Airway and systemic biomarkers of health effects after short-term exposure to indoor ultrafine particles from cooking and candles – A randomized controlled double-blind crossover study among mild asthmatic subjects

• Published in: Particle and fibre toxicology Vol. 20; no. 1; pp. 26 - 18
• Main Authors: Laursen, Karin Rosenkilde, Christensen, Nichlas Vous, Mulder, Frans AA, Schullehner, Jörg, Hoffmann, Hans Jürgen, Jensen, Annie, Møller, Peter, Loft, Steffen, Olin, Anna-Carin, Rasmussen, Berit B., Rosati, Bernadette, Strandberg, Bo, Glasius, Marianne, Bilde, Merete, Sigsgaard, Torben
• Format: Journal Article
• Language: English
• Published: London BioMed Central 10.07.2023; BioMed Central Ltd; BMC
• Subjects: Air exposure; Air pollution; Albumin; Albumins; Analysis; Arbetsmedicin och miljömedicin; Asthma; Biological markers; Biomarkers; Biomedical and Life Sciences; Biomedicine; Blood; Blood lipids; Burning; C-Reactive Protein; Candles; Cells (biology); Chambers; Composition; Cooking; Cross-Over Studies; Cytokines; Deoxyribonucleic acid; DNA; DNA repair; Double-blind studies; Droplets; Emissions; Environmental aspects; Environmental Health; Exposure; Farmakologi och toxikologi; Gene expression; Genotoxicity; Health aspects; Health Sciences; Human exposure; Humans; Humidity; Hälsovetenskap; Indoor air; Indoor air quality; Inflammation; Lipids; Lipoproteins; Medical and Health Sciences; Medicin och hälsovetenskap; Metabolites; Metabolomics; Nanotechnology; Occupational Health and Environmental Health; Outdoor air quality; Oxidative stress; Oxidatively damaged DNA; Particulate matter; Pharmacology and Toxicology; Pharmacology/Toxicology; Pneumology/Respiratory System; Polycyclic aromatic hydrocarbons; Progenitor cells; Proteins; Public Health; Respiratory tract; SP-A; Surface active agents; surfactant protein-a; Surfactants; Ultrafine particles; Ultrafines; Sweden; Metabolomics; Candles; Cooking; Human exposure; SP-A; Biomarkers; Oxidatively damaged DNA; Ultrafine particles; Inflammation; Indoor air
• ISSN: 1743-8977; 1743-8977
• DOI: 10.1186/s12989-023-00537-7

Background There is insufficient knowledge about the systemic health effects of exposure to fine (PM 2.5 ) and ultrafine particles emitted from typical indoor sources, including cooking and candlelight burning. We examined whether short-term exposure to emissions from cooking and burning candles cause inflammatory changes in young individuals with mild asthma. Thirty-six non-smoking asthmatics participated in a randomized controlled double-blind crossover study attending three exposure sessions (mean PM 2.5  µg/m 3 ; polycyclic aromatic hydrocarbons ng/m 3 ): (a) air mixed with emissions from cooking (96.1; 1.1), (b) air mixed with emissions from candles (89.8; 10), and (c) clean filtered air (5.8; 1.0). Emissions were generated in an adjacent chamber and let into a full-scale exposure chamber where participants were exposed for five hours. Several biomarkers were assessed in relation to airway and systemic inflammatory changes; the primary outcomes of interest were surfactant Protein-A (SP-A) and albumin in droplets in exhaled air – novel biomarkers for changes in the surfactant composition of small airways. Secondary outcomes included cytokines in nasal lavage, cytokines, C-reactive protein (CRP), epithelial progenitor cells (EPCs), genotoxicity, gene expression related to DNA-repair, oxidative stress, and inflammation, as well as metabolites in blood. Samples were collected before exposure start, right after exposure and the next morning. Results SP-A in droplets in exhaled air showed stable concentrations following candle exposure, while concentrations decreased following cooking and clean air exposure. Albumin in droplets in exhaled air increased following exposure to cooking and candles compared to clean air exposure, although not significant. Oxidatively damaged DNA and concentrations of some lipids and lipoproteins in the blood increased significantly following exposure to cooking. We found no or weak associations between cooking and candle exposure and systemic inflammation biomarkers including cytokines, CRP, and EPCs. Conclusions Cooking and candle emissions induced effects on some of the examined health-related biomarkers, while no effect was observed in others; Oxidatively damaged DNA and concentrations of lipids and lipoproteins were increased in blood after exposure to cooking, while both cooking and candle emissions slightly affected the small airways including the primary outcomes SP-A and albumin. We found only weak associations between the exposures and systemic inflammatory biomarkers. Together, the results show the existence of mild inflammation following cooking and candle exposure.