Ion Exchange Extraction of Heavy Metals from Wastewater Sludges. " Journal of Environmental Science and Health Part A-toxic/hazardous Substances & Environmental Engineering, 39. 2 (2004): 455 -464. 4. United States Environmental Protection Agency. http: //water. epa. gov/drink/contaminants/basicinformation/cadmium. cfm 5. http: //cdph. ca. gov/certlic/drinkingwater/Pages/MCLReview 2011. aspx 6. "All the Information on Cadmium. " All the Information on Cadmium. ICd. A North America, n. d. Web. 11 Dec. 2014. 7. Toxicological Profile for Cadmium. Atlanta, GA: U. S. Dept. of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, 1993. Web. 8. Communities, Environment And. Impacts of Metals on Aquatic Ecosystems and Human Health (n. d. ): n. pag. Web. 9. "Result Filters. " National Center for Biotechnology Information. U. S. National Library of Medicine, n. d. Web. 13 Dec. 2014. 10. "Section 5 - V. Health Effects. " Section 5 - V. Health Effects. N. p. , n. d. Web. 14 Dec. 2014. 11. "A-Z Index. " ATSDR. N. p. , n. d. Web. 14 Dec. 2014. 12. "Result Filters. " National Center for Biotechnology Information. U. S. National Library of Medicine, n. d. Web. 14 Dec. 2014.