Original Research

Air pollution and stroke mortality in Arak, Iran: Short-term and long-term exposure effects analyzed using zero-inflated negative binomial

Abstract

Introduction: Air pollution poses significant public health risks in industrial regions, with stroke mortality emerging as a critical outcome. This study examines the association between air pollutant exposure and stroke mortality in Arak, Iran - an industrial city with consistently poor air quality exceeding WHO thresholds.
Materials and methods: We conducted a time-series analysis of 1,010 stroke deaths (2019-2022) using zero-inflated negative binomial regression to model over-dispersed mortality data. Pollutant concentrations (PM2.5
, PM10,NO₂, O₃, SO₂) were collected from four monitoring stations representingindustrial, traffic, and residential z ones. Effects were assessed for short-term (1-3 months) and long-term (6-24 months) exposures, with adjustment for meteorological and demographic confounders.
Results: NO₂ demonstrated the strongest short-term association (2-month RR: 1.50, 95% CI: 1.30-1.75, p<0.001). PM10 showed a slight increase in risk at the 2-month lag (RR: 1.06, 95% CI: 0.98–1.14), although it was not statistically significant. Long-term PM2.5 exposure significantly increased mortality risk (24-month RR: 1.20, 95% CI: 1.05-1.58). A possible inverse association was observed for SO₂ (2-month RR: 0.59, 95% CI: 0.36–0.97),
while O₃ effects varied over time.

Conclusion: Industrial emissions (particularly NO₂ and particulate matter)
significantly contribute to stroke mortality in Arak. The identified exposure response relationships highlight the importance of stricter emission controls on vehicular and industrial sources and targeted health interventions for high-risk populations. Further investigation of pollutant interactions is also essential to better understand their combined effects on stroke mortality.

1. Lee KK, Miller MR, Shah AS. Air pollution and stroke. Journal of stroke. 2018;20(1):2.
2. Brook RD, Rajagopalan S, Pope CA, Brook JR, Bhatnagar A, Diez-Roux AV, et al. Particulate Matter Air Pollution and Cardiovascular Disease. Circulation. 2010 June;121(21):2331–78.
3. Fisher JA, Puett RC, Laden F, Wellenius GA, Sapkota A, Liao D, et al. Case-crossover analysis of short-term particulate matter exposures and stroke in the health professionals follow-up study. Environment international. 2019;124:153–60.
4. Wang Z, Peng J, Liu P, Duan Y, Huang S, Wen Y, et al. Association between short-term exposure to air pollution and ischemic stroke onset: a time-stratified case-crossover analysis using a distributed lag nonlinear model in Shenzhen, China. Environ Health. 2020 Dec;19(1):1.
5. Graber M, Mohr S, Baptiste L, Duloquin G, Blanc-Labarre C, Mariet AS, et al. Air pollution and stroke. A new modifiable risk factor is in the air. Revue neurologique. 2019;175(10):619–24.
6. Lasek-Bal A, Rybicki W, Student S, Puz P, Krzan A, Derra A. Direct Exposure to Outdoor Air Pollution Worsens the Functional Status of Stroke Patients Treated with Mechanical Thrombectomy. Journal of Clinical Medicine. 2024 Jan;13(3):746.
7. Niu Z, Liu F, Yu H, Wu S, Xiang H. Association between exposure to ambient air pollution and hospital admission, incidence, and mortality of stroke: an updated systematic review and meta-analysis of more than 23 million participants. Environmental Health and Preventive Medicine. 2021 Jan 26;26(1):15.
8. Wilker EH, Mostofsky E, Fossa A, Koutrakis P, Warren A, Charidimou A, et al. Ambient Pollutants and Spontaneous Intracerebral Hemorrhage in Greater Boston. Stroke. 2018 Nov;49(11):2764–6.
9. Zhao Y, Kang X, Tian X, Liu L, Zhao Z, Luo L, et al. Long-term exposure to air pollution and cerebrovascular disease: findings from Beijing Health Management Cohort study. Front Environ Sci Eng. 2023 July;17(7):84.
10. Salehi M, Almasi Hashiani A, Karimi B, Mirhoseini SH. Estimation of health-related and economic impacts of PM2. 5 in Arak, Iran, using BenMAP-CE. Plos one. 2023;18(12):e0295676.
11. Fallahzadeh A, Esfahani Z, Sheikhy A, Keykhaei M, Moghaddam SS, Tehrani YS, et al. National and subnational burden of stroke in Iran from 1990 to 2019. Ann Clin Transl Neurol. 2022 May;9(5):669–83.
12. Kazemi Z, Yunesian M, Hassanvand MS, Daroudi R, Ghorbani A, Sefiddashti SE. Hidden health effects and economic burden of stroke and coronary heart disease attributed to ambient air pollution (PM2.5) in Tehran, Iran: Evidence from an assessment and forecast up to 2030. Ecotoxicology and Environmental Safety. 2024;286:117158.
13. Razzaghi S, Mousavi S, Jaberinezhad M, Farshbaf Khalili A, Banan Khojasteh SM. Time-Series analysis of short-term exposure to air pollutants and daily hospital admissions for stroke in Tabriz, Iran. PloS one. 2024;19(11):e0309414.
14. Dehghani MH, Hopke PK, Asghari FB, Mohammadi AA, Yousefi M. The effect of the decreasing level of Urmia Lake on particulate matter trends and attributed health effects in Tabriz, Iran. Microchemical Journal. 2020 Mar 1;153:104434.
15. Nabizadeh R, Yousefi M, Azimi F. Study of particle number size distributions at Azadi terminal in Tehran, comparing high-traffic and no traffic area. MethodsX. 2018 Jan 1;5:1549–55.
16. Salehi M, Mirhoseini SH, Karimi B, Hashiani AA. Association between airborne particles and meteorological parameters in Arak industrial city. Journal of Air Pollution and Health. 2021;
17. Karimi B, Shokrinezhad B. Spatial variation of ambient PM2.5 and PM10 in the industrial city of Arak, Iran: A land-use regression. Atmospheric Pollution Research. 2021;12(12):101235.
18. Karimi A, Shirmardi M, Hadei M, Birgani YT, Neisi A, Takdastan A, et al. Concentrations and health effects of short-and long-term exposure to PM2.5, NO2, and O3 in ambient air of Ahvaz city, Iran (2014–2017). Ecotoxicology and environmental safety. 2019;180:542–8.
19. Salehi M, Almasi Hashiani A, Karimi B, Mirhoseini SH. Estimation of health-related and economic impacts of PM2.5 in Arak, Iran, using BenMAP-CE. Plos one. 2023;18(12):e0295676.
20. Verhoeven JI, Allach Y, Vaartjes IC, Klijn CJ, de Leeuw FE. Ambient air pollution and the risk of ischaemic and haemorrhagic stroke. The Lancet Planetary Health. 2021;5(8):e542–52.
21. Gharibvand LK, Jamali AA, Amiri F. Changes in NO2 and O3 levels due to the pandemic lockdown in the industrial cities of Tehran and Arak, Iran using Sentinel 5P images, Google Earth Engine (GEE) and statistical analysis. Stoch Environ Res Risk Assess. 2023 May 1;37(5):2023–34.
22. Liang R, Chen R, Yin P, van Donkelaar A, Martin RV, Burnett R, et al. Associations of long-term exposure to fine particulate matter and its constituents with cardiovascular mortality: A prospective cohort study in China. Environment International. 2022;162:107156.
23. Xue T, Tong M, Wang M, Yang X, Wang Y, Lin H, et al. Health Impacts of Long-Term NO2 Exposure and Inequalities among the Chinese Population from 2013 to 2020. - Consensus. [cited 2025 Jan 22]; Available from: https://consensus.app/papers/health-impacts-of-longterm-no2-exposure-and-inequalities-xue-tong/dd24f68dffe15ca99b66e985725dcffe/
24. Chen PC, Sung FC, Mou CH, Chen CW, Tsai SP, Hsieh DHP, et al. A cohort study evaluating the risk of stroke associated with long-term exposure to ambient fine particulate matter in Taiwan. Environ Health. 2022 Dec;21(1):43.
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IssueVol 10 No 4 (2025): Autumn 2025 QRcode
SectionOriginal Research
DOI https://doi.org/10.18502/japh.v10i4.20615
Keywords
Air pollution; Stroke mortality; Industrial emissions; Time-series analysis; Iran
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How to Cite
1.
Poorsaadat L, Almasi-Hashiani A, Amini P, Koolivand A, Nasrollahi M, Mirhoseini SH. Air pollution and stroke mortality in Arak, Iran: Short-term and long-term exposure effects analyzed using zero-inflated negative binomial. JAPH. 2025;10(4):487-498.