1. Chemical Pollutants Metals and Non-metals Chemical Pollutants
Heavy metals represent a common type of chemical pollution in water. They can be found naturally in bedrock and sediment or they may be introduced into water from industrial sources and household chemicals. Heavy metals harm humans through direct ingestion of contaminated water or through accumulation in the tissues of other organisms that are eaten by humans. The following are some common heavy metals found in water:
Mercury (Hg): Enters the environment through the leaching of soil due to acid rain, coal burning, or industrial, household, and mining wastes. Causes damage to nervous system, kidneys, and vision.
Lead (Pb): Sources include paint, mining wastes, incinerator ash, water from lead pipes and solder, and automobile exhaust. Causes damage to kidneys, nervous system, learning ability, ability to synthesize protein, and nerve and red blood cells.
Cadmium (Cd): Sources include electroplating, mining, and plastic industries, as well as sewage. Causes kidney disease.
Arsenic (As): Enters the environment through herbicides, wood preservatives, and mining industry. Causes damage to skin, eyes, gastrointestinal tract, and liver. May also cause cancer.
Aluminum (Al): Enters the environment through leaching due to acid deposition. Causes anemia and loss of bone strength, and may also contribute to dementia and Alzheimer’s disease.

2. Mercury, Arsenic, and Lead
Lead found in blood sample from 1 of 10 Washingtonians
Arsenic found in urine samples from 4 of 10 Washingtonians
Mercury found in hair samples from 10 of 10 Washingtonians

3. Mercury 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
Mercury

4. Wonderland Mercury Nitrate
Mercury nitrate was used in the felting process and constant exposure to the chemical eventually caused the hatters to develop mercury poisoning. The connection between mercury poisoning and the hatters' behavior was not understood at the time, but the term "mad as a hatter" was in common usage.
Mercury Nitrate
Symptoms included tremors, emotional instability, insomnia, dementia and hallucinations

5. Natural Groundwater Contaminants
Fluoride and Arsenic

6. India 95 % Failure of 246 surface irrigation projects
21 million backyard tube wells
$600 electric pumps
(1% of GDP)
95 %
In Tamil Nadu, a state with more than 62 million people in southern India, wells are going dry almost everywhere. According to Kuppannan Palanisami of Tamil Nadu Agricultural University, falling water tables have dried up 95 percent of the wells owned by small farmers, reducing the irrigated area in the state by half over the last decade. 16
As water tables fall, well drillers are using modified oil-drilling technology to reach water, going as deep as 1,000 meters in some locations. In communities where underground water sources have dried up entirely, all agriculture is rain-fed and drinking water is trucked in. Tushaar Shah, who heads the International Water Management Institute’s groundwater station in Gujarat, says of India’s water situation, “When the balloon bursts, untold anarchy will be the lot of rural India.” 17
At this point, the harvests of wheat and rice, India’s principal food grains, are still increasing. But within the next few years, the loss of irrigation water could override technological progress and start shrinking the harvest in some areas, as it is already doing in China. 18
water tables falling by 20 feet per year
What do you do when your water table falls? 6

7. Deeper Wells and Fluoride
Naturally occurring element in Granite
which dissolves into the groundwater
Water near the surface is generally unaffected
Lowering water tables = deeper wells
Deep wells can contain granite and high fluoride levels
Fluoride in water can be a cumulative poison
What’s the obvious question?

8. Intentional Fluoridation of Water in the U.S.
Fluoridation became an official policy of the U.S.
Public Health Service in 1951.
By 1960 water fluoridation had become widely used
in the U.S. reaching about 50 million people.
By 2006, 69.2% of the U.S. population on public water
systems were receiving fluoridated water.

9. How does it work? Ca5(PO4)3OH
Tooth enamel is made of a mineral called hydroxyapatite
Ca5(PO4)3OH
Bacteria in the mouth create acids (H+)
Hydroxyapatite is subject to dissolution by acids (H+)
Fluoridation changes the chemical composition of
hydroxyapatite to a crystal less subject to acid dissolution

10. F- Ca5(PO4)3 OH Sodium fluorosilicate (Na2SiF6) Sodium fluoride (NaF)
NaF Na+ + F-
Ingestion of fluoridated water increases
the F- concentration in saliva
F- replaces OH in hydroxyapatite making fluoroapatite F-
Ca5(PO4)3 OH
Fluoroapatite is less soluble in acid than hydroxyapatite

11. Fluoride concentrations
In U.S. tap water
0.5 – 1.0 mg/L
Lower values in warm climates

12. Fluoride levels > 1.5 mg/L
Dental Fluorosis
Intake:
1.6 to 6.6 mg/day
Colorado Brown Stain
Permissible fluoride limit in India is 1.2 mg/L
Fluoride levels between 5-25 mg/L have been found

13. Skeletal Fluorosis Intake Fluoride levels > 10 mg/L
9 mg/day to 12 mg/day
Fluorosis has risen from 1 million to 25 million
and threatens 60 million people in India.

14. Extra Credit:
The chemical that made the Mad Hatter mad _____
Country affected by fluoride poisoning __________
Fluoride is naturally occurring. True or False
Colorado Brown Stain is a name for ____________

15. Groundwater and Arsenic

16. Natural waters, in general, contain low levels of total arsenic
Arsenic is Naturally Occurring
occurs primarily in association with sulfur-containing minerals
Natural waters, in general, contain low levels of total arsenic
Mobilization of arsenic in the environment arises from anthropogenic activities related to mining and ore processing, metallurgy, agriculture, wood preservation, and industry.
mining and ore processing, metallurgy,
agriculture, wood preservation, and industry. 16

17. Inorganic Forms of Arsenic
AsO3-3
AsO4-3
Arsenite
Arsenate
Low Oxygen
High Oxygen
Arsenite is more toxic than arsenate, interfering with
enzyme activities which catalyze metabolic reactions
Arsenite compounds are also more mobile in the environment
due to higher solubility compared to arsenate compounds
Both arsenate and arsenite are chronic accumulative toxins

18. “The World’s Largest Mass Poisoning”

19. Bangladesh and W. India
ranked among the world's 10 poorest countries

20. Himalayas Accumulation of thick muds in the floodplains and deltas
Floodplain and Delta of the
Ganges and Brahmaputra
Rivers.
Himalayas
Floodplain: area paralleling a
river that is periodically inundated
Ganges-Brahmaputra Delta
Deltas are formed from the deposition
of sediment carried by the river as
the flow leaves the mouth of the river
Accumulation of
thick muds
in the floodplains
and deltas

21. water-borne pathogens
Bangladesh Prior to 1970s
One of the highest infant mortality rates in the world
Principally due to waterborne disease.
Ineffective water and sewage systems
Periodic monsoons and floods
water-borne pathogens
cholera, dysentery
Deaths Due to Surface water contamination: 250,000/yr

22. First 1 million wells were sunk with aid from
Deaths Due to Surface water contamination: 250,000/yr
The Solution: Tap groundwater resources
easy
inexpensive
available
First 1 million wells were sunk with aid from
World Governments
UNICEF
World Bank

23. 12 million hand-operated tube wells
deliver water to over 80% of the rural village population
Infant mortality and diarrheal illness reduced by 50%

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

25. WHO/U.S limit: 10 ppb Bangladesh limit: 50 ppb
Old U.S. standard was 50 ppb, but was changed to 10 ppb in This put between 35 and 38% of wells out of compliance in Arizona and California.
Delta and Floodplain Regions
Some wells contain ppb
Majority of wells > 50 ppb arsenic 25

26. Above 10 ppb: 57 million people Above 50 ppb: 35 million people
Exposure Estimates
Above 10 ppb: 57 million people
Above 50 ppb: 35 million people
Accumulative Toxin
Early Symptoms:
Skin lesions and thickening
Strong skin pigmentation
Long-term Exposure
breathing problems death if exposed to high levels lung and skin cancer peripheral nervous system

27. 2003 Studies

28. 83 million people
Bihar: 40% wells contaminated

29. Red River Delta
11 million people
First wells sunk
7 years ago

30. Mercury
Got Fish?

31. Mercury Advisories 70% of states Where does it come from?
Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emissions from human-related activities. Human health concerns arise when fish and wildlife from these ecosystems are consumed by humans.
During the past decade, a new trend has emerged with regard to mercury pollution. Investigations initiated in the late 1980's in the northern-tier states of the U.S., Canada, and Nordic countries found that fish, mainly from nutrient-poor lakes and often in very remote areas, commonly have high levels of mercury. More recent fish sampling surveys in other regions of the U.S. have shown widespread mercury contamination in streams, wet-lands, reservoirs, and lakes. To date, 33 states have issued fish consumption advisories because of mercury contamination
70% of states
Where does it come from? 31

32. Mercury is naturally occurring
Enters water bodies principally from the atmosphere
Mercury is naturally occurring
(coal, volcanism, rock weathering)
The number 1 anthropogenic source
is the combustion of coal
These continental to global scale occurrences of mercury contamination cannot be linked to individual emissions of mercury, but instead are due to widespread air pollution. When scientists measure mercury levels in air and surface water, however, the observed levels are extraordinarily low. The droplet of mercury shown in this slide is about 1 gram; the same amount that is in a standard mercury thermometer and the total amount that is deposited annually on a lake in northern Wisconsin with a surface area of 27 acres.
48 tons of elemental mercury to the atmosphere each year. 32

33. Mercury
The drinking water standard for Mercury is mg/L.
blindness, deafness brain damage digestive problems kidney damage lack of coordination cognitive degeneration
1 gram
When scientists measure mercury levels in air and surface water, however, the observed levels are extraordinarily low. The droplet of mercury shown in this slide is about 1 gram; the same amount that is in a standard mercury thermometer and the total amount that is deposited annually on a lake in northern Wisconsin with a surface area of 27 acres.
Electrical products such as dry-cell
batteries, fluorescent light bulbs,
switches, and other control equipment
account for 50% of mercury used. 33

34. Fluorescent Lights Phosphor Coating Voltage
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.
Phosphor
Coating
Hg gas UV
Voltage

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

36. Forms of Mercury The dominant inorganic forms are Hgo and Hg2+.
Hg2+ often occurs as HgCl2 (mercuric chloride)
in many aqueous environments.
Hg2+
(inorganic) interacts with soil and sediment
particles (- charge) becoming part of lake
bottom sediments (limits availability)

37. Interaction with Sediment Particles
- charge
Small organic and
Inorganic particles
Hg2+
Hg2+
Hg2+
- charge
- charge

38. - charge Mercury Bound to Sediments sediments Hg2+ Hg2+
Mercury, however, can undergo chemical
changes in lakes which render mercury
more environmentally dangerous
Hg2+
Hg2+
sediments
Negatively charged particles bind mercury
And retain it in bottom sediments.
- charge 38

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

40. Methylmercury is strongly accumulated in the body
Mercury Methylation
Methylation: conversion of inorganic forms of mercury,
Hg2+, to an organic form: methyl mercury
under anaerobic conditions
Hg (CH3Hg+) methylmercury
particularly coal. Although inorganic mercury is only a trace constituent of such fuels, their large scale combustion in the United States alone results in release of some 48 tons of elemental mercury to the atmosphere each year. About 3 times as much additional inorganic mercury is contributed by natural sources such as volcanoes, forest fires and weathering of mercury-bearing rocks.[3]
Methylmercury is strongly accumulated in the body
and is generally more toxic than inorganic Hg 40

41. Sulfate Respiration C6H12O6 + 3SO42- + 3H+ = 6HCO3- + 3HS-
Mercury Methylation
Requires 4 elements:
anaerobic conditions
a carbon source (organic sediments)
a source of sulfur (SO4-)
sulfur reducing bacteria
Occurs primarily in bottom sediments as a byproduct of the life processes of anaerobic sulfate-reducing bacteria (SO4 to HS-) that live in high sulfur, low oxygen environments.
Sulfate Respiration
Sulfate occurs widely in seawater, sediment, or water rich in decaying organic material The exact mechanisms by which mercury enters the food chain remain largely unknown and may vary among ecosystems. Certain bacteria play an important early role. Bacteria that process sulfate (SO4=) in the environment take up mercury in its inorganic form and convert it to methylmercury through metabolic processes. The conversion of inorganic mercury to methylmercury is important because its toxicity is greater and because organisms require considerably longer to eliminate methylmercury.
C6H12O6 + 3SO H+ = 6HCO3- + 3HS-
When sulfur accepts electrons it is said to be “reduced”.
Desulfuromonas,
Pseudomonas 41

42. However, bacterial sulfate respiration requires sulfate.
The exact role of sulfate-reducing bacteria
In mercury methylation is poorly understood
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
Sulfate
the State of Florida has issued human health advisories that ban or restrict consumption of freshwater fishes from over 2 million acres of the Everglades and Big Cypress Swamp. Although Hg contamination has been detected at levels of concern in largemouth bass throughout the State (Lange et al. 1993), maximum concentrations found in Everglades largemouth bass (4.4 mg/kg)
and bowfin (>7 mg/kg) are the highest Hg contaminant levels thus far reported from Florida waters. 42

43. Hg2+ from coal, volcanism, rock weathering, point sources
Water
Sediments
(Bound)
Sulfate concentrations in EAA runoff and Lake Okeechobee releases are on
average more than 50 times background concentrations in the pristine Everglades
Sulfur reducing bacteria, low O2
methylmercury
Aquatic Organisms 43

44. Methylmercury is strongly accumulated in the body
Enhanced Risk
Methylmercury attaches to proteins in animals (enters food chain)
Methylmercury has a half-life in human blood of about 70 days
(almost twice as long as inorganic mercury (Hg2+).
Methylmercury is strongly accumulated in the body
and is generally more toxic than inorganic Hg
Bioaccumulation: concentration of a chemical in
organisms relative to the amount in water.
Biomagnification: concentration of a chemical in
organisms as it moves up the food chain.

45. Bio-magnification

46. Bioconcentration and Biomagnification
Chemical Concentration in organism
Chemical Concentration in water
BAF =
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.
                                     
Like many environmental contaminants, mercury undergoes bioaccumulation. Bioaccumulation is the process by which organisms (including humans) can take up contaminants more rapidly than their bodies can eliminate them, thus the amount of mercury in their body accumulates over time. If for a period of time an organism does not ingest mercury, its body burden of mercury will decline. If, however, an organism continually ingests mercury, its body burden can reach toxic levels. The rate of increase or decline in body burden is specific to each organism. For humans, about half the body burden of mercury can be eliminated in 70 days if no mercury is ingested during that time. Biomagnification is the incremental increase in concentration of a contaminant at each level of a food chain
Methylmercury is first taken up by bacteria and tiny plants and animals known as plankton.
Then the plankton and bacteria are eaten by small fish.
These small fish are eaten by larger predatory fish which accumulate large amounts of methylmercury in their tissues.
The large fish are caught and eaten by humans and animals, exposing them to large amounts of methylmercury which will accumulate in their bodies as well. 46

47. Minamata Bay 1963 plastics, drugs, and perfumes acetaldehyde
Chisso Corporation, a company located in
Kumamoto Japan, dumped an estimated
27 tons of mercury compounds into Minamata Bay
Between 1932 and 1968.
1963
Part of the problem in establishing guidelines has been the lack of good data. To arrive at their current action level, the FDA looked at data from several studies of methylmercury poisoning and at the amount of fish consumed by the U.S. population--the best available data at the time. Two of the worst poisoning incidents occurred in Minamata and Niigata, Japan. In the 1950s, 111 people died or suffered from nervous system damage in Minamata, while 120 people were poisoned in Niigata. Both incidents were caused when people ate fish--often daily over extended periods--from waters that were severely polluted with mercury from local industrial discharge. In particular, 23 children in Minamata had severe psychomotor retardation resulting from their mothers' eating contaminated fish while pregnant. Yet the mothers themselves showed only mild manifestations of poisoning or no damage at all.
plastics, drugs, and perfumes
acetaldehyde
As of March 2001, 2,265 victims had been officially recognized
(1,784 died) and over 10,000 had received compensation from Chisso 47

48. Assessing Your Risk http://www.edf.org/page.cfm?tagID=17694
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.
Fish sticks and "fast-food" are commonly made from fish that are low in mercury.

49. Next: Other Bioaccumulative Toxins