A cohort study was undertaken of 2119 workers from Denmark who were potentially exposed to phenoxy
herbicides. The workers were from two factories that produced phenoxy
herbicides since 1947 and 1951, respectively. They had been employed either in the manufacture of phenoxy
herbicide or in the manual service functions. The main product was 4-chloro-2-methylphenoxyacetic
acid (
MCPA). From 1947 to 1993 the 2119 workers had a slightly lower overall
cancer incidence than the Danish population (observed = 204; expected [Exp] = 234.23; standardized incidence ratio [SIR] = 0.87; 95% confidence interval [CI] 0.8-1.0). Four
soft-tissue sarcoma cases were observed (Exp = 2.47; SIR = 1.62; 95% CI = 0.4-4.1). All four cases occurred among men from Kemisk Vaerk Køge (Exp = 1.68; SIR = 2.38; 95% CI = 0.7-6.1). There were six cases of
non-Hodgkin's lymphoma (Exp = 5.07; SIR = 1.10; 95% CI = 0.4-2.6) and no significantly elevated risk of other
cancers. Based on small numbers, the study suggests an association between the exposure to
MCPA and related phenoxy
herbicides and the risk of
soft-tissue sarcoma. The study does not indicate a risk of
non-Hodgkin's lymphoma after exposure to these phenoxy
herbicides or a risk of other
cancer diseases.