Herbicides and adjuvants: an evolving view

Area of Science:

• Environmental Toxicology
• Endocrinology
• Occupational Health

Background:

• Pesticide applicators frequently use adjuvants with herbicides.
• Adjuvants are often paraffinic oils or surfactant mixtures.
• The role of adjuvants and herbicides in reproductive effects is not well understood.

Purpose of the Study:

• To investigate the in vitro genotoxicity of herbicides and adjuvants.
• To conduct an in vivo human study on the endocrine effects of pesticide exposure.
• To explore the relationship between herbicide/adjuvant use and hormonal changes in agricultural workers.

Main Methods:

• In vitro genotoxicity testing using the micronucleus assay for herbicides and adjuvants.
• A prospective, controlled in vivo study with age- and smoking-matched agricultural workers (n=78).
• Blood samples analyzed for hormone levels (free testosterone, FSH) before, during, and after the pesticide application season.

Main Results:

• In vitro: All four tested adjuvants showed positive dose-response effects; one herbicide showed a significant dose-response.
• In vivo: Herbicide-only applicators showed significant endocrinologic differences compared to controls.
• Specific findings: elevated free testosterone and decreased FSH in herbicide applicators.

Conclusions:

• Adjuvants are not inert and possess toxicological activity.
• Herbicide exposure in agricultural workers is associated with significant endocrine alterations.
• Further research is needed to understand the independent or additive toxic effects of adjuvants and herbicides.