Study Designs in Air Pollution Epidemiology

London fog obviously revealed the role of air pollution in increasing mortality and morbidity rates associated with this phenomenon but several studies in the 70’s and 80’s couldn’t establish sufficient link between air pollution and death. In the 1990’s, time series studies conducted in a different locations, showed that air pollution levels, even at lower concentrations, were associated with increased rates of morbidity and mortality in several cities in all over the world. Since several studies have been designed for investigating the association between air pollution and health outcomes in recent years with controversial conclusions, this article reviews the latest studies in this field. We also will mention main strengths and weaknesses of epidemiological designs including time-series, case-crossover, cross sectional, panel and cohort studies in indoor and outdoor air pollution epidemiology.