title: Impaired lung function in individuals chronically exposed to biomass combustion.
abstract: BACKGROUND
  The use of biomass for cooking and heating is considered an important factor associated with respiratory diseases. However, few studies evaluate the amount of particulate matter less than 2.5 μm in diameter (PM2.5), symptoms and lung function in the same population.
  
  
  OBJECTIVE
  To evaluate the respiratory effects of biomass combustion and compare the results with those of individuals from the same community in Brazil using liquefied petroleum gas (Gas).
  
  
  METHODS
  1402 individuals in 260 residences were divided into three groups according to exposure (Gas, Indoor-Biomass, Outside-Biomass). Respiratory symptoms were assessed using questionnaires. Reflectance of paper filters was used to assess particulate matter exposure. In 48 residences the amount of PM2.5 was also quantified. Pulmonary function tests were performed in 120 individuals.
  
  
  RESULTS
  Reflectance index correlated directly with PM2.5 (r=0.92) and was used to estimate exposure (ePM2.5). There was a significant increase in ePM2.5 in Indoor-Biomass and Outside-Biomass, compared to Gas. There was a significantly increased odds ratio (OR) for cough, wheezing and dyspnea in adults exposed to Indoor-Biomass (OR=2.93, 2.33, 2.59, respectively) and Outside-Biomass (OR=1.78, 1.78, 1.80, respectively) compared to Gas. Pulmonary function tests revealed both Non-Smoker-Biomass and Smoker-Gas individuals to have decreased %predicted-forced expiratory volume in the first second (FEV1) and FEV1/forced vital capacity (FVC) as compared to Non-Smoker-Gas. Pulmonary function tests data was inversely correlated with duration and ePM2.5. The prevalence of airway obstruction was 20% in both Non-Smoker-Biomass and Smoker-Gas subjects.
  
  
  CONCLUSIONS
  Chronic exposure to biomass combustion is associated with increased prevalence of respiratory symptoms, reduced lung function and development of chronic obstructive pulmonary disease. These effects are associated with the duration and magnitude of exposure and are exacerbated by tobacco smoke.
authors.affiliation: Department of Pathology, University of Sao Paulo School of Medicine, Sao Paulo, Brazil. burns@usp.br
authors.forename: Luiz Fernando Ferraz
authors.initials: LF
authors.lastname: da Silva
authors.forename: Silvia Regina Dias Médici
authors.initials: SR
authors.lastname: Saldiva
authors.forename: Paulo Hilário Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Marisa
authors.initials: M
authors.lastname: Dolhnikoff
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D056804:Biofuels; D018533:Biomass; D001938:Brazil; D003296:Cooking / Q000379:methods*; D003371:Cough / Q000139:chemically induced; D004417:Dyspnea / Q000139:chemically induced; D006801:Humans; D008875:Middle Aged; D052638:Particulate Matter / Q000633:toxicity*; D012120:Respiration Disorders / Q000139:chemically induced*; D012129:Respiratory Function Tests; D012135:Respiratory Sounds / Q000187:drug effects; D012424:Rural Population; D014505:Urban Population; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D056804:Biofuels; D052638:Particulate Matter