Background: Epidemiological studies have provided strong evidence that fine particulate matter (PM2.5; aerodynamic diameter ≤ 2.5 μm) can exacerbate asthmatic symptoms in children. Pro-oxidant components of PM2.5 are capable of directly generating reactive oxygen species. Oxidative burden is used to describe the capacity of PM2.5 to generate reactive oxygen species in the lung.
Objective: In this study we investigated the association between airway inflammation in asthmatic children and oxidative burden of PM2.5 personal exposure.
Methods: Daily PM2.5 personal exposure samples (n = 249) of 62 asthmatic school-aged children in Montreal were collected over 10 consecutive days. The oxidative burden of PM2.5 samples was determined in vitro as the depletion of low-molecular-weight antioxidants (ascorbate and glutathione) from a synthetic model of the fluid lining the respiratory tract. Airway inflammation was measured daily as fractional exhaled nitric oxide (FeNO).
Results: A positive association was identified between FeNO and glutathione-related oxidative burden exposure in the previous 24 hr (6.0% increase per interquartile range change in glutathione). Glutathione-related oxidative burden was further found to be positively associated with FeNO over 1-day lag and 2-day lag periods. Results further demonstrate that corticosteroid use may reduce the FeNO response to elevated glutathione-related oxidative burden exposure (no use, 15.8%; irregular use, 3.8%), whereas mold (22.1%), dust (10.6%), or fur (13.1%) allergies may increase FeNO in children with versus children without these allergies (11.5%). No association was found between PM2.5 mass or ascorbate-related oxidative burden and FeNO levels.
Conclusions: Exposure to PM2.5 with elevated glutathione-related oxidative burden was associated with increased FeNO.
1Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA; 2Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada; 3Air Health Science Division, Health Canada, Ottawa, Ontario, Canada; 4Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada; 5Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia; 6Département de santé environnementale et de santé au travail, Université de Montréal, Montreal, Quebec, Canada; 7Institut National de Santé Publique du Québec, Montréal, Quebec, Canada; 8Department of Medicine, McGill University, Montreal, Quebec, Canada; 9Division of Clinical Epidemiology, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
Recommended Citation:
Caitlin L. Maikawa,1,2 Scott Weichenthal,et al. Particulate Oxidative Burden as a Predictor of Exhaled Nitric Oxide in Children with Asthma[J]. Environmental Health Perspectives,2016-01-01,Volume 124(Issue 10):1616