I don't think the final question is how much do we need to avoid. We are protecting ourselves and the things we want to keep alive in the future. We have to the

I don't think the final question is how much do we need to avoid. We are protecting ourselves and the things we want to keep alive in the future. We have to then ask, "Will this permanently destroy us or our living space?". Also, science determines LD50 all the time. What they often do not check is what amount of pesticide needs to be consumed before your health or intelligence drop by 10%. Those would be excellent numbers to have available.