Mosquitoes are progressively becoming resistant to industrial repellents and insecticides. This is the case for pyrethroids used on bednets.
Pyrethroids are toxic. Aquatic ecosystems are particularly vulnerable to the impact of permethrin. A fragile balance exists between the quality and quantity of insects and other invertebrates that serve as fish food. The 48-hour LC50 for rainbow trout is 0.0125 mg/L for 24 hours, and 0.0054 mg/L for 48 hours. The 48-hour LC50 in salmon is 0.0018 mg/L. As a group, synthetic pyrethroids were toxic...
