Major Determinants of Water Quality and the Impact or Availability of Water Pollutants Organisms Solubility Oxygen pH Nutrients (N, P) Metals (Hg, Pb, As) Organic Chemicals (PCBs, Dioxins)

Nutrients: Nitrogen and Phosphorus Both are limiting to primary productivity Excess amounts can severely alter ecosystems Availability in the environment is controlled by Oxygen pH Organisms Sources: fertilizers, manures, wastewater discharge

Nitrogen Dominant Forms: NH 4 + and NO 3 - Forms are controlled by organisms NH 4 + is converted to NO 3 - by aerobic bacteria Forms are controlled by Organisms Oxygen pH NO 3 - is much more mobile in the environment than NH 4 +

the highest density of point sources in the entire St. Johns River. Within this area, the river receives about 30 percent of its total amount of nitrate and ammonia nitrogen and 33 percent of its phosphate As the lower St. Johns River widens downstream of Palatka, the speed of water flow decreases, making the river lake-like and making conditions favorable contaminant accumulation. The roughly 30,000 acres of row crop agriculture in this area of the river basin supplies 40 percent of the spring season inorganic nutrients that enter the river between Palatka and Green Cove Springs. Algae typically peak in this area. Large, prolonged high tides can cause water to reverse its flow in the river as far upstream as Lake George. This delays the dispersal of pollutants. St. Johns Wastewater Treatment Agriculture Slow Flow of contaminants Surface Water and Nitrates

residential and commercial septic systems in rural areas about 300 row crop and vegetable farms 44 dairies with more than 25,000 animals 150 poultry operations with more than 38 million birds Lower Suwannee River Watershed Nitrates NO 3 Drinking water standard: 10 ppm

Phosphorus Availability and pH Low pH High pH Aluminum and Iron phosphates Calcium Phosphates Insoluble solids There is a limited ability of soils to immobilize phosphorus If the capacity is exceeded, phosphorus becomes mobile Mobile phosphorus can contaminate surface and groundwater

Phosphorus loading to S. Florida Ecosystem Inputs North and South of Okeechobee Dairy/Beef Agriculture (EAA) Kissimmee Basin

Organic soils possessing high natural fertility Historically flooded Everglades Agricultural Area

Under flooded conditions, oxygen levels tend to be low The diffusion of oxygen through water is about 1000 times slower than diffusion through air Water restricts the movement of oxygen Flooded Marsh Anaerobic heterotrophs: live in low-oxygen environments

Aquatic Plants and Algae Die Heterotrophic microorganisms decompose tissues Aerobic heterotrophic organisms use oxygen Oxygen becomes depleted in water; it cannot diffuse fast enough to support aerobic heterotrophs Anaerobic heterotrophs become dominant

C 6 H 12 O 6 + 3NO H 2 O = 6HCO NH kJ C 6 H 12 O 6 + 3SO H + = 6HCO HS kJ C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O 2880 kJ Anaerobic respiration is less efficient and produces less energy. Therefore, anaerobic decomposition is much slower than aerobic decomposition. e-

Buildup of Organic soils Organic matter decomposes slowly when submerged in water. (anaerobic decomposition) Soils throughout the glades historically have been submerged. (anaerobic conditions) Led to vast amounts of organic matter accumulation, sometimes >20 ft. thick. Organic matter continues to accumulate as long as flooded conditions persist.

EAA Drainage exposes soils to oxygen and decomposition by aerobic heterotrophic organisms which can more efficiently decompose organic matter Drainage

Subsidence of Organic soils Greater than 10 feet

1912 to 2000

Chemical Pollutants

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

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 Mercury, Arsenic, and Lead

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 Nitrate Symptoms included tremors, emotional instability, insomnia, dementia and hallucinations Wonderland

-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

Natural Soil and Water Contaminants

water table falling by 20 feet per year 21 million backyard tube wells Failure of 246 surface irrigation projects $600 electric pumps (1% of GDP) India 95 % What do you do when your water table falls?

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 groundwater can contain high fluoride levels Fluoride in water can be a cumulative poison

Intentional Fluoridation of Water in the U.S. Fluoridation became an official policy of the U.S. Public Health Service in 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.

How does it work? Tooth enamel is made of a mineral called hydroxyapatite Ca 5 (PO 4 ) 3 OH Hydroxyapatite is subject to dissolution by acids (H + ) Fluoridation changes the chemical composition of hydroxyapatite to a crystal less subject to acid dissolution Bacteria in the mouth create acids (H + )

Ca 5 (PO 4 ) 3 Sodium fluorosilicate (Na 2 SiF 6 ) Sodium fluoride (NaF) NaFNa + + F - OH Ingestion of fluoridated water increases the F - concentration in saliva F - replaces OH in hydroxyapatite making fluoroapatite F-F- Fluoroapatite is less soluble in acid than hydroxyapatite

Fluoride concentrations In U.S. tap water 0.5 – 1.1 mg/L Lower values in warm climates

1.6 to 6.6 mg/day Colorado Brown Stain Dental Fluorosis Intake: Permissible fluoride limit in India is 1.2 mg/L Fluoride levels between 5-25 mg/L have been found Fluoride levels > 1.5 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. Skeletal Fluorosis Intake Fluoride levels > 10 mg/L

Soil, Groundwater, and Arsenic

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

Inorganic Forms of Arsenic AsO 4 -3 AsO 3 -3 ArseniteArsenate 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

“The World’s Largest Mass Poisoning”

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

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

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 cholera, dysentery water-borne pathogens Deaths Due to Surface water contamination: 250,000/yr

The Solution: Tap groundwater resources easy inexpensive First 1 million wells were sunk with aid from World Governments UNICEF World Bank

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

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

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

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

2003 Studies

83 million people Bihar: 40% wells contaminated

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

Mercury Got Fish?

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

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.

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 mg/L. 1 gram annually

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

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

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)

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

- 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

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

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

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 H + = 6HCO HS - Sulfate Respiration Requires 4 elements: anaerobic conditions a carbon source (organic sediments) a source of sulfur (SO 4 - ) sulfur reducing bacteria Desulfuromonas,Pseudomonas

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

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

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

Bio-magnification

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 =

Chisso Corporation, a company located in Kumamoto Japan, dumped an estimated 27 tons of mercury compounds into Minamata Bay Between 1932 and 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

Assessing Your Risk 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.

Next: Other Bioaccumulative Toxins