Human health and environmental issues concern side effects of locust control operations. The main human health issue consists in the use of inappropriate pesticides and formulations or unnecessary exposure during pesticide handling and spraying operations. Plant protection staff and workers involved in these operations are under greater risk but rural populations living in treated areas can also be exposed to pesticides. Environment, i.e. soil, water, vegetation and non-target organisms, is also under potential threat due to pesticide misuse.
Special emphasis must be given to human health and environment in all aspects of locust management, with adoption of appropriate behaviours and specific measures before, during and after control operations. There are currently different ways to significantly reduce undesirable or unforeseen negative impacts of locust control operations using pesticides:
- Systematic use of protective clothing by staff involved in control operations and pesticide management
- Updated spraying practices with adequate equipment
This includes barrier treatments (sprayed swaths separate by untreated strips), which limit the quantity of pesticides used, reduce the surface sprayed and create areasfree from pesticides within the controlled sites. It also comprises ready-to-use pesticide formulations (such as Ultra-Low Volume ones), which facilitate logistics (no water) and decrease risks for operators and the environment.
- Use of less harmful pesticides, usually called “alternatives to conventional (chemical) pesticides”
Amongst alternatives to conventional pesticides, two categories are more frequent: the Insect Growth Regulators or IGRs, which are synthetic molecules hampering the moult process (from one hopper instar to the next one); and bio-pesticides using the spores of entomo-pathogenic fungus specific to locusts and grasshoppers, which grow on the locust cuticle (external skeleton) and whose mycelium develops within the locust body, eventually provoking the death.
- Information of populations
Precautionary measures must be adopted, such as absence from areas under treatments, withholding and re-entry periods, no re-use of empty pesticide containers, etc.
Impact of locust spraying operations on human health and the environment also needs to be monitored. This includes assessment of their potential effects on human health (operators and local populations) and fauna (non-target organisms such as beneficial arthropods, birds, mammals, reptiles, aquatic fauna, etc.) as well as sampling for pesticide residues in soils, water, vegetation, fauna, etc. in order to detect and evaluate any side effects -and correct them if needed.
Training and refreshing of plant protection staff and operators involved in control operations, monitoring of control operations (quality and efficacy) and pesticide management (handling, transport, storage, clean-up and disposal) are pre-requisites for improving human health and environmental aspects in locust management. Awareness raising and education of concerned local populations is also necessary, together with information of decision makers.
More information is provided in the webpage “Safety and Environmental Precautions: How to Reduce Risks to Human Health and the Environment”. Reference can also be made to the FAO brochure «Fighting the locusts… safely» and to the Desert Locust Guidelines n. 6 «Safety and Environmental Precautions».
Overview on locust management and related human health and environment aspects in Caucasus and Central Asia (CCA)
Attention dedicated to human health and environmental issues is still poor in CCA. Regarding control operations, the most common method is full cover treatment and the most common technique remains water-based spraying, using emulsifiable concentrate (EC). Ultra-low volume (ULV) spraying is still marginal, even though it is slowly making its way into practice. Conventional chemicals, i.e. synthetic pyrethroids (registered in all countries and the largest group of insecticides used) and organophosphates, are the most used in CCA. New and alternative types of chemical insecticides are also present, mainly with Insect Growth Regulators that are now registered in seven CCA countries (no biopesticides registered so far for locust control; research is carried out in some countries).
There are some mitigation measures (training, guidelines, protective clothing, etc.) but monitoring of spraying operations is rarely done and potential impacts on human health and the environment rarely assessed. However, local populations are usually well informed prior and during control operations.
For more info, see the “Analytical Report on Locust Situations and Management in Caucasus and Central Asia”.