BACKGROUND: Short-term exposure to high levels of air pollution can increase stroke risk. In this study we investigated the short-term effects of air pollution on hospital admissions for stroke in a setting where pollutant levels are rather low. We also addressed methodological issues in evaluating the short-term effects of air pollution. METHODS: Daily admissions of ischemic (n = 11,267) and hemorrhagic (n =1,681) stroke were obtained from a Swedish quality register for stroke, Riks-Stroke. We used two types of exposure data: (1) daily measured background levels of ozone, temperature and particles with a diameter < 10 microm (PM(10)) and (2) modeled levels of a mixture of NO and NO2 (NOx) at the residential address of each individual. RESULTS: We estimated a 13% (95% confidence interval, 4-22%) increased risk for hospital admissions for ischemic stroke for levels of PM 10 above 30 microg/m(3) compared to < 15 microg/m(3) , whereas temperature above 16 degrees C decreased the risk. No consistent associations were found for hemorrhagic stroke or for ischemic stroke and ozone or NOx . CONCLUSION: Particulate air pollution and temperature seemed to be associated with ischemic stroke hospital admissions. Individual exposure modeling facilitates a detailed exposure assessment but may also be more prone to misclassification errors. The time series and case crossover approaches yielded similar effect estimates.
BACKGROUND: Short-term exposure to high levels of air pollution can increase stroke risk. In this study we investigated the short-term effects of air pollution on hospital admissions for stroke in a setting where pollutant levels are rather low. We also addressed methodological issues in evaluating the short-term effects of air pollution. METHODS: Daily admissions of ischemic (n = 11,267) and hemorrhagic (n =1,681) stroke were obtained from a Swedish quality register for stroke, Riks-Stroke. We used two types of exposure data: (1) daily measured background levels of ozone, temperature and particles with a diameter < 10 microm (PM(10)) and (2) modeled levels of a mixture of NO and NO2 (NOx) at the residential address of each individual. RESULTS: We estimated a 13% (95% confidence interval, 4-22%) increased risk for hospital admissions for ischemic stroke for levels of PM 10 above 30 microg/m(3) compared to < 15 microg/m(3) , whereas temperature above 16 degrees C decreased the risk. No consistent associations were found for hemorrhagic stroke or for ischemic stroke and ozone or NOx . CONCLUSION: Particulate air pollution and temperature seemed to be associated with ischemic stroke hospital admissions. Individual exposure modeling facilitates a detailed exposure assessment but may also be more prone to misclassification errors. The time series and case crossover approaches yielded similar effect estimates.
Authors: Jessica A Montresor-López; Jeff D Yanosky; Murray A Mittleman; Amir Sapkota; Xin He; James D Hibbert; Michael D Wirth; Robin C Puett Journal: J Expo Sci Environ Epidemiol Date: 2015-09-02 Impact factor: 5.563
Authors: Gregory A Wellenius; Mary R Burger; Brent A Coull; Joel Schwartz; Helen H Suh; Petros Koutrakis; Gottfried Schlaug; Diane R Gold; Murray A Mittleman Journal: Arch Intern Med Date: 2012-02-13
Authors: Francesco Corea; Giorgio Silvestrelli; Andrea Baccarelli; Alessandra Giua; Paolo Previdi; Giorgio Siliprandi; Nicola Murgia Journal: Neurol Int Date: 2012-08-24