Lead arsenate
Lead arsenate is a chemical compound. Its chemical formula is PbHAsO4. It has lead, hydrogen, and arsenate (HAsO42-) ions in it. The lead is in its +2 oxidation state.
Properties
Lead arsenate is a white solid. It is highly toxic because of the lead and the arsenic in it. It does not dissolve in water.
Preparation
It was made by reacting lead nitrate with arsenic acid.
Uses
It was the most used insecticide that had arsenic in it. It was used against the potato beetle and the spongy moth. It replaced the even more toxic Paris Green. It was later used to kill certain moths, mosquitoes, and pests of cranberries. It was found that it stayed inside fruits even after washing off, so it was replaced with DDT. It was completely banned in 1988.
Lead Arsenate Media
Ad for Sherwin-Williams pesticides from the 1911 Door County Democrat. Today, about 3.9% of the land in the county is classified as "impaired" by the local government due to persistent contamination of the soil and groundwater.