1. Chemical Pollutants Mercury and Synthetic Organics

2. Mercury

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

4. 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.

5. 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

6. 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 phosphorus to fluoresce and emit visible light. Voltage Hg gas UV Phosphor Coating

7. 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 4 mg Hg

8. Forms of Mercury The dominant inorganic forms are Hg o and Hg 2+ in many aqueous environments. Hg 2+ (inorganic) interacts with soil and sediment particles (- charge) becoming part of lake bottom sediments (limits availability) Hg o exists as both a liquid and a gas Hg 2+ is the dissolved form in water

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

10. - 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

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

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

13. 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 e-

14. 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 The exact role of sulfate-reducing bacteria In mercury methylation is poorly understood C 6 H 12 O 6 + 3SO 4 2- + 3H + = 6HCO 3 - + 3HS -

15. Sulfate concentrations in EAA runoff and Lake Okeechobee average more than 50 times background concentrations than in the pristine Everglades Sulfate The addition of sulfate to water stimulates the inadvertent methylation of inorganic mercury Potassium Sulfate Calcium Sulfate Elemental Sulfur Fertilizers

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

17. 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 (twice as long as inorganic mercury (Hg 2+ ). Methylmercury attaches to proteins in animals (enters food chain) Methylmercury can be accumulated in the body and is generally more toxic than inorganic Hg

18. 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. 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. Bioaccumulation and Biomagnification Chemical Concentration in organism Chemical Concentration in water BAF =

19. Bio-magnification Biomagnification: concentration of a chemical in organisms as it moves up the food chain.

20. 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 Albacore tuna) pose the greatest risk. Some of the most commonly eaten that are low in mercury are shrimp, canned light tuna, salmon, pollock, and scallops.

21. Other Bioaccumulative Toxins Synthetic Organic Chemicals

22. Dioxins Pesticides PCBs Flame Retardants PBDE Dioxin PCB DDT Organochlorines Organic = carbon-rich compounds dichlorodiphenyltrichloroethane Polybrominateddiphenyl ether

23. Viktor Yushchenko Ukrainian President Potential Toxicity 6,000 times the usual concentration in his body July November the second highest dioxin level ever measured in a human 2004 dioxin

24. Chemicals like dioxin are acutely toxic In high doses, but they also can bioaccumulate at lower doses, creating chronic toxicity The cause of their ability to bioaccumulate is related to their water solubility.

25. Sodium Chloride350 g/L Potassium Chloride280 g/L Water Solubility NaClNa + + Cl -

26. Water Molecules are Polar + + - Unequal distribution of electrons Oxygen is electron-greedy

27. NaClNa + + Cl - Na + Cl - Sodium Chloride water solubility: 350 g/L

28. Contrast with Organic Chemicals

29. Organic Chemicals Greases, Oils, Paints, Pesticides, Industrial Chemicals Grease and Oil Carbon83 to 87% Hydrogen10 to 14% C 16 H 14 OS Oil Paint Composed mostly of carbon and hydrogen, and possessing no electrical charge. Carbon-rich compounds

30. Dioxin PCB DDT Principally carbon, hydrogen C 11 H 18 O 2 Cl 4 C 14 H 22 Cl 5 C 12 H 21 Cl 8 Generally poorly soluble in water

31. Dioxin Dioxin water solubility: 0.2 µg/L

32. Dioxin PCB DDT 10 µg/L 0.2 µg/L Uncharged and principally carbon, hydrogen < 0.1 µg/L

33. Toxaphene: 3 mg/L Dieldrin: 186 ug/L Chlordane: 9 ug/L

34. These types of chemicals are poorly soluble in water In what substances do they dissolve? Greases, Oils, Paints, Pesticides, Industrial Chemicals

35. Hexane D-limonene oil Common Organic Solvents Carbon-based petroleum

36. Organic Solvents water Carbon-based compounds dissolve more easily in carbon- based solvents. carbon Dioxin carbon Organic solvents *

37. What is the most common solvent used every day?

38. - SO 4 Detergents hydrophobic hydrophilic SO 4 - High Carbon Concentration

39. Vegetable Oil (insoluble in water) Detergent Micelles

40. Synthetic Organics and Organisms

41. Synthetic organic chemicals can be acutely toxic In high doses, but they also can bioaccumulate creating chronic toxicity at lower doses Their ability to bioaccumulate is related to their poor water solubility.

42. Principally Carbon and Hydrogen Bioaccumulation in Organisms Lipid Tissue in Organisms carbon

43. Bioaccumulation in Organisms The chemical essentially dissolves into the lipid tissues carbon Dioxin

44. Synthetic organic chemicals are poorly soluble in water They are soluble in organic solvents and lipids Lipids are found in all organisms Despite low levels of organic chemicals in water due to their low water solubility, high amounts can accumulate in the tissues of living organisms

45. Magnification of 800 x Water Concentration = 0.2μg/L Zooplankton concentration = 160 μg/L Bioaccumulation

46. Bio-Magnification Water and phytoplankton to zooplankton: 800 x Zooplankton to fish: 31 x Overall: 120,000 times original concentration in water Fish to eagle: 4.8x

47. PCBs and Pesticides Bioaccumulative Organics

48. PCBs Electrical equipment plasticizers in paints, plastics and rubber products pigments, dyes and carbonless copy paper PCBs were “banned” in 1979 Used as insulating fluids and coolants in electrical equipment and machinery from 1929-1977. EPA estimates that 150 million pounds of PCBs are dispersed throughout the environment, including air and water supplies; an additional 290 million pounds are located in landfills in this country some PCBs act like hormones, and other PCBs are nerve poisons

49. PCBs in Marine Mammals Hazardous Waste level (Canada) Killer Whales (1000 ppm) High on food chain Lipid tissues

50. Seawater Arctic cod muscle Narwhal blubber 14 - 46 ppb 0.0003 ppb 2440 - 9160 ppb Toxaphene 50,000 X ~ 8 M X carbon lipid 400,000 tons: 1946 to 1974 (670 chemicals)

51. Toxaphene and Mirex: 1959 - 1976 highest levels ever recorded in a living organism.

52. Persistence in the Environment

53. Where in these environments do we find high levels of carbon? Many synthetic organic chemicals, particularly those like PCBs and DDT are very persistent in the environment. They last for decades. They become stored in organic materials that naturally occur in aquatic and terrestrial systems

54. Water Organic Sediments Environmental Persistence Solubility of < 0.1 μg/L Organic chemicals become stored in organic sediments This protects them from degradation and increases their lifetime in the environment DDT

55. DDT 28 days 15 – 20 years PCBs 1 month 2-6 years > 60 years up to 150 years ½ Life and Organochlorines Dioxin 1 - 30 years (7 years in humans) Muck: high in organic carbon

56. Lake Michigan µ g PCB/Kg sediment (parts per billion) EPA 2004 mg Carbon /g sediment N Concentration Organic Carbon PCBs “banned” in 1979 Open water PCB concentration = < 1 part per trillion

57. Lake Erie PCB levels PCBs After 30 years, PCBs continue to persist in the Environment EPA, 2004

58. Persistence in the Environment Old sediments

59. Florida Lakes and Organics

60. DDT dichloro-diphenyl-trichloroethane First Modern Pesticide Insecticide developed to combat insect-borne disease Use was later expanded to include agriculture 1948 Nobel Prize in Physiology and Medicine

61. Launch of the Environmental Movement 1962 human volunteers ingested 35 mg of DDT primates were fed 33,000 times more DDT than the estimated exposure Thinning egg shells Lower hatching rates Declining Eagle population Carcinogenic decline in the eagle population occurred before the DDT years (bounties between 1917 and 1942) http://faculty.unionky.edu/rbotkin/RECM_480_ISSUE_16A_YES_BLUE.PPT#291,22,Issue%2016:%20Yes

62. DDT levels ranging from 2,200 to 110,000 µg/kg (ppb) in organic soils and sediments. Torry and Rita Islands Organic soils

63. Historically characterized by clear water and a highly prized sports fishery, it served as a popular destination for boaters, swimmers, and fishermen for decades. Lake Apopka 30,800 acres mean depth is 5.4 feet 15 miles northwest of Orlando

64. Agriculture Pesticide Use in Agricultural Area Pesticide use included high amounts of DDT

65. "Lake Apopka is a big chemical soup," Michael Fry, a researcher from the University of California Tower Chemical Company Produced dicofol, a mixture of the pesticide DDT and DDE, a by-product of DDT. Periodic spills occurred there, but a particularly large accident in 1980 caused dicofol to spread into the lake Sediment Organic carbon content ranges from 33 to 37%

66. In the 1970s, scientists considered Lake Apopka a prime place to harvest eggs and hatchlings to study them in captivity. In 1980 and 1981, scientists counted populations of 1,200 to 2,000 alligators in a single night on the lake By the late 1980s, they counted only 150 per night

67. Alligator Population crash was linked to poor egg viability Alligators typically produce 40-45 eggs with a hatching rate of about 65%. In Lake Apopka, only 15-20% hatch

68. Apopka's juvenile alligators have abnormal testes and ovaries and abnormal hormone balances DDE, a breakdown product of DDT, is a major contaminant in Lake Apopka DDE is known to block the action of testosterone Estradiol Testosterone Apopka males had high levels of estradiol relative to testosterone DDT, DDE and Feminization of Alligators

69. ' Teeny Weenies ' Alligators in Florida's Lake Apopka have Smaller Penises Kyla Dunne for PBS June, 1998 http://www.mindfully.org/Pesticide/Alligators-Apopka-PBS2jun98.htm

70. Assessing the Danger: Octanol Synthetic Organics, Organochlorines

71. Solubility Hexane Acetone Lipids Carbon-based compounds dissolve more easily in carbon- based solvents. organochlorine carbon Dioxin Organic Sediments carbon

72. How strong is the interaction? Bioaccumulation Persistence

73. An Important Organic Solvent:Octanol C 8 H 18 O Octanol is used as a reference organic solvent for neutral organic chemicals c c c c c c c c

74. Octanol and Water Octanol and water are immiscible (they do not mix) Octanol is less dense than water: 0.824 g/cm3 octanol water C 8 H 18 O

75. Octanol (Carbon/Hydrogen) water Carbon/hydrogen Partitioning Between Octanol and Water C 10 H 20

76. Octanol-Water Partitioning Coefficient Kow = Concentration of chemical in octanol Concentration of chemical in water At equilibrium

77. water 1 L Octanol 1L Water Add 10 mg chemical separate chemical Analyze the water phase for the chemical. Difference between initial amount and amount in water = amount in octanol The ratio between the two yields the K ow octanol

78. Add 10 mg chemical separate Chemical In octanol Chemical In water 0.01 mg L 9.99 mg L Water phase octanol phase Kow = 9.99 mg L 0.01 mg L = 999 1 L Octanol 1L Waterl

79. K ow of some Organochlorine Compounds DDT 8,000,000 PCBs 2,000,000 + Dieldrin1,600,000 Mirex3,000,000 A high K ow indicates strong interaction with organic solvents and, therefore, sediments and lipid tissues chemical in octanol chemical in water

80. Range for Some Modern Pesticides Kow = 2 – 10,000 mL/g Dicamba = 4 Malathion = 2919 Chlorpyrophos = 10,521 Far less potential for bioaccumulation Rapid Breakdown (1/2 life measured in days or weeks) Inhibit acetyl cholinesterase, an enzyme necessary for proper nervous system function Can be more acutely toxic diazinon

81. What is the most common component? Water Filters Carbon

82. Is this effective at removing Synthetic organic chemicals from your tap water? Is it more effective removing chemicals with a high or low Kow?

83. These filters, by nature, are quite small and because filter effectiveness is dependent on contact time of the water with the filter media, a larger, high-quality solid carbon block filter will be more effective at reducing contaminants at the same flow rate. A high-quality solid block activated carbon replacement filter will filter water for between 7 and 10 cents per gallon. 2 gallons of filtered water per day would cost between $50 and $100 per year Most Common Filtration Solid Carbon Block faucet mount filters