It is now generally acknowledged that particulate air pollution can cause respiratory symptoms and that indoor dust particles may be associated with mucous membrane irritation and odour annoyance. One reason for this may be that dust particles adsorb large quantities of gases and other volatile compounds. It is therefore important to be able to determine the chemical compounds adsorbed onto indoor dust particles. In this thesis, a new technique was developed that can analyse chemical compounds in indoor dust particles in a simple yet accurate way. In its basic configuration, it comprises a one stage thermal desorption oven, a gas flow cell with a miniaturized GC column, and a nitrogen-flushed photo diode array (PDA) detector for fast UV spectra recording. The dust sample is thermally desorbed in the oven and the released compounds are flushed onto the GC column by means of a carrier gas stream; the separated compounds are then registered by the PDA detector and identified by their characteristic gas-phase UV spectra. Using this set-up, a number of volatile organic as well as inorganic compounds were identified in indoor dust particles, e.g. nitric oxide, ammonia, hydrogen sulphide, pyridine, 2-furaldehyde, 2-methylfuran, and isoprene. Moreover, acrylate monomers were identified in dust samples from a secondary school with problems due to powdering floor polish. An instrumental set-up with higher performance was achieved by interfacing the gas flow cell to a capillary GC column. When airborne indoor dust samples were analysed by this system and by GC-MS under similar conditions of thermal desorption (150 °C) and GC separation, the two analytical systems were found to be complementary. GC-UV together with GC-MS was thus demonstrated to be considerably more powerful than GC-MS alone for the analysis of volatile organic compounds (VOC) in indoor dust. When airborne dust samples from damp (n=9) and control (n=9) residences were analysed for VOC and microorganisms, identifications made by culture and microscopy of the major moulds found, i.e. Aspergillus, Cladosporium and Penicillum, coincided with the identification of VOC known to be produced by these species. A number of additional VOC were also found, some of which may be irritating to the skin, eyes or respiratory tract if present at higher concentrations. Quantitative GC-UV analysis of indoor dust from 389 residences in Sweden showed that the VOC found at the highest concentrations were saturated aldehydes (C5-C10), furfuryl alcohol, 2,6-di-tert-butyl-4-methylphenol, 2-furaldehyde, and benzaldehyde. Alkenals were also found, notably 2-butenal (crotonaldehyde), 2-methyl-propenal (methacrolein), hexenal, heptenal, octenal, and nonenal. GC-UV was also applied (together with GC-MS) to determine VOC in dust from residences of 198 children with symptoms of asthma and/or allergy (cases) and from residences of 202 children without symptoms (controls). The mean concentration of nicotine was found to be significantly higher in dust from case residences, while the mean concentrations of hexane, nonanal, octane, 2-pentylfuran and tridecanol were significantly higher in dust from control residences. In a stepwise logistic regression model, nicotine, hexanal, furfuryl alcohol, nonane, butanol, and octenal showed increased relative risks, expressed as odds ratios comparing cases with controls. By contrast, benzaldehyde, nonanal, butenal, hexane, tridecanol, and pentylfuran showed decreased relative risks. These findings point to the possibility that not only environmental tobacco smoke but also other emissions in the indoor environment may be linked to the increased prevalence of asthma and/or allergy in children. It is concluded that GC-UV may be used as an alternative or complement to GC-MS for measuring chemicals in indoor dust, thus improving the survey and control of human exposure to particle-bound toxicants and other chemicals. / Copyright Agreement: Figure 3 included in the PDF file abowe is the exclusive property of SAGE Publications (http://www.sagepublications.com/), or its licensors and is protected by copyright and other intellectual property laws. The download of the file(s) is intended for the User's personal and noncommercial use. Any other use of the download of the Work is strictly prohibited. User may not modify, publish, transmit, participate in the transfer or sale of, reproduce, create derivative works (including coursepacks) from, distribute, perform, display, or in any way exploit any of the content of the file(s) in whole or in part. Permission may be sought for further use from Sage Publications Ltd, Rights and Permissions Department, 1 Oliver's Yard, 55 City Road, London EC1Y 1SP Fax: +44 (020) 7324-8600. By downloading the file(s), the User acknowledges and agrees to these terms.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:liu-5199 |
| Date | January 2004 |
| Creators | Nilsson, Anders |
| Publisher | Linköpings universitet, Yrkes- och miljömedicin, Linköpings universitet, Hälsouniversitetet, Linköping |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | Linköping University Medical Dissertations, 0345-0082 ; 856 |
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