Asthma Symptoms, Lung Function, and Markers of Oxidative Stress and Inflammation in Children Exposed to Oil Refinery Pollution

Abstract

Objectives. Little is known about the effects of exposure to petroleum refinery emissions on respiratory health in children. We evaluated lung function and markers of inflammation and oxidative stress in children and adolescents with and without asthma or wheezing symptoms living in a petrochemical polluted area (Sarroch, Sardinia) versus a reference area (Burcei). Methods. Parents of 275/300 6- to 14-year-old children living in Sarroch and parents of 214/323 children living in Burcei answered a questionnaire on respiratory symptoms and risk factors. Measurements of forced expiratory volume after 1 second (FEV₁) and of forced expiratory flow rates at 25–75% of vital capacity (FEF_25–75) were available in 27 and 23 asthma/wheezing-positive subjects and in 7 and 54 asthma/wheezing-negative subjects in Sarroch and in Burcei, respectively; for fractional exhaled nitric oxide (FE_NO) corresponding figures were 27 and 24 and 8 and 55 in Sarroch and in Burcei, respectively. Malondialdehyde–deoxyguanosine (MDA–dG) adduct levels in nasal mucosa were measured in 12- to 14-year-old adolescents (8 and 14 asthma/wheezing-positive and 20 and 28 asthma/wheezing-negative subjects in Sarroch and in Burcei, respectively). Air pollutants were assessed during 3 weeks, starting 1 week before lung function, FE_NO, and MDA–dG measurements. Generalized linear models were used to estimate the effect of the area of residence adjusting for confounders. Results. Weekly average concentrations of sulfur dioxide were 6.9–61.6μg/m³ in Sarroch versus 0.3–7.6μg/m³ in the rural area of Burcei; of nitrogen dioxide, 5.2–28.7μg/m³ versus 1.7–5.3μg/m³; and of benzene, 1.8–9.0μg/m³ versus 1.3–1.5μg/m³, respectively. Children living in Sarroch versus children living in the reference area showed an increase in wheezing symptoms {adjusted prevalence ratio=1.70 [90% confidence interval (CI)=1.01; 2.86]}; a decrease in lung function [variation in FEV₁=−10.3% (90% CI=−15.0; −6.0%) and in FEF_25–75=−12.9% (90% CI=−20.7; −4.3%)]; an increase in bronchial inflammation [variation in FE_NO=+35% (90% CI=11.7; 80.1%)]; and an increase in MDA–dG adducts of +83% (90% CI=22.9; 174.1%). Conclusions. Data from this small study are consistent with the role of environmental pollutants on lung function and inflammation.

• air pollution
• biomarkers
• malondialdehyde
• nitric oxide
• wheezing

Acknowledgments

This study was financed by the Municipality of Sarroch; the Ministry of Welfare, project RF-SAR-2006-387926, and the Ministry of Education, University and Scientific Research, projects 2006131039 and 2007252HT8.