Spirometric values determined from the flow-volume loops of 60 healthy young smokers (mean age, 28 +/- 0.6 yr) were correlated with measurements of the release of extracellular and intracellular reactive oxidants (RO) as determined by luminol-enhanced chemiluminescence (LECL) from peripheral blood activated with the synthetic chemotactic tripeptide FMLP combined with cytochalasin B (CB). Fractionation and reconstitution experiments revealed that LECL originated predominantly from polymorphonuclear leukocytes (PMNL). Circulating total leukocyte counts and serum thiocyanate levels were also determined. The data were analyzed using Spearman's correlation coefficient and by multiple regression analysis. Cigarette smoking was associated with elevated intracellular and especially extracellular LECL responses, the latter being strongly correlated (p less than 0.0001) with cigarettes smoked per day, serum thiocyanate levels, circulating leukocytes, and PMNL counts. Abnormalities of the spirometric parameters FEV1/FVC, FEF50/FVC, FEF25, FEF25-75, and FEF75-85 correlated best with extracellular LECL (p less than 0.0002 to p less than 0.0001), but also with pack-years (p less than 0.006 to p less than 0.0001), cigarettes smoked per day (p less than 0.008 to p less than 0.0002), thiocyanate levels (p less than 0.04 to p less than 0.002) and leukocyte counts (p less than 0.03 to p less than 0.002). According to stepwise multiple regression analysis of the data the combination of the independent variables extracellular LECL, pack-years, and numbers of circulating PMNL accounts for 35.6% of the variation in lung function in the group of cigarette smokers, with LECL being the most important contributor (26%).(ABSTRACT TRUNCATED AT 250 WORDS)