LIF bio-aerosol threat triggers: then and now

DeFreez, Richard K.

doi:10.1117/12.835088

Cited by 24 publications

(8 citation statements)

References 33 publications

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“…In parallel, the Naval Research Laboratory (NRL) demonstrated an elastic scatteringcued fluorescence sensor at 266 nm Seaver et al 1999). A collaboration between LL, NRL, and Edgewood Chemical and Biological Center led to an improved breadboard capability under the Rapid Agent Aerosol Detector (RAAD) program initiated in 2002 (DeFreez 2009;Jeys et al 2007) that employed an 808-nm structured beam as the cueing laser ), 355-nm polarized elastic scattering, dual fluorescence excitation at 266 and 355 nm (Sivaprakasam et al, 2004) that triggered laser-induced breakdown spectroscopy (Hybl et al 2006) at suspect events. The RAAD sensor was slated in 2017 to be the detector under the Enhanced Maritime Biological Detection (EMBD) program.…”

Section: Lif For Early Warning Of Human Pathogensmentioning

confidence: 99%

Real-time sensing of bioaerosols: Review and current perspectives

Huffman

Perring

Savage

et al. 2019

Aerosol Science and Technology

181

138

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Detection of bioaerosols, or primary biological aerosol particles (PBAPs), has become increasingly important for a wide variety of research communities and scientific questions. In particular, real-time (RT) techniques for autonomous, online detection and characterization of PBAP properties in both outdoor and indoor environments are becoming more commonplace and have opened avenues of research. With advances in technology, however, come challenges to standardize practices so that results are both reliable and comparable across technologies and users. Here, we present a critical review of major RT instrument classes that have been applied to PBAP research, especially with respect to environmental science, allergy monitoring, agriculture, public health, and national security. Eight major classes of RT techniques are covered, including the following: (i) fluorescence spectroscopy, (ii) elastic scattering, microscopy, and holography, (iii) Raman spectroscopy, (iv) mass spectrometry, (v) breakdown spectroscopy, (vi) remote sensing, (vii) microfluidic techniques, and (viii) paired aqueous techniques. For each class of technology we present technical limitations, misconceptions, and pitfalls, and also summarize best practices for operation, analysis, and reporting. The final section of the article presents pressing scientific questions and grand challenges for RT sensing of PBAP as well as recommendations for future work to encourage high-quality results and increased cross-community collaboration.

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Section: Lif For Early Warning Of Human Pathogensmentioning

confidence: 99%

Real-time sensing of bioaerosols: Review and current perspectives

Huffman

Perring

Savage

et al. 2019

Aerosol Science and Technology

181

138

View full text Add to dashboard Cite

show abstract

“…Technologies based on ultra-violet laser-induced fluorescence (UV-LIF) are capable of real-time, in situ detection and classification for biological and other organic carbon aerosols (e.g., [35][36][37][38], see a review by DeFreez [39]). A single-particle fluorescence spectrometer [SPFS, ref [38] can obtain the dispersed fluorescence spectra (280-700 nm) of individual airborne aerosol particles (1-10 lm size range) as they flow through the sensor.…”

Section: Introductionmentioning

confidence: 99%

Single particle size and fluorescence spectra from emissions of burning materials in a tube furnace to simulate burn pits

et al. 2013

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A single-particle fluorescence spectrometer (SPFS) and an aerodynamic particle sizer were used to measure the fluorescence spectra and particle size distribution from the particulate emissions of 12 different burning materials in a tube furnace to simulate open-air burning of garbage. Although the particulate emissions are likely dominated by particles \1 lm diameter, only the spectra of supermicron particles were measured here. The overall fluorescence spectral profiles exhibit either one or two broad bands peaked around 300-450 nm within the 280-650 nm spectral range, when the particles are illuminated with a 263-nm laser. Different burning materials have different profiles, some of them (cigarette, hair, uniform, paper, and plastics) show small changes during the burning process, and while others (beef, bread, carrot, Styrofoam, and wood) show big variations, which initially exhibit a single UV peak (around 310-340 nm) and a long shoulder in visible, and then gradually evolve into a bimodal spectrum with another visible peak (around 430-450 nm) having increasing intensity during the burning process. These spectral profiles could mainly derive from polycyclic aromatic hydrocarbons with the combinations of tyrosine-like, tryptophan-like, and other humiclike substances. About 68 % of these single-particle fluorescence spectra can be grouped into 10 clustered spectral templates that are derived from the spectra of millions of atmospheric aerosol particles observed in three locations; while the others, particularly these bimodal spectra, do not fall into any of the 10 templates. Therefore, the spectra from particulate emissions of burning materials can be easily discriminated from that of common atmospheric aerosol particles. The SFFS technology could be a good tool for monitoring burning pit emissions and possibly for distinguishing them from atmospheric aerosol particles.

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“…The IBAC samples ambient air at 3 L/min and provides the total number concentrations for fluorescent particles (particle number per liter of air, particles/L) every second. The IBAC utilizes ultraviolet laser induced fluorescence (UV‐LIF) at an excitation wavelength of 405 nm to discriminate fluorescent particles from ambient background particles . The particles are binned into two size categories: 0.5‐1.7 and 1.7‐10 μm .…”

Section: Test Facility Study Design and Methodsmentioning

confidence: 99%

Impact of air‐handling system exhaust failure on dissemination pattern of simulant pathogen particles in a clinical biocontainment unit

et al. 2018

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Biocontainment units (BCUs) are facilities used to care for patients with highly infectious diseases. However, there is limited guidance on BCU protocols and design. This study presents the first investigation of how HVAC (heating, ventilation, air-conditioning) operating conditions influence the dissemination of fluorescent tracer particles released in a BCU. Test conditions included normal HVAC operation and exhaust failure resulting in loss of negative pressure. A suspension of optical brightener powder and water was nebulized to produce fluorescent particles simulating droplet nuclei (0.5-5 μm). Airborne particle number concentrations were monitored by Instantaneous Biological Analyzers and Collectors (FLIR Systems). During normal HVAC operation, fluorescent tracer particles were contained in the isolation room (average concentration = 1 × 10 ± 3 × 10 /L ). Under exhaust failure, the automated HVAC system maximizes airflow into areas adjacent to isolation rooms to attempt to maintain negative pressure differential. However, 6% of the fluorescent particles were transported through cracks around doors/door handles out of the isolation room via airflow alone and not by movement of personnel or doors. Overall, this study provides a systematic method for evaluating capabilities to contain aerosolized particles during various HVAC scenarios. Recommendations are provided to improve situation-specific BCU safety.

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LIF bio-aerosol threat triggers: then and now

Cited by 24 publications

References 33 publications

Real-time sensing of bioaerosols: Review and current perspectives

Real-time sensing of bioaerosols: Review and current perspectives

Single particle size and fluorescence spectra from emissions of burning materials in a tube furnace to simulate burn pits

Impact of air‐handling system exhaust failure on dissemination pattern of simulant pathogen particles in a clinical biocontainment unit

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