Confirmation of chemical sensitivity by means of double-blind inhalant challenge of toxic volatile chemicals.

Fifty chemically sensitive patients with vascular, asthmatic and arthritic signs, ranging in age from 21 to 61, were exposed to double-blind challenges of ambient doses of inhaled toxic chemicals in a specially designed booth in an Environmental Control Unit (ECU). Primary signs and symptoms were recorded before and after challenge with five chemicals and three placebos. Inhaled challenges included phenol (less than .0025 ppm), petroleum-derived ethyl alcohol (less than .5 ppm), formaldehyde (less than .2 ppm), chlorine (less than .3 ppm), and pesticide (2, 3,-D at less than .0034 ppm). Placebos were water or saline. A set on testing criteria were evaluated for maximizing the likelihood of well-defined, reproducible information from these ambient-dose double-blind challenges. For best results, these testing criteria include: Before testing, the patient must be housed in a chemically less polluted environment. The individual must have been de-adapted to food, air, and water pollutants by means of a water fat for three to four days. At the time of the challenge, the patient must be on food and water previously determined to be safe. An enclosed non-pulluted challenge booth must be used for these chemical exposures. Sign and symptom scores appropriate for that patient must be recorded, before and after challenge. Appropriate doses of the chemical in question (determined by air concentration and length of exposure) are necessary to investigate a particular problem. The conclusion of the study is that in these patients, chemical sensitivity clearly does exist (pulse rate differences between positive responses and placebo - p .001).(ABSTRACT TRUNCATED AT 250 WORDS)