APPLICATION OF FUZZY CLUSTERING TO DATA DEALING WITH PHYTOTOXICITY

There is a lack of knowledge in the scope of phytotoxicity because the concentration of chemicals in the environment and their uptake by vas cular plants is quite difficult to control. Fuzzy clustering, a cluste ring method which derives the degree of membership to each cluster, wa s applied to analyze TOXSCREEN, a dataset of chemicals tested with soy bean and barley under identical conditions. The clustered variables we re the partition coefficients octanol-water (K-OW) and atmosphere-wate r (K-AW), the molecular weight (MW) and effective concentration regard ing 50% of the experiment population (EC(50)). The clustering of only physical parameters yielded in a good separation of aromatics and non- aromatics, but cluster decomposition in the sense of phytotoxicity was rather poor. Adding EC(50) resulted in the good decomposition of chem icals with different toxicity.