May 22, 2011 – How Insecticides Work
QUESTION:
How do sodium channel inhibitors have an effect on insects and how do they endanger people?
ANSWER:
I suppose we could say that insecticides have the ability to affect humans in the same way they do insects, since in general the nervous systems of mammals and bugs work in pretty much the same way. We all have neurons that carry nerve signals to and from the brain and the chemistry involved is the same. There are some insecticides that may have very little effect on a human nervous system but be highly effective on that of an insect, such as many of the natural tree oils. These interfere with the neurotransmitter Octopamine, which regulates much of the metabolism in insects but is an enzyme that is not present in mammals.
But, for most nerve functions a nerve cell (neuron) is activated by some stimulus and the impulse moves from neuron to neuron to finally reach the brain for some interpretation and action. Of course this normally happens instantly. That signal is transformed to an electrical impulse of ions in order to pass along each neuron, and it moves through various "channels, one of which is the Sodium Channel. There also are "gates" that open or close to allow these ions to pass through or to block their movement. More specifically we might have certain pesticides that will interfere with this gate in the sodium channel by inhibiting a protein called GABA (gamma amino butyric acid). This protein is there to stop nerve impulses from continuing to fire by closing the gate, and if the pesticide has "inhibited" that protein the gates cannot close properly and the neuron continues to fire the signal along, well after it should have stopped doing so. The gates in the channel stay open and the ions just keep passing on through.
This results in tremors and eventually a loss of control of metabolic functions as they are overworked. In other words, it screws up the nervous system by interfering with the proper function of the neurons. The Synthetic Pyrethroids and Natural Pyrethrum are some of these GABA-gated Sodium Channel blockers. Similarly there are GABA-gated Chloride Channel blockers such as some chlorinated hydrocarbons and fipronil, and they would act in a similar manner except on this different channel (chloride instead of sodium).
How do they endanger humans? Well, these active ingredients work in the same way on humans as they do on bugs, but it is DOSE RELATED. The amount of an active ingredient that affects an ant or cockroach so seriously that it endangers that bug's health is so infinitesimal compared to the amount that would be needed to affect a human that we have this huge safety factor. A safety factor, that is, if we use the products correctly and according to the Label and good common sense. We mix them at the proper concentration, apply them to the proper places where we minimize human contact, and we keep people off treated surfaces until the treatment is dry.
View past Ask Mr. Pest Control questions.
How do sodium channel inhibitors have an effect on insects and how do they endanger people?
ANSWER:
I suppose we could say that insecticides have the ability to affect humans in the same way they do insects, since in general the nervous systems of mammals and bugs work in pretty much the same way. We all have neurons that carry nerve signals to and from the brain and the chemistry involved is the same. There are some insecticides that may have very little effect on a human nervous system but be highly effective on that of an insect, such as many of the natural tree oils. These interfere with the neurotransmitter Octopamine, which regulates much of the metabolism in insects but is an enzyme that is not present in mammals.
But, for most nerve functions a nerve cell (neuron) is activated by some stimulus and the impulse moves from neuron to neuron to finally reach the brain for some interpretation and action. Of course this normally happens instantly. That signal is transformed to an electrical impulse of ions in order to pass along each neuron, and it moves through various "channels, one of which is the Sodium Channel. There also are "gates" that open or close to allow these ions to pass through or to block their movement. More specifically we might have certain pesticides that will interfere with this gate in the sodium channel by inhibiting a protein called GABA (gamma amino butyric acid). This protein is there to stop nerve impulses from continuing to fire by closing the gate, and if the pesticide has "inhibited" that protein the gates cannot close properly and the neuron continues to fire the signal along, well after it should have stopped doing so. The gates in the channel stay open and the ions just keep passing on through.
This results in tremors and eventually a loss of control of metabolic functions as they are overworked. In other words, it screws up the nervous system by interfering with the proper function of the neurons. The Synthetic Pyrethroids and Natural Pyrethrum are some of these GABA-gated Sodium Channel blockers. Similarly there are GABA-gated Chloride Channel blockers such as some chlorinated hydrocarbons and fipronil, and they would act in a similar manner except on this different channel (chloride instead of sodium).
How do they endanger humans? Well, these active ingredients work in the same way on humans as they do on bugs, but it is DOSE RELATED. The amount of an active ingredient that affects an ant or cockroach so seriously that it endangers that bug's health is so infinitesimal compared to the amount that would be needed to affect a human that we have this huge safety factor. A safety factor, that is, if we use the products correctly and according to the Label and good common sense. We mix them at the proper concentration, apply them to the proper places where we minimize human contact, and we keep people off treated surfaces until the treatment is dry.
View past Ask Mr. Pest Control questions.
