Water UK

Summary

 • UK water suppliers place the highest priority on assuring the quality of water provided to their customers.

 • Some concern has been expressed about the potential for certain chemicals that may be present in river water to disrupt hormone systems by acting like oestrogens. However, recent research carried out for the European Commission has shown that treatment and other barriers are effective in preventing such substances reaching drinking water.

 • Based on the current best scientific evidence, in 2003 an EU conference of experts concluded that it is neither necessary nor practical to set any formal statutory standards for endocrine disrupters in drinking water.

 • It will, however, be important for environmental authorities to work with industry and other parties to take every practicable action to minimise the occurrence of such substances in the environment.

 • Water suppliers will also continue to work with the appropriate authorities to ensure that such substances also do not arise from material used in the treatment and transport of drinking water.

Technical background

Where do Endocrine Disrupting Chemicals (EDCs) come from?

Questions have been raised about the risks to the aquatic environment from man-made chemicals that have shown oestrogen-like activity in experimental systems. However, most of these substances, including, for example, alkyl phenols and certain pesticides, are invariably much weaker (usually more than 100,000 times) in activity than natural or synthetic oestrogens and are only active in mammals at levels much higher than those encountered through environmental exposure.

Research has also demonstrated that even some well treated sewage effluents can have an oestrogenic effect in fish. The agents responsible result largely from the excretion of natural and/or synthetic hormones from men and women and the effect appears to dissipate very quickly once effluent is dispersed in the receiving river. A number of important research programmes are continuing to shed light on the occurrence, behaviour and effects of EDCs in the environment. Water UK follows all such research closely and water suppliers will continue to support such research.

What standards exist for EDCs in drinking water?

The WHO has taken the view that it is not appropriate to try and establish a guideline value for endocrine disrupters as a group of substances. However, the WHO does consider endocrine disruption as a toxicological endpoint when developing guideline values for chemical contaminants in drinking water. A European workshop of regulators, water suppliers, researchers and other stakeholders also decided, based on high quality European research, that the risk of contamination of drinking water was small and that specific regulations were not appropriate. Ensuring good treatment and control of products in contact with drinking water was considered the best way forward.

Direct evidence for the effects in man as a consequence of exposure through a range of environmental routes is very limited and in many cases contradictory or controversial. There is evidence that some hormonally related cancers may be increasing in a number of countries. Some findings also suggests that human sperm quantity and quality has been declining since the 1940s. Although such changes could possibly be induced by environmental chemicals, there is little good evidence to support this and they could equally well be the result of lifestyle changes (e.g. diet, stress, smoking, drinking alcohol).

Epidemiological evidence from different countries continues to support the view that drinking water is not likely to be involved in the possible effects in man discussed above, even if these effects are shown to be a consequence of exposure.

How is the quality of drinking water assured?

An independent study by the Fraunhofer Institute, entitled Study on endocrine disrupters in drinking water - Final report (February 26, 2003), for the European Commission, concluded that exposure to EDCs from consumption of drinking water is very unlikely to occur, even if the highest concentration of an individual EDC reported for drinking water is considered for its effects on humans.

Tests carried out on surface water have shown positive results in sensitive bioassays in fish and in bioassays in vitro. However, no such positive results have been found with drinking water. Recent studies using extremely sensitive analytical techniques have been negative. Generally, the nature of EDCs means that they are unlikely to remain dissolved in water and that water treatment will provide further significant barriers. There is now a body of experimental evidence to support these arguments. Much of the research has been carried out with the cooperation of UK drinking water suppliers, and the UK water industry continues to support and carry out research in this field.

It has been suggested that substances present in some materials used to transport drinking water may be of concern. There are tight regulatory controls on the materials that can be used in contact with drinking water and all research on this topic to date is reassuring.

Phill Mills
Director of Water Services
020 7344 1833