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Arsenic Contamination A Great Threat to Subcontinent

What is Arsenic. Natural and abundant element found in soil, air, and waterSolubilityInsoluble in water when in natural formSoluble in water when oxidizedMore toxic in this formMost likely to form compounds with oxygen, chlorine, sulfur, carbon, hydrogen, lead, gold, and iron2 typesInorganic: usually with oxygen, chlorine, or sulfur; most toxic (ex. arsenite)Organic: usually with carbon or hydrogen (ex. di-methyl arsonic acid).

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Arsenic Contamination A Great Threat to Subcontinent

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    1. Arsenic Contamination A Great Threat to Subcontinent Dr. M. A Naeem Associate Professor Soil Science Abid Hussain MSc Hons Agri. Soil Sciences

    2. What is Arsenic Natural and abundant element found in soil, air, and water Solubility Insoluble in water when in natural form Soluble in water when oxidized More toxic in this form Most likely to form compounds with oxygen, chlorine, sulfur, carbon, hydrogen, lead, gold, and iron 2 types Inorganic: usually with oxygen, chlorine, or sulfur; most toxic (ex. arsenite) Organic: usually with carbon or hydrogen (ex. di-methyl arsonic acid)

    3. Introduction Arsenic contamination is a growing problem throughout the world

    4. Arsenic Occurrence In Asia: Bangladesh, India, China, Viet Nam, Cambodia, Myanmar, Pakistan, Lao PDR, Nepal … Elsewhere: Argentina, Canada, Hungary, Mexico, Peru, Nicaragua, Romania, USA

    5. Bangladesh Epidemic Problem originated in the 1970s UNICEF program to provide “safe” water Arsenic wasn’t a known pollutant at the time Saved thousands of lives from microbial pathogens, but … 35-77 Million citizens at risk of arsenic poisoning (Out of a pop. of 125 Million)

    6. Bangladesh Epidemic The World Health Organization has set a guideline value of 0.01mg/l or 10 ppb Bangladesh wells range from 0 to 1660 ppb

    7. In Pakistan 1978 water sources contained arsenic concentration up to 10 ppb 209 sources remained between 10-50 ppb and 31 sources had arsenic concentration level above 50ppb. Dadu, Khairpur, Nawabshah and Thatta districts had relatively higher number of water sources with high concentration of arsenic, Situation could be alarming as other districts might also have arsenic contaminated water sources.

    8. Pakistan Cont..

    10. Sources of Arsenic Natural sources Weathering of rocks Volcanic activity can add Groundwater in contact with rocks that are high in arsenic animals and plants make organic arsenic compounds in oceans Mining/smelting of copper, gold, lead and zinc ores.

    11. Sources of Arsenic Cont.. Medical use of arsenic Wastewater from industries Wood preservation (greenish CCA pressure treated wood is treated with chromated copper arsenate, an arsenic and chromium containing preservative (70% of world Arsenic pollution) Pesticide use Burning materials with arsenic in them

    13. Health Risks Arsenic poisoning appears after 10 years of consumption as arsenicosis Can lead to:

    14. Health Risks 10 year old children are developing the arsenicosis Cancers appear after 20 years Huge epidemic expected in the near future

    16. Treatment Options Treatments are limited Consumption of only arsenic free water Zinc, Selenium, and Vitamin A for repair of the skin Chelation therapy Not proven to help patients

    18. The 8 threats to soil to be monitored (red = priority)

    19. Q ???????

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