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. The World Health Organization suggests that one of the most preventable causes of stroke may be reducing PM exposure, decreasing human mortality by almost 750,000 deaths per year. Looking at long-term neurological diseases, constant exposure to PM leads to an immunological response that stimulates the production of pro-inflammatory cytokines. As a result of constant inflammation, cell proliferation is reduced and toxicity and cell death is more likely. These factors may contribute to diseases such as Alzheimer’s Disease, Parkinson’s Disease, and other conditions that arise from decreased brain volume and obstructive cell debris and plaques.
Although the exact mechanisms of neurological disease are still not fully understood, there is strong evidence reflecting a relationship between environmental conditions and the onset of disease. Especially in communities with high air pollution and low air quality, aggregation of PM may lead to disproportionately higher incidences of detrimental health effects. Considering the increase of urban development and air pollution, it is necessary to observe how human health may be impacted by climate change and recognize the relationship between environment and health.
Wright, Joshua C., and Yuchuan Ding. “Pathophysiological effects of particulate matter air pollution on the central nervous system.” Environmental Disease 1.3 (2016): 85.