Phenoxyacetic acid herbicides and chlorophenols and the etiology of lymphoma and soft-tissue neoplasms.
The phenoxyacetic acid herbicides and the chlorophenols are compounds of economic importance. The herbicide 2,4-D is widely used in agriculture, industry, and the home. Recently, concern has arisen over their safety as a result of studies linking these compounds with soft-tissue sarcomas and non-Hodgkin's lymphomas. We reviewed the available literature in order to advise a provincial government regulatory body and investigated methodologic issues by examining the pattern of reported cases in Alberta. We conclude that, taking into account the serious limitations on methodology in the available data, the evidence for a causal association is strongest for non-Hodgkin's lymphomas and probably reflects either a weak effect or, possibly, a confounding exposure associated with the use of 2,4-D. Given the worst-case assumptions, however, the potency of 2,4-D as a carcinogen is probably weak. Its intrinsic toxicity is less than that of alternative herbicides and the hazard posed by its use is probably much less than either the use of chemical alternatives or manual cleaning of vegetation, which carry a high risk of occupational injuries.
Kelly
S J
SJ
Occupational Health Program, University of Alberta Faculty of Medicine, Edmonton, Canada.
Guidotti
T L
TL
D002733:Chlorophenols / Q000009:adverse effects*; D006540:Herbicides / Q000009:adverse effects*; D006801:Humans; D008223:Lymphoma / Q000139:chemically induced* / Q000145:classification / Q000453:epidemiology; D016273:Occupational Exposure; D010642:Phenoxyacetates / Q000009:adverse effects*; D012107:Research Design; D012509:Sarcoma / Q000139:chemically induced* / Q000145:classification / Q000453:epidemiology; D012983:Soft Tissue Neoplasms / Q000139:chemically induced* / Q000145:classification / Q000453:epidemiology
D002733:Chlorophenols; D006540:Herbicides; D010642:Phenoxyacetates