Sediment toxicity assessment with Photobacterium phosphoreum: A preliminary evaluation of natural matrix effect

In environmental toxicity testing, Microtox(R) Solid-Phase Test (SPT) is on e of the most sensitive sediment bioassays; its real sensitivity and discri minatory power is however still unclear. SPT protocol is subject to several interferences related to the matrix variability that make it difficult to screen the genuine toxicity of solid-associated contaminants. In order to estimate natural matrix effect, correcting raw data from the ma in interference due to smaller particle size, it has been developed a preli minary relationship between the "natural" toxicity of 2 sets of clean refer ence samples of sediment (physically and chemically characterized) and grai n-size particles. We also conducted some trial applications on harbour samp les sediment, with the aim to purpose an example of harbor sediment toxicit y classification.