Huffington Magazine Issue 6 | Page 48

HUFFINGTON 07.22.12 CHEMISTRY LESSONS ute quantity can bring about vast changes in the body.” Lanphear of Simon Frasier University notes that we are now worrying about even smaller exposures than Carson was suggesting. “Parts per billion,” he says. Recent research has also questioned the popular notion that “the dose makes the poison.” Minuscule concentrations of chemicals that disrupt hormones — common in industrial pollution, pesticides and plastics — may have potent effects, sometimes even when large doses of the same chemical appear harmless. Some chemicals also can accumulate in the environment and the human body, where they can combine and interact with other chemicals. “This is why there is no ‘safe’ dose of a carcinogen,” Carson wrote. Carson pointed out one combination of chemicals that had already raised red flags among scientists: malathion mixed with other organophosphate pesticides. Administered together, she wrote, “a massive poisoning results — up to 50 times as severe as would be predicted on the basis of adding together the toxicities of the two.” Organophosphates, including malathion, are still in use today. “Things are far more complicated chemically than they were in Carson’s time,” says Wargo. “There are so many uses of many more active ingredients, inert ingredients and differently formulated products that it’s become difficult for governments to identify the risks.” “We are now living in a world probably beyond what Carson could have ever imagined, in terms of the number of chemicals kids interact with every day,” says Pingree. “And we’re having all the impacts that she worried about.”