At the level of the individual thallus, acidity affects nitrogen fixation, photosynthesis, growth, and cellular ultrastructure Belnap et al. Besides these direct effects on physiological processes, environmental acidity can affect cryptogamic communities indirectly by altering substrate chemistry, thereby affecting species diversity and composition at the community level. Bark pH interactions Ecological studies of epiphyte communities have shown that, even in unpolluted areas, natural variations in bark chemistry have a major impact on which species are present Farmer, et al.
Figure S2 Indicator OTUs from the first experiment were consistent for occupants regardless of sampling method. Eight of these ten OTUs were also significant indicator taxa included in Table 3.
Figure S3 Significant differences among occupant personal microbial clouds are not explained by temporal changes in background airborne microbial assemblages.
We detected marginal differences in background bacteria i. These differences, however, were negligible when compared to differences among the different occupants. Left Community similarities in the left plot occupied samples from the first experiment; same data as shown in Fig.
This difference was significantly more pronounced than that of unoccupied samples right taken simultaneously during sampling periods. Figure S4 At 1 air change per hour leftoccupants were, on average, detectable inside the chamber, but less so in exhaust air.
When air exchange rates were tripled rightthese signals disappeared, and not a single occupant was consistently detectable, even in occupied indoor air.
Humans emit upwards of biological particles per hour, and have long been known to transmit pathogens to other individuals and to indoor surfaces. However it has not previously been demonstrated that humans emit a detectible microbial cloud into surrounding indoor air, nor whether such clouds are sufficiently differentiated to allow the identification of individual occupants.
We used high-throughput sequencing of 16S rRNA genes to characterize the airborne bacterial contribution of a single person sitting in a sanitized custom experimental climate chamber. We compared that to air sampled in an adjacent, identical, unoccupied chamber, as well as to supply and exhaust air sources.
Additionally, we assessed microbial communities in settled particles surrounding each occupant, to investigate the potential long-term fate of airborne microbial emissions.
Most occupants could be clearly detected by their airborne bacterial emissions, as well as their contribution to settled particles, within 1. Bacterial clouds from the occupants were statistically distinct, allowing the identification of some individual occupants.
Our results confirm that an occupied space is microbially distinct from an unoccupied one, and demonstrate for the first time that individuals release their own personalized microbial cloud.
Human microbiome, Indoor microbiology, Built environment, Indoor air, Microbial cloud Introduction Humans harbor diverse microbial assemblages in and on our bodies HMP Consortium,and these distinctly human-associated bacteria can be readily detected inside of buildings on surfaces, in dust, and as bioaerosols Hospodsky et al.
Human-associated bacteria disperse into and throughout the built environment by three primary mechanisms: Recent studies of built environment microbes have largely focused on direct human contact with surfaces, and demonstrated that people can leave behind bacterial signatures indicative of particular body parts and types of bodily contact Flores et al.
Given the long-term identifiability of the human microbiome Franzosa et al. Bioaerosols airborne biological particles including bacteria and bacteria-laden particles have often been the focus of infection-control studies, but their role in seeding the built environment microbiome is poorly understood.
Research on bioaerosols to date has rarely focused on the direct emission of bioaerosols from human sources, because it is difficult to disentangle direct emission from resuspension of dust observationally Meadow et al.An Experiment to Determine the Air Quality in the Region of SE Portland.
1, words. 8 pages. Assessing the Responsibilities of Private and Federal Organizations in Solving Environmental Problems.
1, words. 6 pages. A Research on an Environmental Problem Related to Soils and Its Solutions. 1, words. 4 pages. Portland air quality index is 32, ranked #10 in Oregon. Historical Portland - OR PM10, PM, TSP, carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone information also .
Sep. 25, — Outdoor air pollution is a major contributor to indoor air pollution -- but high-efficiency particulate air (HEPA) filters used in the home significantly reduce fine-particulate.
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The February/March edition of the FHWA Air Quality and Sustainability Newsletter includes information concerning the energy independence and economic growth Executive Order, a Q&A on the Emergency Relief Program and Resilience, and an Atlanta peer exchange on climate resilience.
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