[Serum thiocyanate level as a discriminating element in evaluation of exposure to carbon monoxide].

Blood carbon monoxide concentration levels in two groups of subjects to a different degree of exposure are examined in the light of the subjects declared smoking habits and serum thiocyanate levels. The latter parameter proved an effective pointer to individual exposure to CO due to tobacco combustion. Assessment of the results showed that it could be proposed as an indicative and discriminating test of habitual exposure to CO, so as to enable expired CO and HbCO values to be interpreted in occupationally exposed subjects.