The Influence of Soil Characteristics on the Toxicity of Oil Refinery Waste for the Springtail Folsomia candida (Collembola).

We determined the toxicity of oil refinery waste in three soils using the springtail Folsomia candida (Collembola) in bioassays. Sublethal exposure to a concentration series of API-sludge presented EC50's for reproduction of 210 mg/kg in site soil; 880 mg/kg in LUFA2.2- and 3260 mg/kg in OECD-soil. The sludge was the least toxic in the OECD-soil with the highest clay and organic matter content, the highest maximum water holding capacity, and the least amount of sand. It was the most toxic in the reference site soil with the lowest organic matter content and highest sand content. The results emphasized the important role of soil characteristics such as texture and organic matter content in influencing toxicity, possibly by affecting bioavailability of toxicants.