Many chemicals released into the environment are believed to disrupt normal endocrine functions in humans and animals.
These endocrine disrupting chemicals (EDCs) affect reproductive health and development. A major group of EDCs that could
be responsible for reproductive effects are those that mimic natural oestrogens, known as xeno-oestrogens. A number of in
vivo and in vitro screening strategies are being developed to identify and classify xeno-oestrogens, in order to determine
whether they pose a health risk to humans and animals. It is also important to be able to apply the assays to environmental
samples for monitoring purposes. In South Africa information on the levels of EDCs in water is limited. While establishing
the recombinant yeast screen bioassay (RCBA) using the yeast strain Sacchyromyces cerivisiae for oestrogenic activity,
problems were experienced with contamination. Four South African laboratory water sources were assessed. From the results
it was clear that the water used in the preparation of the medium for the assay was the source of oestrogenic contamination.
Care should be taken to eliminate all possible sources of contamination in the test procedures to eliminate the reporting of
false positive results. The fact that South African laboratory and surface waters tested positive for estrogenic activity has far
reaching implications regarding reproductive and general health.
de Jager, C
du Toit, D
Endocrine disrupting chemicals
Oestrogenic activity using a recombinant yeast screen assay
(RCBA) in South African laboratory water sources