Abstract

The authors investigated the risk of wheezing illnesses in relation to contemporaneous pollutant exposures (gas cooking, heating, and smoking) in childhood and adolescence in a cohort of 2,289 United Kingdom subjects. Data from two questionnaires assessing wheezing at ages 7-8 and 15-17 years and one questionnaire on current and past pollutant exposures at age 16-18 years were studied (1987-1996). The 1,868 subjects returning all three questionnaires were divided into three groups representing childhood (10.5%), adolescent (10.9%), and persistent (i.e., both; 16.3%) wheezing and compared with 1,165 controls (62.4%) without wheezing. The estimated risks of childhood wheezing were increased by exposure to any gas in childhood (odds ratio (OR) = 1.47, 95% confidence interval (CI): 1.05, 2.04) and exposure to a gas hob in childhood (OR = 1.56, 95% CI: 1.13, 2.16) and were increased further in those persistently exposed. Risk of persistent wheezing in adolescence was paradoxically reduced by exposure to a gas hob (OR = 0.67, 95% CI: 0.50, 0.91), possibly because of selection avoidance. Contemporaneous exposure to combined smoking by both parents was associated with wheezing in all groups (odds ratios ranged from 1.62 (95% CI: 1.06, 2.46) to 1.93 (95% CI: 1.10, 3.38)). Maternal smoking alone was associated with persistent wheezing and with both childhood (OR = 1.90, 95% CI: 1.06, 3.39) and persistent (OR = 2.18, 95% CI: 1.15, 4.14) wheezing if smoking occurred throughout childhood and adolescence. The authors conclude that exposures to gas cooking and smoking in childhood and adolescence increase the overall risk of wheezing.