[Effect of passive smoking on bronchial reactivity in school children].

Passive smoking on the part of children leads to an increase in the incidence of upper airway infections in early childhood, an elevated incidence of childhood asthma, and an aggravation of existing asthma. We investigated the bronchial reactivity of 80 healthy, symptom-free schoolchildren, 44 from smoking families (SF), 36 from non-smoking families (NF), employing treadmill exercise during which the subjects inhaled cooled air (-2 degrees C), and compared the results obtained with those found in a group of 27 children with asthma (A). A positive bronchial reaction (50 per cent Raw increase following exercise on the treadmill) was observed significantly more frequently in the SF group than in the NF group (22 out of 44 children as compared with 10 out of 36 children, p less than 0.05); both groups differed significantly from the group of asthmatics (21 out of 27 children). It is concluded that bronchial hyperreactivity occurs more frequently in clinically healthy, passively smoking children as compared with a control group.