Toxicity classification of pesticide using the component and cluster analysis

The toxicity of 17 agricaltural chemicals were examined by acute and reproduction tests using crustaceans (Ceriodaphnia dubia and Daphnia magna), early life stage toxicity test using zebrafish, Danio rerio, and growth inhibition test using green algae (Pseudokirchneriella subcapitata). Principal component and cluster analyses were then applied to the toxicity data to classify these chemicals. Seven pesticides exhibited high acute toxicity to crustaceans (LC5Os were below 10 ppb). EC50s for C. dubia and D. magna reproduction tests were lower than LC50 values of most pesticides used in this study. A few of them exhibited fairly high toxicity to either D. rerio or P. subcapitata (EC50s were below 10 ppb). The principal component analysis of these toxicity data revealed that three components mainly contributed to the toxic effects of the pesticides: components highly toxic to crustaceans, fish, and green algae, respectively. Cluster analysis was then carried out based on the data of the principal component analysis. Results indicate that these 17 chemicals were classified into 6 categories. This study demonstrated the importance of using various organisms to understand the toxic effects of chemicals on the ecosystem.