In 1993, 4521 schoolchildren in Oslo, Norway, participated in a European study on air pollution and respiratory health. Incorporated in the primary questionnaire were five questions taken from a study performed 12 years earlier on 1772 schoolchildren in the same city. The response rate was 85% in 1993 vs 95% in 1981. The current and cumulative prevalences of doctor‐diagnosed asthma in 1993 were 4.2% and 8.0%, respectively, compared to 2.2% (P<0.01) and 3.4% (P<0.01) in 1981. Attacks of breathlessness during the last 3 years were experienced by 7.1% in 1993 and 3.3% in 1981 (P<0.05). Wheezing or breathlessness on exposure to pollen in 1993 and 1981 was reported by 6.1% and 3.7% (P<0.01), respectively; to animals by 4.0% and 2.8% (P<0.05); and to exercise by 10.2% and 4.8% (P<0.01). The prevalence of occasional wheezing and the cumulative prevalence of doctor‐diagnosed eczema, urticaria, and hay fever were not significantly altered. To summarize, a higher prevalence of both doctor‐diagnosed asthma and symptoms of obstructive airways disease was reported by children attending primary school in Oslo in 1993 than 12 years earlier. No increase was observed in the prevalence of other atopic diseases.

We examined how chronic respiratory symptoms, reported in a questionnaire, and results of skin prick tests and spirometry predicted variability in peak expiratory flow (PEF) among 6-12-yr-old children (n = 1,854). After characterization with skin tests and spirometry, children were followed for 2-3 mo during the winter of 1993-1994. Peak expiratory flow was measured daily in the morning and evenings. Children with asthmatic symptoms (wheeze and/or attacks of shortness of breath with wheeze in the past 12 mo and/or ever doctor diagnosed asthma) had a greater variation in PEF than children with dry nocturnal cough as their only chronic respiratory symptom. Similarly, doctor-diagnosed asthma was associated with a greater variation in PEF, also among children with asthmatic symptoms. Peak flow variability increased with an increasing number of symptoms reported in the questionnaire. Atopy, positive skin test reactions to house dust mite and cat and lowered level (as % of predicted) in FEV1 and in MMEF were also associated with an increased variation in PEF. All the differences were observed in both diurnal and day-to-day variation in PEF. In conclusion, chronic respiratory symptoms reported in a questionnaire, spirometric lung function and skin prick test results among asthmatic children predicted variation in PEF measured during a 2-3 mo follow-up. The difference in morning PEF coefficient of variation (CV) between children with asthmatic symptoms and children with cough only was somewhat bigger in girls than in boys. The effect of atopy on morning PEF CV was somewhat bigger in young than in older children.

Unilateral airway occlusion permits measurement of single lung function. Since the results suggest that the occluded lung influences the mobility of the contralateral hemithorax, we wanted to test this hypothesis.In eight healthy subjects, we measured, using computed tomography, lung parenchymal area and inner rib cage parasagittal and transverse diameters at three different levels and at maximal inspiration and expiration. These measurements were made without and during balloon occlusion of one mainstem bronchus at residual volume (RV) and at total lung capacity (TLC).Unilateral occlusion at RV reduced the ipsilateral diameters in maximal inspiration, but the increase during inspiration was still 39-50% of that without occlusion. The inspiratory increase in contralateral diameters was reduced to 64-80% of the increase without occlusion. Occlusion at TLC reduced the expiratory decrease in ipsilateral diameters to 37-57% of that without occlusion. The expiratory decrease on the contralateral side was reduced to 56-70% of that without occlusion. Due to accompanying mediastinal shifts the parenchymal areas of the occluded lung barely changed. In contrast, the contralateral area was 86-97% of that without occlusion.We conclude that the movement of the two hemithoraces are, at least partially, interdependent. The occluded hemithorax prevents full expansion/compression of the nonoccluded contralateral side, whilst its own mobility appears to be increased by the presence of this nonoccluded side. Potential negative effects are outweighed by the physiological benefit of the coupling, as this mechanism could secure ventilation to a chest half without own movement. Eur Respir J., 1996, 9, 140- In two previous studies on healthy subjects, we occluded one mainstem bronchus with an inflatable balloon and measured the function of the other single lung. When one lung was occluded at total lung capacity (TLC), the other lung could not empty properly [1]. When it was occluded at residual volume (RV), the other lung could not expand fully [2]. These results indicate that the two lungs cannot be at opposite extreme volumes at the same time. The mobility of the rib cage is one of the factors that determine maximal filling and emptying of the lungs [3,4]. When one lung is occluded at RV or TLC, the hemithorax on that side cannot expand or compress properly. We wondered if the reduced mobility on the occluded side also limited the movement of the nonoccluded hemithorax. If so, this could explain our physiological finding.The purpose of the present study was, therefore, to determine how occlusion of a single lung at RV and TLC affects the mobility of the chest wall, both on the occluded and the nonoccluded side. Subjects and methods SubjectsEight healthy volunteers, six females and two males, aged 19-44 yrs, were studied. They had no history of respiratory or cardiac disease or recent airway infection. Their ventilatory lung function was within normal limits as determined by dynamic spirometry on the day of investigation [5]...