title: Inflammatory potential in relation to the microbial content of settled dust samples collected from moisture-damaged and reference schools: results of HITEA study.
abstract: Aiming to identify factors causing the adverse health effects associated with moisture-damaged indoor environments, we analyzed immunotoxicological potential of settled dust from moisture-damaged and reference schools in relation to their microbiological composition. Mouse RAW264.7 macrophages were exposed to settled dust samples (n = 25) collected from moisture-damaged and reference schools in Spain, the Netherlands, and Finland. After exposure, we analyzed production of inflammatory markers [nitric oxide (NO), tumor necrosis factor-α (TNF-)α, interleukin (IL)-6, and macrophage inflammatory protein (MIP)2] as well as mitochondrial activity, viability, apoptosis, and cell cycle arrest. Furthermore, particle counts, concentration of selected microbial groups as well as chemical markers such as ergosterol, 3-hydroxy fatty acids, muramic acid, endotoxins, and glucans were measured as markers of exposure. Dust from moisture-damaged schools in Spain and the Netherlands induced stronger immunotoxicological responses compared to samples from reference schools; the responses to Finnish samples were generally lower with no difference between the schools. In multivariate analysis, IL-6 and apoptosis responses were most strongly associated with moisture status of the school. The measured responses correlated with several microbial markers and numbers of particles, but the most important predictor of the immunotoxicological potential of settled dust was muramic acid concentration, a marker of Gram-positive bacteria.
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.|School of Bioscience, Cardiff University, Cardiff, UK.
authors.forename: K
authors.identifier: 0000-0002-4888-9203
authors.initials: K
authors.lastname: Huttunen
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Tirkkonen
authors.affiliation: Living Environment and Health Unit, National Institute for Health and Welfare, Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Täubel
authors.affiliation: Division Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Krop
authors.affiliation: Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Mikkonen
authors.affiliation: Living Environment and Health Unit, National Institute for Health and Welfare, Kuopio, Finland.|Department of Public Health, University of Helsinki, Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Pekkanen
authors.affiliation: Division Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Heederik
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Spain.|CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.
authors.forename: J-P
authors.initials: JP
authors.lastname: Zock
authors.affiliation: Living Environment and Health Unit, National Institute for Health and Welfare, Kuopio, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Hyvärinen
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.|Living Environment and Health Unit, National Institute for Health and Welfare, Kuopio, Finland.
authors.forename: M-R
authors.initials: MR
authors.lastname: Hirvonen
mesh_terms: D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000009:adverse effects* / Q000032:analysis; D000818:Animals; D019742:Chemokines, CC / Q000032:analysis; D004391:Dust / Q000032:analysis*; D004731:Endotoxins / Q000032:analysis; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D004875:Ergosterol / Q000032:analysis; D005387:Finland; D015850:Interleukin-6 / Q000032:analysis; D019402:Macrophage Inflammatory Proteins / Q000032:analysis; D051379:Mice; D008928:Mitochondria / Q000382:microbiology / Q000502:physiology; D009112:Muramic Acids / Q000032:analysis; D009426:Netherlands; D009569:Nitric Oxide / Q000032:analysis; D012574:Schools; D013030:Spain; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: C095218:Ccl9 protein, mouse; D019742:Chemokines, CC; D004391:Dust; D004731:Endotoxins; D015850:Interleukin-6; D019402:Macrophage Inflammatory Proteins; D009112:Muramic Acids; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D004875:Ergosterol
keywords: In vitro; Inflammation; Microbial markers; Moisture damage; Settled dust; Toxicity