BackgroundThere is considerable literature indicating a link between PM and cardiovascular morbidity and mortality, particularly in the elderly (Koken et al, 2003). Particles defined as any particle measuring less than or equal to ten micrometers (< 10 µm PM10) or two point five micrometers (< 2.5 µm PM2.5) that form from solid particles and liquid droplets. Most particles are formed due to vehicle intakes, industrial processes or wood combustion. Additionally, it has also been suggested that ultrafine particles measuring less than or equal to 2.5 µm are considered more harmful to health than particles larger in aerodynamic diameter, as PM2.5 can penetrate deeper into the lungs. than PM10 (Park, et al., 2010). Although ambient air pollution has declined in recent decades due to strict air pollution control policies, there is little evidence directly supporting the extent to which these control measures have improved public health (Ton , et al, 2010). Investigative research has observed evidence supporting the association between air pollution and particulate matter and an increase in cardiovascular events. A more in-depth understanding of the mechanisms associated with these observations is needed. It is important to further examine these associations with more specific outcomes that may suggest specific pathways (Zanobetti & Schwartz, 2005). The purpose of this article is to present an analytical assessment of the data on the association of PM and incidence between cardiovascular morbidity and mortality. Methodological issues Several reports have addressed the issue of weather conditions and mortality; extreme temperature factors are associated...... middle of article ...... heart rate variability: the Multi-Ethnic Study of Atherosclerosis (MESA). Approximately. Health outlook. 2010 October;118(10):1406-1411.4. Schneider A, Hampel R, Ibald-Mulli A, Zareba W, Schmidt G, Schneider R et al. Changes in heart rate deceleration capacity and heart rate variability induced by ambient air pollution in individuals with coronary heart disease. Toxicol Fiber Part. 2010;7:29.5. Tonne C, Beevers S, Kelly FJ, Jarup L, Wilkinson P, Armstrong B. An approach to estimating the health effects of changes over time in air pollution: an illustration using admissions to cardiorespiratory hospitals in London . Occupy Environ Med. June 2010;67(6):422-427.6. Zanobetti A, Schwartz J. The effect of particulate air pollution on emergency admissions for myocardial infarction: a multicity cross-case analysis. Approximately. Health outlook. august 2005;113(8):978-982.