An exploratory analysis of the occupational correlates of large pigmented nevi at Lawrence Livermore National Laboratory.

To examine the association between exposure to occupational factors and the presence on the body of large pigmented nevi greater than 5 mm, data were collected from 110 employees of Lawrence Livermore National Laboratory employed between 1969 and 1980. In this exploratory prevalent case-control study analysis, 38 employees reported having at least one large pigmented nevus and 72 reported none. Occupational factors associated with the presence of large pigmented nevi (adjusted for age and the number of sunburns per year under age 21) were being an engineer (prevalence odds ratio [POR] = 3.20, 95% confidence interval [CI] = 1.0,10.6) or an electrical engineer (POR = 2.56, 95% CI = 0.3,20.3), being hired at Lawrence Livermore National Laboratory before 1962 (POR = 3.07, 95% CI = 1.2,7.7), and having one's skin exposed to rare earth metals (POR = 3.78, 95% CI = 0.9,15.1).