Keck School preventive medicine researchers may have propelled numerous policy changes on the use of hair dye throughout Europe.
According to a study published in last February’s issue of the International Journal of Cancer, the USC research team found that women who use permanent dyes at least once a month for a year or longer have twice the risk of bladder cancer as non-users even after adjusting for smoking. Those who used dyes more often and for longer periods, as well as hairdressers (who use dyes on their clients), face an even higher risk. Study authors in preventive medicine included J. Esteban Castelao, Manuela Gago-Dominguez, Ronald Ross, Mimi Yu and Jian-Min Yuan. The findings were part of a continuing study on bladder cancer incidence.
The hair dye study results raised concerns in Europe, where as in the United States about one-third of women over age 18 dye their hair.
The European Commission, a body that drafts legislation for members of the European Union, quickly asked for a review of the research. The commission’s Scientific Committee for Cosmetic Products and Non-food Products Intended for Consumers then declared in June that the research was sound, and the results call for more investigation into the components of hair dyes.
“We’re pleased that European officials want to look further into the relationship between hair dyes and bladder cancer,” said Gago-Dominguez, lead author of the study. USC researchers found that the use of permanent dyes not temporary or semi-permanent dyes were associated with an increased risk of the malignancy.
Noting the cancer risk was “of concern,” the European Commis-sion’s committee has demanded data from manufacturers about the exact chemicals contained in the dyes and how the human body absorbs them.
Officials also called for follow-up epidemiological studies in the European Union, and requested that the European Commission take further steps to control the use of hair dye chemicals.
Legislators have not taken similar action in the United States, where regulatory policies differ. The U.S. Food and Drug Administration only regulates cosmetics after they are released to the marketplace, and it does not have authority to require manufacturers to file data on ingredients or report cosmetic-related injuries.
The FDA provides general information on hair dye ingredients as well as requirements for safety and labeling on its Web site, atwww.cfsan. fda.gov/~dms/cos-prd.html.