title: The IVAIRE project--a randomized controlled study of the impact of ventilation on indoor air quality and the respiratory symptoms of asthmatic children in single family homes.
abstract: A randomized controlled trial was carried out to measure the impact of an intervention on ventilation, indoor air contaminants, and asthma symptoms of children. Eighty-three asthmatic children living in low-ventilated homes were followed over 2 years. Several environmental parameters were measured during the summer, fall, and winter. The children were randomized after Year 1 (43 Intervention; 40 Control). The intervention included the installation of either a Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV). During the fall and winter seasons, there was a significant increase in the mean ventilation rate in the homes of the intervention group. A statistically significant reduction in mean formaldehyde, airborne mold spores, toluene, styrene, limonene, and α-pinene concentrations was observed in the intervention group. There was no significant group difference in change in the number of days with symptoms per 14 days. However, there was a significant decrease in the proportion of children who experienced any wheezing (≥1 episode) and those with ≥4 episodes in the 12-month period in the intervention group. This study indicates that improved ventilation reduces air contaminants and may prevent wheezing. Due to lack of power, a bigger study is needed.
  
  
  CONCLUSIONS
  Positive findings from this study include the fact that, upon recruitment, most of the single family homes with asthmatic children were already equipped with a mechanical ventilation system and had relatively good indoor air quality. However, the 8-h indoor guideline for formaldehyde (50 μg/m3) was frequently exceeded and the ventilation rates were low in most of the homes, even those with a ventilation system. Both ERVs and HRVs were equally effective at increasing air exchange rates above 0.30 ACH and at preventing formaldehyde concentrations from exceeding the 50 μg/m3 guideline during the fall and winter seasons. Furthermore, the ERVs were effective at preventing excessively low relative humidities in the homes. Based on observed difference of risk, intervention to increase ventilation in five sample homes and children would prevent 1 home to exceed the indoor air long-term formaldehyde guideline and prevent 1 asthmatic child experiencing at least one episode of wheezing over a year.
authors.affiliation: Environmental Health and Toxicology Division, Institut national de santé publique du Québec (INSPQ), Quebec City, QC, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Lajoie
authors.affiliation: NRC Construction, National Research Council of Canada, Ottawa, ON, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Aubin
authors.affiliation: Environmental Health and Toxicology Division, Institut national de santé publique du Québec (INSPQ), Quebec City, QC, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Gingras
authors.affiliation: Department of Pediatrics, Mother Child Centre, Québec University Hospital Centre (CHUQ), Quebec City, QC, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Daigneault
authors.affiliation: Department of Pediatrics and of Social and Preventive Medicine, Sainte-Justine University Hospital Centre, Université de Montréal, Montréal, QC, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Ducharme
authors.affiliation: Environmental Health and Toxicology Division, Institut national de santé publique du Québec (INSPQ), Quebec City, QC, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Gauvin
authors.affiliation: Formerly with Policy and Research, Canada Mortgage and Housing Corporation (CMHC), Ottawa, ON, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Fugler
authors.affiliation: Environmental Health and Toxicology Division, Institut national de santé publique du Québec (INSPQ), Quebec City, QC, Canada.
authors.forename: J-M
authors.initials: JM
authors.lastname: Leclerc
authors.affiliation: NRC Construction, National Research Council of Canada, Ottawa, ON, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Won
authors.affiliation: Environmental Health and Toxicology Division, Institut national de santé publique du Québec (INSPQ), Quebec City, QC, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Courteau
authors.affiliation: Environmental Health and Toxicology Division, Institut national de santé publique du Québec (INSPQ), Quebec City, QC, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Gingras
authors.affiliation: Health Canada, Air Health Effects Division, current affiliation with World Health Organization, European Centre for Environment and Health, Bonn, Germany.
authors.forename: M-È
authors.initials: MÈ
authors.lastname: Héroux
authors.affiliation: NRC Construction, National Research Council of Canada, Ottawa, ON, Canada.
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.affiliation: NRC Construction, National Research Council of Canada, Ottawa, ON, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Schleibinger
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D016902:Air Pollution, Indoor / Q000517:prevention & control*; D001249:Asthma / Q000503:physiopathology / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D012135:Respiratory Sounds; D014691:Ventilation
chemical_list: D000393:Air Pollutants
keywords: Asthma; Children; Field study; Home; Indoor air; Respiratory symptoms; Ventilation