Ultrafine and Fine Particle Number and Surface Area Concentrations and Daily Cause-Specific Mortality in the Ruhr Area, Germany, 2009-2014

• Published in: Environmental health perspectives 2018-02, Vol.126 (2), p.027008-027008
• Main Authors: Hennig, Frauke, Quass, Ulrich, Hellack, Bryan, Küpper, Miriam, Kuhlbusch, Thomas A J, Stafoggia, Massimo, Hoffmann, Barbara
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Air Pollutants - toxicity; Air pollution; Air Pollution - adverse effects; Air Pollution - analysis; Airborne particulates; Cardiovascular disease; Cardiovascular diseases; Cardiovascular Diseases - epidemiology; Cardiovascular Diseases - mortality; Cause of Death; Confidence intervals; Distribution; Environmental Exposure - adverse effects; Environmental Exposure - analysis; Environmental health; Epidemiology; Germany - epidemiology; Health aspects; Humans; Influenza; Lungs; Measurement; Measurement techniques; Medical research; Medicin och hälsovetenskap; Mortality; Nanoparticles; Nitrogen dioxide; Outdoor air quality; Particle mass; Particle Size; Particle size distribution; Particulate matter; Particulate Matter - analysis; Particulate Matter - toxicity; Patient outcomes; Poisson density functions; Pollutants; Public health; Regression analysis; Regression models; Respiratory Tract Diseases - epidemiology; Respiratory Tract Diseases - mortality; Risk factors; Seasons; Size distribution; Statistical analysis; Surface area; Time Factors; Urban areas
• ISSN: 0091-6765; 1552-9924; 1552-9924
• DOI: 10.1289/EHP2054

Although epidemiologic studies have shown associations between particle mass and daily mortality, evidence on other particle metrics is weak. We investigated associations of size-specific particle number concentration (PNC) and lung-deposited particle surface area concentration (PSC) with cause-specific daily mortality in contrast to PM . We used time-series data (March 2009-December 2014) on daily natural, cardiovascular, and respiratory mortality (NM, CVM, RM) of three adjacent cities in the Ruhr Area, Germany. Size-specific PNC (electric mobility diameter of 13.3-750 nm), PSC, and PM were measured at an urban background monitoring site. In single- and multipollutant Poisson regression models, we estimated percentage change (95% confidence interval) [% (95% CI)] in mortality per interquartile range (IQR) in exposure at single-day (0-7) and aggregated lags (0-1, 2-3, 4-7), accounting for time trend, temperature, humidity, day of week, holidays, period of seasonal population decrease, and influenza. PNC and PSC were highly correlated and had similar immediate (lag0-1) and delayed (lag4-7) associations with NM and CVM, for example, 1.12% (95% CI: 0.09, 2.33) and 1.56% (95% CI: 0.22, 2.92) higher NM with IQR increases in PNC at lag0-1 and lag4-7, respectfully, which were slightly stronger then associations with IQR increases in PM . Positive associations between PNC and NM were strongest for accumulation mode particles (PNC 100-500 nm), and for larger UFPs (PNC 50-100 nm). Associations between NM and PNC changed little after adjustment for O or PM , but were more sensitive to adjustment for NO . Size-specific PNC (50-500 nm) and lung-deposited PSC were associated with natural and cardiovascular mortality in the Ruhr Area. Although associations were similar to those estimated for an IQR increase in PM , particle number size distributions can be linked to emission sources, and thus may be more informative for potential public health interventions. Moreover, PSC could be used as an alternative metric that integrates particle size distribution as well as deposition efficiency. https://doi.org/10.1289/EHP2054.