Canada: Linking Environmental Exposure To Illness In Human Health Claims

Last Updated: April 19 2018
Article by Marc McAree and Victoria Chai

Injured individuals seeking to prove in Court a health claim that arises from an environmental exposure can experience evidentiary challenges. Plaintiffs can overcome these challenges by leading evidence (including expert evidence) to prove, on a balance of probabilities, that:

  • They were exposed to an environmental factor (i.e., asbestos, ozone, talcum powder, benzene or volatile organic compounds such as industrial degreasers) that is toxic
  • They experienced a health condition relating to that exposure, and
  • Their health condition was caused by the environmental exposure for which they seek a legal remedy.

Show Me The Proof

Documentary evidence of chemical exposure is helpful in proving health claims, although this evidence may be difficult to come by.

Often the only available evidence is subjective evidence – a plaintiff's own experience of feeling unwell – which may or may not be believed by a Court.1 Disbelief may occur where the Court concludes that a plaintiff's health problem is "psychological" rather than physical.2

In these cases, the success of the health claim depends on the plaintiff's credibility. Where a Court finds a plaintiff incredible, that Court may decide that the claimant's evidence is "exaggerated"3 or that his or her symptoms result from other factors or pre-existing conditions.4 Courts have found plaintiffs' subjective evidence not to be credible where the plaintiffs did not report the symptoms to others or did not seek medical care.5

Timing Is Everything

To establish that an environmental exposure caused a health condition, proof of timing and duration of that particular exposure is important. Proving a causal connection can be challenging where individuals were exposed to multiple toxic compounds for varying lengths of time and thereafter develop health conditions. Proof can also be challenging after much time passes between the time of exposure and development of symptoms of the illness. Although, some exposures, such as to asbestos fibers, are medically known to have a long latency.

Judges Are Not Scientists Or Doctors

Health claims involve the added challenge for claimants of Courts having to rule on complex scientific or medical issues. While absolute scientific or medical certainty is not required to prove in law that a particular event caused a plaintiff's injury,6 Courts have in some cases required plaintiffs to prove the cause of their symptoms with near scientific certainty. Scientific certainty presents a much higher burden than the "more likely than not" standard of legal causation.

Medical experts can assist Courts to rule on complex scientific issues. Often Courts will recognize that the cause of a medical condition is beyond the expertise of a judge or jury, and will determine that expert evidence is necessary7. Where experts are involved, a "battle of the experts" often ensues. Winning the Court's favour can involve the Court believing one expert over another. The expert that is more objective and persuasive is often the one that wins the day.

Judicial Inclination

Plaintiffs bringing health claims may also experience a Court's reluctance to accept alternative medicine. Some Courts prefer the evidence of traditional medical practitioners over alternative medical practitioners.8 There is bias in the health care system that pits traditional versus non-traditional medicine against one another. This is so even though the subjectivity of the claimant's medical complaint is often better told through both forms of medicine.

WSIB to Review GE Worker Claims

The Ontario Workplace Safety and Insurance Board (WSIB) is poised to rule on these issues as the Board reconsiders health claims made by 250 former General Electric (GE) employees who worked with toxic substances at the GE Plant in Peterborough.9

The WSIB's reconsideration follows a Toronto Star investigation which found that "more than half of the 660 occupational disease claims made by employees of GE Peterborough have been denied, abandoned, or withdrawn for apparently insufficient evidence" that the employees' diseases are work-related.10

In their initial hearings, some GE workers had difficulty finding documentation to prove what chemicals they were exposed to and the duration and timing of their exposure.11 The WSIB previously dismissed one GE worker's compensation claim because he could only prove that he was exposed to asbestos for 11 of the 15 years alleged.12

The WSIB has awarded compensation to 30 of the first 47 GE workers whose claim files were recently reopened.13 As of early 2018, the WSIB has reviewed two-thirds of the reopened claims.14

Be Proactive

Injured individuals who initiate health claims must be prepared to confront evidentiary challenges head on. Individuals injured from environmental exposures should act proactively to:

  • Gather documents that indicate what the individual was exposed to, and the timing and duration of that exposure
  • Record the nature, timing, and progression of any symptoms experienced during and after the exposure(s) and detail how those symptoms differ from those of any pre-existing condition. Consider expressing the severity of symptoms to friends and colleagues and seek medical attention. Suffering in silence can work against the claimant if the individual later chooses to proceed with a claim
  • Consider retaining legal counsel to assist in determining the strength of the potential claim and whether the individual should pursue a claim, and the deadline date by when the law requires commencement of a claim, and
  • Work with legal counsel to retain a medical expert(s) to opine about the causal connection, prepare an experts' report and testify. Consider carefully and early on how any Court or Tribunal will receive the medical expert's credentials, experience and opinion.

Looking Forward: Change is coming

More and more, links between environmental exposures and health impacts are being uncovered through scientific study, brought to public attention through journalistic reporting, and considered by Courts in deciding health claims. Scientific, public, and judicial understanding of the causal connection between environmental toxic exposure and health impacts is growing.

As judicial understanding catches up with the science and as the relationship between certain environmental exposures and illnesses are better understood, more health claims will succeed and the authors predict that more companies will be held accountable.

Written with the assistance of Raeya Jackiw, Student-at-Law.


1. Moseley v Director, Ministry of the Environment, [2014] OERTD No. 23.

2. Nichols v Koch Oil Co, [1998] BCJ No 1944 at para 72.

3. Stucke v Richard McDonald & Associates Ltd., 2006 ABQB 239 at para 49.

4. Stucke v Richard McDonald & Associates Ltd., 2006 ABQB 239, Nichols v Koch Oil Co, [1998] BCJ No. 1944, and Manitoba, Workers Compensation Board Appeal Commission, Public Decision No. 99/2013.

5. Stucke v Richard McDonald & Associates Ltd., 2006 ABQB 239.

6. BC (Workers' Compensation Appeal Tribunal) v Fraser Health Authority, 2016 SCC 25.

7. Pettipas v Bell Aliant Regional Communications Inc, 2015 NSSC 58 at para 58.

8. MacIntyre v Cape Breton District Health Authority, 2009 NSSC 202.

9. Monsebraaten, L. and Mojtehedzadeh, S. WSIB to review more than 250 General Electric plant claims in Peterborough, September 18, 2017, online at:

10. Mojtehedzadeh, S. Lethal Legacy: General Electric's Peterborough plant was a symbol of opportunity for generations of workers – but did it also make them sick? Toronto Star, December 17, 2016, online at: [Lethal Legacy]; Mojtehedzadeh, S. and Monsebraaten, L. GE workers paying price for decades of exposure to toxic chemicals: Report, May 18, 2017, online at:

11. Lethal Legacy.

12. Lethal Legacy.

13. Mojtehedzadeh, S. WSIB reverses majority of denied GE Peterborough cancer claims: Toronto Star, Dec. 17, 2017, online at:

14. Giunta, Mark. GE Peterborough occupational health claims review more than half complete: WSIB: Global News, February 27, 2018, online at:

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

Marc McAree
Victoria Chai
In association with
Related Topics
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of

To Use you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions