Long-term exposure to air pollution components (total and source-specific) and incidence of stroke and cardiac events in the Heinz Nixdorf Recall study

Abstract

OPS 06: Health effects of source-specific outdoor air pollution, Room 117, Floor 1, August 27, 2019, 10:30 AM - 12:00 PM Background/Aim: Epidemiological studies have established that air pollution (AP) exposure adversely affects cardiovascular health. However, there has been little research on the effects of source-specific (industry and traffic) AP and individual components of particulate pollution. We therefore investigated the association between long-term exposure to components of total and source-specific AP and incidence of stroke and cardiac events (CE). Methods: We used data from the Heinz Nixdorf Recall cohort study (N = 4,814, aged 45–75). We estimated long-term residential AP exposures over the baseline period (2001-2003) using the European Air Pollution Dispersion chemical transport model (EURAD). Exposure was modelled for total NO2, total and source-specific particulate matter (PM) PM10, PM2.5, accumulation mode particle number concentration (PNAM), and PM components (anthropogenic organic compounds, black carbon, elemental carbon, NH4, NO3, SO4). Outcomes were defined as time to first stroke or CE during follow-up (until 2017). We applied Cox proportional hazards model to estimate hazard ratios (HR) per interquartile range increase in exposure to each pollutant/component, controlling for baseline sex, age, socio-economic status, body mass index, smoking, alcohol consumption, physical activity, nutrition, and traffic noise. In the analyzed population without stroke or CE prior to baseline (N = 4,224), a total of 120 strokes and 200 CE were observed during the study period (mean follow-up 12 years). Results: We observed positive associations between AP exposure and incidence of stroke, e.g. for industry-specific PM10 (HR: 1.34, 95% CI: 1.01, 1.78 per 2.22 µg/m3), industry-specific PNAM (HR: 1.28 [1.00, 1.64] per 208 particles/mL), and traffic-specific PNAM (HR: 1.30 [1.01, 1.68] per 138 particles/mL). Point estimates for CE were less consistently elevated. Adjustment for traffic noise did not change the results substantially. Conclusions: Our results support a positive association of long-term residential exposure to source-specific AP and PM components with incidence of stroke.