Viktor A. YushchenkoUkrainian opposition presidential candidate

Among the Most Toxic Chemicals Known to Humankind

DioxinPCDDspolychlorinated dibenzo dioxins

Dioxin levels 80 times the State of Michigan cleanup standards were found near parks and residential areas in a floodplain south of the City of Saginaw at the confluence of the Tittabawassee and Saginaw Rivers.

Among the Most Toxic Chemicals Known to Humankind

DioxinPCDDspolychlorinated dibenzo dioxins

Dioxin is formed as an unintentional by-product of industrial processes involving chlorine, e.g. waste incineration, chemical and pesticide manufacturing and pulp and paper bleaching. Dioxin was present in Agent Orange (a defoliant used in the Vietnam War), was found at the Love Canal (a chemical dump site in Niagara Falls, NY) and was the basis for evacuations at Times Beach, MO (where contaminated waste oil was spread on dirt streets). TR SR

SB

Confluence

Among the Most Toxic Chemicals Known to Humankind

DioxinPCDDspolychlorinated dibenzo dioxins

Research on dioxin sources concluded that the chemical was a ubiquitous product of the combustion of organic matter and the author of the study commented that, “We now think that dioxins have been with us since the advent of fire.”

Among the Most Toxic Chemicals Known to Humankind

DioxinPCDDspolychlorinated dibenzo dioxins

The Hites GroupIndiana University

Association of dioxin with sediment.

Persistence of dioxin.

Geochronology of sediment.

Unimagined riches and Glory.

Nobel Prize.

Dawn of Fire.

0 600 1200 1800

0

4

8

12

16

20

24

1980

28

1965

1950

1935

1920

Concentration (ppt)

Dep

th in

Sed

imen

t (cm

)

Among the Most Toxic Chemicals Known to Humankind

DioxinPCDDspolychlorinated dibenzo dioxins

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800

600

400

200

0

Mill

ions

of P

ound

s

1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980

Production of Chloro-aromatics

Among the Most Toxic Chemicals Known to Humankind

DioxinPCDDspolychlorinated dibenzo dioxins

2011 - EPA and Dow Chemical Co. sign a legal agreement requiring Dow to clean up sediment in a three-mile stretch of the Tittabawassee River next to Dow's Midland Plant.

• Cap contaminated sediment with clean material.

• Remove and treat DNAPL (Dense Nonaqueous Phase Liquids)

• Isolate contaminated sediment with sheet pile and a capand capture water within the sediment and treat it.

• Dredge and dispose of contaminated sediment

Management Actions