ATLA::Alternatives to Laboratory Animals

Volume 29, Number 3

Study of the environmental hazard caused by the oil shale industry solid waste.

ATLA 29, 259-267, May/June 2001

Lee Põllumaa,¹ Alla Maloveryan,¹ Marina Trapido,² Helgi Sillak³ and Anne Kahru¹

¹National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, Estonia; ²Institute of Chemistry, Tallinn Technical University, Akadeemia tee 15, Tallinn, Estonia; ³Virumaa Environmental Research Laboratory, Pargi 15, Jõhvi, Estonia

SUMMARY

The environmental hazard was studied of eight soil and solid waste samples originating from a region of Estonia heavily polluted by the oil shale industry. The samples were contaminated mainly with oil products (up to 7231 mg kg) and polycyclic aromatic hydrocarbons (PAHs; up to 434 mg/kg). Concentrations of heavy metals and water-extractable phenols were low. The toxicities of the aqueous extracts of solid-phase samples were evaluated by using a battery of Toxkit tests (involving crustaceans, protozoa, rotifers and algae). Waste rock and fresh semi-coke were classified as of "high acute toxic hazard", whereas aged semi-coke and most of the polluted soils were classified as of "acute toxic hazard". Analysis of the soil slurries by using the photobacterial solid-phase flash assay showed the presence of particle-bound toxicity in most samples. In the case of four samples out of the eight. chemical and toxicological evaluations both showed that the levels of PAHs, oil products or both exceeded their respective permitted limit values for the living zone (20 mg PAHs kg and 500 mg oil products kg): the toxicity tests showed a toxic hazard. However, in the case of three samples, the chemical and toxicological hazard predictions differed markedly: polluted soil from the Erra River bank contained 2334 mg oil/kg, but did not show any water-extractable toxicity. In contrast, spent rock and aged semi-coke that contained none of the pollutants in hazardous concentrations, showed adverse effects in toxicity tests. The environmental hazard of solid waste deposits from the oil shale industry needs further assessment.

Keywords: oil shale industry solid waste, soil, toxicity, Toxkits, test battery, solid-phase flash assay, Daphnia, protozoa, photobacteria, algae, rotifers, polycyclic aromatic hydrocarbons, oil products, risk assessment