The French data primarily used to date to measure the short-term effects of air pollution on human health have been mortality or hospital admission data. Another health indicator, represented by medication sales, has recently been proposed and used to measure the effects of air pollution. Time series of drug sales were compiled from an epidemiological surveillance network established in 1993 at the initiative of pharmacists and the city of Le Havre. This network, comprising some forty pharmacists, made it possible to study the relationship between air pollution and sales of respiratory medications. This study examines the possibility of developing a health indicator using data provided by the Regional Union of Health Insurance Funds (URCAM), which could be used to assess the short-term effects of air pollution on human health. (adapted from the text)