Hexavalent chromium is a known
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 of four 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. Proportionate mortality and proportionate
cancer mortality ratios (PCMR) were calculated. The overall risk for
lung cancer was a PCMR of 1.51 (confidence limits [CL] 1.29-1.74) for white men and 1.34 (CL 1.00-1.75) for black men. These risks increased with increasing duration of employment and latency since time of first employment. The PCMR for greater than 20 years duration of work and more than 20 years since first exposure was 1.94 (CL 1.15-3.06) for white men and 3.08 (CL 1.13-6.71) for black men. The risk for
lung cancer for white men remains elevated more than 20 years after exposure has ceased (PCMR, 1.29; CL 1.03-1.60). The PCMR for nasal cavity/sinus
cancer was also found to be a significantly increased, 5.18 (CL 2.37-11.30). A cluster of
bladder cancer was seen among black workers from one facility, (PCMR, 3.30; CL 1.42-6.51). Despite the cessation of exposure, former
chromium workers remain at significantly 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 texts for
lung cancer.