Heating of indoor dust causes reduction in its ability to stimulate release of IL-8 and TNFα in vitro compared to non-heated dust

• Published in: Indoor air Vol. 14; no. 4; pp. 226 - 234
• Main Authors: Mathiesen, M., Pedersen, E. K., Bjørseth, O., Egeberg, K. W., Syversen, T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Munksgaard International Publishers 01.08.2004
• Subjects: Cell Culture; Endotoxin; Heating; IL-8; Indoor Dust; TNFα
• ISSN: 0905-6947; 1600-0668
• DOI: 10.1111/j.1600-0668.2004.00234.x

Dust is a major contaminant of the indoor air environment and may affect human health. Indoor dust accumulates on surfaces including heaters and light fixtures, and will be heated when these devices are used. Heat treatment of the dust may change its biologic properties and in this study we simulated the heat treatment with a dust-heating model (50-250 degree C). The residual and the non-heated dust from seven samples were tested in cultures of fresh peripheral blood mononuclear cells and in A549 cell culture using the release of TNF alpha and IL-8, respectively, as effect indicators. The endotoxin-content and the particle size distribution of the residual and the non-heated dust suspensions were determined for some of the samples. We found that the residual dust had less ability to induce the release of TNF alpha and IL-8. The cytokine decline pattern was similar for all the dust tested and could partly be explained by the reduction in endotoxin content or possibly by inhibitory decomposition products. No correlation was found between the measured particle size distribution and the decreased cytokine levels. The results in this study suggest that the residual dust promotes reduced cytokine response and thereby a possibly lower inflammation reaction in the airways if suspended and inhaled compared with the non-heated dust.