On June 27, 2022, the Ontario Environmental Health Advocates Group posted a major research and review report, Putting the Chemicals Back in Multiple Chemical Sensitivity to refute what we believe are the erroneous and dangerous conclusions of the literature review and definitional paper on MCS, Multiple Chemical Sensitivity Syndrome: An integrative approach to identifying the physiopathological mechanisms, released in French in June 2021 by the National Public Health Institute of Quebec. The release included a short Key Messages and Summary in English. Along with other advocate groups, especially L’Association pour la santé environnementale du Québec / Environmental Health Association of Québec, our counterargument warned that the INSPQ report represents a clear and present danger to people living with MCS – more than 1.1 million Canadians – and with other chronic, complex diseases such as myalgic encephalomyelitis (ME) [also known as ME/CFS, and formerly as chronic fatigue syndrome] and fibromyalgia (FM). The INSPQ report places these in the same “basket” as MCS, framing all of them as anxiety disorders, not biophysical diseases. Further, in the case of MCS, the INSPQ reports claims it has nothing to do with chemicals. We strongly disagree and we support these advocates’ call to have the report withdrawn from the National Institute’s website


“Today,” says lead author Varda Burstyn, “a new, enhanced 2nd edition of our comments on and refutation of the INSPQ’s report is being released. All the original material is still there. But we have reformatted our Executive Summary and have added some new content to the complete report that strengthens our critique and the case we make against the fundamental conclusions of the that report: that MCS and ME are anxiety disorders, not biophysical ones, with biophysical causes and mechanisms.” 

“We have done this,” Maureen MacQuarrie, the collaborating author, explains, “by including a discussion, spread over several parts of our report, of the implications of an important recent article, released less than one year after the INSPQ report and co-authored by Marie-Ève Tremblay, one of the three principal authors of that report. This article, “The Pathobiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Case for Neuroglial Failure” was published in Frontiers in Cellular Neuroscience in May, 2022. It presents a detailed hypothesis supporting the biological, including very possibly immunological, origin and mechanisms of ME – a view we agree with. We have drawn on it in a number of ways, including to expand our Part 9, devoted to ME and to long COVID.”  

“The article’s approach contradicts the key conclusion of the INSPQ report that ME is an anxiety disorder,” says Varda Burstyn. “We show how the approach of this article is similar to the one we take to ME and also to MCS. And this apparent contradiction leads us to call for a clarification of which approach – the biophysical or the psychological – is the right one? We hope Dr. Tremblay will weigh in as we think it’s critical that policy makers everywhere have the benefit of her clarification, since the implications of the INSQP report’s conclusions for clinical programs, disability rights, public health policy and research directions are both negative and dangerous.” 

“In the preface to the second edition, we’ve introduced the discussion of this new article, and as well we have provided a page by page list of where this discussion takes place as well as where other additions have been made to the first edition,” Maureen MacQuarrie clarifies. “Although this second edition replaces the first, which can now be discarded, this guide will make it easier for anyone who has already read our report to find the changes quickly if they wish. We invite everyone to download the second edition, and by all means, distribute it widely.” 

“The Ontario Environmental Health Advocates will be sending this report to key people in the Quebec, Ontario and federal governments, as well as to researchers and clinicians more broadly,” Varda Burstyn concludes. “With huge long COVID numbers now being added to our ME numbers – long COVID is a condition that for many is clinically indistinguishable from ME – and with over a million Canadians with MCS grotesquely neglected, all of us must work to put an end once and for all to the psychologizing of these illnesses. Our report can be grasped as a tool in that work, which is now more timely than ever.” 


 “The year 2021 was, for the most part, a really good year in MCS studies, advancing understanding in a number of important ways” says environmental health writer and consultant Varda Burstyn, the lead author of Putting the Chemicals Back into Multiple Chemical Sensitivity. “A number of important new articles were published. But then, we read the report from Quebec’s INSPQ, and the sirens went off. Because we realized that if its conclusions were accepted by medical and health authorities, anywhere, people with MCS, as well as ME and other complex diseases, would be imperilled, and all the good work done by so many advocates, researchers and physicians would be endangered.” 

“That’s why we decided to write our own report, and to research and reference it extensively,” says Maureen MacQuarrie, the collaborating author, a former lawyer and policy adviser, and now a member of the Steering Committee for the ICanCME Research Network and clinical care working group. “We knew that by showcasing the research omitted by the INSPQ plus the new research, we could refute their conclusions and, at the same time, give people a great idea of the really good work being done out there today.” 

“This new report is important for all kinds of people,” says Adrianna Tetley, the former CEO of the Alliance for Healthier Communities, board member of MEAO and former co-chair of the Ontario Centre of Excellence in Environmental Health business case project. “Policy makers, health providers, those working in the disability field, and many others urgently need to understand what MCS really is, and they’ll gain new knowledge about ME too. They need this as responsible partners in the effort in front of all of us, which is to modernize health care in general to address complex, environmentally-linked diseases, including long-COVID – a modernization that is very overdue.” 

“We identified some very excellent new research in neurological and immunological factors, and unpacked it to make it accessible to all,” Varda says. “We gave a lot of space to the clinical experience, and to patient experience – both left out of the INSPQ report. In addition, and crucially, we placed MCS within the field of environmental health where it belongs. We drew both on important existing work and on wonderful new work that shows how seriously everyday toxics impact neurological and immunological, as well as many other aspects of health. All that was lost or ignored in the INSPQ report, and the result was an astounding mistake in describing common chemicals as ‘harmless.’” 

“Everyone has a stake in this refutation of the conclusions of the INSPQ report,” says Denise Magi, President of MEAO, “because we are all targeted by it, and we all need the new type of medicine that our critique explains and proposes.” 

“The new practical recommendations in this report, including those for a new paradigm for clinical care, are excellent, and so badly needed,” says Ted Ball, health systems design consultant, patient advocate and former co-chair of the OCEEH business case project. “Reading this report, even the executive summary alone, is revelatory, of MCS, and of studies in environmental health more broadly. It is a highly rewarding investment of time and paints a clear picture of the direction we need to go in and how to do it.” 




Putting the Chemicals Back in “Multiple Chemical Sensitivity”: Ontario Advocates Address Syndrome de sensibilité chimique multiple, une approche Intégrative pou iIdentifier les mécanismes physiopathologiques/ Multiple Chemical Sensitivity Syndrome, an Integrative Approach to Identifying the Pathophysiological Mechanisms. Lead author Varda Burstyn Collaborating author Maureen MacQuarrie for the Ontario Ad Hoc Environmental Health Advocates. June 27, 2022. 

Two other highly relevant documents from the Ontario process to create a network of care for people with ES/MCS, ME/CFS and FM, that are extensively cited in the new report are can be downloaded with a click here: 

Recognition, inclusion and equity: Solutions for people living in Ontario with ES/MCS, ME/CFS and FM – The Business Case Proposal, Steering Committee of the OCEEH Business Case project, November 2013. Commissioned by the Ontario Ministry of Health in 2012 and submitted in late 2013, it was supported by several in-depth research documents, all available at http://recognitioninclusionandequity.org/resources/ 

 “Part 3: Community Voices” & “Part 4: Special Issues.” These sections detailing the findings of a major, qualitative needs-identification study in Ontario have been excerpted from Recognition, inclusion and equity – The time is now: Perspectives of Ontarians living with ES/MCS, ME/CFS and FM, Varda Burstyn and MEAO, 2013. The study was designed and conducted by Ann Phillips and Erika Halapy and written by Varda Burstyn. 

We also invite you to visit the website of the ASEQ-EHAQ, and add your voice in response to their request for people’s experience with the INSPQ report here. Visit https://aseq-ehaq.ca/en/we-invite-you-to-make-your-voice-heard/ 



Business case study for an Ontario Centre of Excellence in Environmental Health 

You may also be interested in reading a number of additional documents from the Ontario process to create a network of care for people with ES/MCS, ME/CFS and FM, especially those cited and analyzed in the new report, as well as the related and relevant links below. 

Additional research reports from multiple components of 2011-2013 study project funded by the Ontario Ministry of Health and Ontario Trillium Foundation, to prepare a business case for a three tiered network of care called the Ontario Centre of Excellence in Environmental Health (OCEEH). http://recognitioninclusionandequity.org/resources/ 

Ontario Task Force on Environmental Health 2016-2018. 

Interim report 2017: Time for Leadership: Recognizing and Improving Care 

Final report 2018: Care Now: An Action Plan to Improve Care for People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), Fibromyalgia (FM) and Environmental Sensitivities/Multiple Chemical Sensitivity (ES/MCS).  

CareNow Ontario – advocacy focused on driving the development of a system of care for people with ES/MCS, ME/CFS and FM







Damiani, G., Alessandrini, M., Caccamo, D., Cormano, A., Guzzi, G., Mazzatenta, A., Micarelli, A., Migliore, A., Piroli, A., Bianca, M., Tapparo, O., & Pigatto, P. D. M. (2021). Italian Expert Consensus on Clinical and Therapeutic Management of Multiple Chemical Sensitivity (MCS). International Journal of Environmental Research and Public Heath, 18 (21) 11294. Available at https://doi.org/10.3390/ijerph182111294 

Masri, S., Miller, C.S., Palmer, R. F. & Ashford, N. (2021). Toxicant-induced loss of tolerance for chemicals, foods, and drugs: assessing patterns of exposure behind a global phenomenon. Environ Sci Eur, 33, 65. Available at: https//doi.org/10.1186/s12302-021-0004-z

Miller, C.S., Palmer, R.F., Dempsey, T.T., Ashford, N.A., and Afrin, L.B. (2021). Mast cell activation may explain many cases of chemical intolerance. Environmental Sciences Europe, 33. Article 129. Available at https://doi.org/10.1186/s12302-021-00570-3 

Molot, J. (2021). Response to the report of the National Institute of Public Health Québec (INSPQ) on Multiple Chemical Sensitivity (MCS) – Summary. October 15, 2021. Submitted by ASEQ-EHAQ. Available at https://aseq-ehaq.ca/pdf/Response_INSPQ_Short-Summary_EN.pdf Accessed April 15, 2022. 

Molot, J., Sears, M., Marshall, L., & Bray, R. I. (2021). Neurological susceptibility to environmental exposures: pathophysiological mechanisms in neurodegeneration and multiple chemical sensitivity. Reviews on Environmental Health. Published online September 16, 2021. Available at https://doi.org/10.1515/reveh-2021-0043 

Renz-Polster, H., Tremblay, M. E., Bienzle, D., & Fischer, J. E. (2022). The Pathobiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Case for Neuroglial Failure. Frontiers in cellular neuroscience, 16, 888232. https://doi.org/10.3389/fncel.2022.888232 

Barrett, E. S., & Padula, A. M. (2019). Joint Impact of Synthetic Chemical and Non-chemical Stressors on Children’s Health. Current environmental health reports, 6(4), 225–235. Available at https://doi.org/10.1007/s40572-019-00252-6 


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