MCS Prevalence: Dissecting the News

There has been a bit of media coverage this week of a recent study noting that 20 percent of low-income patients screened by two Texas family medicine practices were found to have "chemical intolerance" or Multiple Chemical Sensitivity (MCS). A number of news outlets, including CNBC, Fox News, and the Chicago Tribune reprinted a Reuters article on the study. As usual when MCS-related news is reported, there are aspects of the coverage to both applaud and bemoan.

Here's my take on the study and the coverage:

  • The essential bit of news is that a significant percentage of patients recruited from the waiting rooms of two family medicine clinics were given a screening survey and found to meet the diagnostic criteria for MCS. I'm glad that the prevalence of the disorder is being reported, because MCS is far more common than most people imagine, and an awareness of the size of the issue may spur action.

  • The study found a prevalence rate of 20% among the patients examined. This is, as the report suggests, "sizeable,” but it isn't a total surprise or completely out of line with previous findings. Previous studies of the general population have found MCS prevalence rates between 11 and 33%. Studies of specific populations have found much higher rates. A study of Gulf War veteran outpatients, for example, found a rate of 86%.

  • The report noted that the patients in the study were low-income and stated that previous studies focused on "higher-income, white people." If that's true of previous studies, I'm unaware of it. In fact, this report of a prevalence study noted that "both allergy and chemical sensitivity were distributed widely across age, income, race, and educational groups" and one published in the American Journal of Epidemiology stated that "marital status, employment, education, geographic location, and income were not predictive of reported chemical sensitivities ." Studying sub-groups for rates of chemical sensitivity has merit, but I hope all people will take the issues seriously and realize that no one is immune.

  • The author of the Reuters report states that an MCS diagnosis is "controversial." I suppose that's true, in the strictest sense of the word, but only because of the special interests with deep pockets that work hard to make it so. See the previous post titled “The Misinformation Campaign” for more information.

  • The author notes that there is no agreement on the cause of MCS. That is also technically true, I suppose, because companies that manufacture chemicals don't "agree" (at least publicly) that their products have anything to do with the symptoms MCS patients experience. It's very reminiscent of previous denials by tobacco companies that their product had any association with lung cancer.

  • The study found that the patients with chemical sensitivity had higher rates of depression and anxiety than others. This is a touchy subject among many with MCS, because those who attempt to disprove the validity of the condition generally try to paint it as a mental disorder. Fortunately, the report quoted lead researcher Dr. David A Katerndahl who noted that "some people might become depressed or anxious because of their chemical intolerance symptoms." Of course we do. I imagine that people with cancer or those injured in automobile accidents also have higher rates of depression and anxiety. A study published in the journal Environmental Health Perspectives notes that only 1.4% of patients with chemical sensitivities had a prior history of emotional problems, but 37.7% developed emotional problems after the physical symptoms emerged. See this previous post for an overview of research pointing to physical, rather than psychological causation.

  • Only one-fourth of the patients found to have MCS had been previously diagnosed. This is an important point. If people don't associate their symptoms with exposures, they don't know to avoid (or at least attempt to avoid) substances that cause their distress. Katerndahl also pointed out that chemically sensitive patients are often intolerant of many medications, which is important for their physicians to understand.

  • I found a bit of good news in Katerndahl's statement that among primary care doctors there is a growing acceptance of the validity of MCS. I pray that acceptance turns into action and that doctors will work to make their offices and clinics less toxic and more chemically safe for all of their patients.

  • The suggestion for those with MCS is that they get a referral to go see an allergist. This is, unfortunately, not likely to be of much help to most who suffer from chemical sensitivities. Although people can have both allergies and MCS, true allergies involve an immune response that differs from the detoxification abnormalities common in MCS. Appropriate and helpful medical care for those with chemical sensitivities is extremely hard to find. An interesting study of treatment efficacy found that survey participants with MCS had consulted an average of 12 healthcare providers each and found 3 to be helpful. They had spent over one-third of their annual income on health care costs. The survey rated the perceived efficacy of 101 treatments and found the three most highly rated interventions to be creating a chemical-free living space, chemical avoidance, and prayer.

Knowing how many people suffer from MCS is important. The real question, though, is how many is too many? How many must suffer before we make changes in our product choices? How many people is it OK to shut out of our churches? These are questions that deserve serious consideration.

How to Know if a Product is Safe

People often ask me about the safety or toxicity of various products. Sometimes I know the answer and sometimes I don't. It isn't easy to keep up with the barrage of new offerings continually entering the marketplace, and since formulations change constantly, even a product that was safe one week may not be so the next.

It's important for consumers to be aware of the chemical safety of the products they use, but manufacturers certainly don't make that task easy. There are large loopholes in labeling laws, and a great deal of marketing hype that is often difficult to decipher. Manufacturers have responded to the rising demand for safer products in varying ways. Some have introduced less toxic products into their consumer lines (while generally continuing to sell their toxic standard-bearers) and others have simply re-branded products as "all-natural," "non-toxic," or "green." These terms are used indiscriminately and have very little meaning. Consumer Reports' Greener Choices website has a helpful label search function which notes, for example, that the "non-toxic" label is not meaningful, verified, consistent, or free from conflict of interest.

The term "green" is especially problematic. A green product is purported to be better for the environment than standard fare, but better for the environment does not necessarily mean better for human health. Recycling a toxic product, for example, does not make it less toxic. People who are chemically sensitive often call themselves "canaries" after the birds that miners once took with them to warn of harmful gases. Perhaps we should adopt the color of the canary as a new standard and look for products that are not just green, but also yellow, or safe for human use.

Although it is difficult to get all the information needed to make truly informed product choices, there are some general rules of thumb. Products purchased at health food stores or from companies that cater to the health-conscious are generally safer than products purchased at major retail outlets, although there may be exceptions. There are also websites that help provide information and there are clues to toxicity even on imperfect labels. Reading labels is important and it is wise to note the following warnings or listed ingredients:

  • Fragrance - Products do not have to have any odor at all to be toxic (carbon monoxide, for example, is both odorless and deadly), but synthetic fragrances are almost always problematic. (For more information, see the previous post entitled Fragrance Facts.) Heavy fragrances are often added to a product to cover the odor of other objectionable chemicals. I've recently begun seeing the word "aroma" in ingredient lists and assume it is simply another term for synthetic fragrance. If anyone knows otherwise, please let me know.

  • Keep out of reach of children - A product containing this warning is obviously hazardous to some degree, and is likely to be harmful for adults as well.

  • Use in a well ventilated area - Abundant ventilation is always a good idea, but seeing the advice on a product label may indicate that another product is a safer choice.

  • Wash hands well after using - Obviously, washing hands frequently is a good idea for many reasons, but seeing the advice on a product label may mean that the product contains toxic chemicals likely to be absorbed through the skin.

The following websites are helpful (though sometimes hard to navigate) resources for evaluating aspects of safety for certain products:

  • HealthyStuff.org evaluates the safety of products in many categories, including children’s goods, pets, cars, and apparel.

  • The Household Products Database is offered by the U.S. Department of Health and Human Services and provides health and safety information on household products of many kinds, including yard, home maintenance, auto, home office, and arts and crafts.

  • Skin Deep is a searchable safety guide to cosmetics and personal care products.

Making informed product choices is more challenging that it needs to be, but it isn't impossible. Sometimes a quick internet search using the product name and the word "toxic" is all that is needed to obtain good information. A search for "non-toxic alternatives to . . ." can also yield helpful results at times. No matter the inconvenience, educating ourselves about product toxicity and making safer choices is worth the effort. The seemingly small choices we make in the products we use can have profound and life-altering consequences, not only for ourselves, but also for those around us. Let's value our health and the health of those who share the air enough to take this issue seriously.

How Beautiful

I've just returned from a vacation trip to Yellowstone National Park. It's very difficult for me to stay in motels or in other people's homes, so my husband and I travel in a 29-year-old campervan. The campervan makes travel possible, but not completely easy. Taking a trip always involves unavoidable chemical exposures, but most of the time the benefits of getting away make it worth the physical cost.

I've been to Yellowstone before, and my soul was as fed by the vast unspoiled beauty this time as it was on my previous visit. This trip had an added bonus, though. This time I was able to attend an outdoor worship service. Actually, I got to attend two: one Sunday morning and another one later that evening. The evening service was a bit problematic because of bug repellant, which many people applied at the same time and in close proximity to me. I moved away from the group, but was able to stay for the service, and was grateful for that.

Fortunately, the chemical exposures were very low for the morning worship gathering. There was a lot going on in my head and heart during that service and I found myself getting very emotional. Primarily I felt gratitude and joy for the opportunity to worship with others, since it's a very rare privilege for me these days.

As I sat in the midst of strangers from all over the country who had come together because of a common love for Jesus, I kept thinking of a line from an old Twila Paris song: "How beautiful is the body of Christ." Yellowstone is full of natural beauty, but I had to agree, looking around at the other worship participants representing parts of Christ's body on this earth, that they were beautiful, too.

There were also a lot of memories coming to the surface that morning. The summer after my freshman year in college I served as a summer missionary in a tourist area, and one of the things I did was to lead worship services in a number of campgrounds. The morning service at Yellowstone was led by a college girl, and when I looked at her I saw a younger me.

I began to wonder what I would tell the younger me, if I could. I wasn't naïve or untouched by life's challenges at that age. My mother died when I was 13, so I already knew that life could be hard. I never imagined MCS, though. I never imagined being shut out of church.

I think what I would tell my younger self is that corporate worship is a valuable treasure that shouldn't be taken for granted. I would say that providing worship services in unconventional settings is an important ministry and well worth the effort. I would thank the younger me for being part of providing worship opportunities for all sorts of people, some of whom might, like the current me, have no other options.

Would the younger me listen to the current me if I told her to value and store up in her heart every element of every worship service she was able to attend? Probably not. At the time, the ability to freely worship with others seemed to be a "given" rather than the privilege it really is. Now I understand. Now, when I'm able to worship with others I soak up all the moments of corporate grace and I treasure them. I truly treasure them.

The Misinformation Campaign

Many illnesses are misunderstood. People with MCS often have more than ignorance to fight, however. Some large and powerful corporations have reasons to make sure that chemical sensitivity isn't accepted as a valid condition and that chemical safety isn't called into question.

Dr. Ann McCampbell has written an excellent analysis of the situation entitled Multiple Chemical Sensitivities under Siege. I recommend it, not only for people curious about MCS, but for anyone interested in how public opinion about medical issues may be shaped. McCampbell details the activities of chemical manufacturers and the pharmaceutical industry. (Oddly, many drug manufacturers also make pesticides.) She writes about non-profit organizations with benign-sounding names and notes that the activities of one of them include the following:

  • publishing newspaper advertisements made to look like legitimate news stories stating that MCS “exists only because a patient believes it does and because a doctor validates that belief”

  • paying a medical journal to publish the proceedings of an anti-MCS conference which was partly organized by a firm owned by their executive director

  • sending anti-MCS literature to a state disability agency developing a report on MCS which included advice on how to avoid accommodating chemically sensitive employees

  • sending a representative to a Medicaid Advisory Committee meeting to urge that Medicaid benefits be denied for the diagnosis and treatment of chemical sensitivities

  • providing a representative to speak against MCS at a continuing medical education (CME) conference for physicians where he failed to disclose his industry affiliations as required by CME guidelines

  • sending a member to speak to the staff at an independent living center where he berated them for providing a support group for people with MCS.

In Isaiah 1:17, God instructs His people to defend the oppressed. There are people all over the world today being oppressed in significant, obvious, and life-altering ways. There may also, however, be less obvious forms of oppression occurring right before our eyes. In the realm of MCS, there is a great deal of very real suffering that is being caused by those with power, resources, and vested interests. Those who suffer from MCS need healthy advocates and defenders. Will you be one?

How Does Someone Become Chemically Sensitive?

It seems likely that chemical sensitivity has a variety of etiologies, similar to the way that nausea may be caused by such diverse factors as food poisoning, chemotherapy, and pregnancy. At the heart of the matter, however, is generally a problem with the body's detoxification system. When people are unable to fully process toxins they accumulate and cause damage and symptoms.

Despite the determined efforts of some to paint MCS as a psychological disorder, there is no shortage of evidence proving it to be a very real physical condition. For instance:

  • Animal models point to a physical cause. Studies show that animals exposed to repeated low levels of chemicals over a period of time can become extremely reactive and sensitive to minute traces of those chemicals.

  • People who became sick after exposure to certain chemicals in Operation Desert Storm were found to have lower amounts of a specific enzyme than others who had higher amounts and weren’t sickened.

  • Women with a genetic profile involving two genes associated with detoxifying toxic compounds were found to be over 18 times more likely to have MCS compared to women with a different genetic makeup. Women with variations in just one of the implicated genes were also more likely to develop chemical sensitivities.

  • Genetic abnormalities can themselves be caused by chemicals. Many chemicals are capable of mutating genes or turning them on or off.

  • Lab tests of some MCS sufferers reveal abnormal activity in one or more of the eight enzymes involved in heme production. (Heme is the primary component of hemoglobin in red blood cells.)

  • Nasal abnormalities consistent with chronic inflammation have been found in patients with MCS. Damaged mucosa enhances absorption of inhaled chemicals, and often permits rapid entry into the brain.

  • Testing often shows people with chemical sensitivities to be “pathological detoxifiers” in which Phase I of liver detoxification is faster than Phase II, leading to a buildup of toxic metabolites in the body.

  • Groups of independent researchers have found distinct abnormalities of brain metabolism in people with MCS. The neurotoxic pattern is very different from the abnormalities reported in psychiatric disease.

  • Tests measuring blood flow to the brain (SPECT scans) show differences between MCS patients and normal controls. MCS patients demonstrate severe deterioration when they are challenged by chemicals in concentrations found in everyday situations.


Certain people may be more likely than others to become chemically sensitive, but no one is immune to the danger. We all have finite bodies capable of detoxifying a limited chemical burden, and it's impossible to know who might be one exposure away from exceeding that limit. Although it's wise to reduce and eliminate all chemical exposures, some substances are especially likely to set people on the road to MCS. These are known as "sensitizers." Pesticides and formaldehyde (found in many personal care, cleaning, building, and furniture products) are known sensitizers that are very important to avoid.

People with chemical sensitivities need your help to function in this world. Those without chemical sensitivities need your help to stay that way. You, yourself, may be one chemical exposure away from developing MCS. Reducing chemical exposures is the right thing to do for everyone's sake.

For more information:
http://www.environmentalhealth.ca/Ross2000.html
http://www.sciencedirect.com/science/article/pii/S0041008X99987033 http://www.nettally.com/prusty/case-control%20study.pdf http://www.environmentalhealthnews.org/ehs/news/epigenetics-workshop http://www.mcsrr.org/factsheets/porphyri.html http://www.mcsbeaconofhope.com/meggsa2.html http://www.digitalnaturopath.com/treat/T355089.html

Who Regulates the Products We Use?

It's surprising to many people (it certainly was to me) to learn how many products make it to our store shelves without being tested for safety. I always assumed that either the EPA (Environmental Protection Agency) or the FDA (Food and Drug Administration) was in charge of regulating such things as personal care and cleaning products. Nope.

The government's own FDA website has a page entitled What FDA Doesn't Regulate. Here's what they have to say about "consumer products":

"The agency has no jurisdiction over many household goods. The Consumer Product Safety Commission (CPSC) is responsible for ensuring the safety of consumer goods such as household appliances (excluding those that emit radiation), paint, child-resistant packages, and baby toys."

See some things left out? How about the EPA? They say this:

"EPA has no authority to regulate household products (or any other aspect of indoor air quality). . . .Even if we had authority to regulate indoor air quality, it would be difficult to regulate household (or other) products because we have no authority to collect information on the chemical content of products in the marketplace (nor does any Federal Agency)."

If governmental agencies don't have the authority to protect us from toxins in common products, our choices are to either trust the manufacturers or do our own homework. This is more challenging than you might think, due to inadequate labeling laws (a topic I'll probably address in a future post), but is still both possible and necessary. Some basic Christian principles include taking care of our bodies (1 Corinthians 6:19-20) and loving our neighbors as ourselves (Matthew 22:39). Knowing whether the products we use are toxic to ourselves and those around us is part of that.

Yes, it's a pain. Yes, it's easier to just buy what's cheap or what removes stains with the least effort. But doing our homework on this issue matters. It matters a lot.