ABSTRACT
Air pollution is a major horror in many cities in Iran especially in Tehran. The cost of traffic congestion in the capital is put at two billion hours of time wasted each year. Tehran has also recorded SO[2] levels four times the standard prescribed by the World Health Organization. Tehran is the capital of the Islamic Republic of Iran with almost 11 million inhabitants [one sixth of the country's population], and is the most densely populated city of the country. The purpose of this research was to investigate the effects of air pollution on cardiorespiratory system. We assessed the relationship between the levels of air pollutants and emergency visits for asthma and cardiovascular diseases in Tehran, Iran. Two research questions investigated in this study were as follows: a] Which criteria elements of hazardous toxic air pollution were associated most strongly with the level of hospital admissions for cardiorespiratory conditions? b] What proportion of the variation in hospital admissions for cardiorespiratory conditions was explained by variations in levels of air pollution? During a 12-month period [from April 2004 to March 2005], the concentrations of 5 air pollutants [CO, NO[2], O[3], SO[2] and PM[10]] were measured in four stations located in north, west, south and central part of Tehran. The level of air pollution was calculated according to PSI [Pollution Standard Index]. Based on the results obtained during the study period, concentration of CO was reported as "above standard" on most of the days, leading to an "unhealthy" situation. 51.9% of measurements were made at PSI 300. For ozone [O[3]], all measurements were at standard conditions, PSI