Short-term associations between ambient air pollution and emergency department visits for Alzheimer’s disease and related dementias

Abstract

Background: Dementia is a seriously disabling illness with substantial economic and social burdens. Alzheimer’s disease and its related dementias (AD/ADRD) constitute about two-thirds of dementias. AD/ADRD patients have a high prevalence of comorbid conditions that are known to be exacerbated by exposure to ambient air pollution. Existing studies mostly focused on the long-term association between air pollution and AD/ADRD morbidity, while very few have investigated short-term associations. This study aims to estimate short-term associations between AD/ADRD emergency department (ED) visits and three common air pollutants: fine particulate matter (PM2.5), nitrogen dioxide (NO2), and warm-season ozone. Methods: For the period 2005 to 2015, we analyzed over 7.5 million AD/ADRD ED visits in five US states (California, Missouri, North Carolina, New Jersey, and New York) using a time-stratified case-crossover design with conditional logistic regression. Daily estimated PM2.5, NO2, and warm-season ozone concentrations at 1 km spatial resolution were aggregated to the ZIP code level as exposure. Results: The most consistent positive association was found for NO2. Across five states, a 17.1 ppb increase in NO2 concentration over a 4-day period was associated with a 0.61% (95% confidence interval = 0.27%, 0.95%) increase in AD/ADRD ED visits. For PM2.5, a positive association with AD/ADRD ED visits was found only in New York (0.64%, 95% confidence interval = 0.26%, 1.01% per 6.3 µg/m3). Associations with warm-season ozone levels were null. Conclusions: Our results suggest AD/ADRD patients are vulnerable to short-term health effects of ambient air pollution and strategies to lower exposure may reduce morbidity.

Impact of heat on respiratory hospitalizations among older adults living in 120 large US urban areas

“…For all models, the cumulative effect is the sum of the relative risk (RR) estimates across lag days 0-6 associated with a specific temperature value relative to the LUC-specific warm-season median temperature (reference exposure). We report lag-response associations, cumulative percent change in hospitalizations (%Δ= (RR-1)*100), and 95% confidence intervals (CIs) comparing high warm-season temperatures (95th ambient temperature percentile) to median warm-season temperatures (40–43).…”

Opinion: how are advances in aerosol science informing our understanding of the health impacts of outdoor particulate pollution?

“…These maps were created using a combination of AOD data and in-situ PM chemical composition measurements to constrain and downscale coarse CTM outputs to spatial scales commensurate with population density distributions. The resulting maps offered the possibility to assess the contributions of different anthropogenic emission sectors to regional and global mortality burden (Mcduffie et al, 2021;Chen et al, 2021b), and to identify which PM constituents are for example associated with an increased risk of dementia and Alzheimer's disease (Shi et al, 2023).…”

“…Short-term exposure to PM pollution has been linked to sudden infant death and higher mortality and morbidity rates, caused by cardiorespiratory issues, renal complications, and mental disorders. These effects are particularly pronounced in children and individuals with chronic conditions (Heft-Neal et al, 2018) (Zhang et al, 2023;Liu et al, 2023;Guo et al, 2023). According to a recent multi-location assessment, every 10 µg m -3 increase in daily PM levels increases the mortality risk by 0.7% (Liu et al, 2019).…”

“…Given the sharp rise in dementia incidence beyond the age of 75 and our increasingly ageing society, global dementia cases are forecasted to triple by the year 2050. Recent studies have shown that every 5 μg m -3 increase in annual PM concentrations results in a 13% increased risk of first-time hospital admissions for dementia (Shi et al, 2020), with elemental carbon and sulfate particles having the strongest effects (Shi et al, 2023). While more research is necessary to confirm this connection and understand the underlying biological pathways involved, these studies constitute a first step towards the development of interventions to slow the trajectory of cognitive decline and ensure the wellbeing of our aging society.…”