Hair Dye-cancer link discovered

Women who routinely dye their hair – and the hair stylists who apply the colour – have an increased risk of bladder cancer, says a study in the current International Journal of Cancer.

Researchers at the University of Southern California said women who use permanent hair dyes once a month for one year or more double their risk for bladder cancer.

After 15 years, the risk is tripled, said the authors of the study, which looked at 1,514 bladder cancer patients. Hairdressers who applied dyes for at least 10 years had five times the normal risk of developing bladder cancer.

Absorbed

Study authors said semi-permanent and temporary rinses were not implicated and could be considered as an alternative. They may still contain the same chemicals, called arylamines, that are absorbed through the scalp and skin, but the concentrations are considerably lower in both semi-permanent colours and lighter shades, the study said. The chemicals pass through the bladder and are expelled through urine.

Occupational Risk

Dr. Nhu Le, a statistician/epidemiologist at the B.C. Cancer Agency, said previous studies have found an occupational risk of bladder cancer among hairdressers. But the UCLA study is the first to establish a link between customers and dyes, he said.

Toronto Star Newspaper,
February 2001