True or false: Chemicals you swallow or inhale are poisoning you or causing cancer.
This is false, but hundreds of organizations continually claim otherwise, often to persuade you to buy something “safer” (and costlier) or to generously fund them. The science of toxins is called toxicology. One of its founders, Paracelsus (circa 1500), said, “All substances are poisons. The right dose differentiates a poison from a remedy.” So too much of anything is harmful, but lower doses are not only harmless, but frequently beneficial.
Only about 10 percent to 25 percent of people need to limit salt intake. Other countries recognize this fact, making the United States almost unique in demonizing salt. Or consider BPA, a chemical used in plastic bottles and the linings of food cans which is claimed to cause numerous disorders. Some studies suggested this, but Richard Sharpe of the University of Edinburgh said that “much larger carefully designed studies have failed to confirm these initial studies.” Also, can linings containing BPA have virtually eliminated foodborne illness from canned foods.
What is a carcinogen? To the U.S. Food and Drug Administration, any chemical that causes cancer in lab rodents at any dose is a potential carcinogen. About half of all chemicals — natural and synthetic — are carcinogens by that definition. Many are important economically and make us healthier. The FDA's criteria for a “probable carcinogen” are very high.
So when somebody says you'll be poisoned or get cancer, be skeptical.
Elliott Doane, Oklahoma City