and chlorophenols. Studies among workers involved in the production of 2-methyl-4-chlorophenoxyacetic acid (MCPA), phenoxy herbicides and chlorophenols in the United Kingdom found no excess overall cancer (Coggon et al., 1986, 1991). A study among MCPA workers in Denmark did not show an excess incidence of cancer (Lynge, 1985).

No excess cancer mortality has been found among workers exposed in a flavor and fragrance chemical plant (Thomas, 1987), or in highway maintenance (Bender et al., 1989). A study of Swedish railroad workers (Axelson and Sundell, 1974; Axelson et al., 1980) did find an excess tumor mortality, especially linked to amitrole and the category of all other herbicides.

Zober and colleagues (1990) looked at the 34 year mortality of 247 workers who were partially or heavily exposed to TCDD following an accident at a BASF plant in Germany. No consistent statistically significant overall excess in cancer mortality was observed. Following an accident in a trichlorophenol process plant at Monsanto that resulted in TCDD exposure, the SMR for malignant neoplasms was 1.0 (Zack and Suskind, 1980). After an electrical transformer fire in a Binghamton, New York, office building, no excess in cancer incidence was noted after four years among those potentially exposed to polychlorinated biphenyls (PCBs) and dioxins (Fitzgerald et al., 1989).

Other studies have looked at overall cancer mortality in people exposed to herbicides through environmental accidents or other environmental contamination of water and soil. The overall cancer mortality and incidence in the Seveso population has not been shown to be increased (Bertazzi et al., 1989a,b, 1992; Pesatori et al., 1992). In a Missouri community exposed to TCDD in sludge waste from a chemical production facility, the sample size was too small to evaluate overall cancer mortality (Hoffman et al., 1986). A study of a community in Southern Finland (Lampi et al., 1992) exposed to chlorophenols in contaminated drinking water also did not show an excess risk of overall cancer incidence.

Many of the studies of Vietnam veterans have reported total cancer mortality. A follow-up study of 19,205 Australian Vietnam veterans found no excess of overall mortality or overall cancer mortality compared to 25,677 Vietnam era veterans who served in Australia (Fett et al., 1987a,b). There was no difference in mortality by period of service during the Vietnam conflict (Forcier et al., 1987). A similar study of U.S. Vietnam veterans, the CDC Vietnam Experience Study, also showed no excess overall cancer mortality