This article is a commentary on a study published in the journal J. Occup. Environ. Med. 2002; 44(7):622-627. Its objective is to analyze the potential links between the effects of daily levels of air pollution (compounds: CO, NO₂, SO₂, PM10, and O3) and the number of emergency department admissions for respiratory failure (ICD-10: J40 to J47) among people aged 64 and older in the city of São Paulo, Brazil, during the period from 1996 to 1998. This study helps confirm the existence of a certain effect of air pollution on public health issues, and more specifically on the increase in severe cases of respiratory failure among older adults requiring hospitalization. (Objectives and conclusions of the authors).