Effect of cigarette smoking on white blood cells and erythrocyte enzymes

Healthy volunteers smoked 21 to 26 cigarettes containing different amounts of condensate (tar) and nicotine for 16 wk. Enzymes and metabolites of erythrocyte metabolism were not influenced, with the exception of a slight inhibition of delta-aminolevulinic acid dehydratase. Hematological parameters were normal except the white blood count, which was elevated in smokers but remained within the normal range.