West Nile Virus Response Plan
Return to West Nile Virus Response Plan

APPENDIX C-4

Summary of Toxicological Information on Commonly Used Adulticides

Table 6. Chronic Toxicity in Rats: Ingestion

Active Ingredient Dose (mg/kg/day) Effect at LOEL
NOEL* LOEL**
Malathion 2.4 29 decreased plasma cholinesterase activity and body weights
Naled 0.2 2 decreased brain cholinesterase activity
Permethrin 5 25 increased liver weights
Piperonyl butoxide 50 500 decreased body weight gain, increased organ weights and liver lesions
Resmethrin -# 40 (LDT) enlarged livers and decreased spleen weights
Sumithrin 50 150 decreased body weights, increased liver weights and histopathology of lymph nodes and liver

* No-observed-effect level (NOEL) - The dose of a chemical at which there were no statistically or biologically significant increases in frequency or severity of adverse effects seen between the exposed population and its appropriate control.
** Lowest-observed-effect level (LOEL) - The lowest dose of a chemical in a study that produces statistically or biologically significant increases in frequency or severity of adverse effects between the exposed population and its biological control.
# A NOEL was not established for this study.
LDT - Lowest dose tested in the study.

formatting image

Revised: August 2000