Biological aerosol particles (also known as bioaerosols) are airborne particles that can be derived from virtually any biological processes and were some of the first types of aerosols to be studied. Bioaerosols are involved in a myriad of natural, environmental, agricultural, industrial, and human health processes and are the driving force behind many public health effects by causing a host of allergies and infectious diseases. Bioaerosols are also tremendously complex to study, and despite the long history of their investigation and their broad influence, numerous important questions remain unanswered. Key challenges in the study of bioaerosol include the inherent multi-disciplinarity of the work, often involving not only aerosol science, microbiology, atmospheric science, physics, chemistry, and engineering, but knowledge of building science, ventilation, sampling, human dynamics, medicine, public health, infectious diseases, botany and plant pathology, agriculture, advanced computational analysis, and countless other scientific disciplines. Differences can be further compounded by diversity among researchers with respect to discipline, training, experience, research goals, sources of funding, data-sharing limitations, and security concerns. As a result of the broad diversity of researchers who apply themselves to bioaerosol questions, there is frequently a distinct lack of continuity to technical approaches, and these differences can make comparison across efforts challenging or impossible.
As a part of the 2018 International Aerosol Conference in St. Louis, Missouri, USA, the Bioaerosol Working Group of the American Association for Aerosol Research (AAAR) convened a special session (9BA)Footnote1 dedicated to research challenges unique to the generation, sampling, and analysis of bioaerosols in both laboratory and field studies. Each presenter provided a very short review of key topics, followed by comments about community needs, experimental challenges, and nuances of which bioaerosol scientists should be aware. The session was highly attended, well received, and provided tremendous range of practical experience. At a follow-up meeting on the last day of the conference, leaders in various bioaerosol-associated research fields came together to further discuss how to encourage synergism of practices that would improve the quality and reproducibility of experimental results.
Through these discussions it became evident that, due to the great diversity of applications and topics under the umbrella of bioaerosol research, there was a need to more fully discuss challenges that need to be addressed to achieve deeper synergism between individual investigators and the broader research community. The primary goal of this special issue is to address a need within the bioaerosol community: for better alignment in methodologies; to provide guidance on best-practices; to identify limitations, issues, common errors, or incorrect assumptions; and to encourage specific reporting on key concepts that are often overlooked in bioaerosol studies. The present special issue was conceptualized and eight authors were invited to contribute review and perspective articles surrounding topics to represent a broad spectrum of bioaerosol research activities and goals. The eight lead authors then each assembled an experienced and diverse team of scientists to complete their goal. The teams that completed these eight articles represent a sum 52 authors from 33 institutions in 13 countries, and represent a wide range of scientific backgrounds, disciplines, and training as well as diversity of gender, career stage, type of institution, and national culture. The diversity of perspectives assembled within the special issue is thus central to the goal of counteracting challenges introduced by the multi-disciplinarity and disconnectedness of researchers and communities. The articles cover sampling, assay, enumeration, and real-time sensing techniques; both indoor and outdoor field sampling; laboratory study; natural sources and experimental generation of bioaerosols; and appropriate reference standards. Each provides a different flavor of their respective topics, but common themes are present across the articles. In general, the articles are not meant to be broad, comprehensive reviews, but rather contain brief history and summaries of topics along with relatively brief and focused literature reviews. Each article also includes significant components of perspective, including: assessment of best current practices; misconceptions or errors to be avoided; limitations and current problems to be addressed; recommendations for future work and solutions for sub-communities to work toward; reporting or archiving suggestions or guidelines; and big-picture or grand challenges to be addressed. The eight articles taken together in the special issue entitled “Bioaerosol Research: Methods, Challenges, and Perspectives” thus aims to help connect the path from the tremendous community successes from recent years to pave a way toward next steps in the future.
Special thanks to the lead authors of each of the review articles in this special issue and to Richard Thomas, Jay Eversole, and Josh Santarpia for helping to moderate the IAC meeting discussion.