With the annual spread of some 80 000 tonnes of pesticides, farmers are bound to get hit. However, the context for pesticide spraying has changed considerably over the years, and Europe has outlined new requirements related to the safety of operators, the general public, and the environment.
In 2005 alone, a total of 800 000 French farmers were exposed to pesticides. French public research institute Cemagref's Technologies for Farm-Equipment Safety and Performance Research unit is working to gain knowledge on the exposure of operators to phytosanitary products.
The latest project is building on a 2006 experimental study that centred on apple tree orchards needing some 30 phytosanitary treatments every year. The main objectives of the study were to obtain data on the phytosanitary exposure and contamination of operators, and to enhance the performance of protection cabs used during the spraying process.
For this study, Sonia Grimbuhler, the project manager, and her team evaluated 250 apple farmers on their use of pesticides, and assessed their perception of the risks involved. According to a number of typologies already identified, Ms Grimbuhler established scenarios by considering the most common practices and those resulting in the highest number of contaminations.
The researchers were innovative in their approach in that they took measurements that were as physically close as possible to the operator's actual exposure to products: through contact and inhalation.
The mancozeb and captan fungicides were studied because they are the products most commonly used by apple growers. The researchers monitored skin contamination with the help of patches that were positioned on various points on the farmers, primarily on the skin, work clothes and gloves, and air samples from the subjects' noses and mouths were obtained. Three handling phases were evaluated: mixing, spraying and cleaning of equipment.
The data obtained will be used to provide precise information on the actual exposure levels of operators to phytosanitary products for epidemiological studies, according to the researchers. One of the best ways to help operators better understand how they can improve their techniques is by mapping the most exposed zones of their bodies.
Based on the research, the optimal technical approach for an operator is the use of a pressurised cab supplied via an air filter during the spraying process. Ms Grimbuhler and her team also characterised the granulometric distribution of products during the aerosol phase with and without pressurised and/or air-conditioned cabs.
By placing two, eight-stage cascade impactors inside and outside the cab, at the same level of the operator's nose and mouth, the researchers were able to conduct a chromatographic analysis of the chemical residues. These residues were used to assess the protection provided by the cab models that are currently available on the market.
Cemagref will present the results of the study in the coming months. Also, an information programme for operators is on the cards, providing information on how they can better protect themselves during product use. Ms Grimbuhler has designed a simple, colour-coded system to make it easier for operators to understand the risks involved when they expose themselves to the products.