Interior view of the Dow Chemical Company's lead arsenate plant with partial view of industrial machinery and barrels used for storage and transport. An inorganic pesticide, lead arsenate was first used to combat gypsy moths in apple orchards in the 1890's and was introduced as part of Dow's agricultural products line in 1910. Due to the pesticide's effectiveness, low cost, ease of use, and persistence, farmers widely used lead arsenate for about sixty years before pesticide resistance and decreased efficacy led to use of alternatives like DDT. Concerns about environmental contamination and threats to human health likewise contributed to lead arsenate's decline.