Abstract:
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. Oestrogens and androgens mediate their activity via intracellular receptors – directly in muscular tissue as well as indirectly via stimulation of growth hormones from the pituitary glands and other growth factors from liver plus several other organs. Mancozeb is a metal ethylenebisdithiocarbamate (EBDC) fungicide used to protect many fruits and vegetables and field crops against pathogenic fungal. It causes a variety of defects on the female reproductive system in experimental animals and is therefore considered a suspected EDC. This fungicide can also induce toxic effects in cells of the immune system and other non-immune cells leading to genotoxicity and apoptosis. The mechanisms of EDCs involve divergent pathways including (but not limited to) oestrogenic, antiandrogenic, thyroid receptors; that are highly conserved in wildlife and humans, and which can be modelled in laboratory in vitro and in vivo models. The endocrine disrupting properties of Mancozeb are not known as of yet and therefore the T47D-KBluc reporter gene assay, GH3.TRE-Luc and MDA-kb2 reporter gene assay were used determine the possible endocrine disrupting activity/potential there-of. No activity was detected in any of the assays and no mancozeb was detected in any of the dams either. Oestrogenic activity was detected in Albasini Dam, Nandoni Dam and Xikundu weir but all values were below 0.7 ng/ℓ trigger value for oestrogenic activity in drinking water.
