Mutagen

The first mutagens to be identified were carcinogens, or cancer-causing substances. Early physicians detected tumors in patients more than 2,000 years before the discovery of chromosomes and DNA. In 500 B.C., the Greek Hippocrates named crab-shaped tumors cancer (meaning crab).

In England in 1775, Dr. Percivall Pott wrote a paper on the high incidence of scrotal cancer in chimney sweeps who were typically boys small enough to fit inside chimneys and clean out the soot. Pott suggested that chimney soot contained carcinogens that could cause the growth of the warts seen in scrotal cancer. Over a 150 years later, chimney soot was found to contain hydrocarbons capable of mutating DNA.

In France in the 1890s, Bordeaux wine workers showed an unusually high incidence of skin cancer on the back of the neck. These workers spend their days bending over in the fields picking grapes, exposing the back of their necks to the sun. The ultraviolet (UV) radiation in natural sunlight was later identified as a mutagen.