Advertisement

Illness from low levels of environmental chemicals: relevance to chronic fatigue syndrome and fibromyalgia

  • Iris R. Bell
    Correspondence
    Requests for reprints should be addressed to Iris R. Bell, MD, PhD, Department of Psychiatry, Tucson Veterans Affairs Medical Center, Mail Stop 4-116A, 3601 South Sixth Avenue, Tucson, Arizona 85723
    Affiliations
    Department of Psychiatry, University of Arizona, Tucson, Arizona USA

    Department of Psychology, University of Arizona, Tucson, Arizona USA

    Department of Family and Community Medicine, University of Arizona, Tucson, Arizona USA

    Department of Medicine, University of Arizona, Tucson, Arizone USA

    Department of Psychiatry, Tucson Veterans Affairs Medical Center, Tucson, Arizona, USA
    Search for articles by this author
  • Carol M. Baldwin
    Affiliations
    Department of Psychology, University of Arizona, Tucson, Arizona USA

    Department of Neurology, University of Arizona, Tucson, Arizona USA

    Department of Medicine, University of Arizona, Tucson, Arizone USA

    Department of Psychiatry, Tucson Veterans Affairs Medical Center, Tucson, Arizona, USA
    Search for articles by this author
  • Gary E. Schwartz
    Affiliations
    Department of Psychiatry, University of Arizona, Tucson, Arizona USA

    Department of Psychology, University of Arizona, Tucson, Arizona USA

    Department of Medicine, University of Arizona, Tucson, Arizone USA

    Department of Psychiatry, Tucson Veterans Affairs Medical Center, Tucson, Arizona, USA
    Search for articles by this author

      Abstract

      This article summarizes (1) epidemiologic and clinical data on the symptoms of maladies in association with low-level chemicals in the environment, i.e., environmental chemical intolerance (CI), as it may relate to chronic fatigue syndrome (CFS) and fibromyalgia; and (2) the olfactory–limbic neural sensitization model for CI, a neurobehavioral synthesis of basic and clinical research. Severe CI is a characteristic of 20–47% of individuals with apparent CFS and/or fibromyalgia, all patients with multiple chemical sensitivity (MCS), and approximately 4–6% of the general population. In the general population, 15–30% report at least minor problems with CI. The levels of chemicals reported to trigger CI would normally be considered nontoxic or subtoxic. However, host factors—e.g., individual differences in susceptibility to neurohormonal sensitization (amplification) of endogenous responses—may contribute to generating a disabling intensity to the resultant multisystem dysfunctions in CI. One site for this amplification may be the limbic system of the brain, which receives input from the olfactory pathways and sends efferents to the hypothalamus and the mesolimbic dopaminergic [reward] pathway. Chemical, biologic, and psychological stimuli can initiate and elicit sensitization. In turn, subsequent activation of the sensitized limbic and mesolimbic pathways can then facilitate dysregulation of behavioral, autonomic, endocrine, and immune system functions. Research to date has demonstrated the initiation of neurobehavioral sensitization by volatile organic compounds and pesticides in animals, as well as sensitizability of cardiovascular parameters, β-endorphin levels, resting EEG α-wave activity, and divided-attention task performance in persons with CI. The ability of multiple types of widely divergent stimuli to initiate and elicit sensitization offers a new perspective on the search for mechanisms of illness in CFS and fibromyalgia with CI.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to The American Journal of Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect