元NIEHS(National Institute of Environmental Health Sciences 米国環境健康研究所)勤務のアメリカ人の友人から化学物質過敏症(MCS Multiple Chemical Sensitivity)に関する情報が送ってきました。化学物質へのばく露でMCSが発症すると主張する人が根拠の一つとしている論文 W. Lin et al (2008):TRPM5-Expressing Solitary Chemosensory Cells Respond to Odorous Irritants. Journal of Neurophysiology 99 (3), 1451-1460 http://jn.physiology.org/content/99/3/1451.long と、MCSを告発する活動をしている女性Alison Johnson氏に関する情報 http://www.alisonjohnsonmcs.com/ が引用されていました。Johnson氏はウィスコンシン大学で数学専攻で修士号を取得された方で、MCSを告発するDVDの宣伝も載っていて、クリックすると実際に動画を視聴もできるようになっていました。
一方、上記論文に対して、コメントするに値しないとするDavid E. Hartman博士(Medical & Forensic Neuropsychologyが専門)の以下の反論のメールも載っていました。二重盲検の研究結果が医学関係学術誌に多数掲載されて、MCSについてはすで Psychosomatic Disorder (精神的ストレスによる体調不良)として決着がついた筈ですが、原因としての化学物質ばく露説は否定されても、MCS症状を訴える患者は実際に存在することから、まだこんな論争が行われているようです。(以下の英文の最初の文章は文法的におかしいと思いますので、誰かが引用する過程で言葉が抜けたのかもしれません)
Probably the seminal study is below, demonstrating essentially chance reactivity among patients who believed they chemically sensitive. No physiological basis has been demonstrated to account for extreme claims of odor sensitivity among patients who are not asthmatic or atopic. Environmental activists have inveighed against the toxicity of odorants, and such patients view themselves as canaries in the coal mine; more sensitive than others and bellwethers of our toxic environment. Most of the studies of this population have found very high rates of psychiatric disturbance in such individuals, with somatization, pathological narcissism and sometimes delusional disorders. Many use litigation to manipulate their environment for attention and compensation.
This is not to discount actual allergy, asthma, sensitivity in immunosuppressed individuals, etc., Moreover, I am hardly a fan of the idea that you must pump complex flower-scented hydrocarbons into the air to have a pleasant home. I think we all benefit from living in non-polluted environments. I completely agree with those who would strengthen environmental regulations.
On the other hand, we have to separate the real from the superstitious. Many of these “sensitive” patients demand accommodations down to the atomic level, and report symptoms caused from contact with individuals wearing polyester clothing, reading newspapers, etc. That’s ridiculous. They do not have limbic system neuropathology that renders them unfit to live anyplace but a clean room. They may have severe phobic, paranoid and anxiety disorders, where they attribute their symptoms to a “toxic world.” No filter will eliminate narcissistic, delusional and compensation related demands made by such individuals because their claim of chemical injury is central to their identity and their demands.
Bottom line; we need to care for both groups of people, those with actual physical issues like asthma, and those with severe psychiatric disorders who believe they are being damaged by our industrial society. But helping the latter group does not mean trying to treat somatization, hypochondria, delusions and personality disorder by trying to validate their pathological view of reality. We will never succeed in such an enterprise because there is no physical damage to correct.
David E. Hartman PhD MS ABN ABPP