title: Trace metal exposure is associated with increased exhaled nitric oxide in asthmatic children.
abstract: Children with asthma experience increased susceptibility to airborne pollutants. Exposure to traffic and industrial activity have been positively associated with exacerbation of symptoms as well as emergency room visits and hospitalisations. The effect of trace metals contained in fine particulate matter (aerodynamic diameter 2.5 μm and lower, PM2.5) on acute health effects amongst asthmatic children has not been well investigated. The objective of this panel study in asthmatic children was to determine the association between personal daily exposure to ambient trace metals and airway inflammation, as measured by fractional exhaled nitric oxide (FeNO).
  
  
  
  Daily concentrations of trace metals contained on PM2.5 were determined from personal samples (n = 217) collected from 70 asthmatic school aged children in Montreal, Canada, over ten consecutive days. FeNO was measured daily using standard techniques.
  
  
  
  A positive association was found between FeNO and children's exposure to an indicator of vehicular non-tailpipe emissions (8.9 % increase for an increase in the interquartile range (IQR) in barium, 95 % confidence interval (CI): 2.8, 15.4) as well as exposure to an indicator of industrial emissions (7.6 % increase per IQR increase in vanadium, 95 % CI: 0.1, 15.8). Elevated FeNO was also suggested for other metals on the day after the exposure: 10.3 % increase per IQR increase in aluminium (95 % CI: 4.2, 16.6) and 7.5 % increase per IQR increase in iron (95 % CI: 1.5, 13.9) at a 1-day lag period.
  
  
  
  Exposures to ambient PM2.5 containing trace metals that are markers of traffic and industrial-derived emissions were associated in asthmatic children with an enhanced FeNO response.
authors: Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, 149D Goessman Lab, 686 North Pleasant Street, Amherst, MA, 01003, USA. kpollitt@umass.edu.
authors: Krystal J
authors: KJ
authors: Godri Pollitt
authors: Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, 149D Goessman Lab, 686 North Pleasant Street, Amherst, MA, 01003, USA.
authors: Caitlin L
authors: CL
authors: Maikawa
authors: Health Canada, Air Health Science Division, Ottawa, ON, Canada.|Menzies Institute for Medical Research, University of Tasmania, Private Bag 23, Hobart, TAS, 7000, Australia.
authors: Amanda J
authors: AJ
authors: Wheeler
authors: Health Canada, Air Health Science Division, Ottawa, ON, Canada.|Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada.
authors: Scott
authors: S
authors: Weichenthal
authors: Health Canada, Air Health Science Division, Ottawa, ON, Canada.
authors: Nina A
authors: NA
authors: Dobbin
authors: Health Canada, Population Studies Division, Ottawa, ON, Canada.
authors: Ling
authors: L
authors: Liu
authors: Department of Medicine, Division of Clinical Epidemiology, Research Institute, McGill University Health Centre, McGill University, Montreal, Canada.
authors: Mark S
authors: MS
authors: Goldberg
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000032:analysis*; D001151:Arsenic / Q000032:analysis*; D001249:Asthma / Q000378:metabolism*; D002648:Child; D004784:Environmental Monitoring; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals / Q000032:analysis*; D009569:Nitric Oxide / Q000378:metabolism*; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D008670:Metals; D052638:Particulate Matter; D009569:Nitric Oxide; D001151:Arsenic
keywords: Air pollution; Asthma; Children; Exhaled nitric oxide; Exposure; Lung inflammation; Panel study; Particulate matter; Petroleum refinery; Trace metals; Urban environment