Environmental Illness / MCS

Chemical sensitivity disorder or Multiple Chemical Sensitivity (MCS) is defined as “an acquired disorder characterized by recurrent symptoms, referable to multiple organ systems, occurring in response to exposure to many chemically unrelated compounds at doses below those established in the general population to cause harmful effects.”

Most of us need little convincing that our urban environments are polluted. The belief that the food chain is contaminated with toxic chemicals is universal and readily validated. The exact number of persons suffering from chemical sensitivity is unclear, but the rise in immune and nervous system disorders indicates that this problem is becoming more common, and somewhat more widely recognized.

Everyone knows someone who is sensitive to particular household products. We all recognize that people vary widely in their response to a room full of cigarette smoke – some people can ignore it easily while others react with stuffy nose, teary eyes, coughing, sneezing, shortness of breath. It should be no surprise, therefore, to learn that scientists are now confirming that different people react differently to modern compounds such as dry cleaning solvents, perfumes, detergents, glues, waxes, pesticides and other common household and industrial chemicals.

It has been suggested that MCS is not the best name for this family of ailments because it fails to reflect the importance of the initiating chemical exposure. Toxicant Induced Loss of Tolerance (TILT) better describes the true nature of the illness(es) initiated by a toxic exposure which leads to the loss of tolerance of common chemicals. Different initiating events may give rise to somewhat different ailments, all of which cause sensitivity to chemicals – just as different infectious diseases can all cause a fever.

Some people react violently to chemicals, to the point of being made ill by very low doses of common substances. Typical symptoms include fatigue, severe migraine-like headaches, nausea, that “run down” feeling, rashes, itching, swelling, pain, stuffiness, disorientation, and dizziness. This group of symptoms goes by various names: ecological illness, total allergy syndrome, environmental illness, and MCS.

There are over 70,000 chemicals commercially produced in the United States today. The long-term, low dose effects of many of these chemicals have never been investigated. With the construction of closed buildings, the rise in use of toxic construction materials, and an increase in the use of office machines, an environment of indoor air pollution has been created. Sixty per cent of indoor chemicals are generated by products or machines used indoors.

MCS is thought to afflict somewhere between 2% and 15% of the American public, and appears to be increasing, according to a publication of the American Chemical Society.

The prevailing rational and scientific viewpoint is that although some people are sensitive to small amounts of one or a few specific chemicals, there is no general hypersensitivity to chemicals. Scientifically oriented allergists, psychiatrists and occupational health clinicians suspect that the majority of “MCS” (Multiple Chemical Sensitivity) patients suffer from psychological disorders such as depression, anxiety reactions and somatization (bodily reactions to stress).

On the other hand, clinical ecologists (doctors who specialize in environmental illness), believe that MCS is a widespread condition caused by exposure to common foods, chemicals and other stressors that can sensitize people, causing them to react adversely to even tiny amounts of these substances.

Both inorganic compounds (such as carbon monoxide, nitrous oxide and heavy metals) and organic compounds (pesticides, formaldehyde, phenol, etc.) are involved. A major indicator of chemical sensitivity is multi-system disease: this is because once the chemicals enter the body, they enter the bloodstream and circulate to all parts of the body, even the brain.

Potential chemical toxins include:

  • Formaldehyde which can be found in foam insulation, plywood, particleboard and press cabinets, fabric finishes, new carpet, polyurethane foam rubber (used in pillows, cushions, mattresses and rug padding), mobile homes, adhesives, synthetic clothes that crease resistant, wrinkle resistant.
  • Oil vapors: from oil furnaces, motor-oil air-conditioning filters, electric kitchen appliances such as food processors, blenders, can openers.
  • Polyethylene plastics: fake leather, artificial flowers, shower curtains.
  • Household chemicals such as dry cleaning chemicals in clothes, mothballs, rug-cleaning products, paints, solvents, stain removers, air fresheners, window washing compounds.
  • Polyesters in clothing, upholstery, drapery, furniture and stuffing for pillows and quilts.
  • Pesticides residue on cottons and woolens; residues from exterminators.
  • Epoxy adhesives on plastics, electronic equipment (TVs, microwaves,) which release gases when heated up.
  • Common school paraphernalia such as carbon paper, ink, mimeographic and duplicating chemicals, glue.

Two important phenomena to understand regarding the symptoms are spreading and switching. Spreading occurs when additional organ systems are involved, or when a patient additionally becomes sensitive to inhalants, foods, dust, animal danders, or other environmental exposures. Switching occurs when the same exposure produces entirely different organ involvement e.g. photocopier fumes initially caused headache, and subsequently caused no headache but wheezing.

The main mechanism for chemical sensitivity seems to be the failure of the body’s enzyme detoxification pathways to adequately clear chemical compounds. Both immune and non-immune processes have been involved. Chemical sensitivity can develop after a massive chemical exposure, after specific non-chemical events such as massive trauma or surgery, after severe infections (viral, bacterial, parasitic) or with no identifiable cause.

Because most of the toxic chemicals involved are fat-soluble, they become stored in the body’s fat, resistant to metabolism and excretion. In fact, chemical levels measured from fat biopsies are sometimes 300 times greater than circulating serum levels.

The timing of symptoms after exposure, reproducibility of the symptoms, spreading, and switching must all be investigated. Serum levels of suspected chemicals confirm the diagnosis. If serum levels are negative and suspicion is high, a fat biopsy must be performed to complete the diagnosis. Additionally, chemical challenge tests can demonstrate the cause-and-effect relationship between a chemical exposure and symptoms.


Signs, symptoms & indicators of Environmental Illness / MCS

Symptoms - Cardiovascular  

Heart racing/palpitations

Heart palpitations and dysrhythmias can be caused by chemical exposures in sensitized individuals.

Symptoms - Environment  

Probable environmental illness


(High) chemical sensitivity


(High) cigarette smoke sensitivity

Symptoms - Food - General  

Strong appetite

Symptoms - Gas-Int - General  

Meal-related bloating


(Severe) abdominal discomfort

Symptoms - General  

Constant fatigue

Daytime grogginess is a possible symptom of environmental illness.

Symptoms - Metabolic  


Symptoms - Mind - Emotional  


Symptoms - Mind - General  

Trouble concentrating

Symptoms - Muscular  

Tender muscles


Individual weak muscles

The muscular weakness may be due to a nerve problem caused by chemical exposure and immune system changes associated with MCS.

Symptoms - Nervous  

Numb/tingling/burning extremities

Symptoms - Respiratory  

Air hunger

Symptoms - Skeletal  

Joint pain/swelling/stiffness

Joint pain is a possible symptom of environmental illness.

Conditions that suggest Environmental Illness / MCS


Allergy / Intolerance to Foods (Hidden)

People with multiple chemical sensitivities often have multiple food allergies as well. While reactions to chemicals in the environment are generally quicker and more easily identified, food allergies are usually delayed, making it harder to pinpoint the offending food. People with MCS are often unaware of hidden food allergies which could be contributing to their overall allergic load.


Autoimmune Tendency

Reports of autoimmune markers in MCS patients, like most MCS data, are inconsistent. One report demonstrated antibodies to smooth muscle (muscle tissue that functions without conscious thought – such as the heart) in half the patients seen in a clinical practice. In some cases, MCS could be viewed as a chemically-formed autoimmune disease. [Environ Health Perspect 105(Suppl 2): pp.417-436 (1997)]





An irregular or rapid heart beat and awareness of your heart beating are listed as possible symptoms of environmental illness.


The Immune System  

Chronic Fatigue / Fibromyalgia Syndrome

MCS is a distinct illness that many times is diagnosed secondarily to CFS and/or fibromyalgia.



Please see the link between Autism and the treatment Environmental Medicine.



Headaches, Migraine/Tension

Central nervous system dysfunction is common, resulting in headaches, chronic fatigue, poor short term memory, hyperactivity, and increased appetite leading to food cravings and overeating.





Respiratory complaints include adult onset “asthma”, shortness of breath, and fibrotic lung disease.

Symptoms - Environment  

Confirmed environmental illness

Risk factors for Environmental Illness / MCS

Environment / Toxicity  


Gilbert's Syndrome

People who have Gilbert’s syndrome are more susceptible to toxic reactions to chemicals and drugs. Drugs that are poorly metabolized by those with Gilbert’s syndrome include acetaminophen, menthol, clofibrate and tolbutamide.

Symptoms - Muscular  

History of tender muscles

Symptoms - Urinary  

Bladder infections

Environmental Illness / MCS suggests the following may be present


Allergy / Intolerance to Foods (Hidden)

People with multiple chemical sensitivities often have multiple food allergies as well. While reactions to chemicals in the environment are generally quicker and more easily identified, food allergies are usually delayed, making it harder to pinpoint the offending food. People with MCS are often unaware of hidden food allergies which could be contributing to their overall allergic load.



Respiratory complaints include adult onset “asthma”, shortness of breath, and fibrotic lung disease.

Environmental Illness / MCS can lead to



Please see the link between Autism and the treatment Environmental Medicine.

Recommendations for Environmental Illness / MCS


Dental Metal Removal

Hypersensitivity to dental metals and nickel is frequent in patients with CFS and MCS-like syndromes. Ongoing metal-induced inflammation can be present in the oral cavity and/or in any other place of metal deposition. Metal-driven chronic inflammation may affect the hypothalamic-pituitary-adrenal axis (HPA-axis) and trigger a myriad of non-specific symptoms characterizing CFS, MCS and other related diseases. The removal of metallic restorations can reduce lymphocyte sensitization and improve the health of patients. [Neuroendocrinology Letters, 20: pp.289-298, 1999]


Sauna Detoxification Program

To decrease the fat stores of chemicals, a heat (sauna) detoxification program has been developed consisting of selected nutrients, colon cleansing, heat therapy and massage. The protocol of nutrients, colon cleansing and heat therapy can often reduce the serum levels of these chemicals to “non-detectable”.


Liver Detoxification Support

Reducing the body burden of chemicals can be enhanced by maximizing Phase II liver detoxification pathways with selected nutrients.


Chemical Avoidance

Avoidance of chemicals, especially those you are sensitive to, is the first step in treatment. Face masks and air filters can minimize exposures when total removal is not possible. Circulating clean air into confined spaces will help, but total removal of oneself from the source should be accomplished whenever possible.



Reading List

TIRED OR TOXIC? Is a 400 page book, and the first book that describes the mechanism, diagnosis and treatment of chemical sensitivity, complete with scientific references. It is written for the layman and physician alike and explains the many vitamin, mineral, essential fatty acid and amino acid analysis that may help people detoxify everyday chemicals more efficiently, and hence, get rid of baffling symptoms. Sherry Rogers, MD has written several important books on this subject, any of them being an important read for someone experiencing environmental illness.


Weak or unproven link
Strong or generally accepted link
Proven definite or direct link
May do some good
Highly recommended


Nervous System

A system in the body that is comprised of the brain, spinal cord, nerves, ganglia and parts of the receptor organs that receive and interpret stimuli and transmit impulses to effector organs.


Symptoms resulting from an inclination to vomit.


Hypersensitivity caused by exposure to a particular antigen (allergen), resulting in an increased reactivity to that antigen on subsequent exposure, sometimes with harmful immunologic consequences.


Apprehension of danger, or dread, accompanied by nervous restlessness, tension, increased heart rate, and shortness of breath unrelated to a clearly identifiable stimulus.


Physical manifestations (bodily reactions) to stress. Some psychological precipitant or factor, such as recent trauma or learned behavior, causes a physical manifestation or symptom which has no other known medical explanation. It is not a form of malingering, where someone is faking or intentionally producing the symptom.


Specific protein catalysts produced by the cells that are crucial in chemical reactions and in building up or synthesizing most compounds in the body. Each enzyme performs a specific function without itself being consumed. For example, the digestive enzyme amylase acts on carbohydrates in foods to break them down.


The chemical processes of living cells in which energy is produced in order to replace and repair tissues and maintain a healthy body. Responsible for the production of energy, biosynthesis of important substances, and degradation of various compounds.


The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.


Excision of tissue from a living being for diagnosis.

Immune System

A complex that protects the body from disease organisms and other foreign bodies. The system includes the humoral immune response and the cell-mediated response. The immune system also protects the body from invasion by making local barriers and inflammation.

Autoimmune Disease

One of a large group of diseases in which the immune system turns against the body's own cells, tissues and organs, leading to chronic and often deadly conditions. Examples include multiple sclerosis, rheumatoid arthritis, systemic lupus, Bright's disease and diabetes.


A type of serum protein (globulin) synthesized by white blood cells of the lymphoid type in response to an antigenic (foreign substance) stimulus. Antibodies are complex substances formed to neutralize or destroy these antigens in the blood. Antibody activity normally fights infection but can be damaging in allergies and a group of diseases that are called autoimmune diseases.


(FMS): Originally named fibrositis, it is a mysteriously debilitating syndrome that attacks women more often than men. It is not physically damaging to the body in any way, but is characterized by the constant presence of widespread pain that often moves about the body. Fibromyalgia can be so severe that it is often incapacitating.

Chronic Fatigue Syndrome

CFS (Chronic Fatigue Syndrome) is a disorder of unknown cause that lasts for prolonged periods and causes extreme and debilitating exhaustion as well as a wide range of other symptoms such as fever, headache, muscle ache and joint pain, often resembling flu and other viral infections. Also known as Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS), Chronic Epstein-Barr Virus (CEBV), Myalgic Encephalomyelitis (ME), "Yuppy Flu" and other names, it is frequently misdiagnosed as hypochondria, psychosomatic illness, or depression, because routine medical tests do not detect any problems.


A lung disorder marked by attacks of breathing difficulty, wheezing, coughing, and thick mucus coming from the lungs. The episodes may be triggered by breathing foreign substances (allergens) or pollutants, infection, vigorous exercise, or emotional stress.

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