Air pollution and hospitalization due to angina pectoris in Tehran, Iran: A time-series study

Background: Health effects of air pollution have been studied in many different parts of the world. Although a fairly large number of studies have explored the cardiovascular impacts of air pollution, because of its unique location we studied the association between air pollutants and hospital admissions due to angina pectoris in Tehran for the first time. Methods: This is a retrospective time-series study. The variables of the study include the levels of five air pollutants—nitrogen dioxide (NO 2), carbon monoxide (CO), ozone (O 3), sulfur dioxide (SO 2), and particulate matter