1. Metals and Mercury

2. Not necessarily a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present Coliforms are naturally present in the environment; fecal coliforms only come from human and animal fecal waste. Biological pollution Discovery of coliform bacteria had the greatest impact on municipal water systems and water treatment. 1/3 weight of average uninfected human waste

3. Forms of Water Treatment Suspended Solids Flocculation Sand filtration Flocculation – bringing together of high numbers of small particles to create larger particles which settle out of water quickly. Advanced treatment uses chlorine disinfection To remove pathogenic organisms from water.

4. 1880s Scientists demonstrate that microorganisms can cause disease. First application of chlorine disinfectants to U.S. municipal water facilities in Jersey City and Chicago. 1908 First U.S. drinking water bacterial standard. 1915

5. Over 1,000 U.S. cities employ chlorine disinfection. 1918 More than 19,000 municipal water systems operate throughout the U.S. 1960

6. Biological Pollution and Chlorination Chlorine is currently employed by over 98 percent of all U.S. water utilities that disinfect drinking water

7. Effectiveness of Chlorination: Typhoid Yardstick Deaths per 100,000 1860 1910 1935 Today: < 40 per 200 million people bacterium Salmonella typhi 174 per 100,000 persons died of Typhoid in 1891

8. Metals: Mercury

9. Arsenic Erosion of natural deposits; pesticide waste, runoff from glass & electronics production wastes, treated lumber, groundwater Mercury Erosion of natural deposits; discharge from refineries and factories; runoff from landfills, coal burning Lead Corrosion of household plumbing systems; natural deposits, paint, fuels, electronics Heavy Metals and Metalloids

10. Common Health Effects Lead behavioral problems high blood pressure, anemia kidney damage memory and learning difficulties miscarriage, decreased sperm production reduced IQ Mercury blindness and deafness brain damage digestive problems kidney damage lack of coordination cognitive degeneration Arsenic breathing problems death if exposed to high levels decreased intelligence known human carcinogen: lung and skin cancer nausea, diarrhea, vomiting peripheral nervous system problems

11. Wells in Floodplain and Delta Sediments Water Bearing Muds Natural erosion of arsenic to water- bearing units. Well depths between 20m and 100 m Arsenic

12. Majority of wells > 50 ppb arsenic Some wells contain 500 - 1000 ppb WHO/U.S limit: 10 ppb Bangladesh limit: 50 ppb

13. -lead pipes -lead acetate sugar of lead sweetener for wine Lead (Plumbum) Father of all metals Possible cause of the dementia which affected Roman Emperors and Citizens. Contemporary Sources: Paint, ceramics, glass, soils, pipes, Solder, brass faucets, gasoline

14. Mercury Got Fish?

15. Mercury Advisories 70% of states Where does it come from?

16. Mercury is naturally occurring The number 1 anthropogenic source is the combustion of coal Enters water bodies principally from the atmosphere (coal, volcanism, rock weathering) 48 tons of elemental mercury to the atmosphere each year.

17. blindness, deafness brain damage digestive problems kidney damage lack of coordination cognitive degeneration Mercury Electrical products such as dry-cell batteries, fluorescent light bulbs, switches, and other control equipment account for 50% of mercury used. The drinking water standard for Mercury is 0.002 mg/L. 1 gram annually

18. Fluorescent Lights A typical fluorescent lamp is composed of a phosphor-coated glass tube with electrodes located at either end. The tube contains a small amount of mercury vapor. When a voltage is applied, the electrodes energize the mercury vapor, causing it to emit ultraviolet (UV) energy. The phosphor coating absorbs the UV energy, causing the phosphor to fluoresce and emit visible light. Voltage Hg gas UV Phosphor Coating

19. Each year, an estimated 600 million fluorescent lamps are disposed of in US landfills amounting to 30,000 pounds of mercury waste. Recycling and Handling

20. Forms of Mercury The dominant inorganic forms are Hg o and Hg 2+. Hg 2+ often occurs as HgCl 2 (mercuric chloride) in many aqueous environments. Hg 2+ (inorganic) interacts with soil and sediment particles (- charge) becoming part of lake bottom sediments (limits availability)

21. Interaction with Sediment Particles - charge Hg 2+ Small organic and Inorganic particles Hg 2+

22. - charge sediments Hg 2+ Mercury Bound to Sediments Hg 2+ Negatively charged particles bind mercury And retain it in bottom sediments. Mercury, however, can undergo chemical changes in lakes which render mercury more environmentally dangerous

23. Mercury can be converted to more toxic forms in bottom sediments under anaerobic conditions Mercury Methylation

24. Methylation: conversion of inorganic forms of mercury, Hg 2+, to an organic form: methyl mercury under anaerobic conditions Hg 2+ (CH 3 Hg + ) metylmercury Methylmercury is strongly accumulated in the body and is generally more toxic than inorganic Hg

25. Occurs primarily in bottom sediments as a byproduct of the life processes of anaerobic sulfate-reducing bacteria (SO 4 to HS-) that live in high sulfur, low oxygen environments. Mercury Methylation When sulfur accepts electrons it is said to be “reduced”. C 6 H 12 O 6 + 3SO 4 2- + 3H + = 6HCO 3 - + 3HS - Sulfate Respiration Requires 4 elements: anaerobic conditions a carbon source (organic sediments) a source of sulfur (SO 4 - ) sulfur reducing bacteria

26. However, bacterial sulfate respiration requires sulfate. The addition of sulfate to water stimulates the metabolic activity of sulfate- reducing bacteria and the inadvertent methylation of inorganic mercury Sulfate concentrations in EAA runoff and Lake Okeechobee average more than 50 times background concentrations than in the pristine Everglades The exact role of sulfate-reducing bacteria In mercury methylation is poorly understood Sulfate

27. Hg 2+ from coal, volcanism, rock weathering, point sources Water Sediments (Bound) Sulfur reducing bacteria, low O 2 methylmercury Aquatic Organisms

28. Biomagnification: concentration of a chemical in organisms as it moves up the food chain. Bioaccumulation: concentration of a chemical in organisms relative to the amount in water. Enhanced Risk Methylmercury has a half-life in human blood of about 70 days (almost twice as long as inorganic mercury (Hg 2+ ). Methylmercury attaches to proteins in animals (enters food chain) Methylmercury is strongly accumulated in the body and is generally more toxic than inorganic Hg

29. Bio-magnification

30. Methylmercury is rapidly taken up but only slowly eliminated from the body by fish and other aquatic organisms, so each step up in the food chain (bio)magnifies the concentration from the step below. Bioaccumulation factors (BAF's) of up to 10 million in largemouth bass have been reported for the Everglades. Fish-eating birds, otters, alligators, raccoons and panthers can have even higher bioaccumulation factors. Methylmercury in the organs and tissues causes birth defects & disorders of the brain, reproductive system, immune system, kidney, and liver at extremely low levels in food. Bioconcentration and Biomagnification Chemical Concentration in organism Chemical Concentration in water BAF =

31. Chisso Corporation, a company located in Kumamoto Japan, dumped an estimated 27 tons of mercury compounds into Minamata Bay Between 1932 and 1968. As of March 2001, 2,265 victims had been officially recognized (1,784 died) and over 10,000 had received compensation from Chisso Minamata Bay 1963 acetaldehyde plastics, drugs, and perfumes

32. Assessing Your Risk http://www.edf.org/page.cfm?tagID=17694 http://www.mercuryfacts.org/fSafeFish.cfm Fish sticks and "fast-food" are commonly made from fish that are low in mercury. Nearly all fish and shellfish contain traces of methylmercury. However, larger fish that have lived longer have the highest levels of methylmercury because they've had more time to accumulate it. These large fish (swordfish, shark, king mackerel and tilefish) pose the greatest risk. Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.