A comprehensive review of microbial contamination in the indoor environment: sources, sampling, health risks, and mitigation strategies

Abstract

The quality of the indoor environment significantly impacts human health and productivity, especially given the amount of time individuals spend indoors globally. While chemical pollutants have been a focus of indoor air quality research, microbial contaminants also have a significant bearing on indoor air quality. This review provides a comprehensive overview of microbial contamination in built environments, covering sources, sampling strategies, and analysis methods. Microbial contamination has various origins, including human occupants, pets, and the outdoor environment. Sampling strategies for indoor microbial contamination include air, surface, and dust sampling, and various analysis methods are used to assess microbial diversity and complexity in indoor environments. The review also discusses the health risks associated with microbial contaminants, including bacteria, fungi, and viruses, and their products in indoor air, highlighting the need for evidence-based studies that can relate to specific health conditions. The importance of indoor air quality is emphasized from the perspective of the COVID-19 pandemic. A section of the review highlights the knowledge gap related to microbiological burden in indoor environments in developing countries, using India as a representative example. Finally, potential mitigation strategies to improve microbiological indoor air quality are briefly reviewed.

The distribution characteristics of aerosol bacteria in different types of sheepfolds

“…Upon inhalation, some of these bacteria deposit in the bronchi and bronchioles, disrupting the normal gas exchange in the lungs. Additionally, a portion of these microorganisms enters the circulatory system during the exchange of gases and blood, leading to even more severe health consequences for both humans and animals ( 29 ). Research by Bertrand has demonstrated that exposure to low concentrations of endotoxins, a component of microbial aerosols, can lead to increased lung inflammation ( 30 ).…”

“…Optimizing ventilation systems ensures the circulation of clean air, minimizing the risk of airborne pathogen transmission. Enhancing ventilation systems, incorporating routine air quality monitoring, and implementing sanitation protocols represent proactive measures farmers can take to mitigate the presence of harmful microbial aerosols ( 29 ). Furthermore, the identification of prevalent pathogenic bacteria offers valuable insights for implementing preventive strategies, including vaccination protocols or adjustments to animal husbandry practices, thereby minimizing the potential impact of these pathogens on sheep health.…”

“…Exposure to microbial aerosols poses significant health risks due to their ability to infiltrate the body through various routes, including skin damage, mucosa, the respiratory tract, and the digestive tract. These microorganisms, once inside the body, can inflict irreparable damage on different bodily systems (28). Particularly concerning are airborne aerobic bacteria smaller than 2.0 μm, which can easily enter the body through the respiratory route.…”

Navigating the Aerosolized Frontier: A Comprehensive Review of Bioaerosol Research Post-COVID-19

“…In contrast, active sampling involves drawing a preset volume of air through a pump, allowing airborne microbes to settle on culture media, fine fibers, or porous membrane structures. This method is suitable for microbial sampling of inhalable dust and allows for the quantification of biological aerosol concentrations [10]. Detecting pathogens is vital for controlling and preventing potential deadly disease outbreaks [11].…”