The association between chronic exposure to air pollution and health disorders have been highlighted by numerous environment based studies. Of late, the effect of air pollution on human health is being perceived as a major public health problem, demanding for establishment of stricter standards regarding permissible levels of particulate matter in the outdoor setting.
In the United States, the revised standard level of airborne particulate matter was established at less than or equal to 2.5 ĩm in aerodynamic diameter (PM2.5). Particles of this size have a greater potential to reach the minute airways than larger sized particles. There is a considerable lack in the number of studies conducted on the health risks associated with such fine particles.
Researchers from Johns Hopkins University involved themselves in a study to the specific risk of cardiovascular and respiratory disease as a consequence of acute exposure to fine particulate air pollution. The hospital admission data of more than 11.5 million patients, who lived across 204 urbanized locations in the U.S, were analyzed. On an average, these individuals were based at a distance of 5.9 miles from a PM2.5 monitor.
A slight increase in the rate of hospital admission was observed. Excluding injuries, the hospital admission could be related to PM2.5 exposure. Amongst all the observed health outcomes, the relationship between cardiac failure and PM2.5 exposure was the greatest. A three times higher exposure to PM2.5 was found to increase the cardiovascular risk by a margin of 1.28%.
Individuals living in the Northeastern, Southeastern, South and Midwest were specifically at increased cardiovascular disease owing to high levels of PM2.5. Exposure to particulate matter can induce inflammation, leading to aggravation of a pre-existing lung or cardiovascular disease and compromise on the lung-defense mechanisms.
The results of this present study highlight the need for a critical evaluation of National Ambient Air Quality Standard and establishment of an optimal level. It is equally important to establish appropriate control strategies to preserve the health of the general population, more specifically, the aged.