It is widely acknowledged that our environment is becoming increasingly contaminated with man-made chemicals. Mammals, as well as lower organisms, are vulnerable to exposure to these agents through a variety of different sources and routes and there are concerns that they may be having a detrimental effect on ecological and population health. It is just over 40 years since wildlife studies first suggested that environmental chemicals could be interacting with hormone systems,¹ a hypothesis which has since been consolidated and debated both in the popular press and in the scientific literature. Concerns about environmentally mediated endocrine toxicity have also captured the attention of many national and international health organisations,² as well as lobbying groups such as Greenpeace and the World Wildlife Fund (UK). In recognition of the possibility of an emerging public health threat, the European Commission³ has identified endocrine disrupting chemicals (EDCs) (table 1) as an important public health issue and is currently supporting a number of research initiatives.

Although there is a wealth of laboratory based studies that demonstrate and delineate the range of toxic effects that can be induced following exposure to certain chemicals, extrapolating these observations to the natural environment and to human populations has been difficult. To date the clearest evidence that chemicals can act as endocrine disrupting agents has been derived from observations made in the wildlife setting where reports of deleterious effects on the reproductive system have predominated. However, insufficient epidemiological and laboratory data currently exist to provide an accurate assessment of the risks to public health posed by EDCs in the relatively low ambient doses normally found in the environment. There is indirect evidence from secular changes in childhood growth and reproductive development which suggests exposure to these …