title: Increase of exhaled nitric oxide in children exposed to low levels of ambient ozone.
abstract: Ozone (O3) is known to induce lung function impairment and airways inflammation during episodes of photochemical smog. The aim of the present study was to assess the inflammatory effect of ambient O3 in healthy children using nitric oxide in exhaled air (eNO) as a noninvasive test. The study was performed on 6 groups of children (n = 11-15), aged 6.5 to 15 yr, who attended summer camps in rural areas of the south of Belgium in 2002. Ambient O3 concentrations continuously monitored in the camps ranged from 48 to 221 microg/m3 (1-h maximal concentration). Children remained outdoors during the experimental days, doing various recreational activities but no sports. Lung function tests (forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) and eNO were measured twice in each child in the morning and in the evening. While lung function tests did not show any consistent pattern of decrease at these O3 levels, a highly significant increase in eNO was found in all subjects from an ambient 1-h O3 level of 167 microg/m3. A multivariate analysis did not reveal any influence of age, gender, height, weight, and body mass index (BMI) of the children. The threshold for this O3-induced increase in eNO estimated benchmark dose analysis was 135 microg/m3 for 1-h exposure and 110 microg/m3 for 8-h exposure. These observations suggest that ambient ozone produces early inflammatory changes in the airways of children at levels slightly below current air quality standards.
authors: Industrial Toxicology Unit, Faculty of Medicine, Catholic University of Louvain, Brussels, Belgium. marc.nickmilder@toxi.ucl.ac.be
authors: Marc
authors: M
authors: Nickmilder
authors: Claire
authors: C
authors: de Burbure
authors: Sylviane
authors: S
authors: Carbonnelle
authors: Carbonnelle
authors: C
authors: Sylviane
authors: Xavier
authors: X
authors: Dumont
authors: Dumont
authors: D
authors: Xavier
authors: Alfred
authors: A
authors: Bernard
authors: Bernard
authors: B
authors: Alfred
authors: Alain
authors: A
authors: Derouane
authors: Derouane
authors: D
authors: Alain
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution / Q000009:adverse effects; D001530:Belgium; D002648:Child; D002940:Circadian Rhythm; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000139:chemically induced* / Q000175:diagnosis*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D010126:Ozone / Q000009:adverse effects*; D012129:Respiratory Function Tests; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D009569:Nitric Oxide; D010126:Ozone