title: Acute effects of particulate matter and black carbon from seasonal fires on peak expiratory flow of schoolchildren in the Brazilian Amazon.
abstract: BACKGROUND
  Panel studies have shown adverse effects of air pollution from biomass burning on children's health. This study estimated the effect of current levels of outdoor air pollution in the Amazonian dry season on peak expiratory flow (PEF).
  
  
  METHODS
  A panel study with 234 schoolchildren from 6 to 15 years old living in the municipality of Tangará da Serra, Brazil was conducted. PEF was measured daily in the dry season in 2008. Mixed-effects models and unified modelling repeated for every child were applied. Time trends, temperature, humidity, and subject characteristics were regarded. Inhalable particulate matter (PM10), fine particulate matter (PM2.5), and black carbon (BC) effects were evaluated based on 24-hour exposure lagged by 1 to 5 days and the averages of 2 or 3 days. Polynomial distributed lag models (PDLM) were also applied.
  
  
  RESULTS
  The analyses revealed reductions in PEF for PM10 and PM2.5 increases of 10 µg/m(3) and 1 µg/m(3) for BC. For PM10, the reductions varied from 0.15 (confidence interval (CI)95%: -0.29; -0.01) to 0.25 l/min (CI95%: -0.40; -0.10). For PM2.5, they ranged from 0.46 (CI95%: -0.86 to -0.06) to 0.54 l/min (CI95%:-0.95; -0.14). As for BC, the reduction was approximately 1.40 l/min. In relation to PDLM, adverse effects were noticed in models based on the exposure on the current day through the previous 3 days (PDLM 0-3) and on the current day through the previous 5 days (PDLM 0-5), specially for PM10. For all children, for PDLM 0-5 the global effect was important for PM10, with PEF reduction of 0.31 l/min (CI95%: -0.56; -0.05). Also, reductions in lags 3 and 4 were observed. These associations were stronger for children between 6 and 8 years old.
  
  
  CONCLUSIONS
  Reductions in PEF were associated with air pollution, mainly for lagged exposures of 3 to 5 days and for younger children.
authors.affiliation: Department of Statistics, Fluminense Federal University, Niterói, Brazil.
authors.forename: Ludmilla da Silva Viana
authors.initials: Lda S
authors.lastname: Jacobson
authors.affiliation: National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: Sandra de Souza
authors.initials: Sde S
authors.lastname: Hacon
authors.affiliation: National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: Hermano Albuquerque
authors.initials: HA
authors.lastname: de Castro
authors.affiliation: Institute of Natural and Technological Science, Mato Grosso State University, Cáceres, Brazil.
authors.forename: Eliane
authors.initials: E
authors.lastname: Ignotti
authors.affiliation: Physics Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Artaxo
authors.affiliation: Department of Pathology, University of São Paulo, São Paulo, Brazil.
authors.forename: Paulo Hilário Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.affiliation: Department of Epidemiology, Rio de Janeiro State University, Rio de Janeiro, Brazil.
authors.forename: Antonio Carlos Monteiro Ponce
authors.initials: AC
authors.lastname: de Leon
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000633:toxicity*; D001938:Brazil; D002648:Child; D004784:Environmental Monitoring; D005390:Fires; D006801:Humans; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D012123:Pulmonary Ventilation / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter