Why a bylaw?    To protect human health

 The weight of scientific evidence shows strong relationships between pesticide use and many human health challenges: 
    - cancer
    - learning disabilities
    - asthma
    - infertility
    - miscarriages and stillbirths
    - birth defects
    - neurological difficulties
    - illnesses related to disruption of hormone function

Many studies show the strong correlation between pesticides and harmful effects on human health. Click here to see a few of these studies on our Health Studies page.

Children's Health

When humans are developing and growing, from the fetal stages to teen years, they are particularly at risk of having that development disrupted by synthetic pesticides. Click here for our Children's Health page on how children’s health is affected by pesticides.

Precautionary Principle urged by Scientists

The many, precise ways in which pesticides affect human health have not yet been determined. It is difficult to isolate the effects of pesticide exposure from other environmental factors that might affect health.  Even so, scientists worldwide say we have enough evidence to show that pesticides cause harm. Scientists are urging that the precautionary principle be used:

“ when an activity poses threat to human health or the environment, precautionary measures should be taken, even though the cause and effect relationship is not fully established scientifically.”

How we Are Exposed to Pesticides

Exposure to chemical pesticides that can affect human health happens in a few ways:

1)  Pesticides can be breathed in while pesticides are being applied or as they evaporate after being applied.  Pesticides can actually drift, when being sprayed, up to 2 miles (3.3 kms) depending on the weather conditions. (1)  Environment Canada's Federal Code of Good Practice, states that the herbicide Killex can drift up to 100 meters when the wind is no more than 10 km/hour and the temperature of the day does not exceed 25 degrees Celsius (2). The average wind speed in Calgary is 17 km/hour. (3)
After pesticides are applied, the chemicals release into the air for days, weeks, or even months, with peak concentrations usually from 8 to 24 hours after application. (4) Saskatchewan studies found that about 18 % of 2,4-D (the most common ingredient in lawn weed killers) evaporates. (5)  45 % of the airborne pesticides detected in a California study were from evaporation after pesticides were applied.  (4)

During or after pesticides are applied on your neighbour’s yard, or in a nearby park or boulevard, you may inhale those pesticides.  When you drive along a boulevard that has been sprayed, you may inhale pesticides.

2)  Pesticides are tracked into residences on shoes or clothes that have been on areas where pesticides have been applied.  Pesticides can persist for over a year inside a house, particularly in carpets and other fabrics (e.g. on furniture), and in house dust. (6)

3)   If you spray or otherwise apply pesticides, you can absorb them through your skin.  If you lay on grass or brush against plants that have been treated, you can also absorb them through your skin.  If you bring pesticides into your residence on your clothes or shoes, they may persist for up to a year. From there you may absorb or inhale them.  Children are exposed to them as they play on the floor and put things in their mouths.

“ There is growing evidence of health risks from the variety of chemicals in our environment. Why would we risk cancer and birth defects to eliminate dandelions?”
Dr. David Swann, MLA for Calgary Mountain View

“Environmental illnesses linked to pesticides include development of environmental sensitivities,  worsening of allergies and other chronic illnesses, and chronic fatigue/fibromyalgia syndrome. Reduce the ‘chemical soup’, starting with pesticides, and I assure you that the population will be healthier.” 
Dr. Jennifer Armstrong, Physician, Ottawa
-Environmental Health Clinic, Board of Directors, American Academy of Environmental Medicine

Let’s be smart and protect the health of all Calgarians by phasing out the the unnecessary use of pesticides starting in 2008. 

Click here to read stories of Calgarians and why they think it’s time for Calgary to pass a bylaw phasing out the use of unnecessary pesticides. 

Click here for actions you can take to support a pesticide bylaw.

Click here for how to use natural landscaping practices in your yard.

  Laureen Rama

  "I want to live in a Calgary where the air is healthy for me to breathe"

  Click for the full story.



2) This was found on the Environment Canada web-site in 2002 by the Coalition for a Healthy Ottawa.


4) Susan Kegley, Anne Katten, Marion Moses.  “Secondhand Pesticides: Airborne Pesticide Drift in California.” Pesticide Action Network North America. 2003.  Click here for the full article.

5) Paule Hjertaas, Why, given that pesticides are regulated in Canada, is extra protection for children needed. Briefing Note submitted to the Government of Saskatchewan. p. 6 Citing “Studies at Saskatchewan agricultural research stations estimated post-application volatilization rates for 2,4-D and triallate at about 18 per cent.”

6) Nishioka, Marcia G,; Burkholder, Hazel M.; Brinkman, Marielle C.; “Distribution of 2,4 - Dichlorophenoxyacetic Acid in Floor Dust throughout Homes Following Homeowner and Commercial Lawn Applications: Qualititative Effects of Children, Pets and Shoes.” Environmental Science and Technology, Vol. 33, No. 9, 1999. Click here for a summary of this article.