Ozone, Particulate Matter, and Newly Diagnosed Alzheimer's Disease: A Population-Based Cohort Study in Taiwan

Abstract

Several studies with animal research associate air pollution in Alzheimer's disease (AD) neuropathology, but the actual impact of air pollution on the risk of AD is unknown. Here, this study investigates the association between long-term exposure to ozone (O3) and particulate matter (PM) with an aerodynamic diameter equal to or less than 2.5 μm (PM2.5), and newly diagnosed AD in Taiwan. We conducted a cohort study of 95,690 individuals' age ≥ 65 during 2001-2010. We obtained PM10 and O3 data from Taiwan Environmental Protection Agency during 2000-2010. Since PM2.5 data is only accessible entirely after 2006, we used the mean ratio between PM2.5 and PM10 during 2006-2010 (0.57) to estimate the PM2.5 concentrations from 2000 to 2005. A Cox proportional hazards model was used to evaluate the associations between O3 and PM2.5 at baseline and changes of O3 and PM2.5 during the follow-up period and AD. The adjusted HR for AD was weakly associated with a raised concentration in O3 at baseline per increase of 9.63 ppb (adjusted HR 1.06, 95% confidence interval (CI) 1.00-1.12). Further, we estimated a 211% risk of increase of AD per increase of 10.91 ppb in O3 over the follow-up period (95% CI 2.92-3.33). We found a 138% risk of increase of AD per increase of 4.34 μg/m3 in PM2.5 over the follow-up period (95% CI 2.21-2.56). These findings suggest long-term exposure to O3 and PM2.5 above the current US EPA standards are associated with increased the risk of AD.

Air pollution, a rising environmental risk factor for cognition, neuroinflammation and neurodegeneration: The clinical impact on children and beyond

“…They found a 138% risk of increase of AD per increase of 4.34 μg/m3 in PM2.5 over the 10y follow-up period [85]. Jung's work is very relevant to our work and brings the issue of Alzheimer's disease development over several decades and thus is subject to neuroprotective interventions.…”

Association of Low-Level Ozone with Cognitive Decline in Older Adults

“…Acute or chronic exposure to ozone may induce an inflammatory response in the lungs or generate oxidative stress leading to brain lipid peroxidation, neuronal morphology changes and memory deterioration [34]. Evidence suggests that over time even at low levels (33.3–53.1 ppb) ozone has been shown to be associated with detrimental health outcomes, particularly, increased risk of death from respiratory causes, as per Jerrett et al [35].…”

Exposure to Environmental and Occupational Particulate Air Pollution as a Potential Contributor to Neurodegeneration and Diabetes: A Systematic Review of Epidemiological Research

“…More recently, there has also been evidence from epidemiological and laboratory studies that long-term exposure to particulate air pollution is associated with T2DM [17,18,19,20,21,22,23,24,25], dementia [26,27,28], and other neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD) [28,29]. The ability of inhaled particles to stimulate adverse effects in extrapulmonary sites has been reviewed previously [30], and likely to manifest due to (i) the translocation of particles from the lung to other target sites, or (ii) release of mediators (e.g., cytokines) from the lung which act systemically [30,31].…”