The top crops that use endosulfan are tomatoes, cucurbits (which include melons, cucumbers and squashes), potatoes, apples and cotton. Usage has been decreasing since 2002, when new restrictions were added. In California, about 60,000 pounds were applied to crops in 2008, compared with 151,000 pounds in 2002, according to the California Dept. of Pesticide Regulation.
First registered for use in the United States in the 1950s, endosulfan is one of the most abundant pesticides found in the global atmosphere. And unlike most other organochlorines, which were banned in the 1970s, its concentrations have been increasing since the 1980s in the Arctic and in other remote ecosystems, according to a 2009 study by British and Canadian researchers.
Traces of endosulfan are found on food crops, but EPA officials say the risks from consuming the residue are low. Because organochlorines accumulate in fatty tissue, those who eat high on food chains—such as the Inuit who eat marine mammals —are the most highly exposed.
United Nations countries are evaluating endosulfan for inclusion in the Stockholm Convention, an international treaty which bans or restricts persistent organic pollutants—chemicals that can build up in the environment. A decision by the UN's review committee is expected next year.
The ban on endosulfan will leave dicofol as the last major chlorinated pesticide allowed today in the United States, where it is used to kill mites, mostly on cotton and citrus. Pentachlorphenol is also used as a pesticide, although its use is restricted to treatment of railroad ties and utility poles, not food crops. Lindane is banned from crops but continues to be used in prescription shampoos for treating lice.