Jan 12, 2010
Chemophobia and risk
As a chemist by training, I’ve always been loath to give credence to unfounded criticism of synthetic chemicals that might stoke up chemophobia. Indeed, on several occasions I have written about how our bodies have evolved to cope with all kinds of chemicals regardless of whether they are synthetic or “natural”. I’ve never been a shill for the chemical industry, although I have been accused of it. But, there is so much misguided nonsense about the supposed absolute risks of synthetic chemicals that someone has to provide a little balance.
On at least one occasion, however, I’ve been thwarted in my efforts to provide just such a balanced point of view the issues surrounding chemical safety. Once it was a blinkered features editor on a well-known popular science magazine who simply refused to see past the word “manmade” and had already decided that if the product being discussed wasn’t derived from an extract of hemp or some other natural material and squeezed out by native bushpeople or some such nonsense then it didn’t deserve a mention in the hallowed pages of the magazine.
As a science, chemistry is more than wonderful, it not only sates the inquisitive and repeatedly throws up new puzzles, it also provides us with the materials with which we have built the modern world. As with any human endeavour there is, of course, a price to pay. Many of the essential ingredients of the industrial processes on which our standard of living depends are toxic. There is no way to avoid that issue. Volatile organic compounds are a case in point and several of the most toxic are now banned substances on health and environmental grounds.
Toxicity, however, is about exposure and dose, not about blanket bans. That said, it is sometimes necessary to take a more holistic view of the potential impact of the chemical cocktails with which we surround ourselves in the workplace and in the home. Multiple-chemical sensitivity was a buzz-phrase back in the early 1990s and filled many a column inch in trade magazines such as Chemical & Engineering News (C&EN) and the now-defunct Chemistry in Britain. I’ve still got the pre-PDF “cuttings” mouldering away in a filing cabinet somewhere. But, this syndrome doesn’t seem to feature much in the trade or any other media these days, I suspect its clinical significance like so many other nebulous disorders simply didn’t stand up to close scrutiny. There are many people who will likely disagree, and certainly medicine is far from perfect, but the assumption intrinsic in MCS is that synthetic = bad, which really isn’t the case.
However, Dimosthenis Sarigiannis and colleagues at the European Commission – Joint Research Centre, at the Institute for Health and Consumer Protection, in Ispra, Italy, seem keen to resurrect the notion that mixtures of chemicals are somehow more worrying than a single chemical acting alone.
Writing in the International Journal of Risk Assessment and Management, they assert how current risk assessments address compounds individually whereas real-life human exposure is to mixtures of chemicals present in the environment, the workplace, or consumer products. They suggest that a more connected approach to chemical risk assessment is needed.
Such an approach would combine information from environmental fate analysis, epidemiological data and toxicokinetic models to help us estimate internal exposure. This information might also be coupled to gene expression profiles to provide a signature of exposure to whole classes of toxic compounds so that we might derive a biologically based dose-response estimate. Such an approach will take into account the non-linear relationship between risk and exposure to mixtures of toxic compounds, the team explains.
The team concedes that any such model of risk-exposure will need a large data set to ensure that its predictions are statistically robust. And, I agree that we need to overhaul risk assessment in light of better understanding of how chemical mixtures affect gene expression, metabolism, and other biological processes. They also explain that a linear, additive approach to mixture toxicology is entirely outmoded given the latest evidence on non-additive effects. Again, I agree. This is not chemophobia this is rational assessment.
Sarigiannis, D., Gotti, A., Reale, G., & Marafante, E. (2009). Reflections on new directions for risk assessment of environmental chemical mixtures International Journal of Risk Assessment and Management, 13 (3/4) DOI: 10.1504/IJRAM.2009.030697
This is the state of the art regarding “MCS”: “Recent studies have implicated a number of different perspectives which may be helpful in understanding the cause of chemical sensitivities. A multifactorial model incorporating behavioural, physiological and sociological approaches may be useful. Cultural and historical factors, alongside individual expectations and beliefs, as well as maladaptive learning and conditioning processes, may be important in the specific cause of chemical sensitivities. Iatrogenesis, through the promise of unproven ‘therapies’, may perpetuate reported symptoms further. Although there are many recent experiments implicating potential behavioural or psychological causes for Multiple Chemical Sensitivities, there remains a paucity of treatment trials for this condition.”
Curr Opin Otolaryngol Head Neck Surg. 2007 Aug;15(4):274-80 – http://www.ncbi.nlm.nih.gov/pubmed/17620903
Thanks for your candid comment Ian even though I have some issues with particulars.
“MCS is indeed flagging in scientific literature.”
I have to differ with this. Within this past decade we’ve seen Martin Pall develop a workable theory for how MCS can initiate and perpetuate, along with the related CFS. We’ve seen researchers find six genetic predispositions for it. Pall’s work has entered the mainstream by being included in a major toxicology textbook, and most recently we saw an independent research group confirm his theory with biological markers. Some may not consider this overwhelming scientific progress, but in light of the quality data in the face of aggressive opposition, it’s significant. The only difference here is that MCS faces the battle from the chemical industry. I’m very thankful for those researchers and physicians who are willing to forge ahead and help the people who need it.
Author: IanH
Comment:
MCS is indeed flagging in scientific literature. However the associated illness ME/CFS is not. My experience with patients with ME/CFS is that many of them experience problems with exposure to a number of substances be they chemicals or micro-organisms. The current weight of evidence is that ME/CFS is an immunological illness involving one or more pathogens. The actual cause(s) yet unknown. It is well known that part of the function of the immune system is to detect toxins and to initiate a detoxification of those toxins. This is well mapped out for many pharmaceuticals. (Which are all toxins – just controlled and tested). All pharmaceuticals have “side effects” i.e. unwanted (usually) toxic reactions. some of these toxic reactions are to very small amounts of the drug.
“I do agree that case definition of MCS is absent and that many people with odd ideas jump on the band-wagon.”
One of the problems with case definition is again, the presence of people trying to discredit the illness. Consult with a physician who specializes in it and you’ll find a workable case definition.
“But we must not make the psychologising mistake just because of lack of clear causes and poor case-definition. I know some of my medical colleagues do this but they do it with no evidence for psychogenic cause. Why do they commit this evidential sin you might ask? Arrogance! One of the previous writers alluded to the state of our medical knowledge. The immune system is currently in its infancy.”
Thanks a lot for this.
“A lack of science just means we haven’t done enough and we have a long way to go. We currently do not have enough tools or information to explain to these poor people what the hell is going on in them.”
I’ve had MCS for approximately 14 years. It’s difficult enough to live with the illness itself. The arrogance of deniers makes it that much worse. I’ve been faced with people who use fictitious examples of how people become chemophobes while ignoring the real experiences of MCS sufferers, including myself. No, I did not start out as a treehugging leftie whose hatred of chemicals caused me to start reacting to them. On the contrary, I contracted it as a right-wing ideologue who detested treehuggers and it took me many months to find the association between my reactions and the causes. That first trigger happened to be a fragrance that I used and loved.
“Study after study is showing the potential damage being caused by many chemicals, such as some pesticides and some petrochemicals. Problem is that many of these are liberated on us without thorough testing and with testing only to a level permitted by our medical knowledge.”
And those difficulties are just the beginning. We can’t isolate single chemicals and follow their effects over years, nevermind understand the nearly limitless combinations of chemicals that we ingest and absorb.
“[. . .]But when it comes to non drug chemicals the person reacting is just a nutter and collectively they are a fringe group who have psycholpathology. Come on now. Use your reason.”
Did you mean to say non synthetic chemicals here? I don’t believe I react to non synthetic chemicals myself, but I do know that there are people who do and there are good reasons why. Some of these natural chemicals are certain essential oils and pine. What we have to remember is that we are no longer normal and part of the process is an increased blood-brain barrier permeability.
MCS is indeed flagging in scientific literature. However the associated illness ME/CFS is not. My experience with patients with ME/CFS is that many of them experience problems with exposure to a number of substances be they chemicals or micro-organisms. The current weight of evidence is that ME/CFS is an immunological illness involving one or more pathogens. The actual cause(s) yet unknown. It is well known that part of the function of the immune system is to detect toxins and to initiate a detoxification of those toxins. This is well mapped out for many pharmaceuticals. (Which are all toxins – just controlled and tested). All pharmaceuticals have “side effects” i.e. unwanted (usually) toxic reactions. some of these toxic reactions are to very small amounts of the drug.
In ME/CFS it is now well documented that several biochemical pathways are dysfunctional, eg.
CD8+ cyto-toxic T cells bear activation antigens
CD8+ T cells fail to terminate immune activation
Natural killer cells function very badly in many ways
There is extensive upregulation of the 2,5-oligoadenylate system
There is a marked, consistent increase in the pro-inflammatory cytokines
There is heightened NMDA activity
There is heightened oxidative stress
NF-kappaB activation is consistent with infection or oxidative stress of mitochondria
There is damage to nucleic acids and lipid membranes
There are many more but I selected these because they predict or are a sign of pathogens or toxin metabolism dysfunction. Quite consistent with the concept of MCS.
I do agree that case definition of MCS is absent and that many people with odd ideas jump on the band-wagon. But we must not make the psychologising mistake just because of lack of clear causes and poor case-definition. I know some of my medical colleagues do this but they do it with no evidence for psychogenic cause. Why do they commit this evidential sin you might ask? Arrogance! One of the previous writers alluded to the state of our medical knowledge. The immune system is currently in its infancy.
A lack of science just means we haven’t done enough and we have a long way to go. We currently do not have enough tools or information to explain to these poor people what the hell is going on in them.
Study after study is showing the potential damage being caused by many chemicals, such as some pesticides and some petrochemicals. Problem is that many of these are liberated on us without thorough testing and with testing only to a level permitted by our medical knowledge. As I said every drug has side effects some severe in some people, collectively all the drugs create side effects (toxic reactions ) in millions of people. When they do another drug is tried. But when it comes to non drug chemicals the person reacting is just a nutter and collectively they are a fringe group who have psycholpathology. Come on now. Use your reason.
As Per Dalen, MD, PhD, Associate Professor of Psychiatry at the University of Gothenburg put it:
“It is interesting that another blind spot can be found in the area of placebo. Somatization and placebo are like the two sides of a coin. Both are believed to possess great power, the one of causing disease, the other of restoring health. Their mechanisms of operation are essentially unknown, and systematic studies have in fact yielded little or no evidence in clinical situations.
“There is no denying it; medicine uses a double standard in relation to scientific evidence. The placebo has been an integral part of our medical culture since the 1950s. Somatization gained prominence relatively recently. Scientific ideas normally have an interesting history, including a genealogy and a record of arguments pro and con. Important ideas rarely enter the scene fully fledged and unruffled by controversies, but somatization was presented even without a reference to psychoanalysis.
“Today we are sometimes told that somatization is the disease process to consider when physicians fail to explain the symptoms of the patient. The rather too flattering implication would be that medical science can now explain so many things that most of the remaining problems can be bundled together under a collective psychiatric label without further investigation.”
Dr. Kaye H. Kilburn M.D., Ralph Edgington Professor of Medicine USC Keck School of Medicine:
“Despite awareness that the brain has enormous amplifier capacity, most neurologists ignore–and some deplore–the concept of sensitivity to low concentrations of chemicals. The case in point is Multiple Chemical Sensitivity Syndrome, which is labeled as “fringe” or “kooky,” as if the battlements of medical thought must be defended from such an idea. Some held to these biases while they treated Gulf War veterans who died of premature amyotrophic lateral sclerosis. In contrast, occupational neurotoxicity has a rich history, including the disturbance of brain function by mercury in mirror silverers in 1700, and palsy and psychosis caused by lead, as described in 1737 by Ben Franklin in fellow printers who handled lead type. . . .
“It is strange that few psychiatrists, when evaluating chemically exposed patients, consider that the depression, mania, and other disorders they treat with drugs (chemicals) could be caused by other chemicals. Instead, the tendency is to prescribe more chemicals (drugs), thus further poisoning the brains of such patients.”
Martin Pall has described how symptoms like depression, anxiety, and rage can be physiological of MCS, not to mention the fact that these psychological symptoms are recognized sequelae of any difficult, chronic health condition.
Martin Pall, Professor Emeritus of Biochemistry and Basic Medical Sciences, Washington State University:
“I was delighted when I was asked by the three editors of the future publication, “General and Applied Toxicology, 3rd Edition” (John Wiley and Sons) to write a review on multiple chemical sensitivity (MCS) for this prestigious multivolume set. MCS, as I am sure you know, has been largely ignored by toxicologists in general and I was delighted that these three prominent scientists, all of whom had extensive published research on the actions of chemicals implicated in MCS, asked me to write such an article. THIS WAS IMPORTANT RECOGNITION NOT ONLY FOR MY OWN WORK ON MCS BUT ALSO THAT MCS IS NOW RECOGNIZED AS A TOXICOLOGICAL PHENOMENON.
The paper, entitled Multiple Chemical Sensitivity: Toxicological Questions and Mechanisms is the most extensively documented publication on MCS, and will be a 54 page chapter in this multivolume set. While the majority of this paper comes from my earlier publications on MCS, it also contains several very important sections that are largely novel.
http://www.csn-deutschland.de/blog/en/tags/multiple-chemical-sensitivity/page/10/
Wish my Danish were up to speed – http://www.ncbi.nlm.nih.gov/pubmed/20806486
Should fibromyalgia, chronic fatigue syndrome and multiple chemical sensitivity be treated in psychiatric services? Ugeskr Laeger. 2010 Aug 23;172(34):2327; author reply 2327.