Choroidal Melanoma: Possible Exposure to Industrial Toxins

To the Editor: We have documented two cases of choroidal melanoma and one case of squamous-cell carcinoma of the conjunctiva, occurring over three years (1971–74) in a population of chemical workers at a plant in the Ohio Valley region. The chemical company involved supplied data, unreviewed by ourselves, stating that only these three cases had occurred over a longer (1956–74) period. They noted that the total age-adjusted incidence of all forms of eye cancer in this population over the longer period was 0.5; this figure would represent a six-fold excess of observed over expected cases and would be statistically.