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(18-17) Endocrine disrupting activity in South-African inland waters. Arijs, Katrien*,1, Verslycke, Tim1, Versonnen, Bram1, Vandenbergh, Gert1, Slabbert, Laetitia2, Janssen, Colin1, 1 Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology , Jozef Plateaustraat 22, Ghent, Belgium2 CSIR Environmentek, Water Environment and Forestry Technology, P O Box 395, Pretoria, South-Africa ABSTRACT- As part of a bilateral Belgium-South-Africa project to study possible endocrine disruptive effects occuring in South-African waters, a complementary approach was adopted using both in vivo (fish assays) and in vitro (yeast estrogen screen, YES) test methods. Results of the in vitro study will be presented. Water bodies and rivers within the vicinity of Johannesburg, Pretoria and Vereeniging (South-Africa) were sampled on three different occasions in 2000 and 2001. Water and sediment samples were taken from the Vaal, Jukskei and Rietvlei river catchments. Protocols were optimized for the extraction of organic compounds through solid-phase extraction (water samples) and soxhlet extraction (sediment samples). Extracts were subsequently analyzed for estrogenic activity using a previously described yeast estrogenic screen (YES) with Saccharomyces cerevisiae . A number of water and sediment samples exerted an estrogenic activity in the YES. Activities in both matrices were evaluated by correlation analysis and both spatial and temporal differences are described. The occurrance, distribution and importance of endocrine disruptive effects in urban South-African areas will be discussed. Key words: Endocrine disruption, Yeast estrogen screen, Environmental monitoring |
