Fate and Transport of Microorganisms in Air

Mohr, Alan Jeff

doi:10.1128/9781555815882.ch76

Cited by 40 publications

(51 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In general, bioaerosols range between 0.3 to 100 µm in diameter out of which the respirable size fraction which is of primary concern is 1 to 10 µm (Cox and Wathes, 1995). However, only particles ranging between 1.0 to 5.0 µm generally remain in the air, while the rest larger particles are shortly deposited on surfaces (Mohr, 2001).…”

Section: Introductionmentioning

confidence: 99%

Identification and Characterization of Size-Segregated Bioaerosols at Different Sites in Delhi

Lal

Ghosh

Srivastava

et al. 2017

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

Ambient levels of culturable bioaerosol were measured at four different sites of Delhi, India in six size ranges (> 7.0 µm, 7.0-4.7 µm, 4.7-3.3 µm, 3.3-2.1 µm, 2.1-1.1 µm, < 1.1 µm). The study also accounted the seasonal variation (monsoon, post monsoon, winter and pre-monsoon) of the air microbes. The sampling was carried out for three different fractions of bioaerosols viz. fungi, gram positive and negative bacteria during August 2010 to April 2011 using a six-stage viable cascade impactor sampler. Unlike gram positive and negative bacteria, the concentration of fungal bioaerosol found in different stages at each site seems to follow a typical pattern in all four season. The typical pattern of concentration depicts that majority of the fungal species found in the diameter range of 3.3-2.1 µm, which coincides with the penetration range in the secondary bronchi of the lungs in the human body. This reveals that majority of the immunotoxic and allergic fungi found at this stage are mostly prone to affect the secondary bronchi in human lungs when inhaled. At all four sites maximum fungal concentration (1740.5-3224.7 CFU m -3 ), gram-positive bacterial concentration (2790.6-9428.3 CFU m -3 ) and gram-negative bacterial concentration (1990.3-7609 CFU m -3 ) were found in post monsoon season. In the majority of the sites, minimum concentrations were found in monsoon period which probably may be due to rain wash during the sampling. For all the three bioaerosol fractions no particular relationship pattern was found to exist between their respective concentrations with temperature and relative humidity (RH). However, higher range of variation was observed at higher concentration levels and lower range of variation at low concentration levels for all the three bioaerosol fractions. Most of the fungal bioaerosol identified such as Penicillium sp., Alternaria sp. and Aspergillus sp. are associated with immunotoxic and allergic diseases.

show abstract

Section: Introductionmentioning

confidence: 99%

Identification and Characterization of Size-Segregated Bioaerosols at Different Sites in Delhi

Lal

Ghosh

Srivastava

et al. 2017

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

show abstract

“…In terms of MAR index, high similarities for Taksim, Avcilar and Eminonu were found, especially for MAR value higher than 0.2. The potential hazard caused by bioaerosol depends on the pathogenicity of a specifi c microorganism as well as other factors such as the environmental conditions, which determine the survival of the microorganisms in the air (Mohr 2002). Meteorological conditions (especially wind speed and direction) direct airborne dispersion from the emission points, which follows the pathway and enters the body and also triggers an immunologic response via the potential receptor (Sánchez-Monedero et al 2008).…”

Section: Discussionmentioning

confidence: 99%

Culturable airborne bacteria and isolation of methicillin-resistant coagulase-negative staphylococci from outdoor environments on European side of Istanbul, Turkey

Sivri

Bağcıgil

Metiner

et al. 2016

Archives of Environmental Protection

View full text Add to dashboard Cite

This study is aimed to investigate culturable airborne bacteria concentrations and the composition of methicillin-resistant staphylococci in eleven different locations on the basis of specifi c activities conducted within different parts of the European side of Istanbul. The highest bacterial levels were observed at the Bakirkoy station (1 100 CFU/m 3 ) while the second highest levels were found at the Bahcelievler station (1 040 CFU/m 3 ) in October; the lowest levels (10 CFU/m 3 ) were measured at other different stations (Atakoy, Yesilkoy). Fifteen methicillin--resistant isolates [Staphylococcus hominis (n=11), S. cohnii spp. cohnii (n=2), S. sciuri (n=1), S. capitis spp. capitis (n=1)] were identifi ed. The disc diffusion method was used to identify the antimicrobial resistance of these isolates, it was observed that the most common resistance was to penicillin (P) (n=11), doxycycline (DO) (n=4) and tetracycline (T) (n=5). None of the isolates was resistant to imipenem, amoxicillin/clavulanic acid, vancomycin (IPM, AMC, VA). However, multiple antimicrobial resistance was found to be 26.7%. The results of this study revealed the importance of isolated methicillin-resistant staphylococci in the stations with densely active human population and traffi c, for public health. As a result, the importance of resting along known shorelines, where culturable airborne bacteria concentrations are much lower, and its importance for human health have been emphasized.

show abstract

“…The desiccation rate on surfaces or in aerosols is determined principally by relative humidity and to some degree by the fluid in which the organisms were initially suspended. The loss of water causes a denaturation of proteins in which rapid aerosolization exposes the organism to damaging air-water interface effects (52). Generally, as the rate of evaporation increases, the loss of viability tends to increase.…”

Section: Conceptual Decision Frameworkmentioning

confidence: 99%

“…Thus, influenza virus survives best at relative humidity levels of 50% (68), while poliovirus survives best at a higher relative humidity of above 85%. Some viruses, such as smallpox, survive best at midrange relative humidity, and others survive only at high and low relative humidity (52,70).…”

Section: Conceptual Decision Frameworkmentioning

confidence: 99%

Criteria for Selection of Surrogates Used To Study the Fate and Control of Pathogens in the Environment

Sinclair

Rose

Hashsham

et al. 2012

Appl Environ Microbiol

134

106

View full text Add to dashboard Cite

e This article defines the term surrogate as an organism, particle, or substance used to study the fate of a pathogen in a specific environment. Pathogenic organisms, nonpathogenic organisms, and innocuous particles have been used as surrogates for a variety of purposes, including studies on survival and transport as well as for method development and as "indicators" of certain conditions. This article develops a qualitative surrogate attribute prioritization process and allows investigators to select a surrogate by systematically detailing the experimental process and prioritizing attributes. The results are described through the use of case studies of various laboratories that have used this process. This article also discusses the history of surrogate and microbial indicator use and outlines the method by which surrogates can be used when conducting a quantitative microbial risk assessment. The ultimate goal of selecting a sufficiently representative surrogate is to improve public health through a health-based risk assessment framework. Under-or overestimating the resistance, inactivation, or movement may negatively impact risk assessments that, in turn, will impact health assessments and estimated safety levels. Reducing uncertainty in a risk assessment is one of the objectives of using surrogates and the ultimate motive for any experiment investigating potential exposure of a pathogen.

show abstract

Fate and Transport of Microorganisms in Air

Cited by 40 publications

References 85 publications

Identification and Characterization of Size-Segregated Bioaerosols at Different Sites in Delhi

Identification and Characterization of Size-Segregated Bioaerosols at Different Sites in Delhi

Culturable airborne bacteria and isolation of methicillin-resistant coagulase-negative staphylococci from outdoor environments on European side of Istanbul, Turkey

Criteria for Selection of Surrogates Used To Study the Fate and Control of Pathogens in the Environment

Contact Info

Product

Resources

About