Let science guide herbicide policy
Fearmongering can’t trump the plain facts
City council will soon be discussing the merits of using herbicides to control weeds on Edmonton-owned property such as sports fields, parks and golf courses. This follows a motion by Coun. Ben Henderson to ban the practice.
Herbicide use has been a focus for many years by anti-spraying advocates who believe they should be banned because of their risk to human health. Their position is not supported by science or credible research.
Before discussing the risks of using herbicides, it’s worth taking a moment to understand why we control weeds in the first place.
Few will dispute that our urban green spaces offer both physical and mental health benefits and enhance the environment. For instance, one acre of grass can absorb hundreds of pounds of pollutants in a single year. Grasses also trap dust and dirt released into the atmosphere, and studies show that properly managed turf sequesters significant amounts of carbon. Turf grass is also the best defence against soil erosion, as it binds the soil more effectively than any other plant.
Weeds, however, compete with grasses and other plants for water and nutrients, leaving non-weed plants starving. If left unchecked, weeds have the natural ability to quickly flourish and smother most other plants. On sports fields, weeds can out-compete the turf, compromising playing surfaces and the safety of children that use them.
Regardless of how well green spaces are maintained, the fact is it’s a living ecosystem that fluctuates due to weather, use and maintenance schedules. This means that from time to time, even the best-maintained green spaces will face weed infestations that require intervention through the use of herbicides.
So how can we be assured that the weed control products used by the City of Edmonton are safe and not a risk?
Herbicides are one of the most stringently controlled products in Canada and are regulated by Health Canada. Precaution is the foundation of Canada’s regulatory system, and the primary objective of Health Canada is to prevent unacceptable risks to people and the environment from the use of these products. Health Canada employs more than 300 scientists, including biologists, chemists and toxicologists for the sole purpose of evaluating herbicides. Before approval, the chemical is subjected to a number of assessments.
These include a health assessment that looks at the potential for a herbicide to cause adverse health effects, such as cancer. It also examines all sources of potential exposure, including exposure from contact with treated areas, such as lawns. Scientists take into account that children’s activities are different from those of adults, and therefore children’s potential exposure through non-food routes is specifically examined. The environmental assessment looks at the fate of a herbicide in soil and water and for bioaccumulation in organisms.
If a herbicide fails any of the tests, it cannot be sold in Canada. Virtually no other consumer product has been subject to the same level of scientific scrutiny and regulatory oversight.
There are many types of herbicides available in Canada, most of which are used for agricultural purposes. One product that is used by farmers, landscape managers and homeowners is 2,4D, which is used to control weeds such as dandelions.
The anti-spraying crowd likes to focus on this one product and say there’s not enough information to support its use. This is nonsense. 2,4-D is arguably the most researched chemical compound in use today. It has a remarkable 70-year health and safety record in more than 100 countries, including Canada and the U.S.
Health Canada recently concluded a multi-year scientific re-evaluation of 2,4D and said this in its report: “the herbicide can be used safely according to label directions for a variety of turf applications. Risks to homeowners and their children from contact with treated lawns and turf were not of concern.” I don’t think the regulators could be much clearer about the safety of this product.
City council is often called upon to make decisions about the health and welfare of Edmontonians. This is one of those times when councillors must seek guidance from experts in the field of herbicide chemistry and regulatory oversight. Their decisions must be based on credible science and regulations that are already in place to protect citizens. It should not be based on fearmongering or the biased opinions of a handful of anti-weed-spraying activists.
Virtually no other consumer product has been subject to the same level of scientific scrutiny and regulatory oversight (as herbicides). – Nigel Bowles