Margaret Sears Illuminates Need for Limiting Daily Exposure to Toxic Chemicals


In some contexts ignorance is bliss; in others, it is harmful.

Many of us know little about the makeup of the personal care, household and lawn and gardening products we routinely come into contact with, whether or not we use them ourselves.

In North America and beyond, are we routinely and unknowingly pushing the limits of our bodies, plant life, wildlife, wetlands and water resources too hard through ubiquitous exposure to chemicals, including many hundreds that have been banned or restricted by the European Union?

At 1 p.m. Monday at the Chautauqua Women’s Club, as part of the Chautauqua Professional Women’s Network series, Margaret Sears will address that issue in a presentation titled “Detoxing Daily Exposures.”

“Hundreds of man-made chemicals are in our blood and tissues, our children and our environment,” Sears said. “At low doses, substances can team up to affect development and health from before conception to old age.”

Effects of these chemicals ripple out as substances wash into waterways and spread across the land, she said.

“Historically, most chemicals have been ‘innocent until proven guilty’ — until a great deal of harm has accrued, and scientists prove the culprits,” Sears said.

An Ottawa-based engineer and scientist, Sears has a keen interest in the conduct and interpretation of science in environmental health, and possesses broad knowledge of environmental contributors to health and ill-health. She is a senior clinical research associate at Ottawa Hospital Research Institute, and was also an adjunct investigator at Children’s Hospital of Eastern Ontario Research Institute.

For nearly six years, Sears has also been a board member of Prevent Cancer Now. She said because the mechanisms are similar, there’s a correlation between diagnoses of cancer and diagnoses of other diseases, including diabetes and atrial fibrillation.

“If you prevent cancer, you prevent all sorts of problems,” Sears said.

The analytical skills she learned while earning her bachelor’s degree in chemical engineering and applied chemistry at the University of Toronto, and later her master’s in engineering and doctorate in biochemical engineering at McGill University, have proven invaluable in determining what’s plausible and for making linkages and connections, she said.

Sears has been the lead author of scholarly studies about environmental toxicants and heavy metal detoxification (particularly arsenic, cadmium, lead and mercury), pesticides, bitumen, environmental determinants of chronic disease and medical responses.

“I don’t do these things by halves,” she said. “I go through the peer-reviewed, primary scientific literature.”

Her research findings have been published in Pediatrics and Child Health, Journal of Environmental and Public Health and The Scientific World Journal.

“It amazes me what we do to get rid of a little sliver in our body, but don’t do to rid ourselves of a chemical in our body,” Sears said.

Sears said she became interested in environmental health when she had children.

“We moved from downtown Ottawa outside to the rural lands, which are now part of Ottawa,” she said. “I thought I could have a garden. The first thing I found out from the previous owners, after we bought the house, is that the township had been spraying insecticides for mosquitos once a week, including a nerve gas that had been classified by the World Health Organization. I didn’t want that spray on my organic garden.”

While notifying her new neighbors, she learned that one had been having seizures and another had bad headaches.

When Sears became one of the leaders of a wetlands preservation group, she studied the pesticides used on a local golf course.

She has since collaborated numerous times with scientists, medical providers and policy practitioners, including at the Canadian Institutes of Health Research, the Social Sciences and Humanities Research Council of Canada and the Environmental Health Committee of the Ontario College of Family Physicians.

“In Ontario, there’s a law restricting the chemicals that are permitted to be used on lawns and gardens,” Sears said. “It’s a very good list. I worked with someone from the David Suzuki Foundation to refine that list. It’s fantastic.”

In DSF’s 2010 publication, What’s Inside? That Counts: A Survey of Toxic Ingredients in our Cosmetics, Sears is the first contributor acknowledged. DSF also issued a companion Backgrounder: The “Dirty Dozen” Ingredients Investigated in the David Suzuki Foundation Survey of Chemicals in Cosmetics. 

Sears is the sole author of the 2007 report The Medical Perspective on Environmental Sensitivities for the Canadian Human Rights Commission. Combined with a paper by Cara Wilkie and David Baker, Accommodation for Environmental Sensitivities: Legal Perspective, Sears’ in-depth study persuaded the CHRC to adopt its “Policy on Environmental Sensitivities” in January 2014.

That policy, which classifies environmental sensitivity as a protected disability in Canada, states in part: “Individuals with environmental sensitivities experience a variety of adverse reactions to environmental agents at concentrations well below those that might affect the ‘average person.’ The medical condition is a disability and those living with environmental sensitivities are entitled to the protection of the Canadian Human Rights Act, which prohibits discrimination on the basis of disability.”

A conference call in late 2004 among 15 Canadians concerned about the high cost of cancer cure searches and efforts to control cancer via increased screening and early diagnosis led to the formation of Prevent Cancer Now in 2007. Its vision is of a world where cancer is the exception rather than the rule.

“As in the U.S., the Canadian Cancer Society tends to be weak on primary prevention,” Sears said.

Through public education, awareness-raising, focused advocacy and legislative and policy reforms, the not-for-profit, which Sears has chaired for two years, has been striving to create a Canada-wide movement to prevent cancer by eliminating its preventable causes, including environmental and workplace exposure to carcinogens.

“Going alone, we’ll go slowly; going together we’ll go fast,” Sears said.

Those attending Sears’ talk Monday will learn about key classes of chemicals and how least-toxic approaches — from personal choices to national laws — can simplify life and accelerate change for a healthier, more prosperous world.

“There are so many opportunities every day to make changes in our exposure to chemicals, beginning with the fragranced sheets we wake up in, the products we use when showering and shaving and the nonstick pans we fry eggs in,” Sears said. “Individual exposures won’t put us over the brink, but when teamed up with others, they do.”


The author Deborah Trefts

Deborah Trefts is a policy scientist with extensive United States, Canadian and additional international experience in conservation. She focuses on the resolution of ocean and freshwater-related challenges and the art and science of deciphering and developing public policy at all levels from global to local.