Thornton is a research fellow at Columbia University's Center for Environmental Research and Conservation. Thornton says that evidence exists linking low-level organochlorine exposure to an increased risk of cancer, infertility, impaired child development, and disrupted immune systems. He says we must do away with a regulatory system that looks at one chemical at a time, and replace it with a precautionary approach that addresses major classes of chemicals and industrial processes. We spoke with Thornton about his book, and he began the conversation by launching into a chemistry lesson.
Chlorine is one of the universe's basic elements.
In nature, it exists almost solely in the form of salt - sodium chloride, the extremely stable ionic form of chlorine that is abundant in the seas and in everyone's saltshaker. The environmental issue is not with salt but with chlorine gas and the chemicals that the chemical industry makes from it. Chlorine gas is produced at very large chemical facilities that take a solution of saltwater and zap it with an incredibly powerful electric current, producing an entirely new substance, chlorine gas, a heavy poisonous gas that was used as a chemical weapon in World War I. Chlorine gas combines rapidly with organic matter and produces a new class of chemicals called organochlorines. Organochlorines are generally foreign to nature, but they are produced by the chemical industry in huge amounts - millions of tons per year. They tend to be extremely toxic, many of them are very long living in the environment, and they tend to be fat soluble, which means they build up in the tissues of human beings and other organisms.