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.