Gas cooking, respiratory health and white blood cell counts in children.

The use of gas stoves has been associated with respiratory symptoms of chronic airway inflammation and higher rates of respiratory infections. We used data from a 1992/93 survey of 2,198 East German school children (aged 5 to 14) to assess whether gas cooking increases respiratory symptoms and is associated with a chronic inflammatory process reflected by an increase in white blood cell (WBC) count in children who do not exhibit signs of an acute respiratory infection. We found increases for the respiratory symptoms 'cough without cold' [odds ratio (OR) = 1.68; 95% confidence interval (CI), 1.18-2.39], 'cough in the morning' (OR = 1.58; CI, 1.23-2.04) and 'cough during the day or at night' (OR = 1.42; CI, 1.13-1.78) in children living in homes with gas ranges, but lifetime prevalence of asthma, bronchitis, wheeze, and the prevalence of acute infections were not affected. Furthermore, we examined WBC levels in a subgroup of 1,134 children for whom blood samples were available and who did not suffer from an acute infection. We observed small increases in the risk of having WBC counts above the 75th or 90th percentile (8300 or 9800 cell counts per microliter) when children were exposed to gas cooking after adjustment for age, gender, and passive smoking (OR = 1.30; CI, 0.98-1.73, and OR = 1.38; CI, 0.91-2.10). The strongest effect estimates for chronic inflammation were found for those children likely to have been exposed at higher levels, that is when stoves had no fans, in smaller homes, and for children spending more time indoors.