Re-evaluation of neurobehavioural toxicity of clothianidin using statistical methods for ordered alternatives assuming dose-response effect

Abstract

Neurobehavioural toxicity of clothianidin in previous studies was re-evaluated using statistical methods for ordered alternatives assuming a dose-response effect. In a maternal exposure study, clothianidin was added into the diet to provide levels of 0% (control), 0.002%, 0.006% and 0.018% during the gestation and lactation periods in mice. In exploratory behaviour of male offspring in the F₁ generation, average speed increased significantly in a dose-related manner in the Jonckheere test. Total distance lengthened in the high-dose group and average speed increased in the high-dose group in the Shirley–Williams test. In a two-generation toxicity study, clothianidin was added in the diet to provide levels of 0% (control), 0.003%, 0.006% and 0.012% from 5 weeks of age of the F₀ generation to 11 weeks of age of the F₁ generation in mice. The exploratory behaviour of adult males in the F₀ generation, the average time of movement, and the number of rearing and rearing time increased significantly in a dose-related manner in the Jonckheere test. The average speed increased in the middle- and high-dose groups, number of rearing increased in the high-dose group and rearing time lengthened in middle- and high-dose groups in the Shirley–Williams test. These results suggest that the use of the appropriate statistical methods adjusted to the objectives of the study and the characteristics of the data could provide more definite conclusions.