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

Abstract

Increasing evidence points to an association of airborne pollutant exposure with respiratory, cardiovascular, and neurological pathology. We examined whether or not ground-level ozone or fine particulate matter ≤ 2.5 μm in diameter (PM2.5) was associated with accelerated cognitive decline. Using repeated measures mixed regression modeling, we analyzed cognitive performance of a geographically diverse sampling of individuals from the National Alzheimer's Coordinating Center between 2004–2008. Ambient air concentrations of ozone and PM2.5 were established using a space-time Hierarchical Bayesian Model that statistically merged air monitor data and modeled air quality estimates. We then compared the ambient regional concentrations of ozone and PM2.5 with the rate of cognitive decline in residents within those regions. Increased levels of ozone correlated with an increased rate of cognitive decline, following adjustment for key individual and community-level risk factors. Furthermore, individuals harboring one or more APOE4 alleles exhibited a faster rate of cognitive decline. The deleterious association of ozone was confined to individuals with normal cognition who eventually became cognitively impaired as opposed to those who entered the study with baseline impairment. In contrast to ozone, we did not observe any correlation between ambient PM2.5 and cognitive decline at regulatory limits set by the Environmental Protection Agency. Our findings suggest that prolonged exposure to ground-level ozone may accelerate cognitive decline during the initial stages of dementia development.

Air Pollution, Stress, and Allostatic Load: Linking Systemic and Central Nervous System Impacts

“…Despite their differing properties and potential routes of exposure, both particulate matter and ozone have been associated with a variety of CNS impacts. These include impaired cognitive performance [27][28][29], dementia [30,31], anxiety and depression [32][33][34][35], and suicide [36][37][38]. It should be noted that there is considerable variability in the epidemiologic literature; a more comprehensive overview of associations between particulate matter or ozone and neurological/mental health outcomes is provided in several recent reviews [5,6,20,39,40].…”

Diesel exhaust impairs TREM2 to dysregulate neuroinflammation

“…Air pollution is rapidly increasing in prevalence in multiple countries and is a major contributor to the global burden of disease [ 1 ]. More specifically, components of urban air pollution are associated not only with pulmonary and cardiovascular diseases, but also with central nervous system (CNS) diseases and conditions, including Alzheimer’s disease (AD) [ 2 – 4 ], cognitive decline [ 5 – 8 ], and dementia [ 9 , 10 ]. Accumulating research with murine models demonstrates that components of air pollution impact the CNS and AD-like pathology [ 11 , 12 ].…”

Development of a large-scale computer-controlled ozone inhalation exposure system for rodents

“…Downstream consequences of O 3 exposure include increased susceptibility to respiratory infections and exacerbations of existing airway diseases such as asthma and chronic obstructive airway disease (Ko et al 2007; Ji et al 2011; Kim et al 2011). Long-term exposure to O 3 has also been linked to increased incidence of diabetes, cardiovascular disease, neurological disease, and mortality (Turner et al 2016; Day et al 2017; Jerrett et al 2017; Cleary et al 2018).…”