Symposium
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Environmental
Governance and Analytical Techniques: Environmental Issues Related
to EDC Pollution
9 - 10 February 1999 Tokyo, Japan |
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EDC
Pollution in Japanese Rivers
Taisen Iguchi Department of Biology and Graduate School of Integrated Science Yokohama City University, Japan Many chemicals released into the environment potentially disrupt the endocrine system in wildlife and humans. Some of these chemicals have estrogenic activity by binding to estrogen receptors. Especially, chemicals released into water may alter endocrine and sexual development in aquatic wildlife: hermaphrodites in roach, reproductive toxicity in male zebra fish, modification of the gonadal differentiation in male carps and in turtles, and genital abnormalities in alligators. These deleterious effects have been observed in areas where various products and byproducts of the manufacture of industrial chemicals, pesticides, herbicides, fungicides, etc., are present. Vitellogenin (VTG), a yolk protein normally produced only in the female liver in response to ovarian estrogens, is synthesized in response to exogenous estrogenic chemicals in male fish. There is conclusive evidence from the freshwater environment in the UK that almost all sewage treatment works (STW) discharges and some associated downstream receiving waters contain estrogenic agents. The major estrogenic agents identified in STW effluents were the natural hormones 17?-estradiol (E2) and estrone, the synthetic hormone ethinylestradiol and nonylphenol (NP). Reproductive abnormalities with a wide-spread occurrence were observed in certain fish species: elevated VTG levels and intersex conditions (locally up to 100% in roach, Rutilus rutilus). Field studies showed strong correlative evidence between STW effluents and these conditions. Causal evidence was obtained from caging and laboratory studies. The observed estrogenic effects in fish are not unique to the freshwater environment, as recent studies also indicate elevated vitellogenin levels in estuarine and coastal flounder (Platichthys flesus). Intersex in this species was only locally found in estuaries (up to 20%). Recently the first nationwide survey on EDC in the water environment was carried out by Ministry of Construction and Environment Agency in Japan. Ministry of Construction measured 9 chemicals at 256 locations. Di-2-ethylhexyl phthalate (33.6%), di(2-ethylhexyl) adipate (26.2%), bisphenol A (Bis A, 23.8%) and NP (12.5%) and E2 (56.3%) were detected, but almost no octylphenol (0%), butylbenzyl phtalate (0.4%), di-n-butyl phthalate (4.3%) or styrene monomer (0%) were detected. In 109 river systems, NP (19.3%), di(2-ethylhexyl) adipate (37.6%), Bis A (31.2%) and E2 (58.7%) were detected. In the water flow into the 10 treatment plants, 8 chemicals except styrene were found. In discharged water from 10 treatment plants, 5 chemicals were detected: NP (7), di-2-ethylhexyl phthalate (5), di(2-ethylhexyl) adipate (8), Bis A (9) and E2 (10). EDC concentration was reduced dramatically by sewage treatment plants except E2 which was reduced to 34%.
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