PARENT SESSION

2A - Mixture Toxicity
Hall 6
8:30 AM - 12:30 PM, Monday, 28 April 2003
Chair: Hermens, J.¹, ¹
Co-chair: Toy, R.², Backhaus, T.³, ^{2 3}

(MO6/2) Derivation of environmental risk limits for total petroleum hydrocarbons in the Netherlands.

Verbruggen, Eric¹, Beek, Margriet², Brils, Jos³, Kalf, Dennis², Leslie, Heather⁴, Pijnenburg, Janny⁵, Parkerton, Thomas^{6, 7}, Traas, Theo¹, ¹ National Institute of Public Health and the Environment (RIVM), P.O. Box 1, Bilthoven, NL-3720BA, The Netherlands² Institute for Inland Water Management and Waste Water Treatment (RIZA), P.O. Box 17, Lelystad, NL-8200AA, The Netherlands³ TNO Environment, Energy and Process Innovation (TNO-MEP), Department Ecological RIsk Studies, P.O. Box 57, Den Helder, NL-1780AB, The Netherlands⁴ Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80176, Utrecht, NL-3508TD, The Netherlands⁵ National Institute for Coastal and Marine Management (RIKZ), P.O. Box 20907, The Hague, NL- 2500EX, The Netherlands⁶ Exxon Biomedical Sciences, Inc., East Millstone, 08875, New Jersey, USA⁷ CONCAWE, Boulevard du Souverain 165, Brussels, B-1160, Belgium

ABSTRACT- In the Netherlands generic Environmental Risk Limits (ERLs) are derived for soil, sediment and water quality. Dependent on the purpose, these risk limits should represent a protection level of 50% of the species as a trigger value for soil clean-up (SRC_eco) and 95% of the species as a measure for generic environmental quality (MPC). These ERLs are preferably derived from a species sensitivity distribution of single species laboratory toxicity studies, if enough chronic toxicity data are available. For mineral oil or total petroleum hydrocarbons (TPH) these risk limits were not based on ecotoxicological effect data, but were based on TPH concentrations in relatively clean sediment. To give the newly proposed ERLs for TPH a good scientific basis, chronic sediment toxicity tests were performed for 8 species, of which 5 with fresh water sediment and 3 with marine sediment. A limited comparison between the sensitivity of fresh water and marine species could thus be made. All experiments were performed with sediment spiked with two different types of oil: a type of gas oil and fuel oil. In addition, oil characterisation analyses were performed similar to the TPHCWG method. From these results ERLs for TPH in sediment were calculated, by analogy with the hydrocarbon block method. In this approach the blocks, based on chemical class (aromatics/aliphatics) and carbon number (boiling point), are assumed to be additive. The toxicity of different oil types is attributed to differences in relative composition over the blocks. These data were compared with similar data for toxicity of TPH to terrestrial organisms. Other aspects of toxicity, e.g. physical soiling, were also examined. Further, the results were compared with the toxicity of field samples, in view of the mixture composition of these samples.

Key words: HBM, TPH, SSD, narcosis