This article is a critical analysis of the following study: Aga E, Samoli E, Touloumi G, Anderson HR, Cadum E, Forsberg B, Goodman P, Goren A, Kotesovec F, Kriz B, Macarol-Hiti M, Medina S, Paldy A, Schindler C, Sunyer J, Tittanen P, Wojtyniak B, Zmirou D, Schwartz J, Katsouyanni K. Short-term effects of ambient particles on mortality in the elderly: results from 28 cities in the APHEA2 project. Eur Respir J Suppl. 2003 May;40:28s-33s. The objective of this study is to examine the temporal distribution of the effects of air pollution on short-term all-cause mortality (excluding accidents) and mortality from cardiovascular and respiratory causes, by exploring the particular sensitivity of individuals over 65 years of age. This study reaches the same conclusions as a series of other studies conducted in Philadelphia, São Paulo, Montreal, and the APHEA 2 study covering 29 European cities regarding the greater sensitivity of people over 65 to the effects of air pollution. The study by Filleul et al. covers a smaller population than the study by Schwartz (2000), which uses a similar methodology but yields convergent results. Exposure data are poorly documented; only the minimum, maximum, and average values are specified in the article. The main contribution of this study is to confirm, following Schwartz, that using a two-day latency period may underestimate the effects of air pollution on mortality and, consequently, that accounting for the distribution of effects across multiple latency periods provides a better estimate. (Excerpts from the article)