Endocrine disruptors and health: should South Africa be concerned?

The presence of persistent environmental chemicals with bio-accumulative properties and the potential of bio-magnification are globally of concern. Internationally, cases have been documented of alligators, frogs and fish changing sex as a result of exposure to endocrine disrupting chemicals (EDCs) in polluted aquatic environments. Increased incidences of human testicular cancer, undescended testis and hypospadias, as well as declining semen quality and a growing demand for assisted reproduction have been reported. Taken together, these findings raised the possibility that estrogenic/anti-androgenic environmental pollution plays a role in the pathogenesis of reproductive disorders. The aim is to summarize research performed at the University of Pretoria on EDCs over the past 11 years. Analytical chemistry and bioassays for estrogenicity were performed and various EDCs found in water and sediment samples from rural and urban areas, tap water, several dams and rivers. Exposure to p-nonylphenol, deltamethrin, DDT, cadmium and several phytoestrogens alone and in different combinations demonstrated reproductive toxicity. Eland with histological evidence of chronic estrogenic exposure were found in the same Nature Reserve where intersex catfish occurred in the polluted dams. General and reproductive data have been collected from humans living in a DDT-sprayed malaria area. Overall, environmental and wildlife levels of EDCs were similar, and in various cases much higher than reported from other countries. High estrogenicity was found in water that could not be accounted for by analytical chemistry. South Africa seems not to escape the threat of environmental estrogenic pollution on the health of human, wildlife and animals. Indications are that the pollution may be more severe and widespread than anticipated and there is an urgent need for public awareness and epidemiological data