Evaluation of long-term effects of chemicals and chemical tolerance in aquatic organisms: Report on CERI award in 2023

Abstract

This is the report of CERI award in 2023. We evaluated the long-term effects of chemicals, i.e. carbamate pesticides on the aquatic organisms (cladocerans and chironomids), which contributes to receiving the award. Several chemicals, e.g. pesticides transiently discharge into the river or lake because the chemicals rapidly flow into river by heavy rainfall. Considering the realistic exposure to chemicals, we performed the several multigenerational studies on aquatic organisms under the two conditions; 1) transient exposure (48 h) of the test organisms to the model chemical (insecticides or a pharmaceutical); 2) continuous exposure to the model chemical. In both of cases, a part of species acquired chemical tolerance to the test substance. We then elucidated the several mechanisms of chemical tolerance and the fitness costs. Here, I summarize our findings in this review paper. Additionally, to obtain the information on the multigenerational alteration in chemical sensitivity, I made literature search of the research papers on the multigenerational studies for cladocerans and chironomids. To clarify further long-term effects of chemicals, we should connect each finding in several multigenerational study.