load) and synergism at the time of reaction. (6) the derangement of metabolism that may occur from the initial insults.

To demonstrate cause-and-effect proof of environmental influence on an individual's health, one must understand several important principles and facts. These principles involve those of total body load (burden), adaptation (masking, acute toxicological tolerance), bipolarity, biochemical individuality. Each principle will be discussed separately.

TOTAL BODY LOAD (BURDEN)

This is the patient's total pollutant load of whatever source (usually from air, food and water or surroundings1,2,4. The body must cope with this total burden; usually it must be utilized, expelled or compartmentalized. Total body load includes: (1) physical factors (e.g. hot, cold, weather changes, positive ions.5 electromagnetic phenomena.6 radon); (2) toxic chemicals (e.g. inorganics: Pb, Cd, Hg, A1, Br, etc.; organics: pesticides, formaldehydes, phenols, car exhausts, etc.).7-21 (3) biological (bacteria, virus, parasites, molds,22 food.)23,24 (4) psychological or emotional factors also significantly affect the patient, confirmed by recent work in psychoneuroimmunology, linking the psyche and the neuroendocrine and immune systems.25,26,27,28 Failure to reduce the total body load prior to pollutant challenge will frequently yield inaccurate results. Accordingly, we believe it is essential to conduct investigative procedures in controlled environmental circumstances with the total load reduced.

ADAPTATION (MASKING, ACUTE TOXICOLOGICAL TOLERANCE)

Induced by the internal or external environment, this is a change in the homeostasis (steady state), of body function with adjustment to a new "set point."29,30,31,32 Adaptation is an acute survival mechanism in which the individual "gets used to" a constant toxic exposure in order to survive, at the same time suffering a long-term decrease in efficient functioning and perhaps longevity. Selye was among the first to describe this compensatory mechanism.33 Because of adaptation or tolerance, the patient's total body load may increase undetected because the perception of a cause-and-effect relationship is lost. With no apparent correlated symptoms, repeated exposures may continue to damage his immune and enzyme detoxification systems. 34,35 The eventual result of continued toxic exposure over a period of days, weeks, months to years is end-organ failure.21 Withdrawal or avoidance of an offending substance for at least four days will aid in reducing the total body load, after which a controlled re-exposure challenge will reproduce cause-and-effect reactions. In these deadapted individuals, there is high reproduciblity of these evoked reactions permitting the physician to acquire sound scientific information. 36

BIPOLARITY

After an exposure, the body initially develops a bipolar response of a stimulatory phase



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