Background: A rise in solid or liquid pollutants suspended in the air, including nitrates and sulphates emitted from road traffic, construction, and industry, was found to adversely affect health in both the short and long-term. This study was to investigate effect of short-term exposure to air-pollutants on the occurrence of stroke (Ischemic/Hemorrhagic).

Methods: The study design was a case-crossover study. The case crossover design is a variant of the matched case control study and consists of only cases, which serve as their own controls in the analysis. The data collection was partly prospective and partly retrospective.

Results:  692 stroke (Ischemic and Hemorrhagic) patients were enrolled at tertiary care hospital from Jan 2012 to Oct 2017. The air pollutants studied were PM10 (Particulate Matter), PM2.5, NO (Nitric oxide), NO2 (Nitric dioxide), SO2 (Sulfur Dioxide), CO (Carbon Monoxide), O3 (Ozone), Humidity and temperature. There was no significant association of all stroke occurrences with increased short-term exposure to air pollutant. However, a borderline significant association was observed with simultaneous rise of NO2 and CO with OR 1.29; 95%CI 0.9 to 1.9.

Conclusions: Our data shows no significant association of occurrence of stroke with short-term rise in air pollutants. There may be an association of stroke occurrence with simultaneous rise in NO2 and CO levels. Note: Analysis based on stroke subtype and short-term exposure to air pollutants is currently under process.

AN EXPLORATORY STUDY TO INVESTIGATE THE ASSOCIATION BETWEEN SHORT-TERM EXPOSURE TO AIR-POLLUTION ON THE OCCURRENCE OF ISCHEMIC OR HEMORRHAGIC STROKE IN A CASE CROSSOVER DESIGN