The Relation between Air Pollution and Cardiorespiratory Admissions in Tehran


1 Department of Pediatrics,

2 Chronic Respiratory Disease Research Center, NRITLD, Shahid Beheshti University , MC, Tehran-Iran,

3 Long Island University ,Individual Researcher , Long Island-USA.,

4 Tobacco Prevention and Control Research Center

5 Department of Pulmonary Medicine, NRITLD, Shahid Beheshti University M.C, Tehran - Iran.


Background: 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 SO2 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? Materials and Methods: During a 12-month period (from April 2004 to March 2005), the concentrations of 5 air pollutants (CO , NO2, O3, SO2 and PM10 ) 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). Results: 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≤100 and standard conditions. 34.7% of measurements were at “unhealthy” levels with PSI= 101- 200. 13.2% of measurements were in “very- unhealthy” conditions with PSI= 201- 300. and 0.2% of measurements were recorded in one station and in a “hazardous” condition with PSI>300. For ozone (O3), all measurements were at standard conditions, PSI≤100. The concentration of SO2 on most of the days was at “standard” condition. Only 6% of the measurements (2 samples) were at “unhealthy” or “hazardous” levels, PSI=101-200. Regarding particulate matter (PM10), all samples were evaluated as 88.7% of the measurements were at standard conditions with PSI≤100 while 11.3% of the measurements showed “unhealthy” condition with PSI=101-200. Conclusion: It was observed that carbon monoxide and particulate matter were the main air pollutants in Tehran that had levels higher than standard values. The results showed that the number of admissions because of cardiopulmonary complaint was positively correlated with concentration of all studied pollutants except for ozone (O3). The main source for these air pollutants was motor vehicles. It is notable that atmospheric condition along with geographical situation of Tehran help augment the air pollution in this city. Thus, in addition to encouraging the use of CNG as the combustion material for cars, buses and minibuses, other extensive measures should be implemented in this regard. (Tanaffos 2009; 8(1): 35-40)