John Morrison, Jr., Amar Dhere, Robin Bellinder 2015-10-29 01:40:36
Editor’s note: A quick reaction we received to the cover image of the July/August issue of Resource created a learning opportunity. To represent the theme of global agriculture, we selected a stock photo of a young woman working in a field. The issue went to print, and the woman’s handheld sprayer wand escaped our notice. To more experienced eyes, this pastoral image represents potentially toxic pesticide exposure. We are grateful to the authors of this article for explaining this serious, and all too common, hazard. Around the world, in more regions than we can imagine, farmers apply pesticides using methods that are dangerous to their short-term and longterm health. While there are many other health and safety issues involved in pesticide handling and application, the widespread use of knapsack sprayers with singlenozzle spray wands, especially on smallholder farms, requires workers to apply pesticides directly in front of themselves as they walk through the field or between crop rows. The workers are typically unprotected from the fumes, the airborne spray droplets, and the pesticide-wetted foliage. Safety boots, wet suits, goggles, and respirators are unknown, and typical worker attire may be short pants and sandals. The research literature from India is full of horrific data on the results of repeated pesticide exposures from using knapsack sprayers and single-nozzle wands. Skin disorders are most common, with reports of skin rashes and cancers, but the list of disorders is long and includes poisoning, loss of fingernails, dizziness, brain and nervous system damage, birth defects, miscarriages, muscle cramps, difficulty breathing, abdominal pains, body tremors, coughing, death—and the list goes on. It appears that most of these reported symptoms are the result of direct contact with pesticides. The knapsack sprayer is a useful and economical tool for smallholders; consequently, these portable sprayers are used by millions of farmers. The horror of the current situation is that many action-agency advisors are training farmers in the use of knapsack sprayers using single-nozzle wand attachments. In the extreme, at least one NGO is teaching the “new and improved” method of using a multi-nozzle spray boom carried ahead of the worker to cover a wider swath, while the worker walks closely behind, through the cloud of sprayed pesticide. Let’s assume that the knapsack sprayer tank and pumping unit are here to stay. What can we do to make them safer to use? As an agricultural engineer, with a knapsack sprayer on your back, where would you want the spray nozzles to be located relative to your position? It’s simple—you would want the nozzles to be as far behind you as possible for the particular field operation at hand. The criteria for such technology might be: • Position the spray nozzle or multiple nozzles on a lightweight boom that workers can easily pull behind them across the field or between crop rows. • Use regulated low spraying pressure to minimize pesticide atomization and drift. • Use spray nozzles that develop their full spray pattern at low pressures, again to minimize atomization and drift. • Use a dripless quick disconnect on the pressure line between the knapsack sprayer and the trailing boom for convenient separation of the worker from the boom to facilitate rest breaks and refilling operations. The above criteria are not rocket science, nor are they intended to guarantee complete protection from pesticide exposure, but they seem to be worth field-testing against the current methods. Models of safer sprayer attachments have been developed and have been demonstrated occasionally, but they have not been adopted. We would be interested to learn about any innovations in handheld sprayer design or training that can protect people from the hazards of pesticide exposure. Together, this is a problem that we can solve. ASABE member John Morrison, Jr., Adjunct Professor, University of Tennessee, Knoxville, Tenn., USA, email@example.com; Amar Dhere, Assistant Professor, Department of Science, SVT College of Home Science (Autonomous), SNDT Women’s University, Mumbai, India, firstname.lastname@example.org; and Robin Bellinder, Professor, Department of Horticulture, Cornell University, Ithaca, N.Y., USA, email@example.com.
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