Why are pesticides used?
A diet rich in vegetables and fruit is believed to be one of the best defences against cancer, heart disease and diabetes. Using pesticides to protect our food from damage by weeds, bacteria, fungi and other organisms helps to ensure that a variety of safe, appealing, affordable fruits and vegetables are available to Canadians.
If not properly managed, insects, weeds, fungi and other organisms can affect the quality and quantity of the food we enjoy today. To protect food crops from being destroyed by weeds, pests and diseases, farmers use crop protection technologies also called pesticides. Pesticides are the farmers equivalent of the medicines that doctors use to safeguard our own health.
Herbicides are used to control weeds, insecticides are used to control bugs, and fungicides are used to prevent or cure fungal infections and diseases.
Before a new crop protection product makes it into a farmer’s field an extensive array of scientific evaluation must have taken place. The main function of Health Canada’s Pest Management Regulatory Agency (PMRA) is to decide whether or not pesticides are acceptable for use on crops. This evaluation can include up to 160 separate tests. In all, the development, testing and approval of a product can take up to 10 years.
For human health the most important of the scientific evaluations is to understand how people might be affected. To achieve this, researchers specializing in toxicology – the study of harmful effects of substances safety to humans – go to enormous lengths. They must answer a whole range of questions: Does the chemical change in the human body and where does it end up? Is it in the parts of the crop we eat and how long does it stay there? Will any residue harm us? Typically, Health Canada insists on five million pieces of data to ensure that a product clearly poses no unacceptable risk to human health and the environment. Once crop protection products are registered, they are subject to ongoing testing and monitoring as long as they continue to be approved.
Enormous care is taken when pesticides are used on the farm as many farmers use what is called Integrated Pest Management:
- Crops are monitored for evidence of pests and only treated if absolutely necessary
- Where they are available, natural biological control agents are used such as wasps which prey on insects and pests that cause damage
- Advice on which products to use, when, and at what rate, is provided by qualified crop protection experts
- Detailed records are kept of what was used and when
- Well-trained operators who in some cases hold Certificates of Competence apply products