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Dear editor,

We would like to bring to the attention of International Journal of Stroke readers the possibility of air pollutants as a risk factor for stroke. Air pollution is a health problem, which results in several medical conditions in humans [1]. Although many studies have discussed the side effects of air pollution on human health, there is not yet a consensus on the vascular complications of air pollution [2, 3].

Tehran, the capital of Iran, is one of the most air polluted cities in the world [4]. In 2004, the quality of air was worse than the last few years [5]; so we decided to evaluate the association between the level of air pollutants and the number of stroke admissions in the neurology referral hospitals of Tehran in that year. We used data that included the admission date of 1491 hospitalized patients primarily diagnosed with any type of stroke in eight referral hospitals in Tehran and daily average level of each air pollutant individually (including CO, NOX, SO2) for the same period and place. We evaluated the association between the number of stroke admissions and the level of the selected pollutants, temperature, and humidity on the day of stroke 48 h prior to stroke by analysis of variance and Poisson regression. In this study we found that the level of NOX on the same day; levels of CO, SO2, NOX; temperature and humidity 48 h before stroke had a significant association with the number of stroke admissions.

We concluded that the level of air pollutants and temperature are effective factors in the occurrence of stroke especially 48 h before, which might be due to an incubation time needed for these pollutants to influence the brain. We suggest conducting more studies at an individual level to describe the role of each pollutant in causing stroke in the future.

  • Seyed Massood Nabavi1*,

  • Mozhgan Sadat Jalali1,

  • Saharnaz Nedjat2, Khosro Ashrafi3,

  • and Alireza Salahesh1

  • 1Neurology Department, Shahed University, Tehran, Iran

  • 2School of Public Health, Knowledge Utilisation Research Centre, Tehran University of Medical Sciences, Tehran, Iran

  • 3Environmental Engineering Department, Faculty of Environment, University of Tehran, Tehran, Iran

References

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  2. References
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