J Epidemiol Community Health 61:395-400 doi:10.1136/jech.2005.044743
  • Evidence based public health policy and practice

Air pollution from biomass burning and asthma hospital admissions in a sugar cane plantation area in Brazil

  1. Marcos Abdo Arbex1,2,
  2. Lourdes Conceição Martins1,5,
  3. Regiani Carvalho de Oliveira1,
  4. Luiz Alberto Amador Pereira1,3,
  5. Flávio Ferlin Arbex2,
  6. José Eduardo Delfini Cançado1,
  7. Paulo Hilário Nascimento Saldiva1,
  8. Alfésio Luís Ferreira Braga1,4
  1. 1Núcleo de Estudos em Epidemiologia Ambiental, Laboratório de Poluição Atmosférica Experimental, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
  2. 2Grupo de Fisiopatologia Respiratória e Poluição Ambiental, Escola Paulista de Medicina da Universidade Federal de São Paulo, São Paulo, Brazil
  3. 3Programa de Pós-graduação em Saúde Coletiva, Universidade Católica de Santos, Santos, São Paulo, Brazil
  4. 4Programa de Pediatria Ambiental, Faculdade de Medicina da Universidade de Santo Amaro, São Paulo, São Paulo, Brazil
  5. 5Departamento de Saúde da Coletividade, Faculdade de Medicina do ABC, Santo André, São Paulo, Brazil
  1. Correspondence to:
 Professor Alfésio L F Braga
 Rua Francisco Octávio Pacca, 180, 4 Andar, Grajaú, CEP 04822-030, São Paulo, SP, Brazil; abraga{at}
  • Accepted 21 August 2006


Objective: To evaluate the association between the total suspended particles (TSPs) generated from preharvest sugar cane burning and hospital admission due to asthma (asthma hospital admissions) in the city of Araraquara.

Design: An ecological time-series study. Total daily records of asthma hospital admissions (ICD 10th J15) were obtained from one of the main hospitals in Araraquara, São Paulo State, Brazil, from 23 March 2003 to 27 July 2004. The daily concentration of TSP (μg/m3) was obtained using Handi-vol equipment (Energética, Brazil) placed in downtown Araraquara. The local airport provided the daily mean figures of temperature and humidity. The daily number of asthma hospital admissions was considered as the dependent variable in Poisson’s regression models and the daily concentration of TSP was considered the independent variable. The generalised linear model with natural cubic spline was adopted to control for long-time trend. Linear terms were used for weather variables.

Results: TSP had an acute effect on asthma admissions, starting 1 day after TSP concentrations increased and remaining almost unchanged for the next four days. A 10 μg/m3 increase in the 5-day moving average (lag1–5) of TSP concentrations was associated with an increase of 11.6% (95% CI 5.4 to 17.7) in asthma hospital admissions.

Conclusion: Increases in TSP concentrations were definitely associated with asthma hospital admissions in Araraquara and, despite using sugar cane alcohol to reduce air pollution from automotive sources in large Brazilian urban centres, the cities where sugar cane is harvested pay a high toll in terms of public health.


  • Competing interests: None.

  • This study was partly presented at the ATS International Conference, held in San Diego, California, USA in 2005.