History of Multiple Chemical Sensitivity
Chemical intolerance was first described as a medical condition in the 1950’s. Since that time, it has been referred to as multiple chemical sensitivity (MCS). In those early days, there was no body of scientific evidence that could support the existence of such a phenomenon. It didn’t make sense according to our traditional understanding of toxicology. Conventional physicians assumed that it must be psychological, although there was not much evidence to support that either.
MCS ≠ IEI
In 1996, the World Health Organization (WHO) developed the term, ‘idiopathic environmental intolerance’ (IEI) to label patients with MCS. According to opponents of the existence of MCS as a biological entity, IEI is a better term because it does not imply a chemical cause or susceptibility. Idiopathic means that we don’t know the cause. Using the term intolerance presumes no particular biological mechanism.
Those that support the use of the term IEI suggest that these patients are under the false belief that sensitivity to low-level exposures to multiple chemicals are the cause of their physical and mental symptoms. These opponents to the existence of MCS as a biological condition say that these beliefs are instilled and reinforced by speculation that common chemical exposures must be toxic, by the influence of misguided physicians, by misleading patient support/advocacy networks, and by social contagion. They say the beliefs must be bogus because they cannot be substantiated by science.
False Beliefs? No Science?
The term idiopathic is defined as arising spontaneously from an unknown cause. But, in the 18 years since WHO came up with the label IEI, there has been an abundance of studies that have proven that MCS is a biological phenomenon. For example, several papers have been published, which demonstrate abnormal brain scans in these patients. The most recently published study showed an abnormality in the brain, described as limbic system hyper-reactivity. The limbic system is the part of the brain responsible for survival and adaptation to the environment.
There are other studies concluding that MCS involves mechanisms of limbic system hyperactivity, plus studies showing abnormal genotypes for detoxification, oxidative stress, and upregulation of TRPV1 receptors on neurons. We know the mechanisms. MCS is more likely to occur in people who are genetically predisposed to be poor detoxifiers. Less efficient or over-burdened detoxification systems leads to measurable changes in the ability of nerve cells, to not just be more sensitive to chemical exposures, but to also react adversely causing a variety of neurological symptoms. All these abnormalities have been amply demonstrated in well-designed animal and human studies published in peer reviewed journals. Sensitization to chemicals can and does occur.
It might be understandable that in 1996, before research could prove that these people were reacting to chemical exposures, that WHO could come up with this term. However, the fact that it is still being used by many physicians points to their lack of awareness that the science now validates the biological existence of MCS. To call the condition idiopathic is just wrong.
Why make a big fuss over the name?
MCS patients have challenges. They can have problems accessing common community resources that most persons take for granted, including grocery stores, shopping centres, community meetings, public libraries, restaurants, movies, use of public transportation, the homes of extended family members and friends, offices of dentists and medical doctors, public parks, classes at universities, communities of worship, and most significantly, attending the workplace. Continuing to argue without substantiation that this condition is idiopathic feeds others’ false belief, lack of understanding, and refusal to provide proper accommodation in the workplace. People with MCS are still stigmatized by their condition, creating difficulty accessing appropriate, effective health care.
Many doctors are still either uneducated or misinformed about MCS. There is no education regarding the disorder in medical schools. Often, medical students, residents and practicing professionals will turn to the time-honoured Merck Manual. As accurately stated on their website,
“Healthcare professionals have consulted the Merck Manual for over a century, for trusted, concise and correct discussions of diagnosis and therapy. It is the best, first place to go for clinical decision support.”
Merck Manual and MCS
This manual, which was last updated/revised in May 2014, refers to MCS as IEI. These are some of the key points emphasized:
Based on current evidence, idiopathic environmental intolerance cannot be explained by nonpsychologic factors.
- Encourage psychologic therapies such as graded exposure, and drug treatment of coexisting psychiatric disorders.
We now know that the first key point is wrong.
Even worse, the Merck Manual states that psychological desensitization and graded exposure is a useful technique for therapy, an opinion that is quite weak, given that it is based on just a few cases described in the medical literature. In fact, the most recent case is only a description in a letter to the editor, published by the author of this section of the Manual, and it is already 12 years old. The published literature to date actually points out that MCS patients obtain the most help by living in a chemically-free space and avoiding chemicals.
So why does the Merck Manual state that avoidance behaviors should be discouraged? This advice certainly contradicts the Canadian Human Rights Commission policy, which clearly states that people with MCS have the legal right to accommodation in the workplace, including minimizing or eliminating exposures to chemical triggers.
What’s the harm?
The medical condition we are referring to should no longer be called idiopathic environmental intolerance; it is multiple chemical sensitivity. There is documented neurological dysfunction that is not psychological. Attempts at psychological desensitization by gradually increasing chemical exposures is more likely to cause harm than help.
This potential for harm has more ramifications than it appears because some insurance carriers are denying disability to people with MCS, and instead are forcing them to endure increased exposures as a treatment. These patients have no choice but to do so because they do not have the right to refuse therapy and still expect to be compensated by the insurance carrier. Most significant is the fact that the providers of this ‘insured treatment’ do not inform their clients that they could get worse from the recommended therapy. This is enforced, not informed, consent. And if the patients do get worse and stop the prescribed program, they are denied disability because they refused the recommended treatment – the medical insurance version of Catch 22.
Advances in education in environmental medicine
Medical students, family practice residents, and practicing medical professionals can access proper, evidence-based education in environmental health. They just need to look in the right places. The Canadian College of Family Physicians provides continuing professional development/medical education programs for family physicians and other health care professionals. There are five accredited (Mainpro-C), evidence-based workshops on environmental health, including one entitled, Chronic Pain, Fatigue, and Chemical Intolerance Linked to Environment Exposures: Office Assessment and Management. There is an Environmental Health Clinic at Women’s College Hospital in Toronto, which is a teaching hospital fully affiliated with the University of Toronto. The clinic was established in 1996 by the Ministry of Health and Long-Term Care (MoHLTC) to improve health care for people with environment-linked conditions such as MCS. Medical students and family practice residents from various medical schools have obtained elective training in evidence-based environmental health. This fall, two young doctors have begun a new Fellowship program at the clinic, funded for the next three years by the MoHLTC, and provided in collaboration with the University of Toronto’s Department of Family and Community Medicine and Dalla Lana School of Public Health.
As one of the physicians on staff at this clinic, and a writer and collaborator of the environmental health workshops, I can attest to the fact that the content of these teaching programs, which are evidence-based, is in clear contrast to that provided by the Merck Manual.
The name of this condition is multiple chemical sensitivity and the Merck Manual needs to be better informed.
I took this unusual picture at a road stop in a rural town in Quebec. No one asked me if I wanted to get deodorizer sprayed in my face while I was standing at this urinal.
However, people with multiple chemical sensitivity risk getting sick whenever they go into a public washroom because most bathroom facilities have deodorizers that spray toxic chemicals intermittently in order to cover unpleasant odours with other subjectively preferable scents.
How about walking into a major department store? You can’t shop there without walking through the cosmetic and perfume section. Why are my patients forced to walk by a cocktail of scents when they enter many drug stores in order to fill the prescription that I wrote for them to control the symptoms that these kinds of exposures provoke? More than 40% of people who suffer from migraines report perfume as a trigger. Why do they have to risk a migraine just to obtain the medications which provide relief?
If you’ve been to a department store, or used the facilities in a restaurant or public bathroom, you know what I’m talking about. It’s extremely difficult to go anywhere, or do anything without encountering fragrances. It’s not just perfume and cosmetics. It’s also cleaning supplies. And it isn’t just in public places, it’s also at your workplace and in people’s homes.
What’s the matter with fragrances?
Scented products contain up to 50 different chemicals, known as volatile organic compounds (VOCs). VOCs are also common outdoor air pollutants, released from burning fuel, such as gasoline, wood, coal or natural gas,. However, VOCs are actually found at higher levels indoors. They are released from solvents such as paints and glues, as well as air fresheners, paint thinners, hobby supplies, wood preservatives, automotive products, detergents, fabric softeners, cleaning supplies, degreasers and dry-cleaning fluids.
Breathing low levels of VOCs for long periods of time can increase risk for developing health problems, such as asthma or sensitization to chemicals. Some are carcinogenic.
Does natural mean better?
There is an increasing awareness that we live in a polluted world. This has led to positive changes in the marketing of products. Almost every grocery store now offers organic foods because people want to buy them. You can now buy paints that emit only low levels of VOCs.
Our behaviours drive the markets, but marketers also try to influence us to drive our behaviours towards purchasing their products. We can find substitutes for the more traditional scented cleaning products in the home, which claim to be safer and better for the environment. These products contain many substances, described as natural. They are too numerous to review here. But to make a point, I will mention one common substance found in many cleaning products – caprylyl/myristyl glucoside, which is a surfactant.
Surfactants are necessary to help remove oils and grease found on your counters and clothing. They help oils mix with water. I never learned about this product in medical school, so I looked it up in the library of medicine. I found nothing. I found theMaterial Safety Data Sheet (MSDS) online and there appears to be nothing wrong with it. The online description is that it is plant derived, biodegradable and suitable for wastewater that we generate from sinks and bathtubs, and septic tanks. What I cannot find is what happens to this product when it enters the human body. For example, how do we get rid of it? Do we just urinate it or we have to detoxify and break it down first? How safe is it really? Perhaps it is just one more burden to our body’s detoxification system.
What’s the alternative?
Am I criticizing the use of natural products? Absolutely not. I am in favor of products that are biodegradable, and don’t harm the planet, especially if for now they appear to be safe for humans because there is no evidence that they are not. We need to wash our dishes, pots and pans, clean our toilets and bathtubs, wash our laundry, and dry it without static. So we need products which are effective. The problem is that there is no solid evidence that products claiming to be natural are safe either. We are relying on faulty logic, not science.
Good logic will depend on how one defines natural. If it is defined as ‘not man-made’, then anything that normally exists on the planet is natural, including the mushrooms on your front lawn, mercury, lead, arsenic, petroleum and natural gas. In the context of environmental health, we should be defining natural in terms of safety for human exposure and consumption. Defining a substance as natural should consider whether the exposure has been common, and at levels consistent with what humans have experienced and naturally adapted to, for the last 10,000 years, since the birth of modern mankind.
The detox system does not distinguish between natural and synthetic products; it uses what it can and rejects and eliminates the rest. Caprylyl/myristyl glucoside may be a natural product, because it exists naturally on the planet, but it is not expected to be found consistently in the human body. How much of a burden does it create along with so many other chemical exposures on our detoxification systems?
For now, all we can do is avoid chemical pollutants and try our best to reduce the intake of all natural or artificial substances which are not necessary. Our hair does not need to smell like a bowl of fruit. Our clothes, sheets, and pillow cases do not need to smell ‘fresh’, as defined by scent companies. It does not matter whether the product is made in the laboratory or is extracted from flowers and trees. We are still filling our bodies with products which are not natural inside of us, and which our bodies try to expel.
I’m not sensitive to fragrances, why should I change?
We have detoxification systems inside every cell in order to remove waste products produced naturally by the by-products of maintaining life. When they cannot manage the burden of detoxification, damage occurs. Understand that these detoxification systems are less-than-perfect, and damage to cells is part of the normal process of aging, which eventually leads to malfunction of cells and organs, leading to disease and death. Burdening these detoxification systems further by putting products that are not natural inside of us contributes to that damage continuum as well. And the published evidence suggests that the VOCs are indeed a burden. Just because you can’t feel it happening doesn’t mean that changes are not occurring inside your cells, which can lead to a premature medical condition.
What I’ve learned from my patients
I practice environmental medicine. I have seen more than 12,000 people who have been made sick by the environment from common exposures to every day pollutants, because their detoxification systems could not handle the burden. Most of these people are sensitive to chemical odors and have difficulty entering major department stores and some pharmacy chains. Even stores claiming to sell nothing but natural products provide the same barrier to entry when their scented merchandise is situated at the entrance. The ingredients may be defined as “natural” by some people, but the amount of exposure provided by these products is not normal for humans, and they need to be detoxified too.
Who’s rights and who’s freedoms?
There are no laws that protect people from toxic chemical exposures. Some hospitals or other public places have instituted no-scent policies, but it isn’t mandatory to do so. The fragrance industry is free to create products that can make people sick, while many of my patients have lost the freedom to shop, go to restaurants or movies, or even take long trips because bathroom breaks are an essential part of travelling.
David Suzuki has toured across Canada to obtain public support to enshrine the right to a healthy environment into the Canadian Constitution. I think there should be a subsection to include the right to healthy shopping.