Renzetti G, Silvestre G, D'Amario C, et al. Pediatrics. 2009;123(3):1051–1058
PURPOSE OF THE STUDY. To investigate whether relocating children with asthma from an environment of high pollution to one of low pollution has an effect on short-term airway inflammation.
STUDY POPULATION. This was a case study of 37 children, ≥7 years of age, with untreated, mild, persistent asthma who were recruited from an urban asthma clinic in Italy and followed at a rural school camp for 1 week. The children came from homes that had implemented dust mite precautions, and they stayed in a local hotel at the camp.
METHODS. Environmental measurements were collected from permanent or mobile air quality–monitoring stations (recording concentrations of benzene, particulate matter of ≤10 μm in diameter, ozone, nitrogen dioxide, and carbon monoxide), portable volumetric allergen samplers (recording levels of 23 pollen species), and local meteorological sources. Clinical measurements were collected on day 0 before relocating and on day 7 in the rural environment. Data collected included nasal eosinophils, fractional exhaled nitric oxide (FENO), peak expiratory flow (PEF), and urinary leukotriene E4 (LTE4) levels.
RESULTS. Temperature and atmospheric pressure were significantly lower (P < .0001 and P < .003, respectively) in the rural environment, whereas humidity and wind speed were similar. All pollutants were significantly lower in the rural environment, with the greatest difference seen in benzene (20-fold) and nitrogen dioxide (15-fold) concentrations (P < .0001). Only the Fagaceae pollen species, to which no child demonstrated sensitivity, was significantly higher in the rural environmental (P < .01). The children had positive skin-prick test results to dust mite (100%), Gramineae (43%), Oleaceae (30%), Urticaceae (19%), and Cupressaceae and Betulaceae (3%). There was an average fourfold decrease in nasal eosinophils (P < .002), a decrease in mean FENO (P < .028), and an increase in mean PEF. Urinary LTE4 changes were variable and not consistent among participants.
CONCLUSIONS. Removing children with allergic asthma from a highly polluted environment can rapidly reverse airway inflammation and improve airway function. Decreases in upper and lower airway inflammatory biomarkers (nasal eosinophils and FENO, respectively) and an increase in PEF could not be attributed to altered exposure to aeroallergens. Changes in urinary LTE4 levels were not seen; they may be slower to respond or may depend on other factors.
REVIEWERS COMMENTS. Many studies have demonstrated the negative effect of pollutants on asthma outcomes. Here, the authors attempted to mimic a real-life situation and showed that pollutant effects may be reversible in children. This study supports the theory that the increase in asthma seen in industrialized countries may be the result of crowded, polluted, urban environments. The rapidity of responses in these children has implications for cleanair policies. An important next step would be to examine long-term effects and to compare results with a control group.
- Copyright © 2009 by the American Academy of Pediatrics