Alkylphenols estrogenicity

In general, the main pollution problems associated with surfactants can be summarized as (1) foaming in river and wastewater treatment plants [314,326, 344,348,349,356,357], (2) transformation to bioactive metabolites (i.e., poly-ethoxylated alkylphenols, estrogenic compounds) under aerobic and anaerobic conditions [315,356], and (3) formation of certain cationics which are toxic to microorganisms at high concentrations [356,357]. 

The sheer complexity of environmental mixtnres of EDCs, possible interactive effects, and capacity of some EDCs to bioaccumulate (e.g., in fish, steroidal estrogens and alkylphenolic chemicals have been shown to be concentrated up to 40,000-fold in the bile [Larsson et al. 1999 Gibson et al. 2005]) raises questions about the adequacy of the risk assessment process and safety margins established for EDCs. There is little question that considerable further work is needed to generate a realistic pictnre of the mixture effects and exposure threats of EDCs to wildlife populations than has been derived from studies on individual EDCs. Further discussion of the toxicity of mixtures will be found in Chapter 2, Section 2.6. 

Nimrod, A.C. and Benson, W.H. (1996). Environmental estrogenic effects of alkylphenol ethoxylates. Critical Reviews in Toxicology 26, 335-364. 

Ahel M, Molnar E, Ibric S, Giger W (2000) Estrogenic metabolites of alkylphenol polyethoxylates in secondary sewage effluents and rivers. Water Sci Technol 42 15-22... 

Tabira Y, Nakai M, Asai D, Yakabe Y, Tahara Y, Shinmyozu T, Noguchi M, Takatsuki M, Shimohigashi Y (1999) Structural requirements of para-alkylphenols to bind to estrogen receptor. Eur J Biochem 262 240-245... 

Jobling S, Sheahan D, Osborne JA, Matthiessen P, Sumpter JP (1996) Inhibition of testicular growth in rainbow-trout (Oncorhynchus mykiss) exposed to estrogenic alkylphenolic chemicals. Environ Toxicol Chem 15 194-202... 

The occurrence of APEO or their metabolites (AP and carboxylated derivatives) was also studied in two tributaries of the Llobregat river (northeastern Spain). The Llobregat river is one of the most important sources of drinking water for the Barcelona area with a population of 3.2 million people. Since 1960, the effluents from tannery, textile, pulp and paper industries, situated along the river basin, have discharged into the river and several comprehensive studies [15—17] have been performed in order to determine the levels of estrogenic alkylphenolic compounds (and steroid sex hormones) and to study the effects of WWTP effluents on the reproductive physiology of fish. 

The results were compared with the effects of the main natural estrogen 17(3-estradiol. The following conclusions can be made with regard to alkylphenols ... 

Substitution of the hydroxyl group with a similar-sized propylene oxide derivative creating a propoxylated alkylphenol causes a great reduction in estrogenicity. 

Routledge, E.J. and Sumpter, J.P. (1997) Structural features of alkylphenolic chemicals associated with estrogenic activity. J. Biol. Chem., 272 (6), 3280-3288. 

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