The Use of Pesticides in Agriculture
Many of the improvements made in modern food production over the years are due to the development of techniques such as: improved (and sometimes genetically modified) plant varieties, fertilizers, pesticides and mechanization. While the use of these methods has benefited humans with a global surplus of cheap food, at least for those with the access and the means to purchase it, industrialized production has also resulted in a number of social and environmental costs. The frequent use of pesticides, for instance, is among the more commonly cited problems of conventional production.
Pesticides
A pesticide is any substance or mixture of substances used to prevent, destroy, repel or mitigate pests. The type of pesticide required, be it an insecticide, fungicide, herbicide, nematicide etc. will depend on the type of pest to be destroyed, such as insects, plant diseases, fungi, weeds, or nematodes etc. Different pesticides also have different means of being effective; some need only touch the pest to be deadly while others must be swallowed to be effective. The intention is to produce high quality, pest and disease free products. In doing so, however, pesticides can unwittingly end up causing harm to organisms like humans and wildlife, as well as to the surrounding environment.
Risk to humans and animals
Pesticide exposure can have acute (or short-term) as well as chronic effects on human health. Acute effects tend to occur immediately after heavy exposure to pesticides. Examples of such cases include farmworkers being sprayed by pesticides applied aerially while working in the field or pesticide application operators being overcome by fumes due to inadequate personal protection equipment. Chronic effects of pesticide exposure include health problems such as cancer, birth defects and neurotoxic effects. However, such direct causal relationships are much more difficult to prove due to the longer time period and mitigating lifestyle factors, and therefore remain controversial in the scientific community. Nevertheless, the increasing volume of research describing the impact of pesticides on wildlife suggests that pesticides affect reproduction, growth, neurological development, behavior and the functioning of the immune and endocrine systems.
Humans could also be impacted by pesticides through consumption of food produced with pesticides. Some chemical residues remain on the food product after washing and preparation and end up being ingested. Although the impact of long-term consumption of these residues is unknown, many governments have established Maximum Residue Limits (MRLs) to help safeguard consumer health and to promote good agricultural practices. These limits vary by country, available pesticides, crop, and use. The US government has even created a database accessible to the public called the International Maximum Residue Limits Database (see http://www.fas.usda.gov/htp/MRL.htm accessed Sept. 6). Searchable by crop, pesticide active ingredient and pesticide type, there are currently over 300 fruit, vegetable and nut commodities covered in the database, as well as 272 pesticides and MRL data from 70 countries, the European Union and the Codex Alimentarius Commission (Codex).
How to minimize risk
For food to be sustainable, it should be produced in such a way that it has minimal negative impact on environmental and human health. Ideally, food production should actually contribute to and improve both the environment and human health. To help minimize risk, pesticides should only be of the lowest possible toxicity and be used and applied in the following manner:
- When/where necessary, after sufficient scientific analysis
- Only when able to be stored, transported, and handled according to safe chemical management practices
- When able to be applied correctly, by a trained professional with proper personal protection equipment
- In accordance with all possible health and safety measures and precautions taken
- As part of a broader pest management strategy that may also include biologically based pesticides (pheromones, microbial pesticides) and other integrated pest management strategies
For more information, please consult the following article sources:
Pest Control Canada. http://www.pestcontrolcanada.com/Pesticides/pesticides.htm. Accessed Sept.6
United States Environmental Protection Agency. http://www.epa.gov/pesticides/about/index.htm
Union of Concerned Scientists. http://www.ucsusa.org/food_and_environment/sustainable_food/costs-and-benefits-of-industrial-agriculture.html. Accessed Sept 7, 2006.
Parliament of Canada. “Pesticides: Making the Right Choice for the Protection of Health and the Environment.” Report of the Standing Committee on Environment and Sustainable Development. May 2000. Available http://www.parl.gc.ca/infocomdoc/36/2/ENVI/Studies/Reports/envi01/04-toc-e.html Accessed Sept 9.
