Agriculture consistently remains one of the most hazardous industries. Hazards exist not only on farms, but also within pesticide manufacturers and distributors. Treating seeds with neonicotinoid insecticides is an important strategy to address pest problems. Neonicotinoids are a systemic insecticide that transfuse throughout the entire plant from roots to pollen. While research on the environmental effects of neonicotinoids is growing, research examining the potential adverse effects on humans is in its beginning phases. This pilot project provides an overview of the potential points of neonicotinoid exposure for manufacturers, distributors, and farmers who use seeds coated with neonicotinoid pesticides.
A descriptive, cross-sectional study design was used to collect information characterizing occupational neonicotinoid insecticide handling practices at three different work environments: manufacturers of treated seed, distributors of treated seeds, and at farms where neonicotinoid treated seeds are planted. Potential participants were identified through internet searches of Iowa seed treating facilities and neonicotinoid treated seed distributors as well as snowball sampling for identification of farmers who used neonicotinoid treated seeds.
Participants were interviewed at each worksite. Data were analyzed qualitatively by using a grounded theory approach to examine the written questionnaire responses, field notes, and photographs. The data were relatedly evaluated to identify themes, similarities, and differences between each work environment. Also, these facilities were examined for safety hazards associated with neonicotinoid insecticides during the tasks being accomplished at each site.
The seed treatment sites visited during this project varied greatly in facility size, number of employees and building age. Larger facilities were more likely than semitrucks small facilities to report safety as a priority, and the age of the facility did not seem to affect the chance of exposure to neonicotinoids. The seed distributors studied during this project varied greatly in numbers of full-time and types of safety policies. The most thorough safety policies included an Emergency Action Plan, many different SOPs, yearly safety training, and having the seed treating equipment recalibrated at the start of each season. In addition, most distributors, at a minimum, wore gloves. All the farm workers interviewed planted corn and soy beans and used almost no PPE, with the exception of one farmer who reported wearing gloves while handling treated seeds.
This pilot study provides suggestive evidence for a high potential of neonicotinoid exposure to workers at varying work environments. In order to quantify the range and magnitude of neonicotinoid exposures, future studies are needed that 1) expand the scope of the work environments examined; 2) comprehensively measure neonicotinoid concentrations in all potential exposure (e.g., inhalation, ingestion, dermal) pathways; and 3) perform biomonitoring of neonicotinoids.