Endocrine disrupting chemicals in freshwater and marine water

​Toxicant default guideline values for protecting aquatic ecosystems

October 2000

Description of chemical

Recently there have been increasing reports on the disrupting effects that chemicals released into the environment may be having on the normal endocrine functioning in a variety of aquatic organisms and terrestrial wildlife (Colborn et al. 1996, USEPA 1997b, OECD 1997a). Disruption to the endocrine system affects hormone production and distribution, ultimately impinging on basic life functions such as reproduction and development of the reproductive system, growth, maintenance of the body’s internal environment, and production utilisation and storage of energy (Wilson & Foster 1985). Adverse effects observed have included: abnormal thyroid function and development in fish and birds; decreased fertility and hatching success; either demasculisation and feminisation or defeminisation and masculinisation of various species; decreased offspring survival; and alteration of immune and behavioural function (USEPA 1997b).

These effects have been attributed to various chemicals, including some persistent organochlorines such as PCBs, DDT, dioxin and some pesticides (USEPA 1997b, Toppari et al. 1995). A spill in 1980 of dicofol contaminated with DDT metabolites was associated with severe effects on alligators and turtles in Lake Apopka in Florida, particularly on production and hatching, juvenile survival and normal development of reproductive systems (Guillette 1995, USEPA 1997b). Tributyltin (TBT) is well known for causing imposex (development of male characteristics) in female gastropods (Ellis & Pattisina 1990). Alkylphenols (e.g. nonylphenol and octylphenol) which are breakdown products of alkylphenol polyethoxylates used as industrial surfactants and bases for household products, have been linked with estrogenic effects in fish (Jobling et al. 1996). Harries et al. (1997) detected estrogenic effects in four of five UK rivers tested downstream of sewage treatment plants and wool scouring mills and related these to alkylphenols. Studies downstream of sewage plants in USA have produced similar results (Folmar et al. 1996), and also demonstrated some depression of serum testosterone levels in carp exposed to agricultural runoff. Recent studies (Desbrow et al. 1997) have indicated that the most widespread substances causing estrogenic effects from sewage treatment plants are both natural and synthetic oestrogenic hormones often in only very small quantities. Other chemicals which may cause endocrine disruption, but with little evidence to date in the aquatic environment, are bisphenol A (a plastic monomer), phthalates (Toppari et al. 1995), as well as cadmium, lead and mercury (OECD 1997b). There is also evidence of masculinisation of fish and disruption of reproduction downstream of pulp and paper mills (USEPA 1997b), which may be due to phytosterols released from the wood.

Often the same disruptive effect may be induced additively by mixtures of small quantities of different chemicals (conversely, mixtures of PCBs often have little estrogenic activity due to the mixture of compounds with opposing effects) (McLachlan & Arnold 1996). Secondly, it is thought that such adverse effects may be caused by a single, relatively small dose during a window of vulnerability for the foetus and effects may not appear until later (Center for the Study of Environmental Endocrine Effects 1995).

The current knowledge on endocrine disrupting chemicals is insufficient to make recommendations on water quality guidelines at present. Outcomes from the considerable international activity on endocrine disruptors (OECD 1997a,b, USEPA 1997b) will need to feed into future revisions of the Guidelines. Current challenges include assessing the likelihood of adverse effects on populations and communities, as well as establishing cause-effect relationships for effects observed in the field (USEPA 1997b), improving exposure assessment and assessing the effects of mixtures (Kavlock et al. 1996).

References

ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.

Center for the study of environmental endocrine effects 1995. Discussion draft on environmental endocrine effects: An overview of the state of scientific knowledge and uncertainties. CSEEE, Washington DC.

Colborn T, Myers JP & Dumanoski D 1996. Our stolen future. Little, Brown and Company, New York.

Desbrow C, Routledge E, Sheehan D, Waldock M & Sumpter J 1997. The identification and assessment of oestrogenic substances in sewage treatment works effluents. MAFF Fisheries Laboratory, Essex, and Brunel University, Oxbridge, R&D project 90.

Ellis D & Pattisina LA 1990. Worldwide neogastropod imposex: A biological indication of global TBT contamination? Marine Pollution Bulletin 21, 248-253.

Folmar LC, Denslow ND, Rao V, Chow M, Crain DA, Enblom J, Marcino J & Guillette LJ 1996. Vitellogenin induction and reduced serum testosterone concentrations in feral male carp (Cyprinus carpio) captured near a major metropolitan sewage treatment plant. Environmental Health Perspectives 104, 1096-1101.

Guillette LJ 1995. Endocrine disrupting environmental contaminants and developmental abnormalities in embyros. Human and Ecological Risk Assessment 1 (2), 25-36.

Harries JE, Sheahan DA, Jobling S, Matthiessen P, Neall P, Sumpter JP, Tylor T & Zaman N 1997. Estrogenic activity in five United Kingdom rivers detected by measurement of vitellogenesis in caged male trout. Environmental Toxicology and Chemistry 16, 534-542.

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. Environmental Toxicology and Chemistry 15, 194-202.

Kavlock RJ, Daston GP, DeRosa C, Fenner-Crisp P, Gray LE, Kaattari S, Lucier G, Luster M, Mac MJ, Maczka C, Miller R, Moore J, Rolland R, Scott G, Sheehan DM, Sinks T & Tilson HA 1996. Research needs for the risk assessment of health and environmental effects of endocrine disruptors: A report of the US EPA-sponsored workshop. Environmental Health Perspectives 104 (4), 1-26.

McLachlan JA & Arnold SF 1996. Environmental estrogens. American Scientist 84, 452-461.

OECD 1997a. Draft detailed review paper: Appraisal of test methods for sex-hormone disrupting chemicals. Organisation for Economic Co-operation and Development, Paris.

OECD 1997b. Web page on endocrine disruptors assessment activities at http//www.oecd.org/ehs/endocrine.htm. Organisation for Economic Co-operation and Development, Paris.

Toppari J, Larsen JC, Christiansen P, Giwercman A, Grandjean P, Guillette LJ, Jegou B, Jensen TK, Jouannet P, Keiding N, Leffers H, McLachlan JA, Meyer O, Muller J, Rajpert-De Meyts E, Scheike T, Sharpe R, Sumpter J & Skakkebaek NE 1995. Male reproductive health and environmental chemicals with estrogenic effects. Danish Environmental Protection Agency, Miljoprojekt No 210, Copenhagen, Denmark.
USEPA 1997b. Special report on environmental endocrine disruption: an effects assessment and analysis. US Environmental Protection Agency, EPA/630/R-96/012.

Wilson JD & Foster DW 1985. Williams textbook of endocrinology. 7th edn, WB Saunders Company, Philadelphia, Pa.