Researchers have long struggled to detect evidence of cancer in the skeletons and mummified flesh of the ancient dead. But recorded cases of cancer in ancient populations are rare. Indeed, one study published in 1998 in the Journal of Paleopathology calculated that just 176 cases of skeletal malignancies had been reported among tens of thousands of ancient humans examined. The low number of cases prompted a theory that cancer only began flourishing in the modern industrial age, when carcinogens became more widespread in food and in the environment and when people began living longer, giving tumors more time to grow and proliferate.
But ancient populations, says Albert Zink, a biological anthropologist at the Institute for Mummies and the Iceman in Bolzano, Italy, were no strangers to carcinogens. Soot from wood-burning chimneys and fireplaces, for example, contains substances known to cause cancer in humans. And the bitumen that ancient boat builders heated to seal and waterproof ships has been linked to lung cancer as well as tumors in the respiratory and digestive tracts. “I think cancer was quite prevalent in the past,” Zink says, “more prevalent than we have been able to see.”