Since the early 1990s, the International Agency for Research on Cancer (IARC) began to evaluate the possible carcinogenicity of hair dye use. These investigations were partly based on epidemiological studies that suggested an increased risk of bladder cancer among hairdressers and barbers.141 A review of studies published through 1994 suggested no or weak evidence of hair dye use and several types of cancers.142 The one exception was hematopoietic neoplasms, where it was concluded the data were inconclusive. Correa et al.143 recently reviewed the literature from 1966 through 1996 regarding the potential relationship between hair dye use and the leukemias. In their review, they included 18 epi-demiological studies that explored personal hair dye use and hematopoietic neoplasms, including 14 case-control studies and four cohort studies. In general, most of the individual studies did not report statistically significant associations, with the exception of one study (published in abstract form) that reported an association between ever use of hair dyes and development of acute leukemia (OR = 1.5,95 percent CI = 1.1 to 2.1).144 One of the difficulties in interpreting these studies, which Correa et al. nicely raise in their review, is the potential problem with small numbers. For example, if the focus of the study is on dark permanent dyes (which contain the highest amount of colorant), and assuming that 10 percent of the population is exposed, epidemiological studies would have to include over 300 subjects in order to have sufficient power to detect a statistically significant association. It is also important to note that several studies have not adequately addressed for potential confounding by other variables including cigarette smoking.

The Smoker's Sanctuary

The Smoker's Sanctuary

Save Your Lungs And Never Have To Spend A Single Cent Of Ciggies Ever Again. According to a recent report from the U.S. government. Centers for Disease Control and Prevention, more than twenty percent of male and female adults in the U.S. smoke cigarettes, while more than eighty percent of them light up a cigarette daily.

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