Pesticides: Operator Safety Is Paramount

Farming professionals are the most exposed to pesticides. In France in 2005, they were approximately 800 000 in number. At Cemagref, a goal of the Technologies for farm-equipment safety and performance research unit is to gain knowledge on the exposure of operators to phytosanitary products during their work. For example, in 2006, a major experimental study was launched with the Mutualité Sociale Agricole (agricultural social-insurance fund). The trials focused on apple-tree orchards which require approximately 30 phytosanitary treatments each year. The two goals of the study were to acquire objective data on the phytosanitary exposure and contamination of operators, and to improve the performance of protection cabs used during spraying.

Close tabs on exposure

Sonia Grimbuhler, the project manager, started with a survey on 250 farmers to learn how they use the products and their perception of the risks involved. On the basis of the various typologies identified, she then developed scenarios taking into account the most common practices and those resulting in the greatest contamination. The novel aspect of the work consisted of the efforts to make measurements as physically close as possible to the actual exposure of the operator to products through contact and inhalation. Mancozeb and Captan, the two fungicides most commonly used by apple growers, were studied. Patches, placed at different points on work clothes and on the skin, and cotton gloves were used to monitor skin contamination. Air samples were systematically taken at the same height as the nose and mouth. Finally, the three handling phases were each studied, i.e. mixing, spraying and cleaning of equipment. The resulting data are now used to provide precise information on the true exposure levels of operators to phytosanitary products for epidemiological studies. Mapping of the most exposed zones of the body is an excellent means to convey information to operators on how to improve their techniques.

Air-filtered cabs offering higher performance

During spraying, the best technical solution to ensure operator safety is a pressurised cab supplied via an air filter. Another original aspect of the project consisted in characterising the granulometric distribution of products during the aerosol phase with and without pressurised and/or air-conditioned cabs. The young researcher placed two eight-stage cascade impactors inside and outside the cab at the same height as the operator's nose and mouth. Chromatographic analysis of the chemical residues was used to test the protection provided by a dozen cab models commonly found on the market. In addition, following over 400 lab trials in collaboration with the manufacturers, methods are currently being studied to improve the air-tightness of cabs and the design of the protection-filter systems.

Cemagref will present the study results in 2009. An information programme targeting operators is also planned to improve their protection at each step during product use. To that end, Sonia Grimbuhler has designed a simple, colour-coded system to make clear the level of danger to which operators are exposed when handling the products.