several orders of magnitude higher than levels found in the water [21–23] . USEPA
regulates PCBs under the CWA and has established water quality criteria and toxic
pollutant effluent standards. Based on the carcinogenicity of PCBs, USEPA
published a MCL Goal (MCLG) for PCBs at zero and the MCL of 0.5μg/L
(0.5 ppb) under the SDWA (see Table 4.2).
3.2.2 Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin TCDD)
Dioxin is considered an EDC on the basis of its effects that occur during pregnancy
which result in many malformations observed in the offspring of many species
including humans [24, 25]. Dioxin is a contaminant formed during the manufacture
of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), an herbicidal compound that comprised about 50% of the defoliant Agent Orange, and 2,4,5-T derivatives, as well as
other chemicals synthesized using 2,4,5-trichlorophenol. Dioxins may also be
formed during incineration of chlorinated industrial compounds such as plastic and
medical waste.
Dioxin is one of the most acutely toxic compounds synthesized by modern
chemistry. TCDD is the most toxic member of the 75 dioxins that exist and is the
one most studied. It is almost insoluble in water. TCDD is stable in water,
dimethylsulfoxide, 95% ethanol, or acetone. It can undergo a slow photochemical
and bacterial degradation, though normally it is extremely stable. Dioxin is degraded
when heated in excess of 500
C or when exposed to ultraviolet radiation under
specific conditions. TCDD has no known commercial applications but is used as a
research chemical. TCDD has been found in at least 91 of 1467 National Priorities
List sites identified by the USEPA [9]. Dioxins are widespread environmental
contaminants. They bioaccumulate throughout the food web because of their lipophilic properties and slow metabolic destruction. The primary source of dioxin
exposure to humans is from food.
3.2.3 Furan
Furan is classified as cyclic, dienic ether; it is a colorless, flammable liquid. It is
insoluble in water but is soluble in alcohol, ether, and most common organic
solvents. Furan is used primarily as an intermediate in the synthesis and production
of other organic compounds, including agricultural chemicals (insecticides), stabilizers, and pharmaceuticals [9]. Furan is a carcinogen [26] and its primary route of
potential human exposure is inhalation.
Furan was detected in 1 of 63 industrial effluents at a concentration of less than
10μg/L [9]. Furan was detected in a creek in the Niagara River watershed and in the
Niagara River.
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181
regulates PCBs under the CWA and has established water quality criteria and toxic
pollutant effluent standards. Based on the carcinogenicity of PCBs, USEPA
published a MCL Goal (MCLG) for PCBs at zero and the MCL of 0.5μg/L
(0.5 ppb) under the SDWA (see Table 4.2).
3.2.2 Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin TCDD)
Dioxin is considered an EDC on the basis of its effects that occur during pregnancy
which result in many malformations observed in the offspring of many species
including humans [24, 25]. Dioxin is a contaminant formed during the manufacture
of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), an herbicidal compound that comprised about 50% of the defoliant Agent Orange, and 2,4,5-T derivatives, as well as
other chemicals synthesized using 2,4,5-trichlorophenol. Dioxins may also be
formed during incineration of chlorinated industrial compounds such as plastic and
medical waste.
Dioxin is one of the most acutely toxic compounds synthesized by modern
chemistry. TCDD is the most toxic member of the 75 dioxins that exist and is the
one most studied. It is almost insoluble in water. TCDD is stable in water,
dimethylsulfoxide, 95% ethanol, or acetone. It can undergo a slow photochemical
and bacterial degradation, though normally it is extremely stable. Dioxin is degraded
when heated in excess of 500
C or when exposed to ultraviolet radiation under
specific conditions. TCDD has no known commercial applications but is used as a
research chemical. TCDD has been found in at least 91 of 1467 National Priorities
List sites identified by the USEPA [9]. Dioxins are widespread environmental
contaminants. They bioaccumulate throughout the food web because of their lipophilic properties and slow metabolic destruction. The primary source of dioxin
exposure to humans is from food.
3.2.3 Furan
Furan is classified as cyclic, dienic ether; it is a colorless, flammable liquid. It is
insoluble in water but is soluble in alcohol, ether, and most common organic
solvents. Furan is used primarily as an intermediate in the synthesis and production
of other organic compounds, including agricultural chemicals (insecticides), stabilizers, and pharmaceuticals [9]. Furan is a carcinogen [26] and its primary route of
potential human exposure is inhalation.
Furan was detected in 1 of 63 industrial effluents at a concentration of less than
10μg/L [9]. Furan was detected in a creek in the Niagara River watershed and in the
Niagara River.
4 Endocrine Disruptors
181