A Systematic Review of Two LIF-Based instruments for Bioaerosol Monitoring: Data Treatment, Performance Evaluation, Applications and Comparison of WIBS and Rapid-E

Biological aerosols are ubiquitous and can affect human health and atmospheric processes. Conventional off-line techniques, including culture-based methods, microscopy, and molecular approaches (e.g., PCR/NGS) provide information but are slow and unsuitable for capturing short-term dynamics. Ultraviolet light-induced fluorescence (UV-LIF) instruments enable real-time monitoring of bioaerosol, yet biological attribution remains challenging due to fluorescent interferents (such as PAHs, soot, mineral dust, and biomass-burning particles) and heterogeneous data treatment. This systematic review assesses the state-of-knowledge of two UV-LIF instruments, the Wideband Integrated Bioaerosol Sensor (WIBS) and Rapid-E(+), focusing on monitoring performance, data processing, application in outdoor and indoor environments, and comparison against other methods for the bioaerosols measurements. A literature search was performed on Scopus, Web of Science and PubMed using a search string. A total of 76 original articles were included (60 using WIBS, 13 using Rapid-E(+), 3 using both instruments). Outdoor field deployments dominate (n = 51), followed by laboratory studies (n = 32), whereas indoor campaigns remain scarce (n = 7); 20 studies included comparisons with other approaches for bioaerosol detection. Despite some discrepancies in counting performance of particles, with WIBS more reliably detecting finer particles (especially 1–2 μm) and Rapid-E(+) performing better for larger particles (i.e. > 10 μm), laboratory evidence shows a good ability to discriminate between biological and non-biological particles. The review further provides a structured synthesis of data-treatment approaches, validation needs and practical applicability across laboratory, indoor, outdoor and source-oriented settings. From indoor studies, the role of human occupancy and activities emerged, while in outdoor environments the presence of natural sources of bioaerosol, meteorological and seasonal-related patterns, and the influence of anthropogenic interferents was evident.