Long-term PM2.5 Exposure and Neurological Hospital Admissions in the Northeastern United States

by Thy Annie Nguyen

Many prior studies have suggested that particulate matter (PM) exposure may induce an inflammatory response that leads to neurodegenerative diseases and cognitive decline. PM has been known to carry heavy metals, induce free radicals, and contain carcinogens. Especially with PM2.5 (particulate matter ≤ 2.5 μm) being small enough to potentially cross the blood brain barrier, it is worth studying how these aerial pollutants may affect neurological health. In a study from 1999 to 2010 in the northeastern United States, Kioumourtzoglou et al. (2016) found a correlation between long-term exposure in dense, urban cities that produced large quantities of PM2.5 and accelerated disease progression in Alzheimer’s Disease (AD), Parkinson’s Disease (PD), and dementia. Approximately 9.8 million residents in 50 cities were surveyed while air pollution data was collected from the EPA’s Air Quality System Database. Although the design of the study prohibited an analysis of the role of PM2.5 in disease onset, researchers were able to measure the effects PM2.5 concentrations had on the current population of neurological patients who had already exhibited the onset of disease. Continue reading

Pathophysiological Effects of Particulate Matter Air Pollution on the Central Nervous System

by Thy Annie Nguyen

Human activities have severely impacted air quality. Whereas cardiovascular disease and respiratory conditions have been the main concern in assessing the adverse effects of air pollution, neurological impacts are recently being studied and are equally important. Wright and Ding (2016) review the many adverse effects of particulate matter (PM) exposure and the implications of increased air pollution in highly urbanized communities. From short-term insults to long-term diseases, it was found that PM from air pollution was a direct cause of a myriad neurological diseases as well as increasing mortality and cardiovascular morbidity. PM air pollution consists of “metals, dust, various organic compounds, and microorganisms suspended within aerosolized droplets.” When inhaled, ultrafine PM is small enough to cross blood and mucous barriers, travelling to the brain and other parts of the central nervous system. As ultrafine PM enters these sites, they may directly cause insults on neurological systems through inflammation, inhibiting blood flow, decreased brain volume, increases oxidative stress, and much more. For example, long-term exposure to ultrafine PM has been shown to lead to vascular conditions such as hypertension and atherosclerosis. In addition, blockages in blood vessel in the brain have been strongly associated with increased likelihoods of stroke. Continue reading