The National Toxicology Program and the International Association for Research on Carcinogens classifies naphthalene and PDCB as potential human carcinogens because research has demonstrated that these two chemical compounds have been shown to cause cancer in rodents -- and yet, more than one million pounds of naphthalene and PDCB are used by consumers annually. Naphthalene is found in mothballs and para-dichlorobenzene, PDCB, is found in some air fresheners.While researchers could demonstrate that naphthalene and PDCB caused cancer, they could not explain how. University of Colorado researchers can explain how these chemicals work in the body to create a pathway for the development of cancer. Naphthalene and PDCB block enzymes that normally initiate the programmed cell death required to prevent cells from replicating out of control in the formation of tumors.
