Children's Health

Why a bylaw?    To Protect Children's Health

Children - from being in the womb to their teen years - can find their health and development affected by exposure to even very small (trace) amounts of pesticides.

Studies and Doctors’ Findings

A study done in Mexico compared the development of pre-school children in a valley where agricultural pesticides had been used since 1950 with the development of children in a foothills region nearby where pesticides were rarely used.  The children were from a similar population, culture, and environment; the main difference between them was the use of pesticides in the area where they were born and raised. The children exposed to pesticides (in the valley) had “decreases in stamina, gross and fine eye-hand coordination, 30 - minute memory and the ability to draw a person.” (1)

The children exposed to pesticides also showed more aggressive behaviour, less creativity in their play, and less group play than the children from the communities not exposed to pesticides. (1)  Two years later, the children exposed to pesticides were tested again. “Developmental tasks and problem-solving continued to be delayed.” (2)

A few years later, the same team studied breast development in girls aged 8 to 10 years old from the two Mexican areas. They found that the girls exposed to pesticides had generally larger breasts and yet 1 in 3 had mostly fatty tissue and little mammary gland development in their breasts.  The researchers speculated that the cause of this abnormal breast development was disruption of hormones caused by exposure in the womb to pesticides that effect the endocrine glands. (2)

Recently concern was expressed in Prince Edward Island about an increase in cancer rates in children linked to pesticide use. (3)

Doctors have found an increasing number of birth defects, such as undescended testicles and deformed penises in newborn babies that may be related to pesticide exposure in the womb. (4) (5)

Click here for our Child Health Studies page for studies and articles on the effects of pesticides on children’s health.

How Children are Exposed to Pesticides

Some pesticides have been linked to abnormalities in sperm. (6)  Studies have also found that the pesticides stored in the mother’s body from her exposure before and during pregnancy can be transferred to the baby in the womb. (2)

Babies are also exposed in the womb to pesticides when their mothers eat food on which pesticides were used and when their mothers are exposed to pesticides by breathing them in or absorbing them through their skin. Even very small amounts of pesticides have been linked with interference with the normal development of fetuses. Exposure during a critical time of development in the womb “can cause permanent damage to organs and systems .” (7) (8)

Children and teens are exposed to pesticides when they play and roll in grass in parks or yards that have been treated with pesticides.  They are also exposed when pesticides are in the air, from spraying or simply from the gases coming off areas where pesticides have been applied.  Pesticides brought into a residence on shoes, feet, or clothes, can persist up to a year, meaning the children are continually exposed in their home. As pesticides evaporate and condense inside homes, they tend to concentrate on plastics and synthetic materials. Children may then be exposed as they play with plastic toys or put them in their mouths. (9)

In general, studies find that children have a lower tolerance than adults for pesticides. On the whole, children are typically more sensitive to the effects of pesticides because the enzymes and organs that rid their body of toxic chemicals are not fully developed. Children are also smaller and lighter than adults, so they receive a proportionately larger dose per exposure than adults. (10)

Children’s “immature respiratory systems and immune systems, as well as developing nervous systems, may be more vulnerable” to the harmful effects of pesticides. (11)

Children are also the most likely to be poisoned by drinking or eating pesticides.  A study in the UK found that 50 % of pesticide poisonings occur in children under age 10. (12)   The World Health Organization estimates that 200,000 people are now killed annually around the world by pesticide poisoning, up from 30,000 in 1990;  about 3 million people per year are poisoned by pesticides. (13)   While the children may recover from this, some doctors are concerned about the long-term neurological effects poisoning, or any exposure to pesticides, may have on children. (4)

“The unnecessary use of synthetic pesticides is a serious and far reaching concern for the health of virtually every segment of our society, but most critically for our children. The chemical soup that we have legitimized since the age of chemical evangelism in the 1950's and 60's is now showing up in the vastly increased cancers and chronic diseases that permeate our land.

It is well past time that we take progressive and profound actions to reverse these hazardous practices, and to make our environments safer and more people friendly. It is time to get on board with the growing movement nationally and internationally to be much more conscious and meticulous about what is accumulating in our precious environment and in our sensitive bodies.”

Dr. Robert C. Dickson, MD, Calgary

“It is not a case of innocent until proven guilty. We have ample reason to be concerned. We must act on what we know now, because health risks are cumulative and can last for years.”

Dr. J. Reisman, Chief of Paediatrics, CHEO; Professor and Chairman, Dept. Paediatrics, University of Ottawa (14)

Dandelions don’t hurt children (with the exception of those few who are allergic to them); there is mounting evidence that pesticides do hurt children.  Let’s be smart and phase out the use of unnecessary pesticides in Calgary in 2008.  Our children and their future are worth it.

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

Click here for how to use natural landscape practices in your yard

  Olivia and Rebecca

   “I want to live in a Calgary where I can grow up healthy and strong!” 

  Click here for the full story


1) Guillette, Elizabeth A., et al.  “An Anthropological Approach to the Evaluation of Preschool Children Exposed to Pesticides in Mexico”, Environmental Health Perspectives, 106: 347-353, June, 1998.   Read more . . .

2) Guillette, Elizabeth A., et al. “Altered Breast Development in Young Girls from an Agricultural Environment”. Environmental Health Perspectives, 114: 471-475, November, 2005. Read more . . .

3)  Mittelstadt, Martin, “Pesticides are What is Killing Our Kids”, Globe and Mail, Dec. 12, 2006.  Read more . . .

4) Canadian Association of Physician’s for the Environment,  Lawn Pesticides: Reducing Harm. video, April 2005.  View the video . . .

5) Hjertaas, Paule, Why do parents need information on pesticide dangers and alternatives to pesticides. Briefing Note submitted to the Government of Saskatchewan. .
citing Sandra Steingraber; 2003; Having Faith - her web-site is ; and ; and G.M. Shaw, C.R. Wasserman, C.D. O’Malley, et al, “Maternal pesticide exposure from multiple sources and selected congenital anomalies”, Epidemiology, 1999, 10(1); 60-66.   [link to all these sites]

6) M.Sears, CR Walker, RHC van der Jagt, P Claman. “Pesticide Assessment: Protecting public health on the home turf.” Paediatric Child Health 2006; 11 (4); 229-234. Citing Lerda D., Rizzi, R. Study of reproductive function in persons occupationally exposed to 2,4-dichlorophenoxyacetic acid (2,4-D). Mutat Res 1991; 262:47-50.   Click here for a summary of the article.

7)  Hjertaas, Paule, Why prohibit pesticides in areas where children play. Briefing Note submitted to the Government of Saskatchewan. p. 2 .  Citing “In Harms Way”; Greater Boston Physicians for Social Responsibility, with a link to the leading scientists who endorsed it. Also citing and

8)  Porter, Warren P.; Jaeger, James W.; Carlson, Ian H. “Endocrine, immune, and behavioral effects of aldicarb (carbamate), atrazine (triazine) and nitrate (fertilizer) mixtures at groundwater concentrations.” Toxicology and Industrial Health, 15 (1-2), pages 133-150. 1999.

9) Susan Kegley, Anne Katten, Marion Moses.  “Secondhand Pesticides: Airborne Pesticide Drift in California.” Pesticide Action Network North America. 2003. Citing a) C. Lu and R.A. Fenske. “Air and surface chlorpyrifos residues following residential broadcast and aerosol pesticide applications”, Env Sci Tech, 1998, 32: 1386-90 and b) S. Gurunathan, M. Robson, N. Freeman et al, “Accumulation of chloropyrifos on residential surfaces and toys accessible to children”, Env Health Persp, 1998, 106:9-16.  Click here for full article.

10) This paragraph is from the Coalition for a Healthy Ottawa web-site- FAQ page - FAQ 22, citing Toronto Public Health, April 2002.

11) Muhammad Towhid Salam, Yu-Fen Li, Bryan Langholz, and Frank Davis Gilliland.  “Early-Life Environmental Risk Factors for Asthma: Findings from the Children's Health Study.” Environmental Health Perspectives, 112: 760-765, May, 2004.  Click here for the full study.

12) Van der Gaag N: “Pick Your Poison: the price we pay for using pesticides”. New Internationalist 323:9-11, May/00, p.11.

13) Canadian Assocation of Physicians for the Environment Position statement,
This can be found on our web-site, here.

14) From brochure on Coalition for a Healthy Ottawa web-site: Put Olivia’s photo here - of her in her yard with the hat.  And link to her Mom’s story - REbecca O’Brien.