title: An approach to using heart rate monitoring to estimate the ventilation and load of air pollution exposure.
abstract: BACKGROUND
  The effects of air pollution on health are associated with the amount of pollutants inhaled which depends on the environmental concentration and the inhaled air volume. It has not been clear whether statistical models of the relationship between heart rate and ventilation obtained using laboratory cardiopulmonary exercise test (CPET) can be applied to an external group to estimate ventilation.
  
  
  OBJECTIVE
  To develop and evaluate a model to estimate respiratory ventilation based on heart rate for inhaled load of pollutant assessment in field studies.
  
  
  METHODS
  Sixty non-smoking men; 43 public street workers (public street group) and 17 employees of the Forest Institute (park group) performed a maximum cardiopulmonary exercise test (CPET). Regression equation models were constructed with the heart rate and natural logarithmic of minute ventilation data obtained on CPET. Ten individuals were chosen randomly (public street group) and were used for external validation of the models (test group). All subjects also underwent heart rate register, and particulate matter (PM2.5) monitoring for a 24-hour period.
  
  
  RESULTS
  For the public street group, the median difference between estimated and observed data was 0.5 (CI 95% -0.2 to 1.4) l/min and for the park group was 0.2 (CI 95% -0.2 to 1.2) l/min. In the test group, estimated values were smaller than the ones observed in the CPET, with a median difference of -2.4 (CI 95% -4.2 to -1.8) l/min. The mixed model estimated values suggest that this model is suitable for situations in which heart rate is around 120-140bpm.
  
  
  CONCLUSIONS
  The mixed effect model is suitable for ventilation estimate, with good accuracy when applied to homogeneous groups, suggesting that, in this case, the model could be used in field studies to estimate ventilation. A small but significant difference in the median of external validation estimates was observed, suggesting that the applicability of the model to external groups needs further evaluation.
authors: Pulmonary Division, Heart Institute (Incor), Hospital das Clínicas, Medicine School, University of São Paulo, Brazil. Electronic address: izabela@usp.br.
authors: Izabela Campos
authors: IC
authors: Cozza
authors: Epidemiology Department, Public Health School, University of São Paulo, Brazil.
authors: Dirce Maria Trevisan
authors: DM
authors: Zanetta
authors: Pulmonary Division, Heart Institute (Incor), Hospital das Clínicas, Medicine School, University of São Paulo, Brazil.
authors: Frederico Leon Arrabal
authors: FL
authors: Fernandes
authors: Science and Technology Institute, UNIFESP, São José dos Campos, SP, Brazil.
authors: Francisco Marcelo Monteiro
authors: FM
authors: da Rocha
authors: Experimental Laboratory of Atmospheric Pollution, Pathology Department, Medicine School, University of São Paulo, Brazil.
authors: Paulo Afonso
authors: PA
authors: de Andre
authors: Clinical Medicine Department, Medicine School, University of São Paulo, Brazil.
authors: Maria Lúcia Bueno
authors: ML
authors: Garcia
authors: Pulmonary Division, Heart Institute (Incor), Hospital das Clínicas, Medicine School, University of São Paulo, Brazil.
authors: Renato Batista
authors: RB
authors: Paceli
authors: Pulmonary Division, Heart Institute (Incor), Hospital das Clínicas, Medicine School, University of São Paulo, Brazil.
authors: Gustavo Faibischew
authors: GF
authors: Prado
authors: Pulmonary Division, Heart Institute (Incor), Hospital das Clínicas, Medicine School, University of São Paulo, Brazil.
authors: Mario
authors: M
authors: Terra-Filho
authors: Pathology Department Professor, Medicine School, University of São Paulo, Brazil.
authors: Paulo Hilário
authors: PH
authors: do Nascimento Saldiva
authors: Pulmonary Division, Heart Institute (Incor), Hospital das Clínicas, Medicine School, University of São Paulo, Brazil.
authors: Ubiratan
authors: U
authors: de Paula Santos
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000706:statistics & numerical data*; D002318:Cardiovascular Diseases; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D012119:Respiration
chemical_list: D000393:Air Pollutants
keywords: Air pollution; Heart rate; Inhaled load estimate; Personal exposure; Ventilation