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Safety of malathion dusting powder for louse control
Abstract:
Because some strains of body lice are resistant to DDT and gamma-BHC, there is need for other effective, safe chemicals to control them. Malathion is known to be effective at a concentration of 1%. To test its safety, the bodies and clothing of 39 men were dusted 5 times a week for 8-16 weeks with talcum powder containing 0, 1%, 5%, and 10% malathion. Complaints about odour and skin irritation were roughly proportional to dosage. No change in blood cholinesterase activity was found, except perhaps with 10% powder. Urinary excretion of malathion-derived material was proportional to dosage. No other changes attributable to malathion were observed and the compound is considered safe for control of head and body lice.
Insights
Malathion is a safe and effective chemical for controlling body lice, even at higher concentrations. Studies show no significant adverse effects, making it a viable alternative to DDT and gamma-BHC resistant lice treatments.
Area of Science:
- Medical Entomology
- Toxicology
- Dermatology
Background:
- Insecticide resistance to DDT and gamma-BHC necessitates alternative treatments for body lice.
- Malathion demonstrates efficacy at 1% concentration for louse control.
Purpose of the Study:
- To evaluate the safety of malathion for human use in controlling head and body lice.
- To determine potential adverse effects and safe dosage ranges of topical malathion.
Main Methods:
- 39 men were dusted with talcum powder containing 0%, 1%, 5%, and 10% malathion, 5 times weekly for 8-16 weeks.
- Monitored for skin irritation, odour, blood cholinesterase activity, and urinary excretion of malathion metabolites.
Main Results:
- Adverse effects (odour, irritation) were dose-dependent.
- No significant changes in blood cholinesterase activity were observed, except possibly at 10% malathion.
- Urinary excretion of malathion metabolites correlated with dosage.
Conclusions:
- Malathion is considered safe for topical application in controlling head and body lice.
- The study supports malathion as a safe alternative insecticide for pediculosis treatment.
