Mortality of hematopoietic disorders and hair dye use among barbers.

A total of 8,316 barbers were followed up from 1976 to 1987 to examine the relations between hair dye use and deaths from hematopoietic disorders. The follow-up rate was about 95%. Three leukemia deaths and two malignant lymphoma deaths were observed in this cohort. The observed deaths were less than the expected number calculated from age- and sex-specific mortality of the general population in Japan (3.8 and 3.0, respectively). No deaths from aplastic anemia or the other hematopoietic disorders were observed.