Indoor Air Quality in Critical Indoor Environments: A Review Paper

Abstract Indoor air quality (IAQ) plays a critical role in public health, particularly in environments where individuals spend prolonged periods of time indoors, and this become a key consideration to researchers and health practitioners. This comprehensive review investigates and highlights recent studies, conducted in diverse geographic regions, and published between 2019 and 2024 in peer-reviewed journals on indoor air quality (IAQ) in critical indoor environments such as healthcare facilities, schools, and residential buildings. The purpose of this review is to draw out recent key findings and highlights the gaps associated in air quality studies through a methodological analysis of a series of research articles. Major pollutants identified in such review study include particulate matter, carbon dioxide, carbon monoxide, volatile organic compounds, formaldehyde, and biological contaminants. This study highlights how poor ventilation, seasonal variations, building design, and daily indoor activities contribute to elevated pollutant levels. Evidence shows that these exposures are linked to a range of health outcomes, including respiratory illnesses, cognitive decline, and increased risks for vulnerable populations such as children and patients. The review highlights factors affecting IAQ resulting in exacerbated health risks, in addition to different air quality management strategies providing control programs and special requirements especially for critical indoor settings, where maintaining specific environmental conditions is essential to ensure safety, health, comfort, or proper functioning of sensitive processes or equipment. Considering future developments in IAQ, this review paper provides a forward-looking perspective and a comprehensive air quality management framework to serves as a valuable resource for researchers, engineers, practitioners, and policymakers.