Background: We investigated whether living in areas with higher air pollution levels increases the prevalence of positive skin reactivity in children and the possible synergic effect of air pollution exposure and atopy on respiratory disorders.
Methods: This cross-sectional study was conducted in an urban area, in an industrialized area, and in a rural control area in the Latium region of Italy. A total of 2226 subjects, aged 7 to 11 years, were studied.
Results: The prevalence of children with positive skin test results did not vary significantly over the areas (urban area = 21.0%, industrialized area = 22.0%, rural area = 20.2%). Children living in polluted areas experienced significantly more cough and phlegm (odds ratio [OR] = 1.5), rhinitis (OR = 1.7), pneumonia (OR = 1.7), and early respiratory infections (OR = 1.4) than control subjects. The pattern of the odds ratios for atopy and air pollution suggested that the two factors were probably additive in affecting asthma and early respiratory infections (synergy index [SI] = 1.04 and 1.27, respectively), whereas they seemed to act synergically in regard to cough and phlegm (SI = 1.59), rhinitis (SI = 3.01), and pneumonia (SI = 2.75).
Conclusion: Environmental air pollution seems not to increase the prevalence of atopic status; it seems, however, to enhance the development of clinical symptoms among already sensitized subjects.