Spatiotemporal trends of ambient air CO in Urmia city
Abstract
Introduction: This descriptive-ecological study investigated the seasonal, diurnal, and spatial variations of Carbon monoxide (CO) concentration in Urmia's (Northwest of Iran) ambient air over a six-month period, spanning Winter and Spring.
Materials and methods: Sampling was conducted at 20 stations selected from various urban locations. At each station, a portable environmental gas analyzer was used to measure CO concentration during both morning and evening peak traffic hours.
Results: The results revealed a significant seasonal and diurnal pattern. The highest CO means were observed in the cold months (January and February), peaking at an average of 6.19 ppm in January evenings. This increase is strongly linked to temperature inversion and heightened heating system usage. Statistical analysis confirmed a highly significant difference (P<0.001) in CO means across months and between morning and evening hours, with concentrations being significantly higher in the evening. Although monthly averages are generally below the 8-h national standard (9 ppm), their proximity to the limit and the registration of high peaks (up to 15.10 ppm) indicate a potential health risk during winter. Spatially, zoning maps showed the central, high-traffic area acts as the main pollution hotspot.
Conclusion: The study highlights that even short-term peak CO exposure can be significant, potentially causing headache and behavioral effects. Additionally, the river and surrounding open spaces help reduce pollution, emphasizing the need for integrated air quality management strategies that account for both seasonal and diurnal variations. These findings underscore the critical need for integrated management strategies sensitive to both the time of day and the season.
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19. Hajizadeh Y, Jafari N, Fanaei F, Ghanbari R, Mohammadi A, Behnami A, et al. Spatial patterns and temporal variations of traffic-related air pollutants and estimating its health effects in Isfahan city, Iran. Journal of Environmental Health Science and Engineering. 2021;19(1):781-91.
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22. Ayremloo P, Hosseinpour S, Fouladi-Fard R, Mohammadi A. Spatial analysis and health implications of micro rubber and vanadium in urban street dust in Northwest of Iran. Scientific Reports. 2025;15(1):37553.
23. Hosseinpoor S, Ebrahimi Gangchin L, Mirzazadeh Z, Nuraldin Chaman A, Mohammadi A. Influence of COVID-19 lockdowns on NO2 levels in Urmia city: a comparative analysis between 2018 and 2020. Health Science Monitor. 2024;3(3):216-25.
24. Jang DH, Kelly M, Hardy K, Lambert DS, Shofer FS, Eckmann DM. A preliminary study in the alterations of mitochondrial respiration in patients with carbon monoxide poisoning measured in blood cells. Clinical toxicology. 2017;55(6):579-84.
25. Semmens EO, Leary CS, West MR, Noonan CW, Navarro KM, Domitrovich JW. Carbon monoxide exposures in wildland firefighters in the United States and targets for exposure reduction. Journal of exposure science & environmental epidemiology. 2021;31(5):923-9.
26. Rahnama MR, Abkooh SS. Prediction of CO pollutant in Mashhad metropolis, Iran: Using multiple linear regression. The Geographical Journal. 2023;189(4):715-28.
27. Arab N, Mirkarimi SH. Studying nitrogen pollutant, mono dioxide carbon and dioxide nitrogen in Aghdasiyeh station during 2012 in Tehran. Human & Environment. 2015;13(2):35-43.
28. Aghdasi H, Aali R, Mansouri N, Amini H. Long-term spatial and temporal variability of ambient carbon monoxide in Urmia, Iran. Journal of Advances in Environmental Health Research. 2017;5(2):78-84.
29. Fazlzadeh M, Rostami R, Hazrati S. Concentrations of carbon monoxide in outdoor and indoor air of residential buildings in Ardabil. Journal of Sabzevar University of Medical Sciences. 2016;23(1):161-8.
30. Sari MF, Tasdemir Y, Esen F. Major air pollutants in Bursa, Turkey: their levels, temporal changes, interactions, and sources. Environmental Forensics. 2019;20(2):182-95.
31. Lin YC, Lan YY, Tsuang B-J, Engling G. Long-term spatial distributions and trends of ambient CO concentrations in the central Taiwan Basin. Atmospheric Environment. 2008;42(18):4320-31.
32. Xie Y, Han H, Liu J. Spatial and seasonal variations and trends in carbon monoxide over China during 2013–2022. Atmospheric Environment. 2025;350:121163.
33. Yoo J-M, Jeong M-J, Kim D, Stockwell WR, Yang J-H, Shin H-W, et al. Spatiotemporal variations of air pollutants (O3, NO2, SO2, CO, PM10, and VOCs) with land-use types. Atmospheric Chemistry and Physics. 2015;15(18):10857-85.
2. Baklanov A, Cárdenas B, Lee T-c, Leroyer S, Masson V, Molina LT, et al. Integrated urban services: Experience from four cities on different continents. Urban Climate. 2020;32:100610.
3. Roy R, D’Angiulli A. Air pollution and neurological diseases, current state highlights. Frontiers in neuroscience. 2024;18:1351721.
4. Sun Z, Zhu D. Exposure to outdoor air pollution and its human health outcomes: A scoping review. PloS one. 2019;14(5):e0216550.
5. Frizziero L, Galiè G, Leon-Cardenas C, De Santis M, Losito MS, Tomaiuolo A. Design of a concept vehicle for future-oriented urban mobility using design-driven methodologies. Heliyon. 2023;9(3).
6. Bhuda M, Wichmann J, Shirinde J. Association between outdoor and indoor air pollution sources and atopic eczema among preschool children in South Africa. International Journal of Environmental Research and Public Health. 2024;21(3):326.
7. Flachsbart PG. Human exposure to carbon monoxide from mobile sources. Chemosphere-Global Change Science. 1999;1(1-3):301-29.
8. Nassri M, Barari P, Khanizadeh M, Faridi S, Shamsipour M, Naddafi K, Niazi S, Hassanvand MS. The influence of N95 and surgical masks on carbon dioxide levels: A comprehensive systematic review and meta-analysis. Heliyon. 2024 Aug 30;10(16).
9. Alses M, Alzeer S. Reteracted: Evaluation of some biological parameters of gasoline station attendants in Damascus, Syria. Heliyon. 2021;7(5).
10. Kermani M, Dowlati M, Fallah Jokandan S, Aghaei M, Bahrami Asl F, Karimzadeh S. Evaluation of cardiovascular and respiratory mortality attributed to atmospheric SO2 and CO using AirQ model. Environmental Health Engineering and Management Journal. 2017;4(2):101-8.
11. WHO. https://www.who.int/news-room/feature-stories/detail/what-are-the-who-air-quality-guidelines. 2025.
12. Tiwari S, Dahiya A, Kumar N. Investigation into relationships among NO, NO2, NOx, O3, and CO at an urban background site in Delhi, India. Atmospheric Research. 2015;157:119-26.
13. Liu C, Yin P, Chen R, Meng X, Wang L, Niu Y, et al. Ambient carbon monoxide and cardiovascular mortality: a nationwide time-series analysis in 272 cities in China. The Lancet Planetary Health. 2018;2(1):e12-e8.
14. Jury MR. Meteorology of air pollution in Los Angeles. Atmospheric Pollution Research. 2020;11(7):1226-37.
15. Sommar JN, Andersson EM, Andersson N, Sallsten G, Stockfelt L, Ljungman PL, et al. Long-term exposure to particulate air pollution and black carbon in relation to natural and cause-specific mortality: a multicohort study in Sweden. BMJ open. 2021;11(9):e046040.
16. Majidi M, Ghaemi S, Javaezi M, Delirrad M. A Study on Human Mortalities & Death Registration System in West Azerbaijan Province of Iran. Iranian journal of forensic medicine. 2016;22(3):193-202.
17. Mohammadi A, Faraji M, Conti GO, Ferrante M, Miri M. Mortality and morbidity due to exposure to particulate matter related to drying Urmia Lake in the NW Iran. European journal of internal medicine. 2019;60:e14-e5.
18. Mohammadi A, Faraji M, Mousavi S, Nemati S, Momtaz M, Abdolahnejad A, et al. Health effects of airborne particulate matter related to traffic in Urmia, north-west Iran. Journal of Air Pollution and Health. 2019;4(2):99-108.
19. Hajizadeh Y, Jafari N, Fanaei F, Ghanbari R, Mohammadi A, Behnami A, et al. Spatial patterns and temporal variations of traffic-related air pollutants and estimating its health effects in Isfahan city, Iran. Journal of Environmental Health Science and Engineering. 2021;19(1):781-91.
20. Faridi S, Niazi S, Yousefian F, Azimi F, Pasalari H, Momeniha F, et al. Spatial homogeneity and heterogeneity of ambient air pollutants in Tehran. Science of the total environment. 2019;697:134123.
21. Dastoorpoor M, Riahi A, Yazdaninejhad H, Borsi SH, Khanjani N, Khodadadi N, et al. Exposure to particulate matter and carbon monoxide and cause-specific Cardiovascular-Respiratory disease mortality in Ahvaz. Toxin reviews. 2021;40(4):1362-72.
22. Ayremloo P, Hosseinpour S, Fouladi-Fard R, Mohammadi A. Spatial analysis and health implications of micro rubber and vanadium in urban street dust in Northwest of Iran. Scientific Reports. 2025;15(1):37553.
23. Hosseinpoor S, Ebrahimi Gangchin L, Mirzazadeh Z, Nuraldin Chaman A, Mohammadi A. Influence of COVID-19 lockdowns on NO2 levels in Urmia city: a comparative analysis between 2018 and 2020. Health Science Monitor. 2024;3(3):216-25.
24. Jang DH, Kelly M, Hardy K, Lambert DS, Shofer FS, Eckmann DM. A preliminary study in the alterations of mitochondrial respiration in patients with carbon monoxide poisoning measured in blood cells. Clinical toxicology. 2017;55(6):579-84.
25. Semmens EO, Leary CS, West MR, Noonan CW, Navarro KM, Domitrovich JW. Carbon monoxide exposures in wildland firefighters in the United States and targets for exposure reduction. Journal of exposure science & environmental epidemiology. 2021;31(5):923-9.
26. Rahnama MR, Abkooh SS. Prediction of CO pollutant in Mashhad metropolis, Iran: Using multiple linear regression. The Geographical Journal. 2023;189(4):715-28.
27. Arab N, Mirkarimi SH. Studying nitrogen pollutant, mono dioxide carbon and dioxide nitrogen in Aghdasiyeh station during 2012 in Tehran. Human & Environment. 2015;13(2):35-43.
28. Aghdasi H, Aali R, Mansouri N, Amini H. Long-term spatial and temporal variability of ambient carbon monoxide in Urmia, Iran. Journal of Advances in Environmental Health Research. 2017;5(2):78-84.
29. Fazlzadeh M, Rostami R, Hazrati S. Concentrations of carbon monoxide in outdoor and indoor air of residential buildings in Ardabil. Journal of Sabzevar University of Medical Sciences. 2016;23(1):161-8.
30. Sari MF, Tasdemir Y, Esen F. Major air pollutants in Bursa, Turkey: their levels, temporal changes, interactions, and sources. Environmental Forensics. 2019;20(2):182-95.
31. Lin YC, Lan YY, Tsuang B-J, Engling G. Long-term spatial distributions and trends of ambient CO concentrations in the central Taiwan Basin. Atmospheric Environment. 2008;42(18):4320-31.
32. Xie Y, Han H, Liu J. Spatial and seasonal variations and trends in carbon monoxide over China during 2013–2022. Atmospheric Environment. 2025;350:121163.
33. Yoo J-M, Jeong M-J, Kim D, Stockwell WR, Yang J-H, Shin H-W, et al. Spatiotemporal variations of air pollutants (O3, NO2, SO2, CO, PM10, and VOCs) with land-use types. Atmospheric Chemistry and Physics. 2015;15(18):10857-85.
| Files | ||
| Issue | Vol 11 No 1 (2026): Winter 2026 | |
| Section | Original Research | |
| Keywords | ||
| Carbon monoxide; Urmia; Ambient air; Temporal variation | ||
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This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
How to Cite
1.
Youzbashi Z, Hosseinpour S, Norouzi M, Khorablu R, Mohammadi A. Spatiotemporal trends of ambient air CO in Urmia city. JAPH. 2026;11(1):117-130.
