Science Friday

Cancer, at its core, is a genetic disease: the result of DNA mutations that cause cells to grow out of control and develop tumors. And over the years, scientists have identified certain chemicals, called carcinogens, that are directly linked to those cancer-causing mutations, like those found in cigarettes.But the rates of some cancers, like colorectal and lung, are rising dramatically in certain populations, leaving scientists to wonder what carcinogens they might be missing, and how traditional models of detecting them are falling short.Last year, a landmark study published in the journal Nature confirmed a theory that toxicologists and cancer researchers had long suspected: that certain chemicals, like those found in air pollution, may not directly lead to cancerous mutations, but instead prime already vulnerable mutated cells to become cancerous. Some scientists have dubbed these chemicals “dark matter” carcinogens; they know they’re out there, exerting some kind of effect on increasing cancer rates, but