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2A - Mixture toxicity (MOP/63) Biological Tests for Monitoring Water Pollution caused by Oil Industry. Pavlic, Z.1, Ulm, L.1, Puntaric, D.1, Smit, Z.1, 1 Zagreb Institute of Public Health, Department of Ecology, Zagreb, Croatia ABSTRACT- One of goals of this paper was to estimate the effect which oil industry waste waters might have on water organisms, and also to see the possibility to estimate the influence on underground waters. To achieve this goal, two types of biological tests with different end point measurement have been used. Both tests are these days commonly used for testing products finally deposited in fresh waters: the immobilization test, and the growth inhibition test. Growth inhibition tests have been made using green unicellular algae Raphidocelis subcapitata and Scenedesmus subspicatus and diatoms Skeletonema costatum and Phaeodactylum tricornutum, while immobilization tests have been performed using the cladoceran Daphnia magna. In addition to biological tests, also the chemical analysis has been performed recording 23 parameters: pH, salinity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC), lipophylic substances, hydrocarbons, phenol index, anionic surfactants, non-ionic surfactants, heavy metals (lead, cadmium, mercury, chrome, zinc, nickel and copper), ammonia, nitrites, nitrates, chlorides, and total amount of phosphor. During the twelve month period, two sorts of water samples have been analyzed: waste water at the drain, after the purifying process, and underground water from the piezometer belonging to the oil industry plant. In the same time under laboratory conditions, the influence of substances found has been studied using specific sorts of indicating water organisms. The purpose of this paper was to determine the sensitivity of tested sorts to particular parameters known from previous research and routine analysis to have the highest correlation with mortality or growth inhibition. Using multivariate statistical analysis methods the influence of each parameter on the test results interpretation and differences among tested organisms has been determined. Optimal conditions for systematic test methods has been determined, in order to enhance conditions for estimation the ecological risk based on the test results. Key words: end points, Biological tests, monitoring, oil industry |
