American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Dec 2024
Airborne Nanoparticle Concentrations Are Associated with Increased Mortality Risk in Canada's Two Largest Cities.
Rationale: Outdoor fine particulate air pollution (particulate matter with an aerodynamic diameter ⩽2.5 μm; PM2.5) contributes to millions of deaths around the world each year, but much less is known about the long-term health impacts of other particulate air pollutants, including ultrafine particles (a.k.a. nanoparticles), which are in the nanometer-size range (<100 nm), widespread in urban environments, and not currently regulated. Objectives: We sought to estimate the associations between long-term exposure to outdoor ultrafine particles and mortality. Methods: Outdoor air pollution levels were linked to the residential addresses of a large, population-based cohort from 2001 to 2016. ⋯ We estimated the mortality burden for outdoor ultrafine particles in Montreal and Toronto, Canada, to be approximately 1,100 additional nonaccidental deaths every year. Furthermore, we observed possible confounding by particle size, which suggests that previous studies may have underestimated or missed important health risks associated with ultrafine particles. Conclusions: As outdoor ultrafine particles are not currently regulated, there is great potential for future regulatory interventions to improve population health by targeting these common outdoor air pollutants.
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Am. J. Respir. Crit. Care Med. · Dec 2024
Application of the ERS/ATS Spirometry Standards and Race-Neutral Equations in the COPDGene Study.
Rationale: For spirometry interpretation, the European Respiratory Society (ERS) and American Thoracic Society (ATS) recommend using z-scores, and the ATS has recommended using Global Lung Initiative (GLI) "Global" race-neutral reference equations. However, these recommendations have been variably implemented, and the impact has not been widely assessed in clinical or research settings. Objectives: To evaluate the ERS/ATS classification of airflow obstruction severity. ⋯ Measurements and Main Results: The lowest agreement between ERS/ATS with zGLI Global and the GOLD classification was observed in individuals with milder disease (56.9% and 42.5% in GOLD stages 1 and 2, respectively), and race was a major determinant of redistribution. After adjustment for relevant covariates, zGLI Global distinguished all-cause mortality risk between normal spirometry and the first grade of chronic obstructive pulmonary disease (hazard ratio, 1.23; 95% confidence interval, 1.04-1.44; P = 0.014) and showed a linear increase in exacerbation rates with increasing disease severity in comparison with GOLD. Conclusions: The zGLI Global severity classification outperformed the GOLD criteria in the discrimination of survival, exacerbations, and imaging characteristics.