CHLORINATED HYDROCARBON SOLVENTS AND BILIARY-PANCREATIC CANCER: REPORT OF THREE CASES
Cases of biliary and pancreatic cancer in association with exposure to trichlorinated hydrocarbon solvents were reported. Three men (aged 45 years, 35 years, and 41 years) developed cholangio, ampullary, and pancreatic cancer after prolonged and heavy exposure to chlorinated hydrocarbon solvents for 4 years or less. The histories of two of the patients included direct skin contamination with trichloroethane (79005) or trichloroethylene (79016); they had exposure to other potential carcinogens as well. The other patient, who was exposed to trichloroethane and perchloroethylene (127184), had a strong family history of cancer. Two of the patients died. Other cases and evidence from recent literature were considered. The author concludes that exposure to trichlorinated hydrocarbon solvents is a risk factor for the development of biliary and pancreatic cancer; improved work practices and heightened physician awareness are recommended.
CANCER INCIDENCE AMONG ALACHLOR MANUFACTURING WORKERS
Cancer incidence among alachlor (15972608) manufacturing workers was evaluated via a historical cohort study. The study population included 943 workers with at least 1 year of cumulative employment at an alachlor manufacturing facility in Iowa at some time between March 1968 and December 1990; 96% of those workers were successfully traced. Eighteen workers were diagnosed with cancer during followup. The standardized incidence ratio for all cancers was 1.5 for all workers exposed to alachlor; elevated rates were primarily attributed to colorectal cancer (four cases) and chronic myeloid leukemia (two cases). Elevated rates of colorectal cancer were observed in workers with 5 or more years in jobs with high alachlor exposure. No cancers were found in stomach, thyroid gland, or nasal cavity. The authors conclude that definitive conclusions are limited by the small study population, minimal length of followup, and current information regarding alachlor metabolism; nonetheless, these findings support the need for further evaluation of alachlor exposed cohorts.
COLORECTAL CANCER IN ASBESTOS CEMENT WORKERS IN DENMARK
Colorectal cancer morbidity in a large cohort of asbestos cement workers from Denmark was examined. Information was obtained on workers employed between 1928 and 1984 at an asbestos cement product manufacturing facility; the cohort was followed through 1990. The workers were mainly exposed to high levels of chrysotile (12001295). The total cohort (7,887 men and 576 women) had a standardized incidence ratio of 1.23. There were 857 incident cancer cases among the men and 48 incident cancer cases among the women. The overall excess risk of colorectal cancer was confined to the period 15 years or more since first employment. Men employed in the early production period (1928 through 1950) had a particularly high standardized incidence ratio of 1.47. The excess risk of colorectal cancer morbidity was not confined to a particular region of the large bowel. The authors conclude that there appears to be a 50% excess risk of colorectal cancer morbidity among chrysotile exposed asbestos cement workers in both Sweden and Denmark; the role of chrysotile in the etiology of colorectal cancer remains uncertain.
INCREASED INCIDENCE OF CANCER IN A COHORT OF OFFICE WORKERS EXPOSED TO STRONG MAGNETIC FIELDS
The possibility that a group of office personnel developed cancers due to strong magnetic fields emitted by a three transformer 12 kilovolt substation, located 14 floors below their office, was examined. Magnetic field readings taken in the office were as high as 190 milligauss (mG) at floor level, and 90mG four feet above the floor. After bus bars were lowered, the highest magnetic field levels were 32mG at the floor and 12mG at chair level; magnetic fields generally average 2mG or less in office buildings. A cohort of 243 men and 143 women employed between 1980 and 1994 were studied. Eight invasive cancers were observed, five in men and three in women, compared with 4.2 expected, giving a standardized incidence ratio of 190. Seven cancer cases occurred in workers employed two years or more. Limiting the cohort to those employed more than two years, five cancers were observed in men compared to 1.3 expected, and two cancers occurred in women compared to 0.5 expected. For both porno sexes, seven cancers were observed versus 1.8 expected, giving a standardized incidence ratio of 389. A positive trend of cancer cases with duration of employment was found for males and females. The cancers diagnosed in men included malignant astrocytoma, lymphoma, and malignant melanoma, and in women, breast cancer, colon cancer and malignant melanoma. The author concludes that cumulative magnetic field exposure could be of etiologic importance in the incidence of cancer in these workers.