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Development of a Highly Efficient Personal Sampler to Collect Viable Bioaerosols.

PB2014108842

Publication Date	2011
Personal Author	Cheng, Y. S.; Su, W. C.
Page Count	39
Abstract	Airborne microorganisms (bioaerosols) such as viruses, allergens, bacteria, and fungal spores are almost ubiquitous in the environment. Exposure to bioaerosols in the environment may pose health risks and cause adverse health effects to the general and occupational population. Therefore, it is necessary to employ suitable methods to accurately monitor the concentration of the airborne microorganisms in the environment in order to ensure a sanitary workplace. Personal aerosol sampling is considered the most appropriate method with which to conduct health related exposure assessments. Thus, sampling bioaerosols using personal bioaerosol samplers should be a preferred method for assessing personal exposure to airborne microorganisms. This research designed, fabricated and tested a new personal bioaerosol sampler based on the rationale of a swirling cyclone incorporated a re-circulating liquid film, because bioaerosol sampling into liquid using swirling air in a cyclone features high microbial viability to the collected bioaerosols. The performance evaluation of the prototypes in a mixing chamber demonstrated that these newly developed personal bioaerosol samplers are capable of high-efficiency bioaerosol sampling with cut-off diameter (d50) equal to 0.7 um. In addition, the biological efficiency tests indicated that both samplers could permit acceptable bioaerosol survival rate for the airborne microorganisms collected. For the performance evaluations conducted in wind tunnels, the physical sampling efficiencies (aspiration efficiency, collection efficiency, and the capture efficiency) of the prototypes were tested under realistic sampling conditions. The results of the evaluation showed that the aspiration efficiency obtained from the prototypes agreed well with the ACGIH inhalable convention with slight underestimation. The collection efficiency can generally reach 80% as the aerosol size > 2 um. However, the wall loss of the prototypes was considered high especially for the aerosol size larger than 5 um which cause relatively low capture efficiency for the prototype. The test results acquired from this study enabled a full assessment of the working function of these personal bioaerosol sampler prototypes under practical sampling conditions which can offer insight into possible modifications and improvement in the future.
Keywords	Aerosols Biological agents Air samplers Allergens Bacteria Environmental exposure Fungi Health effects Microorganisms Monitoring Occupational safety and health Performance evaluation Populations Risk factors Work environment
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	Lovelace Respiratory Research Inst., Albuquerque, NM.; National Inst. for Occupational Safety and Health, Washington, DC.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	201423

Development of a Highly Efficient Personal Sampler to Collect Viable Bioaerosols.

Development of a Highly Efficient Personal Sampler to Collect Viable Bioaerosols.
PB2014108842

Publication Date	2011
Personal Author	Cheng, Y. S.; Su, W. C.
Page Count	39
Abstract	Airborne microorganisms (bioaerosols) such as viruses, allergens, bacteria, and fungal spores are almost ubiquitous in the environment. Exposure to bioaerosols in the environment may pose health risks and cause adverse health effects to the general and occupational population. Therefore, it is necessary to employ suitable methods to accurately monitor the concentration of the airborne microorganisms in the environment in order to ensure a sanitary workplace. Personal aerosol sampling is considered the most appropriate method with which to conduct health related exposure assessments. Thus, sampling bioaerosols using personal bioaerosol samplers should be a preferred method for assessing personal exposure to airborne microorganisms. This research designed, fabricated and tested a new personal bioaerosol sampler based on the rationale of a swirling cyclone incorporated a re-circulating liquid film, because bioaerosol sampling into liquid using swirling air in a cyclone features high microbial viability to the collected bioaerosols. The performance evaluation of the prototypes in a mixing chamber demonstrated that these newly developed personal bioaerosol samplers are capable of high-efficiency bioaerosol sampling with cut-off diameter (d50) equal to 0.7 um. In addition, the biological efficiency tests indicated that both samplers could permit acceptable bioaerosol survival rate for the airborne microorganisms collected. For the performance evaluations conducted in wind tunnels, the physical sampling efficiencies (aspiration efficiency, collection efficiency, and the capture efficiency) of the prototypes were tested under realistic sampling conditions. The results of the evaluation showed that the aspiration efficiency obtained from the prototypes agreed well with the ACGIH inhalable convention with slight underestimation. The collection efficiency can generally reach 80% as the aerosol size > 2 um. However, the wall loss of the prototypes was considered high especially for the aerosol size larger than 5 um which cause relatively low capture efficiency for the prototype. The test results acquired from this study enabled a full assessment of the working function of these personal bioaerosol sampler prototypes under practical sampling conditions which can offer insight into possible modifications and improvement in the future.
Keywords	Aerosols Biological agents Air samplers Allergens Bacteria Environmental exposure Fungi Health effects Microorganisms Monitoring Occupational safety and health Performance evaluation Populations Risk factors Work environment
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	Lovelace Respiratory Research Inst., Albuquerque, NM.; National Inst. for Occupational Safety and Health, Washington, DC.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	201423