October is cancer awareness month and the need to examine some reported causes of cancer. Cancer has claimed the lives of many people, loved ones including children globally in the last 20 years.
According to a report by National Cancer Institute, there are concerns that hair dyes may cause cancer.
Many people in the United States and Europe use hair dyes. It is estimated that more than one-third of women over age 18 and about 10% of men over age 40 use some type of hair dye.
Modern hair dyes are classified as permanent (or oxidative), semipermanent, and temporary. Permanent hair dyes, which make up about 80% of currently marketed products, consist of colorless dye “intermediates” (chemicals called aromatic amines) and dye “couplers.”
In the presence of hydrogen peroxide, the intermediates and couplers react with one another to form pigment molecules. Darker colors are formed by using higher concentrations of intermediates. Semi permanent and temporary hair dyes are nonoxidative and include colored compounds that stain hair directly.
Over 5,000 different chemicals are used in hair dye products, some of which are reported to be carcinogenic (cancer-causing) in animals. Because so many people use hair dyes, scientists have tried to determine whether exposure to the chemicals in hair coloring products is associated with an increased risk of cancer in people.
It is not known whether some of the chemicals still used in hair dyes can cause cancer. Given the widespread use of hair dye products, even a small increase in risk may have a considerable public health impact
Over the years, some epidemiologic (population) studies have found an increased risk of bladder cancer in hairdressers and barbers . A report from the International Agency for Research on Cancer (IARC) concluded that some of the chemicals these workers are exposed to occupationally are “probably carcinogenic to humans”.
Although some studies have linked the personal use of hair dyes with increased risks of certain cancers of the blood and bone marrow, such as non-Hodgkin lymphoma (NHL) and Leukemia, other studies have not shown such links.
Studies of breast and bladder cancer have also produced conflicting results. Relatively few studies have been published about the association of hair dye use with the risk of other cancers. Based on its review of the evidence, the IARC Working Group concluded that personal use of hair dyes is “not classifiable as to its carcinogenicity to humans”