"International Symposium on Toxicity Assessment" is a series of international symposia, which started in 1983 and have been on a biennial basis since then. The aim of these symposia is the presentation of scientific surveys and papers relating to the fields of environmental science and more specifically to the topic of toxicity assessment using bioassays. The symposia are designed to encourage the exchange of ideas and knowledge and to strengthen communication and cooperation between environmental researchers and diverse groups of the scientific community concerned by current issues in ecotoxicology.