Chemical Sensitivities

“There are two ways to be fooled: One is to believe what isn’t so; the other is to refuse to believe what is so.” Søren Kierkegaard – as cited by the wise Dr. Stephen Genuis, M.D.

What you will find in this section: 

  • About chemical sensitivity when it becomes a disease
  • The words of sufferers: what it’s like to live with severe chemical sensitivity. The voices come from a ground breaking community consultation and qualitative study done in Ontario in 2012.
  • Research bibliographies
  • Popular, Scientific, and Medical Reading on ES/MCS
  • Some important newer medical and scholarly studies
  • Commercial vs. health interests – text below and in sidebar.
  • Clinics
  • Serious, systems-approach proposals for treatment and support services under consideration
  • Additional Medical and Scientific Sources
  • (Just a few) ES/MCS Organizations
  • Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Fibromyalgia (FM) – click here.

Among the many triumphs of denial and deception in the annals of the chemical industry, one of the greatest sleights of hand is the effective disappearing of a crippling disability – severe chemical sensitivity – through a campaign to make people believe it is basically hypochondria, the displaced symptom of being “emotionally troubled.” But it is all too real and millions suffer from it.

 “When I am exposed to perfumes and other chemicals … nobody can see what is happening in my body, they don’t understand. So my body is burning. My eyes are burning. My throat is burning. I think I am going to throw up. I get migraines. I get shaky and then those other symptoms that I describe, I am also dealing with as well. It is kind of like a package deal that feels like every system in your body is going into hyper-drive and you don’t feel a sense of control of your body and of your life.” Hope MCS

The words of sufferers on this page will give you a window on what it’s like to develop and live with severe chemical sensitivity. All these voices come from participants in a ground breaking community consultation and qualitative study conducted by a team of researchers led by M. Ann Phillips, Ph.D. and epidemiologist Erika Halapy, in Ontario in 2012, reported in detail by me and summarized in Sections 3 and 4 of Recognition, inclusion and equity – The time is now: Perspectives of Ontarians living with ES/MCS, ME/CFS and FM (Varda Burstyn and MEAO, 2013). This report surveyed patients’ experience, needs, and (massive) gaps in services; provided special analysis of women’s, children’s and stigmatization issues; and presented a model of care, and care delivery to correct deficits and remove barriers across government and the public sector services. Download the whole pdf here.

The most common term of pathological chemical sensitivity is Multiple Chemical Sensitivity or MCS. This disorder is also known as Environmental Sensitivities (ES) or Environmental Illness (EI) or Toxicant Induced Loss of Tolerance (TILT). In the World Health Organization’s ICD 10 (International Classification of Disease) you can find ES/MCS listed under a different name: effects of Toxic Injury ICD 10 T51-T65. Names for this condition are a disorderly jumble – with multiple choices depending on emphasis on causation, or symptomatology or links to other conditions – and this adds to the confusion about it. But the condition is very real and has been established in clinical practice for over 60 years. Get to know about it quickly by visiting the Chemical Sensitivity Foundation and watch the video of Dr. Christine Oliver of Harvard University.


Though it affects millions of people, because of its invisibility to those who don’t live with it or a with family member afflicted with it, you may not know much about this particularly perverse disorder. Due to toxic exposures, sometimes combining with some other predisposing factor – such as a poor genetic heritage for detoxification or a previous brain injury or, indeed, a serious infection, people get sick. Multiple organ systems suffer as a result of breathing or ingestion of chemicals that are, in fact, toxic to everyone long term, but at low levels that do not disturb most people, and do not alert them to the danger of the substances. This is why chemical sensitivity is considered so dangerous by the chemical industry: because the chemically sensitive’s reactions point to the toxicity of everyday substances, and in very direct and immediate ways. Check out the sidebar for more on that subject.

“I lived and worked in an environment next to a dry cleaner, and there was a perchloroethylene leak, and that is when I first went blind in one eye. It came back, but not for nine months. From that time on the chemical sensitivities just mushroomed. Actually, domino affects more, not that you’re allergic, you are reactive to this, reactive to that – petro-chemicals, the broad umbrella – and then, these are things I never expected or even heard of.” Claire MCS

Chemical sensitivity can range from a hindrance to a serious disability to a hellish day-to-day condition, and is even life threatening in those with severe levels. And it can – and too often does – completely ruin people’s lives by excluding them from every type of human activity, including love and family relationships, workplaces, schoolrooms and recreational centers.

“I call this the lonely disease. I had friends that don’t bother with me anymore because it takes too much effort to be with me because there are a lot of rules attached to what you can smell like, what you have to do for two or three days before you come and see me. They fell by the wayside. … I don’t have a social life.” Sandra MCS FM

“I’ve lost touch … even family that lives a two-hour drive away. I can’t attend those events because of the driving. I can only drive myself about 15, 20 minutes. But to be in a car for an hour is my max before it interferes with the rest of the week. So I haven’t seen certain family members for a long time.” Sophie FM ME MCS

Alas, due to the widespread, erroneous medical myth, that it is a psychological condition Those who have it are also still frequently stigmatized as hypochondriacs or “emotionally troubled” or malingerers who don’t want to carry their own weight, an additional injury to them that greatly exacerbates their suffering. 

 “Even though I live in the country, on my street a lot of IT people are moving in, and last year my neighbour had a router going through my bedroom window. [I’m EMF sensitive] and I had to get a professional in to do a reading on it, and forward it to my neighbor and it was a really bad feeling. I used to be friendly with this neighbour and no longer. You become isolated and worse than isolated, you actually become hated. … What I would like to see is publicity, that this is real, so that I would have a family, that I wouldn’t be shunned. Shunning was an old fashioned method of really killing people. It was kind of like with voodoo. If your whole tribe is against you, you die. The only way shunning wouldn’t be so prevalent would be through the media.” Claire MCS

Resident of Snowflake, Arizona, a community of people with chemical sensitivity. Photo: High Country News

This shunning is done by medical professionals as well as people in everyday lives. On the Chemical Sensitivities in Ontario page, you can read more about this phenomenon.  But what’s key to remember is that the isolation, the poverty, the housing insecurity and the ‘shunning’ are themselves so intense and prolonged that many people experience severe trauma over and above their crippling and painful chemical sensitivity symptoms.

I have been diagnosed with toxic brain injury, MCS and FM. … I couldn’t work and I couldn’t stand all the smells and everything in [my house] so I had to sell my home. … In November of 2002 I was probably so suicidal because I thought that the rest of my life was going to be spent in a little cottage by the river where it was freezing cold with a composting toilet, by myself in pain. … The whole experience changed me psychologically so much, I lost myself, I died. The real Sandy basically died with this and this person that is left now is a totally new invention, I don’t even recognize myself in the mirror. Sandra MCS FM

The most important factor in the ongoing ignorance and disbelief of pathological chemical sensitivity has been the chemical industry’s influence in shaping medical, governmental and insurance policy making. If this seems hard to believe, consider the tobacco industry and how it reacted to the discovery of the links to cancer, multiply the stakes by some nearly infinite amount and you will understand the commensurate resistance. If everyone understood that millions of people get instantaneously sick from exposures to chemical “air fresheners” or car interiors, or laundry products or building materials or cosmetics – which is the very problem that pushes people with MCS to withdraw from society and avoid indoor air, and that, in turn, makes them literally invisible – they would understand as well that those people truly are the canaries in our chemical coal mine. This would produce a huge crisis of confidence in the modern chemical regime, something the industry wants to avoid at all costs. Therefore the illness has to be denied. Considering how widespread the disorder has become, the denial has been remarkably successful.

“It’s been about half my life that I have had chemical sensitivities, multiple chemical sensitivities. I don’t really know how it started to happen, but I think what happened was when I was young I had a major inner ear infection. Then I went to the hospital; I had surgery; I had tubes put in and I had them taken out. Then I started having the asthma attacks in the fall. Then when I was in my early 20s – I was in nursing school actually – that’s where it started. I started to have reactions to chemicals and perfumes and things around – the cleaners and stuff. I couldn’t even continue in the class. I had moved to Montreal and there I found out that it could be this multiple chemical sensitivities.” Petra MCS

“I can’t eat food from a supermarket because that’s all contaminated with fragrances and laundry product residue. So I need non-supermarket sources of organic food. I must prepare my own food. Mixed, packaged foods have too many sources of contamination, even at the farmers’ market, I bought organic cabbage rolls because, you know, their vegetables were really good for me. I’m eating the cabbage rolls and I can taste dish detergent in them, so I asked, ‘Well, what do you wash your dishes with?’ ‘Oh, we use Palmolive.’ I said, ‘Well it’s in your cabbage rolls’”. LMS MCS

This condition affects all kinds of people: it affects veterans (especially Gulf War 1, but also other wars in which chemicals were/are used), first responders, oil spill workers, workers making chemicals and workers working with chemicals, including plastics and agricultural workers – as well as many people who get sick outside of occupational settings in ‘sick buildings’ or other domestic settings. It happens that more women than men succumb to it overall, thanks to a number of biological and social factors; but when the exposures are intense or protracted, men succumb as well. However, the ‘majority women’ factor activates the well-documented sexist bias – disbelief, minimization, psychologization of illness – in medicine, which adds further to the problem of recognition.

You will often read, even in sympathetic articles, versions of the belief that “we don’t know much about MCS.” This is really misleading and untrue. (just have a look at the research bibliographies below.) At times, this idea may be motivated simply by ignorance of the extant research. But when it comes from the professional deniers with undeclared interest in obscuring the illness, it is motivated by a desire to hide what has been learned and is being learned every day. So, while we do not yet have what’s known as a “biological biomarker” – a diagnostic physiological characteristic unique to MCS – we are getting there through the new science of metabolomics, and through brain imaging and biochemistry.

Recently, characteristics in gut flora, brain functioning, and brain chemistry linked to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (known as ME/CFS, it is another “central sensitivity syndrome”) have been found and are being posited as just these biomarkers (read below). ME/CFS was also characterized as somatization and hypochondria by the medical establishment until the last 3 years. Since then, with funded research, the picture has changed entirely. New funding for research on chemical sensitivity would surely yield equal success. But so far in Canada and the U.S., the government bodies and universities that do such research have not stepped up.

The reason people are so sure that such research would yield such results is that all the new research of the past two decades done by teams of scientists and physicians who follow the evidence of their own senses rather than a baseless mythology – in extensive SPECT scan and fMRI brain imaging, in genetic testing and neurochemistry, in blood tests and biopsies of toxic body burden, in understanding the contribution of processes such as methylation and the role of chronic infections such as Lyme and brain injury – all this new research, in fact, points to physiopathology rather than psychopathology.

Remember: any one of us, any of our children and loved ones, could be blindsided by a toxic exposure – an oil or gas spill, a pesticide encounter, moving into a new home with too many volatile organic compounds (“VOCs”) for us to handle – and that could push any one of us over into disabling MCS. So every one of us has a stake in changing this chemical regime and ensuring that creating treatment and support are accessible and insured for everyone who needs them.


“I was just an ordinary person and then things started slowing down. I was getting fatigued and I was not able to remember a thousand things without writing them down anymore. I found I was writing notes to remember simple things … I started reacting to the cleaners in the hospitals, and in the centres where I would be, to their cleaning things, where I was noticing them but I never noticed them before. Then I got the flu and that was the end. That was the beginning of an incredible journey that I’m still on.” MaryLou ME FM MCS

“I had the flu and then bingo, I couldn’t hold my hands up to type. I couldn’t drive my car. I couldn’t stand. I still had to work. Had a pillow that I laid my arms on so I could type, because I was agency and agency people don’t ever get time off.” Janepher FM MCS

So much more: have a look at the resources that are available to you…

Research bibliographies

Chemical Sensitivity: Pathophysiology or Pathopsychology? Stephen J. Genuis, MD, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada. Clinical Therapeutics/Volume 35, Number 5, 2013 · Atopic Clinical Entities Update

Chemical Sensitivity Foundation – Research page

Chronic, Complex Conditions: Academic and Clinical Perspectives, John Molot, MD, FRCFP, 2013. The clinical appendix to the business case package, this document presented current thinking by physicians and researchers, and recommendations for clinical services. NOTE THE BIBLIOGRAPHY FOR RESEARCH ON ES/MCS. Download Academic and Clinical Perspectives

MCS America – Studies (research) page

Popular and informed reading on ES/MCS

Amputated Lives: Coping with Chemical Sensitivity. Alison Johnson. With a Foreword by L. Christine Oliver, M.D., Harvard Medical School.

…and many others you can find at The Chemical Sensitivity Foundation book page:

12,000 Canaries Can’t Be Wrong: What’s Making Us Sick and What We Can Do About It. Hardcover – June 1, 2014, John Molot, M.D.

Recognition, inclusion and equity – The time is now: Perspectives of Ontarians living with ES/MCS, ME/CFS and FM, Varda Burstyn and MEAO for the OCEEH project, 2013. This report presents a major qualitative survey of patients’ experience, their needs, the (yawning) gaps in service in Ontario – typical across Canada – and provides paticular analysis of women’s, children’s, and stigmatization issues. It then presents an in-depth exploration of the model of care and its proposed delivery system, and an -depth discussion of issues in barrier removal across government and the public sector. Download Recognition, Inclusion, Equity: Patient Perspective, Complete 

The Quantitative Data, Erika Halapy, Epidemiologist, with Margaret Parlor, Statistical Analyst and President, ME/FM National Action Network, 2013. A first-ever compilation and analysis of statistical findings in Canada and Ontario, based primarily on Statistics Canada findings. Download OCEEH_Quantitative Data Report

Some important newer research

Environmental Sensitivities: Chemical, Electrical, and Beyond in special issue of Ecopsychology . Guest editor Pamela Gibson Reed (, who heads the MCS research team at James Madison University ( and

Stephen Genuis, M.D. FRCSC DABOG DABEM:

 “Approach to patients with unexplained multimorbidity with sensitivities.” Stephen J. Genuis MD FRCSC DABOG DABEM and Marko G. Tymchak. Canadian Family Physician. Vol 60, June 2014. Download PDF here.

“Pandemic of idiopathic multimorbidity.”  Stephen J. Genuis MD FRCSC DABOG DABEM. Canadian Family Physician Vol 60, June 2014. Download PDF here.

Stephen Genuis, M.D.: “The chemical disruption of human metabolism,” (Stephen J. Genuis & Edmond Kyrillos (2017): Toxicology Mechanisms and Methods, DOI: 10.1080/15376516.2017.1323986). Please note: This paper shows underlying mechanisms at the cellular level that account for a variety of illnesses which many clinicians have so far seen as separate and unrelated. From a Canadian practitioner/scholar with a stellar track record in treating patients too. Download PDF here.

“Functional brain MRI in patients complaining of electrohypersensitivity after long term exposure to electromagnetic fields. G. Heuser. Rev Environ Health. 2017 Sep 26;32(3):291-299. doi: 10.1515/reveh-2017-0014.

Canadian study: Functional Impairment in Chronic Fatigue Syndrome, Fibromyalgia and Multiple Chemical Sensitivity M. Ruth Lavergne, MSc.; Donald C. Cole, MD, MSc., FRCPC; Kathleen Kerr, MD, Dip Env Health; Lynn Marshall, MD, FAAEM, FRSM. Canadian Family Physician, Feb. 2010. Download Functional Impairment_ EHC Study

Multiple Chemical Sensitivity: Toxicological Questions and Mechanics” Martin L. Pall, Ph.D., General and Applied Toxicology, 3rd edition, 2009. Find at and sexist bias in medicine

“Multiple Chemical Sensitivities: Stigma and Social Experiences.” Juliene G. Lipson, Department of Community Health Systems School of Nursing University of California, San Francisco. Medical Anthropology Quarterly, Vol. 18, Issue 2, pp. 200–213, ISSN 0745-5194, online ISSN 1548-1387. C! 200

‘The Girl Who Cried Pain: A Bias Against Women in the Treatment of Pain.’ Diane E. Hoffman and Anita J. Tarzian. Journal of Law, Medicine and Ethics (29) 2001: 13-27.

Chronic Pain in Women: Neglect, Dismissal and Discrimination, 2010, Mary Lou Ballweg & Carol Drury, The Endometriosis Association. Terrie Cowley The TMJ Association. K. Kim McCleary CFIDS Association of America. Christin Veasley National Vulvodynia Association.

Commercial Versus Health Interests

Commercial versus Health Interests: The Chemical Industry’s Organized Denial of Toxic Injury and Multiple Chemical Sensitivity (“Environmental Illness”) – A Portrait of Disinformation – Two Historical Documents. Ann McCampbell, M.D. 2001 and the American Chemistry Council 1990. Compiled by Varda Burstyn. Downloadable pdf.

(Just a few) ES/MCS Organizations

The Chemical Sensitivity Foundation:

MCS America: 
Scientific and Medical references on MCS America

American Academy of Environmental Medicine

Canadian Lyme Foundation. Lyme disease can create severe chemical sensitivity, among many other problems.


Environmental Health Centre, Dallas. Longest serving, full roster of diagnostic and treatment services. – this website is very educational and merits a visit. Its founder and director William J. Rea, M.D., has published extensively as well as led clinical operations. Find out about his work at

Dr. Wm. J. Rea, Founder and Director, EHCD

Arizona Centre for Advanced Medicine. Another clinic with multiple diagnostic and treatment modalities.

Environmental Health Clinic, Women’s College Hospital. Diagnosis only, limited testing.

Integrated Chronic Care Services (formerly, Nova Scotia Environmental Health Centre). Limited range of diagnostic and treatment options, only government-supported treatment center in Canada, so a step in the right direction.

Dr. Stephen Genuis (Alberta Faculty of Medicine, University of Alberta, Edmonton) – his on-line help for providers and patients

Chemical Sensitivity

Serious, systems-approach proposals for treatment and support services under consideration

Ontario, Canada: The Project for an Ontario Centre of Excellence in Environmental Health (OCEEH): Learn about the groundbreaking 2013 Ontario government funded study that recommended a model of care and system of care delivery for people suffering from ES/MCS, ME/CFS and FM. OCEEH Partner: Association of Ontario Health Centres (AOHC) About the OCEEH project, visit OCEEH Documents, visit

Taragona, Catalonia, Spain: Platform for those living with Central Sensitivity Syndromes

Canadian Human Rights Commission Publications

The Medical Perspective on Environmental Sensitivities, Margaret Sears, M. Eng., Ph.D., 2007. Report prepared for the Canadian Human Rights Commission. Download EnvSensitivity_Medical

Accommodation for Environmental Sensitivities: Legal Perspective, Cara Wilkie and David Baker, 2007. Report prepared for the Canadian Human Rights Commission. Download EnvSensitivity_Legal

Additional Medical and Scientific Sources

American Academy of Environmental Medicine


Association pour la Sante’ Environnemental du Quebec / Environmental Health Association of Quebec. P.O. Box 364, Saint-Sauveur, Quebec J0R 1R0
Phone: (450) 240-5700

Destination NameMyalgic Encephalomyelitis Association of Ontario (MEAO) – also ES/MCS in mandate.  307 – 170 Donway West, Toronto, ON M3C 2G3
416.222.8820 or toll-free 1.877.632.6682 E-mail:

Invisible Disabilities Association.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Fibromyalgia (FM)

These two conditions can be devastatingly debilitating and painful, destroying lives – “invisible disabilities”, too. They often afflict people with ES/MCS, and certainly they occur on their own. All three have been called Central Sensitivity Syndromes (CSS), because they involve problems with the brain and nervous system. For definitions, for news and research, for ongoing action, here are some organizations to visit.



National CFIDS Foundation

National Fibromyalgia and Chronic Pain Association

American Fibromyalgia Syndrome Association


Millions Missing Campaign

ME and FM National Action Canada

Myalgic Encephalomyelitis Association of Ontario (MEAO)

New physical evidence ME/CFS is not a psychological disorder

im_not_lazy_im_sick_shirt-p235055099763546669sabi_400Recent New York Times and scholarly articles pointing to evidence that ME/CFS is a serious physiological disorder, and that also promises to provide biomarkers for the disease: check out these references.

* With thanks to Stephen Genuis for the quotation from Søren Kierkegaard