The impact of flood and post-flood cleaning on airborne microbiological and particle contamination in residential houses.
In January 2011, Brisbane, Australia, experienced a major river flooding event. We aimed to investigate its effects on air quality and assess the role of prompt cleaning activities in reducing the airborne exposure risk. A comprehensive, multi-parameter indoor and outdoor measurement campaign was conducted in 41 residential houses, 2 and 6 months after the flood. The median indoor air concentrations of supermicrometer particle number (PN), PM10, fungi and bacteria 2 months after the flood were comparable to those previously measured in Brisbane. These were 2.88 p cm(-3), 15 μg m(-3), 804 cf um(-3) and 177 cf um(-3) for flood-affected houses (AFH), and 2.74 p cm(-3), 15 μg m(-3), 547 cf um(-3) and 167 cf um(-3) for non-affected houses (NFH), respectively. The I/O (indoor/outdoor) ratios of these pollutants were 1.08, 1.38, 0.74 and 1.76 for AFH and 1.03, 1.32, 0.83 and 2.17 for NFH, respectively. The average of total elements (together with transition metals) in indoor dust was 2296 ± 1328 μg m(-2) for AFH and 1454 ± 678 μg m(-2) for NFH, respectively. In general, the differences between AFH and NFH were not statistically significant, implying the absence of a measureable effect on air quality from the flood. We postulate that this was due to the very swift and effective cleaning of the flooded houses by 60,000 volunteers. Among the various cleaning methods, the use of both detergent and bleach was the most efficient at controlling indoor bacteria. All cleaning methods were equally effective for indoor fungi. This study provides quantitative evidence of the significant impact of immediate post-flood cleaning on mitigating the effects of flooding on indoor bioaerosol contamination and other pollutants.
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Congrong
C
He
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia; Developing Indoor Environments, Finnish Institute of Occupational Health (FIOH), Topeliuksenkatu 41 aA, FI-00250 Helsinki, Finland.
Heidi
H
Salonen
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Xuan
X
Ling
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Leigh
L
Crilley
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Nadeesha
N
Jayasundara
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Hing Cho
HC
Cheung
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Megan
M
Hargreaves
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Flavia
F
Huygens
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia; School of Population Health, The University of Queensland, Herston, Queensland 4006, Australia.
Luke D
LD
Knibbs
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Godwin A
GA
Ayoko
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia. Electronic address: l.morawska@qut.edu.au.
Lidia
L
Morawska
D000336:Aerosols / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D001419:Bacteria / Q000166:cytology; D004391:Dust / Q000032:analysis* / Q000517:prevention & control; D052918:Environmental Restoration and Remediation / Q000379:methods / Q000706:statistics & numerical data*; D055868:Floods; D005658:Fungi / Q000166:cytology; D006798:Housing; D006801:Humans; D010316:Particle Size; D011793:Queensland; D011795:Surveys and Questionnaires; D013997:Time Factors
D000336:Aerosols; D004391:Dust
Bacteria; Fungi; Indoor air; Indoor dust; PM(10); Particle number