Air Pollution Control Technologies for Indoor Particulate Matter Pollution: A Review

Indoor air quality is one of the major concerns in the modern environment since urban residents spend 80–90% of their time staying indoors. Pollutant exposure could be relatively higher indoors due to the increased number of sources along with activities that cause re-suspension of pollutants back into the air stream. Several existing and emerging technologies for indoor particulate matter (PM) control are available; however, there is a lack of a comprehensive review of these technologies for the end-users. Therefore, current study presents a techno-commercial comparison of the existing indoor air pollution control technologies based on several metrics such as particle removal efficiency, cost-commercialization, energy consumption, and by-product emission. Additionally, recent advancements and applications of the aforementioned technologies in real indoor environments have also been reviewed. The study suggests that for efficient particle removal, either high-efficiency particulate air (HEPA) filters or ESP should be preferred. Likewise, for the removal of multiple pollutants like particles, gases and volatile organic compounds simultaneously, emerging technologies can be integrated with pre- or post-stages of conventional technologies. The cost performance index is lowest for HEPA filters and ESP, indicating that they provide a better value for money in terms of performance. Ionization based and emerging PM control technologies should be avoided in case of sensitive populations due to health concern associated with emission of hazardous by-products. Graphical Abstract