CHANGE OF PHISIOLOGICAL ACTIVITI OF DAPHNIA MAGNA, STRAUS UNDER THE INFLUENCE OF DIFFERENT FACTIONS OF OIL PRODUCTS
Petroleum and its products are very dangerous pollutants for the aquatic environment. They damage many natural processes and relationships, change the habitat of aquatic organisms. Assessment of the degree of water pollution by hydrocarbons is complicated by the fact that each oil fraction has a different degree of impact on aquatic organisms. The article shows that in course of bioassay test on Daphnia magna, Straus lethal toxic concentration (LC50) of heavy oil fractions (0.025 mg/dm3) and waste oil products (0.05 mg/dm3) were determined at concentrations 10 times lower than LC50 diesel fraction (0.25 mg/dm3) and 100 times lower than the LC50 of light gasoline and kerosene fractions (from 2.000 mg/dm3). Limited harmless concentrations (BK10), dissolved and dispersed in water of heavy lube oil (0.012 mg/dm3) are 2 times lower than BK10 fraction of diesel fuel (0.025 mg/dm3) and 20 times lower than BK10 light petrol and kerosene petroleum fractions (0.250 mg/dm3). Analysis of the test results proved the need to assess hydrocarbon pollution not only in terms of oil concentration in an aqueous medium, but also in terms of the acute aquatic toxicity.