Change search
ReferencesLink to record
Permanent link

Direct link
Airway effects of diesel exhaust in healthy and asthmatic subjects
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine. (Department of respiratory medicine and allergy)
2002 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Several epidemiological studies have revealed an association between particulate matter (PM) pollution and various health effects. Importantly, there is evidence to suggest that individuals with pre-existing respiratory disease, such as asthma, are more sensitive to elevated ground levels of particulate matter as compared to healthy subjects. Among the various sources of PM pollution, diesel powered vehicles have been identified as important contributors.

The aim of this thesis was to investigate the airway effects of experimental chamber exposure to diesel exhaust (DE) in healthy and asthmatic subjects, focusing on airway responsiveness, airway inflammation and lung function. To achieve a comprehensive picture of the airway responses to DE, a number of different methods were used, including lung function measurements, methacholine inhalation tests, induced sputum and bronchoscopy. Each subject acted as his/her own control by being exposed both to filtered air and DE in a crossover design.

Short term exposure to DE, at a particle concentration (PMi0) of 300 ug/m3, was associated with a clinically significant increase in bronchial hyperresponsiveness in asthmatic subjects. In accordance with the epidemiological data suggesting a 1-4 day lag effect for most health outcomes to PM pollution, the increase was detected one day after DE exposure, indicating a long lasting response to DE in asthmatic airways.

Diesel exhaust induced a range of airway inflammatory changes as reflected in induced sputum, bronchoalveolar lavage and bronchial mucosal biopsies. In healthy subjects, DE exposure was associated with an increase in neutrophils and IL-6 in sputum, elevated levels of IL-8 and IL-6 in bronchial wash (BW), enhanced expression of IL-8 and GRO-a in the bronchial epithelium and with increases in P-selectin and VCAM-1 in the airway mucosa. In contrast, asthmatics responded with an increase in IL-6 in sputum and an enhanced expression of IL-10 in the bronchial epithelium following exposure DE. Thus, clear differences were identified between healthy and asthmatic subjects in the inflammatory response to DE.

Airway epithelial cells constitute the first line of cellular defence towards inhaled air pollutants and increasing evidence suggests that these cells contribute markedly to the initiation of airway inflammatory responses. The bronchial epithelium was identified to have an important regulatory role in response to diesel exhaust, including the capacity to produce chemoattractant and immunoregulatory proteins associated with development of airway inflammation and bronchial hyperresponsiveness.

Lung function measurements revealed that short-term exposure to DE induces an immediate bronchoconstrictive response in both healthy and asthmatic individuals, with significant increases in airway resistance (Raw) following DE exposure.

This thesis also investigated the effects of a lower concentration of DE (PMio 100 ug/m3) than previously studied. It was shown that exposure to DE at a concentration corresponding to a PM level that may be encountered in busy traffic situations, was still associated with potentially adverse airway responses in healthy and asthmatic subjects.

In summary, the results presented here indicate that short term exposure to diesel exhaust, at high ambient concentrations, has the potential to induce a range of biological events in the airways of healthy and asthmatic subjects.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet , 2002. , 60 p.
Umeå University medical dissertations, ISSN 0346-6612 ; 750
Keyword [en]
air pollution, diesel exhaust, airway responsiveness, airway inflammation, lung function, asthmatics, immunohistochemistry, bronchial epithelium
National Category
Respiratory Medicine and Allergy
URN: urn:nbn:se:umu:diva-96901ISBN: 91-7305-172-1OAI: diva2:769163
Public defence
2002-02-16, Sal B, 9 trappor, Byggnad ID (Tandläkarhögskolan), Norrlands Universitetssjukhus i Umeå, Umeå universitet, Umeå, 12:00

Diss. (sammanfattning) Umeå : Umeå universitet, 2002, härtill 4 uppsatser.

Available from: 2015-01-26 Created: 2014-12-05 Last updated: 2015-04-10Bibliographically approved
List of papers
1. Acute exposure to diesel exhaust increases IL-8 and Gro-alpha production in healthy human airways
Open this publication in new window or tab >>Acute exposure to diesel exhaust increases IL-8 and Gro-alpha production in healthy human airways
Show others...
2000 (English)In: American Journal of Respiratory and Critical Care Medicine, ISSN 1073-449X, E-ISSN 1535-4970, Vol. 161, no 2, 550-557 p.Article in journal (Refereed) Published
urn:nbn:se:umu:diva-5160 (URN)10673199 (PubMedID)
Available from: 2006-05-11 Created: 2006-05-11 Last updated: 2015-04-17Bibliographically approved
2. Different airway inflammatory responses in asthmatic and healthy humans exposed to diesel.
Open this publication in new window or tab >>Different airway inflammatory responses in asthmatic and healthy humans exposed to diesel.
Show others...
2004 (English)In: Eur Respir J, ISSN 0903-1936, Vol. 23, no 1, 82-6 p.Article in journal (Refereed) Published
Adult, Airway Resistance/drug effects, Asthma/*physiopathology, Bronchi/chemistry, Bronchoalveolar Lavage Fluid/chemistry, Cell Adhesion Molecules/analysis, Environmental Exposure, Female, Humans, Inflammation/chemically induced, Interleukin-10/analysis, Interleukin-8/analysis/genetics, Lymphocytosis/chemically induced, Male, Middle Aged, Neutrophils/pathology, RNA; Messenger/analysis, Respiratory Mucosa/chemistry, Respiratory System/*drug effects/pathology, Vehicle Emissions/*toxicity
urn:nbn:se:umu:diva-13161 (URN)14738236 (PubMedID)
Available from: 2007-05-03 Created: 2007-05-03 Last updated: 2016-01-22Bibliographically approved

Open Access in DiVA

Airway effects of diesel exhaust in healthy and asthmatic subjects(17035 kB)35 downloads
File information
File name FULLTEXT01.pdfFile size 17035 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Nordenhäll, Charlotta
By organisation
Pulmonary Medicine
Respiratory Medicine and Allergy

Search outside of DiVA

GoogleGoogle Scholar
Total: 35 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 55 hits
ReferencesLink to record
Permanent link

Direct link