Long-term Air Pollution Exposure and Pneumonia Related Mortality in a Large Pooled European Cohort.
Liu, Shuo, Lim, Youn-Hee, Chen, Jie, Strak, Maciek, Wolf, Kathrin, Weinmayr, Gudrun, Rodopolou, Sophia, de Hoogh, Kees, Bellander, Tom, Brandt, Jørgen, Concin, Hans, Zitt, Emanuel, Fecht, Daniela, Forastiere, Francesco, Gulliver, John, Hertel, Ole, Hoffmann, Barbara, Hvidtfeldt, Ulla A, Verschuren, W M Monique, Jöckel, Karl-Heinz, Jørgensen, Jeanette T, So, Rina, Amini, Heresh, Cole-Hunter, Thomas, Mehta, Amar J, Mortensen, Laust H, Ketzel, Matthias, Lager, Anton, Leander, Karin, Ljungman, Petter, Severi, Gianluca, Boutron-Ruault, Marie-Christine, Magnusson, Patrik K E, Nagel, Gabriele, Pershagen, Göran, Peters, Annette, Raaschou-Nielsen, Ole, Rizzuto, Debora, van der Schouw, Yvonne T, Schramm, Sara, Sørensen, Mette, Stafoggia, Massimo, Tjønneland, Anne, Katsouyanni, Klea, Huang, Wei, Samoli, Evangelia, Brunekreef, Bert, Hoek, Gerard, Andersen, Zorana J
Abstract
<h4>Rationale</h4>Ambient air pollution exposure has been linked to mortality from chronic cardiorespiratory diseases, while evidence on respiratory infections remains more limited.<h4>Objectives</h4>We examined the association between long-term exposure to air pollution and pneumonia related mortality in adults in a pool of eight European cohorts.<h4>Methods</h4>Within the multicenter project 'Effects of Low-Level Air Pollution: A Study in Europe' (ELAPSE), we pooled data from eight cohorts among six European countries. Annual mean residential concentrations in 2010 for fine particulate matter (PM<sub>2.5</sub>), nitrogen dioxide (NO<sub>2</sub>), black carbon (BC), and ozone (O<sub>3</sub>) were estimated using Europe-wide hybrid land use regression models. We applied stratified Cox proportional hazard models to investigate the associations between air pollution and pneumonia, influenza, and acute lower respiratory infections (ALRI) mortality.<h4>Measurements and main results</h4>Of 325,367 participants, 712 died from pneumonia and influenza combined, 682 from pneumonia, and 695 from ALRI during a mean follow-up of 19.5 years. NO<sub>2</sub> and BC were associated with 10-12% increases in pneumonia and influenza combined mortality, but 95% confidence intervals included unity [hazard ratios: 1.12 (0.99-1.26) per 10 µg/m<sup>3</sup> for NO<sub>2</sub>; 1.10 (0.97-1.24) per 0.5 10<sup>-5</sup>m<sup>-1</sup> for BC]. Associations with pneumonia and ALRI mortality were almost identical. We detected effect modification suggesting stronger associations with NO<sub>2</sub> or BC in overweight, employed, or currently smoking participants compared to normal weight, unemployed, or non-smoking participants.<h4>Conclusions</h4>Long-term exposure to combustion-related air pollutants NO<sub>2</sub> and BC may be associated with mortality from lower respiratory infections, but larger studies are needed to estimate these associations more precisely.