Chemical Monitoring of Organic Ecotoxicants in Aqueous Systems

Resumo

Monitoring of organochlorine pesticides (OCP), polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) in surface waters, sediments and aquatic lives of the benthic layer from different water systems of Ukraine was carried out. Information about the levels of these organic contaminants was collected, summarized and presented according to universally accepted regulatory standards that determine the toxicity of compounds of these classes. Regularities of variations of ecotoxicants concentrations in five water systems of the Dnipro river and the Black Sea (Dnipro-Bug estuary, the Danube delta, Balaklava bay, Sevastopol bay) were established. It was found that in many bottom sediment samples the recorded levels of OCP, PCB, and PAH exceed the values of TEC (Threshold Effect Concentration) and PEC (Probable Effect Concentration). To assess the toxicity of hydrobionts, the content of OCP and PCB is given as relative to the toxicity equivalent factor (TEF) and toxicity equivalent (TEQ). The levels of PCB in hydrobionts are presented relative to TEQ and indicate that hydrobionts of the bottom layer are significantly contaminated with compounds of OCP and PCB and thus bioconcentration of such organic contaminants by high organisms along the trophic chain is possible.