Luminol-enhanced chemiluminescence (LECL) was used tomeasure reactive oxidant generation by blood phagocytes;22vitamin C23 and urinary cotinine levels2~ were measured usingstandard calorimetric procedures, while vitamin E levelswere measured by high-performance liquidchromatography.~ Leucocyte counts and measurement ofserum IgE and salivary 19A were performed using standardhaematological, radio-immunoassay and rocketelectrophoresis procedures respectively.Lung functions. These were performed with wedgebellows spirometers (Vrtallograph: Buckingham, England)loaned by Medical Specialities (RSA). The tests wereperformed by medical doctors specially trained in thetechniques of lung functions. At least two manoeuvres wereperformed with reproducibility criteria as per therecommendation of the American Thoracic Society.2fi Theequipment was calibrated prior to use and daily thereafter.The children's height and weight were measured withoutshoes, jacket or jersey and recorded to the nearest 0.5 cmand 0.1 kg respectively by trained nursing sisters using ananthropometer. Predicted values were calculated accordingto the method of Knudsen et al."