Chemical composition-viability relationship of bioaerosols through spatial distribution and size-controlled measurements

Abstract Bioaerosols are small airborne particles that can harbor pathogenic microorganisms leading to serious and challenging-to-control diseases such as respiratory syncytial virus (RSV), SARS-CoV-2, and influenza in humans, and porcine reproductive and respiratory syndrome (PRRS) in animals. RSV is particularly hazardous to young children, causing severe lower respiratory tract infections. Unfortunately, there are no effective therapies or vaccines for RSV in the pediatric population. However, by gaining a better understanding of the transmission dynamics of airborne viruses through bioaerosols, we can improve our ability to predict and control their spread through the implementation of administrative and engineering controls such as optimized ventilation designs. The project's broad and long-term objectives are to understand how the bioaerosol's microenvironmental conditions, such as size, chemical composition, and phase status, and environmental conditions, such as temperature, relative humidity (RH), and UV light, can impact the pathogen viability and transmission. Towards this goal, this proposed study aims to develop an innovative method for measuring virus distribution in bioaerosols and understanding their viability decay based on chemical compositions that are more relevant to various respiratory generation locations, specifically for sub-5µm and submicron particles that can transmit long distances. This study will be performed in two aims. First, we will determine the spatial distribution of chemicals and pathogens in bioaerosols. We'll use gold nanoparticles to label RSV and visualize it with advanced electron microscopy and spectroscopy to map the chemical distribution of various components such as salt (Na, K, Cl) and protein. This will help us understand how viruses are distributed in bioaerosols and provide insights into their corresponding survival rate and viability. Second, we will study chemical composition's impact on RSV viability decay for sub-5µm and submicron bioaerosol particles from various generation origins. We will generate monodisperse particles using a unique experimental setup in this size range with various chemical compositions from oral to deep lung, and measure RNA and virus viability to obtain virus decay rates. This aim investigates airborne virus decay rates for submicron and sub-5 m virus-laden particles, critical for long-range airborne transmission, and identifies the relationship between pathogen viability decay rates and chemical compositions from various generation locations. This study proposes a novel gold labeling approach to measure the distribution of viruses within bioaerosol particles. It contributes to our long-term goals by providing insights into the relationship between the chemical composition, virus spatial distribution in bioaerosol particles, and the survival of pathogens. This tool can be applied to various pathogens besides RSV. The proposed work aims to provide a better understanding of how pathogens survive and interact with their microenvironment, going beyond the current state-of-the-art.