Health effects of indoor-air microorganisms

Husman, Tuula

doi:10.5271/sjweh.103

Cited by 238 publications

(167 citation statements)

References 70 publications

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“…These airborne bacteria may have important impacts on human health, serving directly as human pathogens or triggering allergic reactions (Schwartz et al, 1995;Hussman, 1996). In addition, bacterial pathogens of agricultural crops and livestock can be transported through the atmosphere (Romantschuk and Bamford, 1986;Gonzalez et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments

et al. 2010

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Although bacteria are ubiquitous in the near-surface atmosphere and they can have important effects on human health, airborne bacteria have received relatively little attention and their spatial dynamics remain poorly understood. Owing to differences in meteorological conditions and the potential sources of airborne bacteria, we would expect the atmosphere over different land-use types to harbor distinct bacterial communities. To test this hypothesis, we sampled the near-surface atmosphere above three distinct land-use types (agricultural fields, suburban areas and forests) across northern Colorado, USA, sampling five sites per land-use type. Microbial abundances were stable across land-use types, with B10 5 -10 6 bacterial cells per m 3 of air, but the concentrations of biological ice nuclei, determined using a droplet freezing assay, were on average two and eight times higher in samples from agricultural areas than in the other two land-use types. Likewise, the composition of the airborne bacterial communities, assessed via bar-coded pyrosequencing, was significantly related to land-use type and these differences were likely driven by shifts in the sources of bacteria to the atmosphere across the land-uses, not local meteorological conditions. A metaanalysis of previously published data shows that atmospheric bacterial communities differ from those in potential source environments (leaf surfaces and soils), and we demonstrate that we may be able to use this information to determine the relative inputs of bacteria from these source environments to the atmosphere. This work furthers our understanding of bacterial diversity in the atmosphere, the terrestrial controls on this diversity and potential approaches for source tracking of airborne bacteria.

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Section: Introductionmentioning

confidence: 99%

Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments

et al. 2010

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“…Exposure to microbes is recognized as a potential cause of inflammation-related health problems among occupants of moldy buildings (Husman 1996;Peat et al 1998). Many different microbes, including a variety of fungi and bacteria, thrive in the conditions offered by moist building materials, which contain both the nutrients and the moisture needed for microbial growth (Hyvärinen et al 2002;Murtoniemi et al 2001;Nikulin et al 1994).…”

mentioning

confidence: 99%

Production of proinflammatory mediators by indoor air bacteria and fungal spores in mouse and human cell lines.

Huttunen¹,

Hyvärinen²,

Nevalainen³

et al. 2003

Environ Health Perspect

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We compared the inflammatory and cytotoxic responses caused by household mold and bacteria in human and mouse cell lines. We studied the fungi Aspergillus versicolor, Penicillium spinulosum, and Stachybotrys chartarum and the bacteria Bacillus cereus, Pseudomonas fluorescens, and Streptomyces californicus for their cytotoxicity and ability to stimulate the production of inflammatory mediators in mouse RAW264.7 and human 28SC macrophage cell lines and in the human A549 lung epithelial cell line in 24-hr exposure to 10(5), 10(6), and 10(7) microbes/mL. We studied time dependency by terminating the exposure to 10(6) microbes/mL after 3, 6, 12, 24, and 48 hr. We analyzed production of the cytokines tumor necrosis factor-alpha and interleukins 6 and 1ss (TNF-alpha, IL-6, IL-1ss, respectively) and measured nitric oxide production using the Griess method, expression of inducible NO-synthase with Western Blot analysis, and cytotoxicity with the MTT-test. All bacteria strongly induced the production of TNF-alpha, IL-6 and, to a lesser extent, the formation of IL-1ss in mouse macrophages. Only the spores of Str. californicus induced the production of NO and IL-6 in both human and mouse cells. In contrast, exposure to fungal strains did not markedly increase the production of NO or any cytokine in the studied cell lines except for Sta. chartarum, which increased IL-6 production somewhat in human lung epithelial cells. These microbes were less cytotoxic to human cells than to mouse cells. On the basis of equivalent numbers of bacteria and spores of fungi added to cell cultures, the overall potency to stimulate the production of proinflammatory mediators decreased in the order Ps. fluorescens > Str. californicus > B. cereus > Sta. chartarum > A. versicolor > P. spinulosum. These data suggest that bacteria in water-damaged buildings should also be considered as causative agents of adverse inflammatory effects.

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“…There is little doubt that exposure to fungi contributes to respiratory diseases and their symptoms (Al-Doory and Domson 1984;Dillon et al 1999;Husman 1996;Larone 1987;Peat et al 1998;van der Werff 1958;Verhoeff and Burge 1997). The effect of indoor fungal exposures on the respiratory health of children is of particular concern and has been examined worldwide.…”

mentioning

confidence: 99%

Levels of household mold associated with respiratory symptoms in the first year of life in a cohort at risk for asthma.

Gent

Ren

Belanger

et al. 2002

Environ Health Perspect

138

113

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We assessed prospectively the risk of increased incidence of respiratory symptoms after exposure to particular fungal genera in a susceptible population--namely, infants (n = 880) at high risk for developing asthma. Days of wheeze or persistent cough, information on maternal allergy and asthma, socioeconomic variables, and housing characteristics were collected over the course of the infant's first year of life. Exposure to mold was assessed by airborne samples collected at one time early in the infant's life. Fungi were identified to genus level, recorded as colony-forming units per cubic meter (CFU/m3), and then categorized into four levels: 0 (undetectable), 1-499 CFU/m3 (low), 500-999 CFU/m3 (medium), and greater than or equal to 1,000 CFU/m3 (high). Effects of mold on wheeze and persistent cough, adjusting for potential confounding factors, were examined with Poisson regression analyses. The two most commonly found genera were Cladosporium (in 62% of the homes) and Penicillium (41%). Cladosporium was associated with reported mold (p < 0.02) and water leaks (p < 0.003). Rate of persistent cough was associated with reported mold [Rate ratio (RR) = 1.49; 95% CI, 1.18-1.88]. The highest level of Penicillium was associated with higher rates of wheeze (RR = 2.15; 95% CI, 1.34-3.46) and persistent cough (RR = 2.06; 95% CI, 1.31-3.24) in models controlling for maternal history of asthma and allergy, socioeconomic status, season of mold sample, and certain housing characteristics. We conclude that infants in this high-risk group who are exposed to high levels of Penicillium are at significant risk for wheeze and persistent cough.

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Health effects of indoor-air microorganisms

Cited by 238 publications

References 70 publications

Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments

Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments

Production of proinflammatory mediators by indoor air bacteria and fungal spores in mouse and human cell lines.

Levels of household mold associated with respiratory symptoms in the first year of life in a cohort at risk for asthma.

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