Chemical and Biological Compositions Associated with Ambient Respirable Particulate Matter: a Review

Particulate matter (PM) is defined as a mixture of solid and/or liquid particles that remain separately dispersed in air. PM is not a pollutant by itself but a complex and dynamic combination of compound particles with biological and chemical origins. However, fine PM (PM2.5) seems to be incriminated in the respiratory system and poses a severe threat to human health. Several reviews focused on chemistry segments because they mainly contribute to fine PM concentration. Biological elements in PM2.5 should also be considered because they cause multiple allergies and respiratory illnesses. This review has selected articles by following predefined criteria and demonstrated that the biological and chemical parts of fine particles play a significant role in PM2.5 concentration. In addition, justification on the origin or sources of biological and chemical compositions and their effects on health become a concern in this review. Lastly, this review can provide knowledge that can be a useful tool for researchers, designers, engineers and policymakers to consider for further action.