title: Comparison of methods to evaluate the fungal biomass in heating, ventilation, and air-conditioning (HVAC) dust.
abstract: Heating, ventilation, and air-conditioning (HVAC) systems contain dust that can be contaminated with fungal spores (molds), which may have harmful effects on the respiratory health of the occupants of a building. HVAC cleaning is often based on visual inspection of the quantity of dust, without taking the mold content into account. The purpose of this study is to propose a method to estimate fungal contamination of dust in HVAC systems. Comparisons of different analytical methods were carried out on dust deposited in a controlled-atmosphere exposure chamber. Sixty samples were analyzed using four methods: culture, direct microscopic spore count (DMSC), β-N-acetylhexosaminidase (NAHA) dosing and qPCR. For each method, the limit of detection, replicability, and repeatability were assessed. The Pearson correlation coefficients between the methods were also evaluated. Depending on the analytical method, mean spore concentrations per 100 cm2of dust ranged from 10,000 to 682,000. Limits of detection varied from 120 to 217,000 spores/100 cm2. Replicability and repeatability were between 1 and 15%. Pearson correlation coefficients varied from -0.217 to 0.83. The 18S qPCR showed the best sensitivity and precision, as well as the best correlation with the culture method. PCR targets only molds, and a total count of fungal DNA is obtained. Among the methods, mold DNA amplification by qPCR is the method suggested for estimating the fungal content found in dust of HVAC systems.
authors.affiliation: Institut de recherche Robert-Sauvé en santé et sécurité du travail, 505 Boul. de Maisonneuve Ouest, Montréal, H3A3C2, Canada.|Département de santé environnementale et santé au travail, École de santé publique, Université de Montréal, Pavillon Marguerite d'Youville, 2375 Chemin de la côte Ste-Catherine, Montréal, H3T 1A8, Canada.
authors.forename: Marie-Jeanne
authors.initials: MJ
authors.lastname: Biyeyeme Bi Mve
authors.affiliation: Institut de recherche Robert-Sauvé en santé et sécurité du travail, 505 Boul. de Maisonneuve Ouest, Montréal, H3A3C2, Canada.
authors.forename: Yves
authors.initials: Y
authors.lastname: Cloutier
authors.affiliation: Institut de recherche Robert-Sauvé en santé et sécurité du travail, 505 Boul. de Maisonneuve Ouest, Montréal, H3A3C2, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Lacombe
authors.affiliation: Institut de recherche Robert-Sauvé en santé et sécurité du travail, 505 Boul. de Maisonneuve Ouest, Montréal, H3A3C2, Canada.|Département de santé environnementale et santé au travail, École de santé publique, Université de Montréal, Pavillon Marguerite d'Youville, 2375 Chemin de la côte Ste-Catherine, Montréal, H3T 1A8, Canada.
authors.forename: Jacques
authors.initials: J
authors.lastname: Lavoie
authors.affiliation: Département de santé environnementale et santé au travail, École de santé publique, Université de Montréal, Pavillon Marguerite d'Youville, 2375 Chemin de la côte Ste-Catherine, Montréal, H3T 1A8, Canada.
authors.forename: Maximilien
authors.initials: M
authors.lastname: Debia
authors.affiliation: Institut de recherche Robert-Sauvé en santé et sécurité du travail, 505 Boul. de Maisonneuve Ouest, Montréal, H3A3C2, Canada. marchand.genevieve@irsst.qc.ca.|Département de santé environnementale et santé au travail, École de santé publique, Université de Montréal, Pavillon Marguerite d'Youville, 2375 Chemin de la côte Ste-Catherine, Montréal, H3T 1A8, Canada. marchand.genevieve@irsst.qc.ca.
authors.forename: Geneviève
authors.identifier: http://orcid.org/0000-0002-4496-5459
authors.initials: G
authors.lastname: Marchand
mesh_terms: D000389:Air Conditioning; D016902:Air Pollution, Indoor / Q000032:analysis; D018533:Biomass; D015169:Colony Count, Microbial; D004391:Dust / Q000032:analysis*; D004780:Environment, Controlled; D004784:Environmental Monitoring / Q000379:methods*; D006361:Heating; D013172:Spores, Fungal / Q000302:isolation & purification / Q000502:physiology*; D014691:Ventilation
chemical_list: D004391:Dust
keywords: Dust; Fungal biomass; HVAC systems; Indoor air quality; Sampling methods