Applying EPA’s instruction to calculate air quality index (AQI) in Tehran

Keywords: Particulate matter;, Particle;, Ozone ;, Nitrogen dioxide ;, AQHI


Introduction: This study aimed to calculate and evaluate air quality index (AQI) in Tehran according to the EPA’s instruction, and evaluate the obtained values.

Materials and methods: The study period included three years of 2013, 2015, and 2017 within the six-year period of 2013-2017. The concentrations of six studied pollutants were acquired from Department of Environment (DE) and Air Quality Control Company of Tehran (AQCC). EPA’s method was applied to calculate AQI values during the study period, selecting the highest AQI value among all of the pollutants and monitors.

Results: The three-year average of AQI was about 147. During all the three years, the air quality had never been in a “good” condition (AQI<50). About 92%, 91%, 87% of AQIs indicated the conditions unhealthy for sensitive groups (100<AQI<150) or unhealthy for all groups (150<AQI<200). PM2.5 accounted for most of the AQI values in Tehran, followed by NO2 and O3. Evaluating the histogram of AQI values indicated a strange form of distribution, showing a decline in the 100-150 range and a sudden increase just after AQIs higher than 150.

Conclusion: This study indicated that governmental organizations should follow EPA’s instruction for AQI calculations to avoid underestimation of air pollution, and broadcast accurate and reliable AQIs to public. To determine the reason for the abnormal distribution of AQI, further studies with longer study periods are required.


1. Walsh M. Mobile source related air pollution: effects on health and the environment. 2011:803-9.
2. Hadei M, Hashemi Nazari SS, Yarahmadi M, Kermani M, Farhadi M, Shahsavani A. Estimation of gender-specific
lung cancer deaths due to exposure to PM2.5 in 10 cities of Iran during 2013 - 2016: A modeling approach. International Journal of Cancer Management. 2017;10(8):13-21.
3. Hadei M, Hopke PK, Nazari SSH, Yarahmadi M, Shahsavani A, Alipour MR. Estimation of Mortality and Hospital Admissions Attributed to Criteria Air Pollutants in Tehran Metropolis, Iran (2013–2016). Aerosol Air Qual Res. 2017;17:2474-81.
4. Yarahmadi M, Hadei M, Nazari SSH, Conti GO, Alipour MR, Ferrante M, et al. Mortality assessment attributed to long-term exposure to fine particles in ambient air of the megacity of Tehran, Iran. Environmental Science and Pollution
Research. 2018;25(14):14254-62.
5. Soleimani Z, Boloorani AD, Khalifeh R, Teymouri P, Mesdaghinia A, Griffin DW. Air pollution and respiratory hospital admissions in Shiraz, Iran, 2009 to 2015. Atmos Environ. 2019.
6. Le Boennec R, Salladarré F. The impact of air pollution and noise on the real estate market. The case of the 2013 European Green Capital: Nantes, France. Ecol Econ. 2017;138:82-9.
7. Kim Y, Knowles S, Manley J, Radoias V. Long-run health consequences of air pollution: Evidence from Indonesia’s forest fires of 1997. Econ Hum Biol. 2017;26:186-98.
8. Lim CC, Hayes RB, Ahn J, Shao Y, Silverman DT, Jones RR, et al. Association between long-term exposure to ambient air pollution and diabetes mortality in the US. Environ Res. 2018;165:330-6.
9. Donath MY, Shoelson SE. Type 2 diabetes as an inflammatory disease. Nature Reviews Immunology. 2011;11(2):98.
10. Osborn O, Olefsky JM. The cellular and signaling networks linking the immune system and metabolism in disease. Nat Med. 2012;18(3):363.
11. McConnell R, Islam T, Shankardass K, Jerrett M, Lurmann F, Gilliland F, et al. Childhood incident asthma and trafficrelated air pollution at home and school. Environ Health Perspect. 2010;118(7):1021-6.
12. Carlsten C, Dybuncio A, Becker A, Chan-Yeung M, Brauer M. Traffic-related air pollution and incident asthma in a high-risk birth cohort. Occup Environ Med. 2011;68(4):291-5.
13. Yorifuji T, Naruse H, Kashima S, Takao S, Murakoshi T, Doi H, et al. Residential proximity to major roads and adverse birth outcomes: a hospital-based study. Environ Health. 2013;12(1):34.
14. Seifi M, Niazi S, Johnson G, Nodehi V, Yunesian M. Exposure to ambient air pollution and risk of childhood cancers:
A population-based study in Tehran, Iran. Science of The Total Environment. 2019;646:105-10.
15. EPA. Air Quality Index a Guide to Air Quality and Your Health. 2014.
16. EPA. The National Ambient Air Quality Standards for Particle Pollution. In: EPA, editor. 2012.
17. Hopke PK, Hashemi Nazari SS, Hadei M, Yarahmadi M, Kermani M, Yarahmadi E, et al. Spatial and Temporal
Trends of Short-Term Health Impacts of PM2.5 in Iranian Cities; a Modelling Approach (2013-2016). Aerosol Air Qual Res. 2018.
18. Hadei M, Hopke PK, Shahsavani A, Moradi M, Yarahmadi M, Emam B, et al. Indoor concentrations of VOCs in beauty
salons; association with cosmetic practices and health risk assessment. J Occup Med Toxicol. 2018;13(1):30.
19. Hadei M, Hopke PK, Rafiee M, Rastkari N, Yarahmadi M, Kermani M, et al. Indoor and outdoor concentrations of
BTEX and formaldehyde in Tehran, Iran: effects of building characteristics and health risk assessment. Environmental Science and Pollution Research. 2018;25(27):27423-37.
20. Bakhtiari R, Hadei M, Hopke PK, Shahsavani A, Rastkari N, Kermani M, et al. Investigation of in-cabin volatile
organic compounds (VOCs) in taxis; influence of vehicle’s age, model, fuel, and refueling. Environ Pollut. 2018;237:348-55.
21. Khajavi A, Khalili D, Azizi F, Hadaegh F. Impact of temperature and air pollution on cardiovascular disease and death in Iran: A 15-year follow-up of Tehran Lipid and Glucose Study. Sci Total Environ. 2019;661:243-50.
22. Mohseni Bandpai A, Yaghoubi M, Hadei M, Salesi M, Shahsavani A. Concentrations of Criteria Air Pollutants and BTEX in Mehrabad International Airport. J-Mazand- Univ-Med-Sci. 2018;28(160):76-87.
23. Hadei M, Shahsavani A, Kermani M, Emam B, Yarahmadi M, Bakhtiari R. Traffic-related concentrations of BTEX,
formaldehyde and acetaldehyde in Tehran; concentrations and spatial variability. Journal of Air Pollution and Health.
24. Hadei M, Nazari SSH, Yarahmadi E, Kermani M, Yarahmadi M, Naghdali Z, et al. Estimation of lung cancer mortality attributed to lung-term exposure to PM2.5 in 15 Iranian cities during 2015-2016; an AIRQ+ modeling. Journal of Air Pollution and Health. 2017;2(1):19-26.
25. Hadei M, Nazari SSH, Eslami A, Khosravi A, Yarahmadi M, Naghdali Z, et al. Distribution and number of ischemic
heart desease (IHD) and stroke deaths due to chronic exposure to PM2.5 in 10 cities of Iran (2013-2015); An AIRQ+ modelling. Journal of Air Pollution and Health. 2018;2(3):129-36.
26. Moradi M, Hopke P, Hadei M, Eslami A, Rastkari N, Naghdali Z, et al. Exposure to BTEX in beauty salons:
biomonitoring, urinary excretion, clinical symptoms, and health risk assessments. 2019;191(5):286.
27. Yaghmaien K, Hadei M, Hopke P, Gharibzadeh S, Kermani M, Yarahmadi M, et al. Comparative health risk assessment
of BTEX exposures from landfills, composting units, and leachate treatment plants. 2019:1-9.
How to Cite
Yousefi S, Shahsavani A, Hadei M. Applying EPA’s instruction to calculate air quality index (AQI) in Tehran. japh. 4(2):81-86.
Original Research