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What is Environmental Illness?

This page contains the following main sections -

Introduction to Environmental Illnesses

The health condition of Environmental Illness (EI), or severe intolerance, or multiple chemical sensitivity (MCS) goes by many names, including:

bioecologic illness,
cerebral allergy,
chemical hypersensitivity,
chemical injury syndrome,
chemical injury,
chemical intolerance
chemical sensitivity,
ecologic illness,
environmental injury,
immunotoxic syndrome,
multiple chemical sensitivity,
severe intolerance,
total allergy,
toxic encephalopathy,
toxic injury,
toxicant induced loss of tolerance,
twentieth century illness,
universal reactor.

A common description for the environmental illness of a sensitivity or severe intolerance to chemical exposures is multiple chemical sensitivity (MCS). This name that has been used in the medical literature for several decades. All of these above names illustrate that many of us have immune, detoxification, blood-brain barrier, voronasal, or neurological system injuries that are or were probably caused by our ever-more-toxic environment. Recent research has found medical records going back to the 1880's or so, when people were plumbing coal gas into homes for heating and lighting, that appear to describe what is now called MCS. People can become supersensitive or hypersensitive, as much as a hundred to a thousand times more so than most people, and find that exposures to many common materials encountered in daily life trigger serious physical symptoms that may take hours or days to recover from.

MCS Terminology

A person with the illness of chemical sensitivity is usually referred to as having multiple chemical sensitivity (MCS), or a sensitivity, a hypersensitivity, or a severe intolerance. The term "EI's" is often used in referring to several people with MCS. Most people with the health condition refer to themselves as "I have MCS." There are hundreds of medical papers going back several decades that use the term "MCS." The term MCS will be used throughout this website.

MCS Prevalence

MCS is reported as being a problem for up to 26 percent of the American population. Comparable numbers are reported in most industrialized countries worldwide. There is still no cure for the condition; there are (sometimes expensive) supportive medical treatments.

The most practical and effective approach to dealing with MCS is to identify the offending materials that are troublesome for you and comprehensively avoid them. Also locate a health professional who supports MCS - such as an Environmental Medicine doctor, a Clinical Ecologist, Chiropractor, or a Naturopathic doctor.. You must ultimately become a medical expert on your body, and develop your personal healing process to live as effectively as possible.

MCS Economic Costs

In 1998, the New Mexico state epidemiologist estimated that the state was be loosing some 15 million dollars a year in tax revenues because of the low earning capacity of people with MCS. Extrapolating that value out to the nation, as of 1998, as much as 2.32 billion dollars in tax revenues were lost every year by all states.

MCS Aggravants

MCSis a technical illness. That technicality can be a problem for the sufferer who may not be aware of the components in an offending material. The technicality can also be a problem for family and friends who do not understand that our society suppresses the details of the contents of many materials in common use, or the consequences of exposures to special populations. The technicality can be a challenge for medical professionals who have had access to limited information about many of the materials they routinely handle during medical procedures, or may have had limited exposure to the concept of hypersensitivity. The technicality is a problem at the social and political levels where the MCS illness is too often regarded as just "socially inappropriate" behaviour.

Recent neurological studies consider many of the primary aggravants for the basic MCS injury process, except for mercury, to be materials that entered the human environment in only the last 150 years or so. These materials, such as pesticides, formaldehyde based materials, and many petrochemicals, such as perfumed cleaning products, petro-based perfumes, and immunosuppressice medical drugs, are often the most serious MCS aggravants.

Some specific examples -

Some of the MCS literature lists acetone as an aggravant, and gives Finger Nail Polish Remover as an example. In practice, yes, people with MCS do find that a breath of Finger Nail Polish Remover does cause an immediate and severe reaction. But they have negligible reaction to industrial strength acetone used in an open-air environment. The manufacturing chemicals, instead of the acetone, are the MCS aggravant.

People with MCS commonly avoid eating peppers, saying that they sometimes make them sick. Research now recognizes Capsaicin, the main ingredient in hot peppers, as aggravating the NMDA neural receptor, which in turn brings on the MCS syndrome. This shows up just from nibbling a bite of raw Jalepeno pepper and suffering a wipeout the rest of the day.

When some people are beginning to develop the MCS neural injury process, they find that a breath of tobacco smoke causes an immediate reaction. Given the widespread emotionalism that defends the act of smoking in our society, any efforts to find medical relief often become "inappropriate social behaviour" instead of dealing responsibly with a health condition. Sadly, this situation has not been helped by the tobacco industry's long-standing "there is no allergy to tobacco" campaign. Many of these sensitive people have now found out, via clinical testing, that they are probably reacting to the the oxidation products of the pesticides that are common in most tobacco smoke.

A breath of some newspaper inks, especially those commonly used in the advertising sections, sets off the MCS reaction for some people - weak, dopey, dizzy the rest of the day. Some of the medical information sources now do talk about "allergies," or a contact dermatitis, but do not mention sensitivities, which is very unbalanced consumer information. (If advertisers really want to contact potential buyers, they should specify the printers use safer inks!)

Short Term, High Level Prolonged Exposures

Some people develop MCS from a single short term, high level exposure.

Low Level, Prolonged Exposures

Very small low-dose, prolonged exposures to aggravants can cause gradual, subtle, but long term health damage, that can be hard to detect and prevent, but does degenerate into MCS. People vary greatly in their response to chemical exposures. Some will hardly react while others may become very ill. Among the most vulnerable are women, unborn babies, allergy sufferers, workers in high-risk occupations, the poor, the young, the elderly, and the chronically ill.

Causes of MCS

The causes of the MCS illness are varied. And they can be arguable because there is often a considerable time lag between exposure and the development of medically identifiable symptoms. Based on a study across nine European countries in 2005, the Danish Ministry for the Environment considered the following materials as initiators:

Anesthesia gases
Anti-viral Medications
Carpets and Glue
Degreasing Agents
Diesel Exhaust
Hair-care Chemicals
Indoor Pollutants
Mercury Amalgam
New, Renovated Buildings
Organic Solvents
Paint, Lacquers
Printing Materials

The report concluded that solvents and pesticides are the most common MCS initiators and noted that claims that stress or psychosocial factors can initiate MCS are questionable.

Source -

Body Burden

Another aspect of the MCS illness that is getting attention is the concept of a body burden buildup and collapse process. The body burden is an accumulation of supposedly non-toxic chemicals, often ones that came into the human environment in only the last 150 years or so, that the human body does not have explicit evolutionary protection for. These chemicals are often sequestered in fatty tissue, especially in the brain.

During a serious illness, the body can draw energy from those fatty tissue reserves. If the tissue had a buildup of chemicals, those supposedly non-toxic chemicals can be released back into the body in a sudden avalanche. If the release is within the blood chemistry of the brain, a wide range of subtle neurological injury processes are possible.

It is a common story from MCS sufferers that they think they got their MCS from a long illness, or extreme exercise, or general weight loss that did not necessarily have anything to do with pesticide, etc., exposure, that they just "never recovered from." And then their health deteriorated into the MCS condition. I.E., The illness forced the body to use fatty tissue energy reserves that caused a release of sequestered toxins.

More information is at the Environmental Working Group site -

Bodily Detoxification Impairment

DNA studies are showing that many people with MCS often have a genetic impairment in one or more bodily detoxification processes, such as the Cytochrome P450 pathway. Some people with MCS also appear to often have a genetic impairment that may facilitate the subsequent neurological injury processes.

MCS Symptoms

EI symptoms are frequently non-specific (the "sick-all-over" feeling) and traditional medical practices, such as those provided by "classical allergy" specialists, are often of little help. EI sufferers become ill from eating, breathing, or absorbing small amounts of widely-used "safe" chemicals. Some people can further become sensitive to "natural" substances such as cotton, certain foods, molds, etc., but with a hypersensitivity of perhaps 1,000 times that of a normal person, there is always the question of whether a low level contamination with one or more of the MCS aggravants that our current science claims is "safe" is to blame.

MCS Diagnosis

The following criteria are considered diagnostic of MCS as of 1999 -

Source - The Environmental Illness Resource, located in Harrogate, North Yorkshire, HG3 2UB, GB

Sophisticated research procedures, such as challenge QEEG evoked potentials, SPECT scans, and PET scans do demonstrate unique neurological damages that appear to be associated with an MCS reaction. But much more research is needed to develop easily accessible and reliable biomarker tests.

Recent research is demonstrating another metabolic disorder that appears to be part of the MCS puzzle, Orders of Porphyrinopathy. This disorder also shows up in people with chronic fatigue syndrome, fibromyalgia, dental mercury amalgam problems, and silicone implants.

Recent biomarker based research in Paris, France supports regarding MCS as an injury to the blood brain barrier that allow exogenous materials into the limbic area of the brain. This in turn causes cellular inflammation, which in turn degrades immune system roots that in turn cause the many and apparently unrelated MCS symptoms. The emerging field of epigenetics may be involved, where environmental influences, such as pesticides, are observed to alter DNA molecule decoding that in turn causes erratic physiological development. Much more research is needed in this area.

Finding a doctor who recognizes MCS and provides some degree of effective support and treatment is often a challenge. Medical specialty possiblities to check include the group often called "Alternative Medicine practitioners," such as members of the American Academy of Environmental Medicine, Chiropractors, Naturopaths, and Homeopaths.

Yes, it can be an imposition on your health care practitioner, but given the widespread lack of understanding in this illness, do get a written statement for your MCS or severe intolerance diagnosis.

Further Information about MCS

The following papers give detailed summaries of the many physiological changes that are consistently associated with MCS.

A book, published in 2003, "Defining Chemical Injury", by Dr. G. Heuser, gives another detailed summary of the many physiological changes that appear to be common to people with chemical injury.

Acceptance of MCS

MCS is recognized as a disabling condition by the Department of Housing and Development (HUD), the Environmental Protection Agency (EPA), and the National Academy of Sciences. MCS is considered a valid condition for workman's compensation claims, liability, tort, and regulatory The governors of many states have signed proclamations recognizing MCS . (See MCS Awareness Month Proclamation in Colorado.) MCS has been accepted as a disabling illness by Social Security, with a diagnostic code of DI 24515.064.

More information is available on the RMEHA Disability Resources page.

Web References about MCS

Models for MCS

There are several models that attempt to give a detailed physiological and neurological picture of the MCS injury mechanism, including -

Limbic Kindling
Neurological Inflammation
Porphyin Disorder
Toxic Encephalopathy
Toxicant Induced Loss of Tolerance

A website describing the Neurological Inflammation or OO/NOO model is at -

A page describing Toxicant Induced Loss of Tolerance is at -

An emerging hypothesis for MCS amounts to a cascade of several neural and immune system injuries.

First is a genetic deficiency or an injury to the blood brain barrier, possibly caused by exposure to materials, such as mold toxins, or often materials that contain large organic molecules with mercury, phosphorus, chlorine or bromine atoms, or aggravated by a body burden collapse, or by a serious electromagnetic radiation exposure.

The initial injury is then followed by a subsequent neurological injury cascade process that is aggravated by primary toxins that came into the human environment in only the last 150 years or so and produces neural sensitivities as much as 100 to 1,000 times normal.

Poorly detoxified toxins from the neurological injury then appear to set the stage for MCS and several multi-system illnesses, such as chronic fatigue syndrome, and others.

An apoptosis failure in the injured neural cells then appears to permit mitochondria fragments to get into the bloodstream which provokes a mini-blood-poisoning condition that may bring on the many autoimmune and classical allergy conditions that are so common with MCS.

International Classification of Diseases Coding for MCS

There is no International Classification of Diseases (ICD) code in America for the health condition of environmental illness. So the ICD-9 code 989.9, "intolerance to other substances, non-specified" is often used as a diagnosis. MCS is explicitly identified in the ICD codes of several European and countries and actions are underway to recognize it in the ICD codes of all European countries.

MCS is Not an Allergy

It must be noted that sensitivities are not allergies. Use of the word "allergy" amounts to a dangerous semantic minefield, because there are situations where an "allergy-appropriate" emergency response or medical treatment (such as treatment with an immunosuppressive drug) can do more harm than good. Allergies and sensitivities can both cause symptoms that range from being a minor to severe, life threatening reactions, but there are very different physical injury mechanisms involved. Unfortunately, many people (including some medical staff, even researchers!) understand "allergy" to be a much milder condition than a sensitivity.

The discovery of the immune system in the early 1900's established that sensitivity is not an allergy; this is a point some elements of the classical allergy profession have been defending very emphatically ever since.

In MCS, there is no immediate immune system recognition of the primary chemical injury process, although allergies may subsequently develop along with sensitivities because toxins released by the sensitivity injury also can degrade the immune system. Definitely check with your health care professional about this area before accepting just "any" medical treatment.

Many aspects of dealing with medical situations are covered in the following paper -

Idiopathic Environmental Intolerance

Another label being applied to environmental illnesses is idiopathic environmental intolerance or IEI. The dictionary definition of "idiopathic" is of interest - "Of unknown cause." In other words, not caused by chemical exposure, and thus imaginary.

This label came about from a conference in Berlin in the 1990's sponsored by the World Health Organization (WHO) that was going to "solve the chemical injury issue." Information developed in the 1880's when people were having problems from coal gas plumbed into their homes for heating and lighting was ignored.

The immune system was discovered in the early 1900's, and since there was no obvious immune system physical reaction - per the science of that time - the reaction was assumed "impossible;" much attention was paid to that assumption.

The conference paid limited attention to research developed in the 1950's and 1960's when doctors began to accept this illness and develop supporting therapies that apparently helped many people.

Representatives of the European MCS community were not allowed access to the Berlin conference! The European Commission had recommended that both proponents and critics of MCS be included in the conference. But instead, the only non-governmental representatives were full-time employees of the BASF, Bayer, Coca Cola, and Monsanto companies.

The "American position" on MCS was presented by a Ronald Gots, who has been claiming for a long time that MCS is not an illness and was reported to be involved with an industry trade organization, Environmental Sensitivities Research Institute (ESRI), that was founded to "serve the needs of industries affected by MCS litigation". In practice, ESRI supplies "expert witnesses" for opposing legal actions that involve chemical injury, such as applications for disability.

Although the internal report first using the label IEI was embargoed for release, it was published anonymously in the journal Regulatory Toxicology and Pharmacology with an acknowledgement that the publication was made possible by a grant from ESRI, and it was implied that the publication had full WHO sanction. WHO then published a statement "A workshop report to WHO ... presents the opinions of the invited experts and does not represent the decision or stated policy of WHO." The WHO disclaimer went on to say "with respect to MCS, WHO has neither adopted nor endorsed a policy or scientific opinion."

Also of interest, the conference minutes made a special point of expressing appreciation to several pharmaceutical/pesticide and tobacco companies for their extensive financial support in facilitating the conference.

As of ten years after the conference, a final conference report never appeared because people could not agree on conclusions.

As of summer of 2013, web references to ESRI have disappeared and their web site, esri.org, has been taken over by a commercial company.

The IEI label has no medical or scientific basis; it amounts to a sophisticated industry sponsored "confusion science" attempt to derail MCS from being accepted as a serious illness that deserves medical acceptance and real scientific research. Very similar to what our society has seen with the PCB, Dioxin, asbestos, tobacco, pesticide misdirections that delayed our society from coming to grips with the many public health issues that were caused by those materials.

The IEI label was obsolete when it was invented; there is extensive science-based, independent, peer-reviewed research that says this label should be no longer used to disaccomodate people with with the illness of MCS.

MCS is "Controversial"

A reality we live with is a belief held by some people that MCS is somehow "controversial." This belief disaccomodates people with MCS; it is extremely demoralizing to people with MCS; it has diverted people with MCS from appropriate medical support and it generates an common attitude or information environment throughout our society that this illness does not need to be taken seriously. But this label really has several very different meanings.

There are various perspectives about whether any illness should be named describing the cause of the injury process, such as a chemical exposure, or whether the name should the name reflect the body damages that occur because of the injury, such as toxic encephalopathy. The discussions about these perspectives are sometimes called controversial.

MCS is "controversial" because state medical boards have disbarred from medical practice doctors, such as alternative, clinical ecology or environmental medicine specialists, who diagnose and offer support and treatment for the health condition. Such actions have been a disaster for people developing MCS who have been to many doctors, finally find a doctor who supports the health condition, and then finds that he disappears from the community and nobody is willing to talk about it.

Such actions are apparently based on anonymous complaints which are extra-constitutional because the accused doctor cannot face his accuser. The proceedings of state medical boards should be open and the boards should not accept complaints fron vested interests or people with narrow agendas. There should be a sunset law on all medical board hearings that discloses all actions of medical boards after some reasonable time frame, such as ten years.

In any field of study, a hypothesis goes through several stages before it becomes generally recognized as a theory. An important stage is criticism. People who don't agree, or have other views, report their suggestions, criticisms, and very importantly - with documentation. After perhaps many repetitions, the hypothesis becomes generally accepted and adopted as a theory. The understanding of MCS has gone through many variations of this criticism and refinement. This is the way a robust and inquisitive scientific research process works. Unfortunately, people who are perhaps not familiar with the scientific process often seize upon this process as implying MCS is not real, or is not accepted or is controversial. That process has not been the case with MCS.

Sadly, we need to admit that there are vested interests that regard the existance of the illness of MCS as an imposition or affront to their perceived belief system about "how things should be." A paper that discusses these attitudes and their consequences for EI's in detail is -

For one example, in 1990, the Chemical Manufacturers Association (now called the American Chemistry Council), a trade organization supporting many private chemical industry companies, explicitly adopted a position to work with state medical associations to block recognition of MCS. [CMA Environmental Illness Briefing Paper, 1990]

A reality is that MCS is recognized as a health problem for some 11 to 16 percent of the American population. Most people with the health condition refer to themselves as "I have MCS". There are hundreds of medical papers going back several decades that refer to the health condition explicitly as "MCS." Comparable numbers are reported worldwide in most industrialized countries.

If someone says your - whatever - health condition that was diagnosed by a board certified doctor with many years of experience is "controversial," tell them to provide documentation.

MCS is Real.

MCS is a real, serious and sometimes devastating, 24/7 illness that deserves the full acceptance and support of our society at the personal level, at the social level, at the medical level, and especially at the political level.

Some Possible Symptoms of EI/MCS:

Hormone Disruption
Estrogen dominance is common in women, which may put them at risk for several cancers. Reduced testosterone is common in men, which can lead to reduced muscle strength and may put them at risk for several cancers.
Central Nervous System
Aphasia (Difficulty Remembering Words), Attention Deficit Disorder (ADD), Confusion, Dizziness, Fatigue (Chronic Fatigue Syndrome), Severe Headaches, Hyperactivity, Loss of Consciousness, Memory Loss, Sleep Disturbances, Tension, Weakness.
Aggression, Depression, Irritability, Mood Swings/Personality Changes, Paranoia.
Inflamatory Bowel Syndrome or Gastrointestinal
Bloating, Constipation, Cramps, Food Allergies, Nausea, Poor Digestion, Crohn's Disease, Intestinal Hyperpermeability.
Eczema, Flushing, Hives, Itching, Rashes, Sensitivity to Touch.
Backaches, Fibromyalgia, Joint Pain, Muscle Spasms, Poor Coordination/Clumsiness, Swollen Limbs.
Asthma, Bronchitis, Frequent Colds, Shortness of Breath.
Hypertension, Migraines, Rapid or Irregular Heart Beat.
Pre-Menstrual Syndrome (PMS).
Ear, Eye, Nose, Throat
Chronic Post-Nasal Drip, Chronic Sore Throat, Earaches, Intermittent Loss of Voice or Hearing, Nasal Stuffiness, Sinus Infections, Tinnitis (Ringing in Ears), Watery/Itchy Eyes.

It is a very reasonable question from people without environmental illness to ask "How does one accept, accommodate and respect a person with this condition?" See the following page for a discussion of this area which is a very big challenge for everyone of us.

See the following page for one example of an MCS medical support regimen that has been reported to have helped people -

See the following paper from MCS-America for summaries of several MCS treatment and support protocols.

NIEHS Definition of MCS

The National Institute of Health Sciences (NIEHS) has the following definition of Multiple Chemical Sensitivity (MCS) -

(Full URL no longer available.)

Genetic Validation of Detoxification Deficiencies in MCS

As of 2004, research was been published that demonstrates significant genetic differences between people with or without MCS. The study found that some of the body's enzymes that are important to detoxification of toxic compounds are significantly lower in people with MCS. See the study published July 15, 2004 in the International Journal of Epidemiology by Gail McKeown-Eyssen and her colleagues.

Not only were the MCS patients more likely to have significant differences is several genes that would impair their ability to detoxify toxic compounds, but some of them were reported to be more than 18 times more likely to have a specific combination of two forms of the genetic differences.

Multiple Chemical Sensitivity - The End of Controversy

Multiple chemical sensitivity (MCS), where people report being exquisitely sensitive to a wide range of organic chemicals, is almost always described as being "controversial." Often without any documentation. The main source of this supposed controversy is that there has been assumed to be no plausible physiological mechanism for MCS and consequently, it was difficult to interpret the puzzling reported features of this condition. As discussed below, this is no longer true and consequently the main source of such controversy has been laid to rest. There still are many very important issues concerning MCS, such as how it should be diagnosed and treated. These may well be allayed by further studies of the mechanism discussed in the following web publication.

Articles by Dr. Pall -

Dr. Pall has also written a book - "Explaining 'Unexplained Illnesses,'" dated 2007, ISBN 978-0-7890-2388-9, that has an extensive discussion of a common neurological injury cascade mechanism that appears to explain many aspects of MCS, Post-Traumatic Disorder, Fibromyalgia, Gulf War Syndrome, Chronic Fatigue Syndrome and other multi-system illnesses. Notably, this book has some 110 pages of recent small-print citations throughout the medical literature.

Much more and recent information is available at Dr. Pall's web site -

MCS Awareness Month in Colorado

The Governor of Colorado, Bill Ritter, signed a proclamation recognizing May 2011 as Multiple Chemical Sensitivity and Toxic Injury Awareness Month.

The proclamation reads as follows -

"Multiple chemical sensitivity (MCS) and toxic injury affects people of all ages, ethnicity, cultures, and religions; and MCS and toxic injury are often characterized by heightened sensitivity to minute amounts of air pollution, petrochemicals, and other toxins; and MCS and toxic injury are chronic conditions for which there is no known cures, creating multiple, often disabling illnesses, which can be life-threatening; and raising public awareness to educate citizens of the dangers of MCS and toxic injury is one of the many ways we can battle the devastating effects of this chronic incurable condition."

A copy, formatted for printing, is available at -

Wikipedia Definition of Multiple Chemical Sensitivity

The Wikipedia online encyclopedia has become a significant web resource for information about a wide range of issues. Wikipedia does have a page devoted to MCS, but the page lacks much significant information, omitting even such basic details as the prevalence of MCS in the population. For reference, current studies report some 10 ... 15 percent of the people in most industrialized nations are affected. The article does not reference the current very considerable modern research about MCS, and amounts to presenting a very distorted and unrealistic picture of this devastating illness. See the following for their definition of MCS -

Do keep in mind that Wikipedia is an open-source edited website. It has extensive disclaimers that nothing on the website should be trusted. Anyone on the earth can register themselves as a Wikipedia editor, there are no requirements for the expertise to present accurate or reliable information. Editors can make any change they wish, and it goes online immediately.

It is an involved process, but check the authors of Wikipedia pages before taking them seriously. Some authors may have a poor understanding of current research; they may have vested interests; they may have agendas that have nothing to do with presenting a balanced view of MCS.

There is Help! Many of the people in RMEHA have come to a much better understanding of their physical condition and have learned what to do (and not do) to feel healthier, happier and live as effectively as possible within the challenging confines of this illness. Through assistance from Environmental Medicine physicians, books and magazines, web information, appropriate nutrition and supplements, avoiding aggravants, and mutual support, many of our members have improved their health. We would be delighted to hear about your experiences and share the resources we have accumulated! Please contact and/or join RMEHA!

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Revised '21-Aug-2019,14:01:26'