Hexavalent chromium is a knonn carcinogen. Previous epidemiologic studies in the 1950s of United States workers from seven facilities producing chromium compounds from chromite ore have reported a markedly increased risk for dying from lung cancer. As part of a high risk notification project of workers from four of these facilities, a mortality study was performed. The cohort was assembled in 1990-1991 from the Social Security records offour former chromate producing facilities in northern New Jersey. The study subjects were known to have worked at these facilities some time between 1937 and 1971. Proportionute mortality and proportionate cancer mortality ratios (PCMR) were calculated. The overall risk for lung cancer was a PCMR qf 1.51 (confidence limits [CL] 1.29-1.74) for white men and 1.34 (CL I .OO-I. 75) for black men. These risks increased with increasing duration of employment and latency since time offirst employment. The PCMR for greater than 20 years duration of work and more than 20 years since first exposure was 1.94 for white men and 3.08 ) for black men. The risk for lung cancer for white men remnins elevated more than 20 years after exposure has ceased (PCMR, 1.29;. The PCMR for nasal cavir)/sinus cancer was also found to be a significantly increased, 5.18 . A cluster o f bladder cuncer was seen among black workers from one facility, (PCMR, 3.30;. Despite the cessation of exposure, fhrtner chromium workers remain at signijicantly increased risk of lung cancer. Although there have been case reports of nasal cavity/ sinus cancer in association with chromium exposure, this is the first epidemiologic study to report a significant increase in these cancers. Limitations in this study include lack of exposure data and lack of information on smoking habits. The lack of increase in other smoking-related diseases besides lung cancer indicates that the increase in lung cancer cannot be attributed to cigarette smoking. The ongoing elevated risk of lung cancer after cessation of exposure emphasizes the need for developing early detection tests for lung cancer. 0 1996 Wile)-Liss, h i .