Air Pollution and Ischemic Stroke Among Young Adults

Abstract

We have recently presented a new method of assessing spatiotemporal resolved PM 2.5 and PM 10 exposures 18,19 in the Negev (South Israel)-a semi-arid area, located in the global dust belt, which extends from West Africa to the Arabian Desert. 20 Unlike many commonly used exposure models, our model makes use of satellite aerosol optical depth measurements, which allowed us to estimate daily, spatially resolved, PM 10 and PM 2.5 concentration with the inclusion of populations in rural areas not living nearby monitoring stations.Stroke in older patients is mostly related to atherosclerosis. 21 In the young, however, stroke is less common, and the cause is much more diverse and often unexplained. 21 We hypothesize that PM exposure is positively associated with stroke, especially among young adults. Methods Study PopulationWe included all Clalit Health Services members with available geocoded addresses in Southern Israel, admitted to Soroka University Medical Center (SUMC) with hemorrhagic (International Classification of Diseases Ninth Revision [ICD9] 430-432) or ischemic stroke (ICD9 432-435) between the years 2005 and 2012. SUMC is the only medical center providing acute neurological care in the area, serving a population of ≈1 million residents; therefore, all the patients with stroke are referred to SUMC. Clalit Health Service is the largest health care provider in the area, covering ≈70% of the population. To avoid within subject correlation among recurrent events, we used only the first stroke event, within the study period, for each subject. 22Background and Purpose-Studies have demonstrated consistent associations between cardiovascular illness and particulate matter (PM) <10 and <2.5 μm in diameter, but stroke received less attention. We hypothesized that air pollution, an inflammation progenitor, can be associated with stroke incidence in young patients in whom the usual risk factors for stroke are less prevalent. We aimed to evaluate the association between stroke incidence and exposure to PM <10 and <2.5 μm, in a desert area characterized by a wide range of PM. Methods-We included all members of the largest health maintenance organization in Israel, who were admitted to a local hospital with stroke between 2005 and 2012. Exposure assessment was based on a hybrid model incorporating daily satellite remote sensing data at 1-km spatial resolution. We performed case-crossover analysis, stratified by personal characteristics and distance from main roads.

Cardiovascular effects of air pollution

“…As previously described for myocardial infarction, the risk was still increased at pollution levels below current European air quality standards [32]. Exposure to road traffic also increased the risk of stroke, with strong associations with ischaemic stroke observed in subjects living within 75 m of a main road [33]. Hourly or daily changes in pollutant concentrations were also related to an increased risk of stroke and stroke mortality, with a strong association between ultrafine particles and stroke mortality [34].…”

The transport of PM10 over Cape Town during high pollution episodes

“…Due to their small size, PM10 can penetrate human lungs and cause a wide variety of cardiopulmonary diseases (Figure 1.2) (Folinsbee, 1992;Pope and Dockery, 2006;WHO, 2006). Exposure to the pollutant can decrease lung function , aggravate diseases such as asthma (Whittemore and Korn, 1980;Choudhury et al, 1997) and ischemia (Bell et al, 2008;Yitshak-Sade et al, 2015), and raise the likelihood of developing lung cancer (Pope et al, 2002;Parent et al, 2007;. Studies have also linked maternal exposure to PM10 during pregnancy to adverse birth outcomes such as pre-term delivery (Ha et al, 2014), very pre-term delivery (Ha et al, 2014), and low birth weight (Chen et al, 2002;Dugandzic et al, 2006;Bell et al, 2007;Seo et al, 2010;Ha et al, 2014).…”

Fine Particulate Matter (PM 2.5 ) and the Risk of Stroke in the REGARDS Cohort

“…A larger study in Israel, also using satellite-derived measures of exposure, found no overall association between ischemic stroke and same-day PM 2.5 exposure, but did find marginally significant association among those <55 years of age in stratified models. 35 …”