Organic Chemicals and Water

Synthetic Organic Chemicals Dioxins Pesticides PCBs Cleaning agents Chlordane Dioxin PBDE DDT Organochlorines Flame Retardants Principally Carbon, Hydrogen and Oxygen

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

Water Solubility Organochlorines as well as many other synthetic organic compounds are poorly soluble in water

NaClNa + + Cl - Na +

Dioxin

PCB µg/L (50% Cl ) 0.2 µg/L Sodium Chloride350 g/L Potassium Chloride280 g/L Ionic compounds are about 1 billion times more water soluble than neutral organics

Organic Solvents Improving Solubility Hexane Structural/chemical similarity between the chemical and the solvent. Soap/detergents

Structural/chemical similarity between the chemical and the solvent. Lipids and Solubility

Solubility A chemical’s solubility in lipids is inversely proportional to its solubility in water. Carbon/hydrogen Lipid (Carbon/hydrogen) water

Seawater Arctic cod muscle Narwhal blubber ppb ppb ppb Toxaphene Biomagnification BAF = 8 million

What’s been done?

PCBs used extensively in electrical equipment, especially transformers Electrical equipment plasticizers in paints, plastics and rubber products pigments, dyes and carbonless copy paper Solubility: µg/L PCBs were “banned” in 1979 PCBs, valued for chemical stability and fire resistance, were manufactured and processed primarily for use as insulating fluids and coolants in electrical equipment and machinery from

[EPA press release - April 19, 1979] The Environmental Protection Agency today issued final regulations banning the manufacture of polychlorinated biphenyls (PCBs) and phasing out most PCB uses. PCBs are toxic and persistent chemicals primarily used as insulating fluids in heavy-duty electrical equipment in power plants, industries, and large buildings across the country. The EPA rules will gradually end many industrial uses of PCBs over the next five years, but will allow their continued use in existing enclosed electrical equipment under carefully controlled conditions. 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

Spokane River Nov. 2002

Lake Michigan µ g PCB/Kg sediment EPA, 2004 N Concentration PCBs

Lake Erie Sediments PCBs After 25 years, PCBs continue to persist in the Environment EPA, 2004

Poor water solubility High solubility in Lipids and Organic Solvents Potentially long half lives Persistent Organic Pollutants PCB DDTDioxin

Half Life

½ Life The time it takes for a chemical to degrade To ½ of its original concentration. Ci ½ Ci time t 1/2

DDT 28 days 15 – 20 years PCBs 1 month 2-6 years > 60 years up to 150 years ½ Life and Organochlorines Dioxin years (7 years in humans)

Water Column Sediments (longer half-life) Environmental Persistence Solubility of < 0.2 μg/L Short Half life

Environmental Persistence, Half Life and Solubility

An Important Organic Solvent:Octanol C 8 H 18 O Neutral organic chemicals are soluble in organic solvents

The Octanol-Water Partitioning coefficient Octanol and water are immiscible Density: g/cm3 octanol water C 8 H 18 O

Octanol (Carbon/Hydrogen) water Carbon/hydrogen Partitioning C 10 H 20

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

Add 10 mg chemical separate chemical 0.01 mg L 9.99 mg L Water phase octanol phase Kow = 9.99 mg L 0.01 mg L = L Octanol 1L Waterl

K ow of some Organochlorine Compounds PCBs 2,000,000 DDT 4,000,000 Dieldrin 158,000 Toxaphene316,000

Water Column Sediments (Carbon) Environmental Persistence Solubility of < 0.2 μg/L Short Half life