Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa
Thesis (MSc)--Stellenbosch University, 2022.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | en_ZA |
| Published: |
Stellenbosch : Stellenbosch University
2022
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867614076020981760 |
|---|---|
| access_status_str | Open Access |
| author | De Beer, Tanya |
| author2 | Jacobs, Karin |
| author_browse | De Beer, Tanya Jacobs, Karin |
| author_facet | Jacobs, Karin De Beer, Tanya |
| author_sort | De Beer, Tanya |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/126342 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:46:16.958Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/126342 Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa De Beer, Tanya Jacobs, Karin Stellenbosch University. Faculty of Science. Dept. of Microbiology. Indoor air quality Indoor air quality -- Health aspects Microorganisms -- South Africa -- Dispersal Air -- Microbiology -- Environmental aspects Mediterranean climate -- South Africa -- Western Cape Ultraviolet germicidal irradiation Disinfection and disinfectants UCTD Thesis (MSc)--Stellenbosch University, 2022. ENGLISH ABSTRACT: Humans have dramatically increased the amount of time spent indoors in recent years. This has increased our exposure to all elements within indoor air, including building materials, various gases, climatic conditions, as well as microorganisms. Bacteria and fungi are the main constituents of microbial indoor air, most of which are harmless to humans. However, certain microorganisms have adapted to airborne dispersal and can cause adverse health conditions including respiratory illnesses as well as allergies, posing a threat to the basic human right to clean indoor air. The group of microorganisms related to the Mediterranean climate of the Western Cape province is relatively understudied and requires further investigation in order to set recommended limits for indoor pollutants. Furthermore, air sterilisation technologies, such as UV and ozone irradiation systems, have been refined to remove harmful pathogens from indoor environments. With the widespread use of public transportation, the amount of people being exposed to harmful bacteria and fungi have increased due to the easy transmission of these microorganisms in close proximity. As a result, bacteria and fungi constitute a significant biological component of indoor air environments and therefore require a better understanding. Using culture-dependent air sampling methods and sequencing, the diversity of the vegetative bacteria and fungi in residences of the Western Cape province was investigated. Moreover, the susceptibility of these microorganisms to UV and ozone exposure was tested to determine the effectiveness of these indoor air treatment methods. It was found that airborne microbial concentrations showed a significant positive correlation with the temperature, relative humidity, and CO₂ concentrations of the residences analysed in this study. Additionally, all but three residences had microbial concentrations within the recommended guidelines of ~1000 CFU/m³ set by the World Health Organisation. The predominant bacterial genera detected in the residences were Bacillus, Staphylococcus, and Micrococcus and the predominant fungi were species of Cladosporium, Penicillium, Alternaria, Epicoccum, Aspergillus, and yeasts. It was established that the dry Mediterranean climate of this province generates a unique indoor microbial diversity that is consistent with other studies examining indoor air in similar climates. Many of the microbial species detected in the residences are known to cause adverse health effects in humans, emphasising the need to remove indoor contaminants. Lastly, it was revealed that bacteria and fungi were more susceptible to ozone disinfection than UV germicidal irradiation (UVGI). The use of UVGI in public transport vehicles showed that the number of airborne microorganisms is significantly affected by the number of passengers in the vehicle, regardless of an active UVGI system. Although ozonation was shown to be a more powerful sterilisation method, it is still advised to use UVGI as no harmful by-products are formed. Future studies should include more sampling locations as well as the development of next- generation sequencing methodology for microbial air samples to include difficult to culture microorganisms. AFRIKAANSE OPSOMMING: Oor die afgelope paar jaar het tyd wat mense binnenshuis spandeer dramaties verhoog. Dit het daartoe gelei dat die blootstelling aan alle binnenshuise lug-elemente verhoog het, insluitend boumateriaal, verskeie gasse, klimaatstoestande sowel as mikroörganismes. Virusse, bakterieë en swamme is die hoofkomponente van mikroörganismes in binnenshuise lug, waarvan die meeste skadeloos vir mense is. Sekere mikroörganismes het egter aangepas by die binnenshuise lug omgewing en kan nadelige gesondheidstoestande soos allergieë en ander respiratoriese siektes veroorsaak, wat die basiese mensereg van skoon binnenshuise lug in gedrang bring. Die groep mikroörganismes wat geassosieer word met die Mediterreense klimaat van die Wes- Kaap provinsie is relatief onder bestudeerd en vereis verdere ondersoek ten einde aanbevole limiete vir binnenshuise besoedelde stowwe vas te stel. Verder is lug-sterilisasie-tegnologieë, soos UV- en osoon-bestraling-stelsels, verfyn om skadelike patogene uit binnenshuise omgewings te verwyder. Met die wydverspreide gebruik van openbare vervoer het die aantal mense wat aan skadelike bakterieë en swamme blootgestel word, toegeneem omdat hierdie mikroörganismes maklik in die nabye omgeving kan versprei. As gevolg hiervan, vorm bakterieë en swamme 'n beduidende biologiese komponent van binnenshuise lug en vereis dus dat ons dit beter verstaan. Deur gebruik te maak van kultuur-afhanklike metodes en volgorde bepalings, is die diversiteit van die bakterieë en swamme in huise van die Wes-Kaap provinsie ondersoek. Daarmee saam is die sensitiwiteit van hierdie mikroörganismes vir UV- en osoon blootstelling getoets om die doeltreffendheid van hierdie binnenshuise lugbehandeling metodes te bepaal. Daar is gevind dat 'n betekenisvolle positiewe korrelasie bestaan tussen die lug gedraagde mikrobiese konsentrasies en die temperatuur, relatiewe humiditeit en CO₂ konsentrasies van die huise. Daarbenewens het drie van die 17 huise mikrobiese konsentrasies gehad binne die aanbevole riglyne van ~1000 CFU/m³ wat deur die Wêreldgesondheidsorganisasie vasgestel is. Die dominante bakterieë wat in die huise geïdentifiseer was, is Bacillus, Staphylococcus en Micrococcus en die mees geïsoleerde swamme sluit spesies van Cladosporium, Penicillium, Alternaria, Epicoccum en Aspergillus in. Die droë Mediterreense klimaat van hierdie provinsie is dus 'n unieke binnenshuise mikrobiese omgewing wat ooreenstem met ander studies wat binnenshuise lug in soortgelyke klimaat streke ondersoek. Dit is bekend dat baie van die mikrobiese spesies wat in die huise geïdentifiseer word, nadelige gesondheidseffekte by mense veroorsaak, wat die behoefte beklemtoon om binnenshuise kontaminante se teenwoordigheid te verstaan en probleem organismes te verwyder. Laastens is dit aan die lig gebring dat bakterieë en swamme meer vatbaar is vir osoon ontsmetting as UV kiemdodende bestraling. Wat die gebruik van UV kiemdodende bestraling in openbare vervoer betref, word die aantal mikroörganismes in die lug beduidend beïnvloed deur die aantal passasiers in die voertuig, ongeag 'n aktiewe UVGI- stelsel. Alhoewel daar getoon is dat osonering 'n kragtiger sterilisasie metode is, word dit steeds aangeraai om UVGI te gebruik aangesien geen skadelike neweprodukte gevorm word nie. Toekomstige studies behoort meer plekke in te sluit om monsters te neem, sowel as die ontwikkeling van volgende generasie volgorde bepaling vir mikrobiese lug monsters om onkweekbare mikroörganismes in te sluit. Masters 2022-11-21T15:50:47Z 2023-01-23T06:53:07Z 2023-05-21T03:00:19Z 2022-12 Thesis http://hdl.handle.net/10019.1/126342 en_ZA Stellenbosch University xi, 156 pages : illustrations, (some color) maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Indoor air quality Indoor air quality -- Health aspects Microorganisms -- South Africa -- Dispersal Air -- Microbiology -- Environmental aspects Mediterranean climate -- South Africa -- Western Cape Ultraviolet germicidal irradiation Disinfection and disinfectants UCTD De Beer, Tanya Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa |
| title | Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa |
| title_full | Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa |
| title_fullStr | Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa |
| title_full_unstemmed | Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa |
| title_short | Microbial indoor air quality and the use of UVGI treatment in the Western Cape province, South Africa |
| title_sort | microbial indoor air quality and the use of uvgi treatment in the western cape province south africa |
| topic | Indoor air quality Indoor air quality -- Health aspects Microorganisms -- South Africa -- Dispersal Air -- Microbiology -- Environmental aspects Mediterranean climate -- South Africa -- Western Cape Ultraviolet germicidal irradiation Disinfection and disinfectants UCTD |
| url | http://hdl.handle.net/10019.1/126342 |
| work_keys_str_mv | AT debeertanya microbialindoorairqualityandtheuseofuvgitreatmentinthewesterncapeprovincesouthafrica |