Endocrine-disrupting activity of the fungicide mancozeb used in the Vhembe District of South Africa

Abstract

Many chemicals released into the environment are believed to disrupt normal endocrine functions in humans and animals. A major group of endocrine disrupting chemicals (EDCs) that could be responsible for reproductive defects are those that mimic natural oestrogens, known as xenoestrogens. A number of in vivo and in vitro screening strategies are being developed to identify and classify xenoestrogens, in order to determine whether they pose a health risk to humans and animals. 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. The T47D-KBluc, GH3.TRE-Luc and MDA-kb2 reporter gene assays were used to determine the possible endocrine disrupting activity/potential of mancozeb. 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⁻¹ trigger value for oestrogenic activity in drinking water.

Keywords: endocrine disrupting chemicals, reporter gene assays, xenoestrogen