We assessed mortality risks associated with sourcespecific fine particles (PM2.5) in a pooled European cohort of 323,782 participants. Cox proportional hazard models were applied to estimate mortality hazard ratios (HRs) for source-specific PM2.5 identified through a source apportionment analysis. Exposure to 2010 annual average concentrations of source-specific PM2.5 components was assessed at baseline residential addresses. The source apportionment resulted in the identification of five sources: traffic, residual oil combustion, soil, biomass and agriculture, and industry. In single-source analysis, all identified sources were significantly positively associated with increased natural mortality risks. In multisource analysis, associations with all sources attenuated but remained statistically significant with traffic, oil, and biomass and agriculture. The highest association per interquartile increase was observed for the traffic component (HR: 1.06; 95% CI: 1.04 and 1.08 per 2.86 mu g/m(3) increase) across five identified sources. On a 1 mu g/m(3) basis, the residual oil-related PM2.5 had the strongest association (HR: 1.13; 95% CI: 1.05 and 1.22), which was substantially higher than that for generic PM2.5 mass, suggesting that past estimates using the generic PM2.5 exposure response function have underestimated the potential clean air health benefits of reducing fossil-fuel combustion. Source-specific associations with cause-specific mortality were in general consistent with findings of natural mortality.

Background: The evidence linking ambient air pollution to bladder cancer is limited and mixed.

Methods: We assessed the associations of bladder cancer incidence with residential exposure to fine particles (PM_2.5), nitrogen dioxide (NO2), black carbon (BC), warm season ozone (O₃) and eight PM_2.5 elemental components (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) in a pooled cohort (N = 302,493). Exposures were primarily assessed based on 2010 measurements and back-extrapolated to the baseline years. We applied Cox proportional hazard models adjusting for individual- and area-level potential confounders.

Results: During an average of 18.2 years follow-up, 967 bladder cancer cases occurred. We observed a positive though statistically non-significant association between PM2.5 and bladder cancer incidence. Hazard Ratios (HR) were 1.09 (95% confidence interval (CI): 0.93–1.27) per 5 µg/m³ for 2010 exposure and 1.06 (95% CI: 0.99–1.14) for baseline exposure. Effect estimates for NO₂, BC and O₃ were close to unity. A positive association was observed with PM_2.5 zinc (HR 1.08; 95% CI: 1.00–1.16 per 10 ng/m³).

Conclusions: We found suggestive evidence of an association between long-term PM_2.5 mass exposure and bladder cancer, strengthening the evidence from the few previous studies. The association with zinc in PM_2.5 suggests the importance of industrial emissions.

Background: The link between exposure to ambient air pollution and mortality from cardiorespiratory diseases is well established, while evidence on neurodegenerative disorders including Parkinson’s Disease (PD) remains limited.

Objective: We examined the association between long-term exposure to ambient air pollution and PD mortality in seven European cohorts.

Methods: Within the project ‘Effects of Low-Level Air Pollution: A Study in Europe’ (ELAPSE), we pooled data from seven cohorts among six European countries. Annual mean residential concentrations of fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), black carbon (BC), and ozone (O₃), as well as 8 PM_2.5 components (copper, iron, potassium, nickel, sulphur, silicon, vanadium, zinc), for 2010 were estimated using Europe-wide hybrid land use regression models. PD mortality was defined as underlying cause of death being either PD, secondary Parkinsonism, or dementia in PD. We applied Cox proportional hazard models to investigate the associations between air pollution and PD mortality, adjusting for potential confounders.

Results: Of 271,720 cohort participants, 381 died from PD during 19.7 years of follow-up. In single-pollutant analyses, we observed positive associations between PD mortality and PM_2.5 (hazard ratio per 5 µg/m³: 1.25; 95% confidence interval: 1.01–1.55), NO₂ (1.13; 0.95–1.34 per 10 µg/m³), and BC (1.12; 0.94–1.34 per 0.5 × 10^-5m^-1), and a negative association with O₃ (0.74; 0.58–0.94 per 10 µg/m³). Associations of PM_2.5, NO₂, and BC with PD mortality were linear without apparent lower thresholds. In two-pollutant models, associations with PM_2.5 remained robust when adjusted for NO₂ (1.24; 0.95–1.62) or BC (1.28; 0.96–1.71), whereas associations with NO₂ or BC attenuated to null. O₃ associations remained negative, but no longer statistically significant in models with PM_2.5. We detected suggestive positive associations with the potassium component of PM_2.5.

Conclusion: Long-term exposure to PM_2.5, at levels well below current EU air pollution limit values, may contribute to PD mortality.

BACKGROUND: Olfactory impairment is increasingly common with older age, which may be in part explained by cumulative effects of exposure to inhaled toxins. However, population-based studies investigating the relationship between air pollution and olfactory ability are scarce.

OBJECTIVES: We aimed to investigate associations between exposure to common air pollutants and longitudinal change in odor identification.

METHODS: Our study of 2,468 participants (mean age = 72.3 y; 61.1% female), of which 1,774 participants (mean age = 70.5 y; 61.9% female) had at least two olfactory assessments over 12 y of follow-up from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), Stockholm, Sweden. Participants were free from cognitive impairment and neurodegenerative disease at baseline. Odor identification ability was assessed with Sniffin' Sticks. Change in olfactory performance was estimated with linear mixed models. Exposure to two major airborne pollutants [particulate matter with aerodynamic diameter <= 2.5 mu m (PM2.5) and nitrogen oxides (NOx)] for the 5 y preceding baseline was assessed using spatiotemporal dispersion models for outdoor levels at residential addresses.

RESULTS: Participants showed significant decline in odor identification ability for each year in the study {f3 = - 0.20 [95% confidence interval (CI): -0.22, 0.18; p < 0.001]}. After adjustment for all covariates, residents of third [f3= - 0.09 (95% CI: -0.14, -0.04; p < 0.001)] and fourth [f3 = - 0.07 (95% CI: -0.12, -0.02; p = 0.005)] exposure quartiles of PM2.5 had faster rates of olfactory decline than residents from the first quartile. Similar results were observed for the third [f3= - 0.05 (95% CI: -0.10, -0.01; p = 0.029)] and fourth [f3= - 0.07 (95% CI: -0.11, -0.02; p = 0.006) quartiles of NOx].

DISCUSSION: Our results suggest an association between air pollution exposure and subsequent olfactory decline. We speculate that cumulative effects of airborne pollutants on the olfactory system may be one underlying cause of olfactory impairment in aging. 

Background: To identify brain magnetic resonance imaging (MRI) signatures characterizing people with different patterns of decline in cognition and motor function.

Methods: In the Swedish National Study on Aging and Care in Kungsholmen, Stockholm, 385 participants had available repeated brain MRI examinations, where markers of brain volumes and white matter integrity were assessed. The speed of cognitive and motor decline was estimated as the rate of a Mini-Mental State Examination and gait speed decline over 12 years (linear mixed models), and further dichotomized into the upper (25% fastest rate of decline) versus the lower quartiles. Participants were grouped in slow/no decliners (reference), isolated motor decliners, isolated cognitive decliners, and cognitive and motor decliners. We estimated the associations between changes in brain markers (linear mixed models) and baseline diffusion tensor imaging measures (linear regression model) and the 4 decline patterns.

Results: Individuals with concurrent cognitive and motor decline (n = 51) experienced the greatest loss in the total brain (β: −12.3; 95% confidence interval [CI]: −18.2; −6.38) and hippocampal (β: −0.25; 95% CI: −0.34; −0.16) volumes, the steepest accumulation of white matter hyperintensities (β: 1.61; 95% CI: 0.54; 2.68), and the greatest ventricular enlargement (β: 2.07; 95% CI: 0.67; 3.47). Compared to the reference, those only experiencing cognitive decline presented with steeper hippocampal volume loss, whereas those exhibiting only motor decline displayed a greater white matter hyperintensities burden. Lower microstructural white matter integrity was associated with concurrent cognitive and motor decline.

Conclusion: Concurrent cognitive and motor decline is accompanied by rapidly evolving and complex brain pathology involving both gray and white matter. Isolated cognitive and motor declines seem to exhibit brain damage with different qualitative features.

Background: Acute clinical events, such as pneumonia, may impact physical functionality but their effect on cognition and the possible duration of this effect remains to be quantified. This study investigated the impact of pneumonia on cognitive trajectories and dementia development in older people.

Methods: Data were obtained from 60+ years old individuals, who were assessed from 2001 to 2018 in the population-based SNAC-K study (Sweden). Participants were eligible if they were not institutionalized, had no dementia, and did not experience pneumonia 5 years prior to baseline (N = 2 063). A propensity score was derived to match 1:3 participants hospitalized with a diagnosis of pneumonia (N = 178), to nonexposed participants (N = 534). Mixed linear models were used to model cognitive decline. The hazard of dementia, clinically diagnosed by physicians following Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV, was estimated using Cox regression models.

Results: We found a transient impact of pneumonia on cognitive decline in the first 2.5 years (B = −0.94, 95% confidence interval [CI] −1.75, −0.15). The hazard ratio (HR) for dementia was not statistically significantly increased in pneumonia participants (HR = 1.17, 95%CI 0.82, 1.66).

Conclusions: The transient impact of pneumonia on cognitive function suggests an increased need of health care for patients after a pneumonia-related hospitalization and reinforces the relevance of pneumonia prevention.

Background: Air pollution is a growing concern worldwide, with significant impacts on human health. Multiple myeloma is a type of blood cancer with increasing incidence. Studies have linked air pollution exposure to various types of cancer, including leukemia and lymphoma, however, the relationship with multiple myeloma incidence has not been extensively investigated. Methods: We pooled four European cohorts (N = 234,803) and assessed the association between residential exposure to nitrogen dioxide (NO2), fine particles (PM2.5), black carbon (BC), and ozone (O3) and multiple myeloma. We applied Cox proportional hazards models adjusting for potential confounders at the individual and area-level. Results: During 4,415,817 person-years of follow-up (average 18.8 years), we observed 404 cases of multiple myeloma. The results of the fully adjusted linear analyses showed hazard ratios (95% confidence interval) of 0.99 (0.84, 1.16) per 10 mu g/m3 NO2, 1.04 (0.82, 1.33) per 5 mu g/m3 PM2.5, 0.99 (0.84, 1.18) per 0.5 10- 5 m-1 BCE, and 1.11 (0.87, 1.41) per 10 mu g/m3 O3. Conclusions: We did not observe an association between long-term ambient air pollution exposure and incidence of multiple myeloma.

Background/aim: Ambient air pollution has been associated with lung cancer, but the shape of the exposure-response function - especially at low exposure levels - is not well described. The aim of this study was to address the relationship between long-term low-level air pollution exposure and lung cancer incidence.

Methods: The Effects of Low-level Air Pollution: a Study in Europe (ELAPSE) collaboration pools seven cohorts from across Europe. We developed hybrid models combining air pollution monitoring, land use data, satellite observations, and dispersion model estimates for nitrogen dioxide (NO2), fine particulate matter (PM2.5), black carbon (BC), and ozone (O-3) to assign exposure to cohort participants' residential addresses in 100 m by 100 m grids. We applied stratified Cox proportional hazards models, adjusting for potential confounders (age, sex, calendar year, marital status, smoking, body mass index, employment status, and neighborhood-level socioeconomic status). We fitted linear models, linear models in subsets, Shape-Constrained Health Impact Functions (SCHIF), and natural cubic spline models to assess the shape of the association between air pollution and lung cancer at concentrations below existing standards and guidelines.

Results: The analyses included 307,550 cohort participants. During a mean follow-up of 18.1 years, 3956 incident lung cancer cases occurred. Median (Q1, Q3) annual (2010) exposure levels of NO2, PM2.5, BC and O-3 (warm season) were 24.2 mu g/m(3) (19.5, 29.7), 15.4 mu g/m(3) (12.8, 17.3), 1.6 10(-5)m(-1) (1.3, 1.8), and 86.6 mu g/m(3) (78.5, 92.9), respectively. We observed a higher risk for lung cancer with higher exposure to PM2.5 (HR: 1.13, 95% CI: 1.05, 1.23 per 5 mu g/m(3)). This association was robust to adjustment for other pollutants. The SCHIF, spline and subset analyses suggested a linear or supra-linear association with no evidence of a threshold. In subset analyses, risk estimates were clearly elevated for the subset of subjects with exposure below the EU limit value of 25 mu g/m(3). We did not observe associations between NO2, BC or O-3 and lung cancer incidence.

Conclusions: Long-term ambient PM2.5 exposure is associated with lung cancer incidence even at concentrations below current EU limit values and possibly WHO Air Quality Guidelines.

BACKGROUND: Particulate matter (PM) is classified as a group 1 human carcinogen. Previous experimental studies suggest that particles in diesel exhaust induce oxidative stress, inflammation and DNA damage in kidney cells, but the evidence from population studies linking air pollution to kidney cancer is limited.

METHODS: We pooled six European cohorts (N = 302,493) to assess the association of residential exposure to fine particles (PM_2.5), nitrogen dioxide (NO₂), black carbon (BC), warm season ozone (O₃) and eight elemental components of PM_2.5 (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) with cancer of the kidney parenchyma. The main exposure model was developed for year 2010. We defined kidney parenchyma cancer according to the International Classification of Diseases 9th and 10th Revision codes 189.0 and C64. We applied Cox proportional hazards models adjusting for potential confounders at the individual and area-level.

RESULTS: The participants were followed from baseline (1985–2005) to 2011–2015. A total of 847 cases occurred during 5,497,514 person-years of follow-up (average 18.2 years). Median (5–95%) exposure levels of NO₂, PM_2.5, BC and O₃ were 24.1 μg/m³ (12.8–39.2), 15.3 μg/m³ (8.6–19.2), 1.6 10⁻⁵ m⁻¹ (0.7–2.1), and 87.0 μg/m³ (70.3–97.4), respectively. The results of the fully adjusted linear analyses showed a hazard ratio (HR) of 1.03 (95% confidence interval [CI]: 0.92, 1.15) per 10 μg/m³ NO₂, 1.04 (95% CI: 0.88, 1.21) per 5 μg/m³ PM_2.5, 0.99 (95% CI: 0.89, 1.11) per 0.5 10⁻⁵ m⁻¹ BCE, and 0.88 (95% CI: 0.76, 1.02) per 10 μg/m³ O₃. We did not find associations between any of the elemental components of PM_2.5 and cancer of the kidney parenchyma.

CONCLUSION: We did not observe an association between long-term ambient air pollution exposure and incidence of kidney parenchyma cancer.

INTRODUCTION: The independent and joint effect of ischemic heart disease (IHD) and coexisting atrial fibrillation (AF) and heart failure (HF) on dementia risk is largely unknown.

METHODS: This population-based cohort study included 2568 dementia-free participants (age ≥60 years) in SNAC-K, who were regularly examined from 2001–2004 through 2013–2016. Dementia was diagnosed following the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria. Global cognitive function was assessed using a global cognitive composite z-score derived from five cognitive domains. Data were analyzed using Cox, Fine-Gray, and linear mixed-effects models.

RESULTS: Overall, IHD at baseline was associated with multivariable-adjusted hazard ratio (HR) of 1.39 (95% confidence interval = 1.06−1.82) for dementia and multivariable-adjusted β-coefficient of −0.02 (−0.03 to −0.01) for annual changes in global cognitive z-score, independent of AF, HF, and cerebrovascular disease. Coexisting AF or HF did not add further risk to dementia and cognitive decline.

DISCUSSION: IHD is independently associated with dementia and cognitive decline in older adults, whereas coexisting AF/HF is not associated with an increased risk.