Pesticides -- Good for Your Health? - Part 1

June 16, 2002

By Michael Jessen

The strengths of pesticides are also their weaknesses. In other words, the reasons we use pesticides provide the rationale for why we shouldn't.

First, pesticides are effective at what they do -- killing and harming living organisms. But this characteristic also poses a problem as pesticides affect many other species besides the weeds and bugs they are meant to eradicate.

Second, they are easy to manufacture and quite cheap as their development is commonly subsidized by the military-industrial complex. This factor has resulted in their widespread and often indiscriminate use.

The third advantage of pesticides is their prolonged stability. Many can linger in the environment for years. This persistence is also one of their hazards.

A fourth advantage of pesticides is an apparently low toxicity to fauna and humans. Rarely do people or mammals die instantly from exposure to pesticides. This characteristic has contributed to a dearth of knowledge about the lethal effects of pesticides over a period of time.

All of these strengths and weaknesses are summed up in the history of DDT use. About 5 billion pounds of DDT have been applied both indoors and out since it was introduced in 1939. DDT residues were first found in human tissues in 1944 and in human breast milk in 1951. Some scientists warned in the 1950s of the dangers of DDT to fish and wildlife, but the issue didn't take centre stage until Rachel Carson's book "Silent Spring" was published in 1962. She compared the threats of environmental contamination from pesticides with the risks of nuclear war. Carson presented stories about the poisoning of fish, eagles, falcons, and farmworkers. She chronicled a legacy of errors in judgement by those charged with protecting health and environmental quality. DDT was finally banned for domestic use in Canada in 1971 and the US in 1972. Yet 30 years later, DDT residues are still turning up in minimal amounts in Canadian grown carrots exported to the US and in the muscle tissues of char and cod caught in the Canadian Arctic.

The history of pesticide regulation in Canada follows a similar rocky road. In 1969 the Pest Control Products Act (PCPA) is passed by Parliament. The Law Reform Commission recommends 23 improvements to the legislation in 1987 and a major reform of the law is suggested in 1990. Jean Chretien promises to amend the pesticide legislation in the Liberal's Red Book prior to the 1993 federal election. No changes are made to the law and improvements are suggested again in 1994, 1998, 1999 and 2000. Finally, on March 21, 2002, Health Minister Anne McLellan ( introduces Bill C-53, a new Pest Control Products Act, that moves swiftly through first and second reading and is referred to the Standing Committee on Health on April 15. The committee quickly invites comment, convenes 16 meetings, and reports back to Parliament on June 3 with 24 proposed amendments (

The bill is not controversial and is barely reported on in the news media. Both the pesticide industry and environmental groups generally approve of the new legislation. The official opposition supports it and it will probably become law before Parliament rises for the summer recess. The new act is still about granting permission for a pesticide's release rather than attempting to prevent exposures that are unacceptably dangerous. Yes there is a call for greater attention to be paid to the effects of pesticides on children and greater transparency and public access to data during a pesticide's evaluation process. After the legislation is passed, Canada will finally require reporting of pesticide sales and use, thereby becoming one of the last countries in the Organization for Economic Co-operation and Development to do so. After a pesticide is registered, pesticide companies are required to report adverse effects. Thatís the good news.

But while the legislation is a long overdue improvement to a 33 year-old law, some groups argue it still contains flaws. Criticism of the new legislation can be summed up this way: Canada doesn't so much need legislation to control pesticide products, it needs new laws to control pests. By controlling pesticide products, we imply there is a need for them. This distinction becomes even more critical when one considers that an increasing number of crops are genetically engineered to incorporate a pesticide or to become herbicide resistant. The reality is that our governments have a history of approving pesticides for use and later pulling them from the market after harmful effects are found. Aldrin, dieldrin, toxaphene, chlordane, endrin, heptachlor, mirex, aldicarb, DDT, and 2,4,5-T are just a few of the pesticides once lauded as safe only to be banned, usually after years of efforts by health and environmental groups.

These organizations are currently calling for a ban on the use of atrazine, one of the most widely used weed-killers in North America. They have been urging this ban for years. When the Environmental Working Group ( released a report in 1999 stating atrazine was running off cornfields and getting into the tap water of millions of mid-western U.S. homes, farmers' groups and pesticide companies branded the report "alarmist." A year later, a draft report by scientists at the U.S. Environmental Protection Agency upgraded the chemical from a "possible" to a "likely" carcinogen, stating that it could cause uterine, prostate and breast cancer in humans and may also disrupt reproductive development. Today atrazine is still in use across North America, despite the fact many European countries have banned it. Just this month, the Natural Resources Defense Council ( released two new studies that show atrazine poses a significant threat to public health. The group called on the EPA to ban the use of atrazine and launch a criminal investigation of Syngenta, atrazine's principal manufacturer, for allegedly covering up the studies. One of the studies links atrazine to deformities in frogs, causing them to grow both testes and ovaries. A lawsuit against Syngenta brought by factory workers who say they got prostate cancer after being exposed to the chemical has provided new ammunition for critics challenging the EPAís decision two years ago to remove atrazine from its list of substances that probably cause cancer in humans. The NDRC wants the company investigated for not promptly disclosing the workplace cancers, as required by law. The United States uses about 60 million pounds of atrazine per year, and its traces are found in the water supplies of many communities. The EPA is accepting comments about atrazine only until July 5. If you're in favour of a ban on atrazine, the Action Center at will send a letter to EPA administrator Christine Whitman on your behalf after registering on their web site. The site -- a collaborative effort of the world's most influential environmental advocacy organizations -- is also a great source of environmental information.

When it comes to pesticides, one can easily form the opinion that the interests of chemical manufacturers supersede the health of humans. Some of the blame for this can be directed at Paracelsus, a physician-alchemist living in Germany during the sixteenth century who used chemicals to treat illness. Paracelsus claimed simply that all substances are potentially poisonous and that dosage alone differentiates a poison from a harmless compound and even a remedy. Thus the foundation of modern toxicology was laid and this principle -- that dose makes the poison -- has provided the basis for government management of drugs, pesticides, and other contaminants in food, drinking water, and air. While pesticide companies have done the research to discover the dose required to kill a pest, they haven't done similar studies on what doses will harm humans. (If they have, they keep these studies secret.) So legal tolerances for pesticides are set based on the amount required to eliminate the pest, rather than on that required to protect against dangerous levels of human exposure.

According to John Wargo, author of the award-winning book "Our Children's Toxic Legacy: How Science and Law Fail to Protect Us from Pesticides", about 6 billion pounds of pesticides are sold in the global marketplace each year. "These compounds are applied to crops, forests, lawns, gardens, parks, highways, rail lines, power lines, lakes, ponds, swimming pools, office buildings, aircraft, ships, hospitals, schools, and day-care centers," Wargo writes. "Pesticides are also deliberate components of some clothing, shampoos, drugs, paints, wallpaper, shower curtains, rugs, blankets, and mattresses.

"Understanding the health and ecological risks incurred by these uses requires knowing where pesticides are released, how they move through the environment, and where they come to rest," says Wargo. "This knowledge provides the basis for comprehending how humans are exposed to pesticides, which in turn is necessary for understanding the magnitudes of risks these contaminants impose." Wargo is a professor in the School of Forestry and Environmental Studies and director of the Children's Center for Environmental Health at Yale University.

Pesticides are pervasive in our environment. Here are some disturbing facts from the Environmental Defence Canada Foodwatch web site at

 Some 7,000 pesticides are on the market and about 30 million kilograms are applied annually in Canada;

 According to Statistics Canada, pesticide use in Canada rose over 400% between 1970 and 1995;

 Canada used 0.95 kg of pesticides per capita in 1994 (only 6 other OECD countries used more pesticides. Canada ranks 22 out of 28 for per capita usage);

 Hundreds of pesticides on the market, including diazinon and captan, were introduced in the 1960s and 1970s and have not been formally re-evaluated, even though our knowledge of the impacts of toxic chemicals on humans and the environment has changed significantly.

The truly shocking news is that as many as 80,000 different chemicals have been introduced into the world environment and only a handful have been evaluated for their effect on humans. Many -- including atrazine -- are still being studied. That is why the Standing Committee on Environment and Sustainable Development urged a precautionary approach in the decision-making process about pesticide use. In its May 2000 report "Pesticides: Making the Right Choice for the Protection of Health and the Environment" (, the committee said "The lack of scientific certainty should not be allowed to impede effective action to protect human health and the environment against actual or suspected harm caused by pesticides. It is, therefore, imperative that the new Act embrace a precautionary approach in all aspects of decision-making." The report defines the precautionary principle, as it applies to pesticides, this way "Appropriate preventive measures are to be taken where there is reason to believe that a pesticide is likely to cause harm, even when there is no conclusive evidence to prove a causal relation between the pesticide and its effects."

Rather than embracing the precautionary principle, Canada's new Pest Control Products Act relegates it to an obscure section on pesticide re-evaluation. According to testimony from federal officials at the recent parliamentary committee hearing, the government's excuse is that it already uses the ultimate precautionary approach in its pesticide system so there was no need to put it in the act. The officials argued that enshrining the principle throughout the act would actually lower the standard of care they currently use in approving pesticides.

Next time, I'll report on the evidence of harm caused by pesticides, offer some alternatives to these dangerous chemicals, and relate how some communities are becoming proactive about pesticides.

RESOURCES - If you wish to write to Health Minister Anne McLellan about Bill C-53, there is a form on A copy of the bill as amended from committee stage June 3 is available at The Canadian Public Health Association position paper on Bill C-53 is at The Canadian Environmental Law Association briefing note on C-53 is at Pollution Probe's comment on C-53 is at All three of these groups presented their comments to the Standing Committee on Health and urged the inclusion of the precautionary principle in the bill. The Canadian Bar Association letter commenting on C-53 and urging more accountability and public consultation options in the bill is at The CropLife Canada (representing the manufacturers, developers and distributors of pesticides) and Urban Pest Management Council of Canada (representing manufacturers of lawn and garden products) position on C-53 is at Both these groups endorsed the bill as is and neither recommended the precautionary principle. Questions and answers about the proposed new Pest Control Products act can be found at An October 2001 fact sheet on the regulation of pesticides in Canada produced by the Pest Management Regulatory Agency is at The agency's web site is The Campaign for Pesticide Reduction (CPR) is a Canada-wide coalition of health professionals, environmental organizations, labour groups, farmersí associations, academics and activists concerned with pesticide use. The Steering Committee includes the Canadian Environmental Law Association, the Toronto Environmental Alliance, World Wildlife Fund, the Canadian Labour Congress, the Coalition for Alternatives to Pesticides, the Canadian Association of Physicians for the Environment, and the Sierra Club of Canada. CPR's position on C-53 as well as a backgrounder with their suggested changes to the bill is at First published in 1996, a second edition of John Wargo's book was issued by Yale University Press in 1998.

Michael Jessen is a Nelson-based consultant helping businesses and communities profit from environmental leadership. He can be reached at 250-229-5632 or by e-mail at His firm -- Zero Waste Services -- has an award-winning web site at

All columns archived here are copyright © 2000 by Michael Jessen, all rights reserved. If you wish to print an individual column for your own use, please do so. If you wish to publish any of the columns in either print or electronic format, please contact the author at to arrange appropriate payment.