MORTALITY AND CANCER MORBIDITY OF FINNISH CHLOROPHENOXY HERBICIDE APPLICATORS - AN 18-YEAR PROSPECTIVE FOLLOW-UP

An 18-year follow-up for mortality and cancer morbidity was conducted in a cohort of 1,909 men who had started spraying chlorophenoxy herbic ides (mixture of 2,4-dichlorophenoxyacetic acid [2,4-D] and 2,4,5-tric hlorophenoxyacetic acid [2,4,5-T]) in 1955 through 1971. In all, 384 p ersons had died during the follow-up, and there was a slight deficit i n natural deaths (standardized mortality ratio [SMR] 0.84; 95% confide nce interval [CI] 0.75-0.94). By contrast, there was a small, nonsigni ficant increase in accidental and violent deaths. The overall cancer m ortality was slightly less than in the general population (SMR 0.83; 9 5% CI 0.65-1.02), and not a single case of death of non-Hodgkin's lymp homas (NHL) or soft tissue sarcomas (STS) was detected. With regard to cancer morbidity, the incident cases showed a slight deficit compared to the population figure (standardized incidence ratio [SIR] 0.81; 95 % CI 0.67-0.97). One case of NHL was found (2.4 expected with 10 years of latency), but not a single case of STS (0.8 expected with 10 years of latency). While our study does not support the contention that spr aying of 2,4-D and 2,4,5-T containing herbicides carries any significa nt risk of cancer, the medium to low statistical power of the study do es not allow any far reaching negative conclusions regarding the carci nogenicity of the agents. (C) 1994 Wiley-Liss, Inc.