Bioaerosol

Placement of the building in relation to wind directions and surrounding activities, such as other industrial plants and their exhausts and neighboring roads, can be important for the performance of the ventilation system and thus also for the possibility of keeping to the target levels. Trees and bushes generate bioaerosols that may enter the ventilation system. 

Infectious communicable bioaerosols contain bacteria or virus within small droplet nuclei produced from the drying of larger liquid droplets and can transmit disease. 

Infectious non-communicable bioaerosols are airborne bacteria or fungi that can infect humans but that have a nonhuman source. 

The health effects of non-infectious bioaerosols include allergy symptoms, asthma symptoms, and hypersensitivity pneumonitis. 

Boron oxide Bioaerosol Bitumen fume Bromotrifluoro methane Bromoxynil Bromoxynil octanoate Butadiene (1,3-butadiene)... 

The lengthy assay described here may well provide specific information about the identity of the components of the biological sample. More rapid—but less specific—information may be obtained from other technologies, such as the bioaerosol detectors discussed below. 

Dr. Arthur P. S. LAU Applied Technology Center, HKUST Bioaerosol measurements... 

The results of the air quality surveys and interviews with the residents indicated that dust, particulates and bioaerosols are major problems in Hong Kong residential homes. The high level of carbon monoxide produced during cooking must be addressed. Odors are the most common complaints from the residents despite the recorded low level of VOCs. This is understandable since the threshold odor for most of these compounds is very low. The team therefore recommends that the product should feature aerosols (i.e., dust and particulates), bioaerosols (i.e., airborne bacteria and fungi), carbon monoxide and odor (i.e., VOCs) removal technologies. 

Filtration is an efficient and inexpensive method for removing dust, particulates and bioaerosols from indoor air. High efficiency filters can remove up to 95 % of airborne particles as small as 0.3 microns. However, odor associated with gaseous VOCs cannot be removed by simple filtration and must be captured using adsorbents such as activated carbon and charcoal. Frequent replacement is needed since these adsorbents have finite capacity and cannot be regenerated. The aim of this project is to develop an effective remediation technology for common airborne VOCs found indoor. 

The indoor air quality appliance must have better than ninety percent efficient in removing airborne particulates, bioaerosols (i.e., airborne bacteria and fungi spores), carbon monoxide, volatile organic compounds and odors. It must meet or exceed the industry s standards in performance and safety. The product must be able to maintain the pollutants in indoor air at below government IAQ standards and must not emit or produce harmful secondary pollutions during... 

The intrinsic germicidal property of the Ti02 support was also tested for natural indoor bioaerosol. A piece of cotton cloth was coated with a colloidal suspension of the nanostructured Ti02. After drying, a circular piece of the cloth was cut and fitted inside the Andersen viable single-stage sampler in such a way... 

Five weeks air survey was conducted to determine the air quality at the clinic. The reception area has a lower bioaerosol loading of 300-800 CFU/m3 owing to better airflow and open floor plan. The doctor s consultation room displays 2-to-3 times higher amount of airborne bioaerosol (i.e., 600-1400 CFU/m3) due to poor air ventilation. The airflow is roughly 0.1 m3/s, giving an overall air... 

Tables 12.9-5 and 12.9-6 summarize the results of the three months period when weekly measurements were conducted. The temperature and humidity of the clinic is relative constant at around 23 °C and 80 %, but the bioaerosol level changes by the hour and day-to-day depending on the number of patients and outside air quality. The Prototype Unit was placed in the doctor s consultation room and the airflow was set at normal-speed (Fig. 12.9-12c), allowing a complete exchange of the room s air every 30 minutes. The air sample from the reception and doctor s consultation room were sampled within 20 minutes of each other. The data in the tables show that the airborne microorganisms in the doctor s consultation room remained higher compared to the reception area. However, this is a significant improvement when compared to the level when the Prototype Unit was not in use. Data obtained by measuring the inlet and outlet bioaerosol in the Prototype Unit indicated that 60 % and 67 % reduction in airborne bacteria and fungi was obtained, respectively. The performance was maintained during the six months test.

Four prototypes were built and tested during the months of September and October 2003. The new prototypes were tested and the performances for VOC and bioaerosol removal and remediation were within 90 % of the benchmark unit (cf. Table 12.9-3 Fig. 12.9-10). Permission was obtained to field test two... 

Bayer, C. M., The Effect of Building Bake-Out Conditions on Volatile Organic Compound Emissions, in Indoor Air Pollution—Radon, Bioaerosols, VOC s (J. G. Kay, G. E. Keller, and... 

Naik, D. V., C. J. Weschler, and H. C. Shields, Indoor and Outdoor Concentrations of Organic Compounds Associated with Airborne Particles Results Using a Novel Solvent System, in Indoor Air Pollution—Radon, Bioaerosols, VOC s (J. G. Kay, G. E. Keller, and J. F. Miller, Eds.), Chap. 6, pp. 59-70, Lewis Publishers, Chelsea, MI, 1991. 

D. P. Fergenson et al., Reagentless Detection and Classification of Individual Bioaerosol Particles in Seconds, Anal. Chem. 2004, 76, 373 ... 

Seedorf J (2004) An emission inventory of livestock-related bioaerosols for lower Saxony, Germany. Atmos Environ 38 6565-6581... 

Obtaining SERS spectra from pollen and in particular from the cellular interior is of interest as it may provide higher sensitivity for detection of pollen fragments in bioaerosols, and may also enable studies of allergologically relevant pollen molecular constituents. Sengupta et al. published SERS spectra from suspensions of cottonwood and redwood pollen as well as two types of grass and compared them with spectra from bacteria [54, 90]. The spectra were obtained from suspensions of pollen particles in silver colloids. As the amount of pollen used was not quantified in these experiments, it remains unclear... 

Beside the identification of single bacterial cell or spores by means of Raman spectroscopy, the localization of these cells inside partly complex matrices has to be performed. One approach is the combination of Raman spectroscopy, fluorescence spectroscopy and digital imaging techniques. This method was applied to detect traces of endospores and other biothreat organisms even in the presence of complex environmental matrices like bioaeroso-lic background, nasal mucin [67], or tap water [68], Another fully automated device was built to analyze bioaerosols in clean room environments, where prior to the Raman identification method a particle preselection took place [69]. 

Viable aerosol samples can be collected on microscope slides and counted directly, with or without staining to reveal or differentiate biological material. Unfortunately this procedure does not show which, if any, of the collected microorganisms are viable. In this case counts are reported as microorganisms or bioaerosol particles. 

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