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


METHODS
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 (microg/m(3)) 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 microg/m(3) 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.


CONCLUSIONS
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.
Arbex
Marcos Abdo
MA
Núcleo de Estudos em Epidemiologia Ambiental, Laboratório do Poluição Atmosférica Experimental, São Paulo, Brazil.
Martins
Lourdes Conceição
LC
de Oliveira
Regiani Carvalho
RC
Pereira
Luiz Alberto Amador
LA
Arbex
Flávio Ferlin
FF
Cançado
José Eduardo Delfini
JE
Saldiva
Paulo Hilário Nascimento
PH
Braga
Alfésio Luís Ferreira
AL
D000383:Agriculture; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D001249:Asthma / Q000209:etiology*; D018533:Biomass; D001938:Brazil; D004784:Environmental Monitoring / Q000379:methods; D019317:Evidence-Based Medicine; D006760:Hospitalization; D006801:Humans; D017745:Incineration; D016014:Linear Models; D009784:Occupational Diseases / Q000209:etiology*; D031786:Saccharum; D001335:Vehicle Emissions
D001335:Vehicle Emissions