Associations of Fine and Ultrafine Particulate Air Pollution with Specified Cardiovascular Causes of Death

Abstract

P-030 Background: Particulate air pollution has been associated with cardiovascular mortality. Toxicological and epidemiological studies suggest that the smallest particles are especially harmful. However, there is a lack of long, continuous measurement series of finer particle fractions, especially ultrafine particles (<0.1 μm). We have daily data on ultrafine particle concentrations since 1998. Therefore, we examined the associations of daily levels of ultrafine and fine (<2.5 μm) particles with cause-specific cardiovascular mortality. Methods: Ultrafine particle number concentrations were monitored with a differential mobility particle sizer in 1998–2002 at a central outdoor monitoring site. Deaths due to all cardiovascular diseases (ICD-10: I00-I99; N=13 839), stroke (I60-I61, I63-I64; N=2783), ischemic heart diseases (I20-I25; N=8014) and other heart diseases (I30-I51; N=1167) were analyzed separately. The associations between daily levels of air pollution and deaths were evaluated using Poisson regression and controlling for time trend, temperature, relative humidity, barometric pressure, weekday and general holidays. Results: The median concentration for ultrafine particles was 9700 1/cm3 and for PM2.5 8.5 μg/m3. We found no consistent associations between ultrafine particles and mortality. There was some evidence of a positive association between fine particles and ‘other’ heart diseases with 4.15% (95% CI,1.3–9.9) increase in mortality for an interquartile increase in PM2.5 at lag 1. Conclusions: We found no strong associations between particulate air pollution and cardiovascular mortality when analyzing all seasons together. Based on our earlier experience on respiratory mortality, additional analyzes will be performed by warm and cold season separately.