The increasing impurities in the air in megacities and associated public health concerns have received growing attention over the past few decades. This study focused on evaluating and investigating the air quality around the McMillan NCore-PAMS site from February to July 2007 through a comparison of the appearance frequency of airborne bacteria and air pollutants. Gram-positive bacteria exhibited a lower appearance frequency in summer relative to February when the temperatures were lower. A high appearance frequency of gram-negative bacteria in summer months when temperatures were higher was observed, and a low appearance frequency in spring and winter when temperatures were lower. Nineteen common bacteria were identified. The most frequent were Proteus mirabilis, Enterobacter cloacae, and Pseudomonas luteola. EPA recorded nitrogen dioxide, ozone, and particulate matter 2.5 at McMillan NCore-PAMS. Their AQI values and concentrations were below the unhealthy standard level of EPA, but few of their peak values were considered in this study. These peak values and the higher number of gram-negative bacteria CFUs count were simultaneously high in the same summer months. Statistical calculations of the grams CFUs count and the concentration and AQI values of the above pollutants were performed; but no correlations of statistical significance were identified.

This research study reports a simultaneous increase between aerosols and airborne bacteria during the summer months of the observation period but not a correlation. The peaks of the bacteria and pollutants may be due to events that affected this small increase in the data. More studies of this type are needed to establish a baseline for more comprehensive evaluations of the influence of air quality on aerobiology in urban zones, for bacteria might be as important as other chemicals in the atmosphere. Furthermore, policies need to be in place for the combination of air bacteria and air chemistry, a census on air bacteria is needed, and studies are needed to determine what amount of air bacteria represents a health threat to the population.