ABSTRACT
N,N-Diethyl-m-toluamide (m-Det) is a widely used insect repellent readily available in various formulations. Radiolabeled (14C) m-Det was evaluated for rate and extent of skin penetration in three animal species. Absorption was quantitated in excreta for 7 days following a single dermal application and deposition monitored in tissues at necropsy. The potential for transplacental transfer and bioaccumulation of absorbed m-Det the fetus was also assessed following repeated applications to pregnant rabbits. Significant dermal absorption of the repellent was noted in all species, primarily in the first few hours, and was essentially complete after 3 days. No bioaccumulation of the labeled moiety was noted in tissues at 7 days. Pregnant rabbits receiving repeated dermal applications throughout gestation showed no evidence of bioaccumulation of the chemical in maternal tissue or individual fetuses. It is suggested that m-Det should not present a dermatoxic hazard to man and that topical absorption should be less than 10% of the applied dose.
Subject(s)
Benzamides/metabolism , DEET/metabolism , Insect Repellents , Absorption , Administration, Topical , Animals , DEET/administration & dosage , Dogs , Female , Injections, Intravenous , Male , Maternal-Fetal Exchange , Pregnancy , Rabbits , Rats , Rats, Inbred Strains , Species Specificity , Tissue DistributionABSTRACT
Rats were injected i.p. with the organophosphate insecticide ABATE and tested over the next 16 days. Animals given 1000 mg/kg showed impaired performance of a previously conditioned avoidance response 6 days after injection but not 2, 8, 10, or 16 days after injection. No behavioral changes were observed in animals given 316 or 562 mg/kg. A subsequent experiment showed that the avoidance impairment in animals given 1000 mg/kg was accompanied by significant erythrocyte, plasma, and brain cholinesterase activity inhibition and decreased spontaneous motor activity. If administration of the same ABATE dose was distributed over 6 days (167 mg/kg/day), cholinesterase and motor activity depression was still evident but conditioned avoidance performance was unimpaired. The results were interpreted as differential behavioral adaption to repeated injections of ABATE.
Subject(s)
Avoidance Learning/drug effects , Cholinesterases/metabolism , Insecticides/toxicity , Temefos/toxicity , Animals , Brain/enzymology , Cholinesterase Inhibitors/toxicity , Cholinesterases/blood , Erythrocytes/enzymology , Male , Motor Activity/drug effects , RatsABSTRACT
Studies were conducted to assess hazards to personnel exposed to hexachloroethane (HCE) in an industrial setting. Acute testing in laboratory animals indicated HCE was moderately toxic orally and could produce reversible eye irritation and mild skin irritation. Percutaneous absorption appeared to have no practical significance. The subchronic vapor inhalation toxicity was determined in rats, guinea pigs, Japanese quail and dogs in a 6-week test, monitoring pulmonary function changes, teratogenicity and operant behavioral changes in addition to clinical chemistry, hematology and histopathology. Concentrations of 260 ppm HCE vapor caused severe systemic effects in dogs, moderate effects in guinea pigs and rats and almost no responses in quail. No differences were found between exposed and control animals at 3 months after termination of these exposures. Minimal toxic effects were found following similar 6-week tests at levels of 48 ppm with no detectable changes at 15 ppm of HCE.
Subject(s)
Hydrocarbons, Chlorinated/toxicity , Abnormalities, Drug-Induced , Animals , Behavior, Animal/drug effects , Body Weight/drug effects , Coturnix , Dogs , Enzyme Induction , Ethane/analogs & derivatives , Ethane/toxicity , Female , Guinea Pigs , Hydrocarbons, Chlorinated/administration & dosage , Irritants , Male , Microsomes, Liver/enzymology , Mutation , Oxygen Consumption/drug effects , Rabbits , Rats , Respiration/drug effectsABSTRACT
Three (14)C-labeled candidate insect repellents, cyclohexamethylene carbamide, n-butylsufonimidocyclohexamethylene and 2-hydroxyethylcyclohexane carboxylate were evaluated for skin penetration in dogs and rabbits. Absorption of the repellents was determined by monitoring excreted urine daily for seven days following topical application. Significant percutaneous absorption of all three repellents occurred within 24 hours. (14)C-cyclohexamethylene carbamide showed the greatest absorption. Measurable amounts of radioactivity persisted at the application site for both species after seven days.
Subject(s)
Insect Repellents/metabolism , Skin/metabolism , Administration, Topical , Animals , Azepines/metabolism , Cyclohexanecarboxylic Acids/metabolism , Dogs , Insect Repellents/administration & dosage , Insect Repellents/urine , Rabbits , Sulfones/metabolismABSTRACT
Laboratory studies were conducted to acquire information concerning the acute toxicity of malathion in animals under various conditions of exposure. The responses in rabbits and quail exposed to aerosols generated from technical grade malathion (95%) and approximating an ultra-low volume ground spray were compared with those from a 6% malathion/No. 2 fuel oil mixture simulating a high volume spray. Results indicate that technical grade malathion (95%) as an ultra-low volume spray and at effective insecticidal concentrations in particle sizes having a mass median diameter of about 12 mu is relatively nonhazardous compared to the possible toxic fuel oil effects of a 6% malathion/No. 2 fuel oil mixture with a mass median diameter of 25 mu. Based on blood plasma cholinesterase activity analyses, quail were more sensitive to equivalent malathion exposure concentrations than were rabbits. Oral administration of technical grade malathion to rabbits resulted in reduction of plasma and erythrocyte cholinesterase activity at dosages of 120, 300, and 600 mg/kg with death resulting from 1200 mg/kg.
