title: Ambient air pollution and apnea and bradycardia in high-risk infants on home monitors.
abstract: BACKGROUND
  Evidence suggests that increased ambient air pollution concentrations are associated with health effects, although relatively few studies have specifically examined infants.
  
  
  OBJECTIVE
  We examined associations of daily ambient air pollution concentrations with central apnea (prolonged pauses in breathing) and bradycardia (low heart rate) events among infants prescribed home cardiorespiratory monitors.
  
  
  METHODS
  The home monitors record the electrocardiogram, heart rate, and respiratory effort for detected apnea and bradycardia events in high-risk infants [primarily premature and low birth weight (LBW) infants]. From August 1998 through December 2002, 4,277 infants had 8,960 apnea event-days and 29,450 bradycardia event-days in > 179,000 days of follow-up. We assessed the occurrence of apnea and bradycardia events in relation to speciated particulate matter and gaseous air pollution levels using a 2-day average of air pollution (same day and previous day), adjusting for temporal trends, temperature, and infant age.
  
  
  RESULTS
  We observed associations between bradycardia and 8-hr maximum ozone [odds ratio (OR) = 1.049 per 25-ppb increase; 95% confidence interval (CI), 1.021-1.078] and 1-hr maximum nitrogen dioxide (OR =1.025 per 20-ppb increase; 95% CI, 1.000-1.050). The association with ozone was robust to different methods of control for time trend and specified correlation structure. In secondary analyses, associations of apnea and bradycardia with pollution were generally stronger in infants who were full term and of normal birth weight than in infants who were both premature and LBW.
  
  
  CONCLUSIONS
  These results suggest that higher air pollution concentrations may increase the occurrence of apnea and bradycardia in high-risk infants.
authors: Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA. jennifer.peel@colostate.edu
authors: Jennifer L
authors: JL
authors: Peel
authors: Mitchel
authors: M
authors: Klein
authors: W Dana
authors: WD
authors: Flanders
authors: James A
authors: JA
authors: Mulholland
authors: Gary
authors: G
authors: Freed
authors: Paige E
authors: PE
authors: Tolbert
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D001049:Apnea / Q000139:chemically induced* / Q000175:diagnosis; D001919:Bradycardia / Q000139:chemically induced* / Q000175:diagnosis; D016001:Confidence Intervals; D005260:Female; D005845:Georgia; D006699:Home Care Services; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000139:chemically induced* / Q000175:diagnosis; D016015:Logistic Models; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D016017:Odds Ratio; D018709:Statistics, Nonparametric
chemical_list: D000393:Air Pollutants