Using scanning electron microscopy to measure air particulates

The importance of air particulates is often overlooked. Yet, it is crucial to the health of humans and other animals alike. In this study, a method of measuring air quality is proposed, using a scanning electron microscope (SEM). To determine whether this is an effective way of measuring particulate matter (PM) level in the air, roads with various substrate composition and ambient surroundings were selected to simulate various air conditions. Indoor air quality within specific buildings on the UPEI campus was also measured to further test this method. Air particles that settled on metal stubs at the various study sites were counted using a SEM. In terms of replicability, three, blind trials were performed for all the SEM photos taken. Correlation values for these trials were all above 0.7, indicating a strong, linear correlation coefficient r. In terms of this method's reliability, however, we learned that correlation values decrease as the number and the size of the particles decrease. Finally, for the indoor air samplings, the correlation coefficient between Dylos monitor and SEM count were weak and negatively correlated, indicating little to no correlation between the two data sets. In conclusion, as a stand-alone method, SEM is not as effective as previously anticipated. However, it does offer information towards the physical appearance of the particulates, which can provide valuable insights towards the air we breathe.