Bacterial and fungal aerosol in indoor environment in Upper Silesia, Poland

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Abstract

The purpose of this study was to find the typical concentration levels of bacterial and fungal bioaerosol in healthy and moldy homes as well as in office rooms in Upper Silesia Industrial Zone. Airborne bacteria and fungi were collected using the 6-stage Andersen impactor inside and outside of buildings. It was found that the typical level of bacterial aerosol indoors is about 103 CFU m−3 in homes and 102 CFU m−3 in offices. Only Micrococcus spp was present in all homes studied, constituting 36% of the bacterial genera. The second most common was Staphylococcus epidermidis, present in 76% of homes and constituting 14% of the total. The concentration of fungal aerosol in winter ranged from 10 to 102 CFU m−3 in healthy homes and from 10 to 103 CFU m−3 in homes with mold problems. In summer these values were elevated reaching 103 CFU m−3 in healthy homes and 103–104 CFU m−3 in moldy buildings. In healthy homes the relative concentration of observed species, including Penicillium, ranged from 3 to about 50% while in moldy homes the highest concentration of Penicillium accounted for 90% of the total fungi. However, the differences between viable fungal species as well as concentrations observed in moldy and healthy homes seem to be too small to be a reason of significantly higher risk for allergic asthma symptoms in any group of buildings. Comparison of the respirable fraction of airborne bacteria and fungi with literature data suggests that the percentage of respirable fungi and bacteria is generally not dependent on the type of home, building material, geographical factors and particulate air pollution.

Introduction

Bioaerosols are artificially generated or naturally occurring particles of biological origin suspended in the air. Viable particles can exist in the airborne state as single cells or as clumps of microorganisms as small as 1–10 μm in size, and non-viable bioaerosol particles cover a wide size range. The definition of bioaerosols generally includes those bioaerosols which have combined with non-bioaerosols (rafting). Many indoor bioaerosols originate outdoors but specific bioaerosol sources may develop due to microbial growth in a building's heating, ventilation and air-conditioning (HVAC) system. An important source of airborne bacteria in the indoor environment is the occupant. Recently new sources of bioaerosols have appeared in commercial and other laboratories through the introduction of biotechnology, with the utilization of microorganisms to produce useful pharmaceutical products, enzymes and food substitutes (Lacey and Dutkiewicz, 1994).

Airborne bacteria and fungi can be the cause of a variety of infectious diseases as well as allergic and toxic effects. Epidemiological investigations have shown that the “sick-building syndrome” and hypersensitivity diseases (for example, humidifier fever or asthma) are often associated with exposure to large concentrations of airborne microbes (ACGIH, 1989; Dales et al., 1991; Husman et al., 1993).

Infectious and non-infectious diseases caused by inhalation of different bioaerosols depend not only on the biological properties and chemical composition of these bioaerosols but also on the number inhaled and the site of their deposition in the respiratory system. Because the deposition site of particles is directly related to the aerodynamic diameter of the particle, the health effect of bioaerosols depends highly on their physical properties and especially their size distribution. Particles larger than 10 μm have a low probability of entering and traversing the nasal region of the respiratory naseo-pharyngeal tract. Bioaerosols 5–10 μm in aerodynamic diameter are mainly deposited in the upper respiratory system and can cause, for example, allergic rhinitis. Particles smaller than 5 μm, the so-called respirable fraction, are able to penetrate into the alveoli and can lead to allergic alveolitis and other serious illnesses (Lacey and Crook, 1988; Chatigny and Macher, 1989; Burge, 1990; Owen et al., 1992; Seltzer, 1995).

The aim of this study was to characterize the indoor bioaerosols (bacteria and fungi) in Upper Silesia to guide future determination of some criteria for assessing Silesian indoor air quality. This region is an extensively urbanized and industrialized province in southern Poland where coal mining and metallurgy are still major industrial activities. Previous studies have shown that the dominant tropospheric particles in this region are created by inefficient coal combustion (Pastuszka et al., 1989, Pastuszka et al., 1993; Pastuszka and Okada, 1995) and that these particles are fundamentally different from typical coal fly ash spheres (Rietmeijer and Janeczek, 1997). This highly polluted outdoor air is (excluding cigarette smoking) the main source of particulate matter in the indoor environment of Upper Silesia (Pastuszka et al., 1996). Because bacteria and other bioaerosols may attach to other particles (“rafting”) and be transported with them (Owen et al., 1992; Nevalainen et al., 1993; Chanda, 1996), it follows that in air with high concentrations of particulates, the typical size distribution of bioaerosols can be changed resulting in altered size distributions of respirable bacteria and other bioaerosols.

Section snippets

Methods

Measurements were carried out in 1996–1998 in 70 dwellings, mostly flats in 4–10 storey buildings, classified with and without mold problems. Candidates for moldy homes were identified from clinical records at the Institute of Occupational Medicine and Environmental Health, for patients reporting a wide variety of asthma symptoms (e.g., cough, wheeze, shortness of breath, chest tightness), who declared that they live in moldy homes. These homes were then inspected for the presence of mold, and

Results and discussion

The concentrations of bacterial and fungal aerosols in the outdoor environment are shown in Table 1 while the indoor data are presented in Table 2 (fungi) and 3 (bacteria). The results show that in the outdoor environment the concentrations of bacteria and fungi are similar and depend strongly on season. Outdoor bacterial and fungal concentrations in summer are an order of magnitude higher than winter (Table 1).

Because there was no seasonal difference in bacterial concentration in the indoor

Summary and conclusions

In Upper Silesia the typical concentration level of bacterial aerosol in homes is 103 CFU m−3. The level of the indoor fungal aerosol in this region in healthy homes is 10–102 CFU m−3 in winter and 10–103 CFU m−3 in summer. Generally, in moldy homes the concentration of airborne fungi is elevated, reaching 104 CFU m−3 in some dwellings.

Respirable bacteria represent 50% of the total, and respirable fungi represent 70 and 80% of the total in summer and winter, respectively. This relationship

Acknowledgments

The authors wish to thank Dr. Rafał Górny, Mrs. Gabriela Scigała and Mrs. Beata Łudzen-Izbińska, IOMEH, Sosnowiec, Poland, for skilful assistance. We also express our gratitude to Dr. Marek Rakowski, IOMEH, for constructive comments and discussions. The stay of J.S. Pastuszka at the University of California Davis was supported by The Kosciuszko Foundation, New York, NY.

References (55)

  • J.S. Pastuszka et al.

    Features of atmospheric aerosol particles in Katowice

    Poland. The Science of the Total Environment

    (1995)
  • F.J.M. Rietmeijer et al.

    An analytical electron microscope study of airborne industrial particles in Sosnowiec

    Poland. Atmospheric Environment

    (1997)
  • W.R. Solomon

    A volumetric study of winter fungus prevalence in the air of midwest homes

    Journal of Allergy and Clinical Immunology

    (1976)
  • American Conference of Governmental Industrial Hygienists, (ACGIH), 1989. Guidelines for the assessment of bioaerosols...
  • Atlas, R.M., Bartha, R., 1981. Microbial Ecology: Fundamentals and Applications. Addison-Wesley Publishing Company,...
  • D.E. Aylor et al.

    The role of electrostatics in spore liberation by Drechslera turcica

    Mycologia

    (1980)
  • L. Braback et al.

    Urban living as a risk factor for atopic sensitization in Swedish schoolchildren

    Pediatric Allergy and Immunology

    (1991)
  • H. Burge

    Bioaerosols: prevalence and health effects in the indoor environment

    Journal of Allergy and Clinical Immunology

    (1990)
  • Commission of the European Communities, (CEC), 1993. Indoor Air Quality and Its Impact on Man. Report No. 12:...
  • S. Chanda

    Implications of aerobiology in respiratory allergy

    Annals of Agricultural Environmental Medicine

    (1996)
  • Chatigny, M.A., Macher, J.M., 1989. Sampling airborne microorganisms. In: Hering, S.V. (Ed.), Air Sampling Instruments....
  • R.E. Dales et al.

    Respiratory health effects of home dampness and molds amond children

    American Journal of Epidemiology

    (1991)
  • J.A. DeKoster et al.

    Bioaerosol concentrations in noncomplaint, complaint and intervention homes in the Midwest

    American Industrial Hygiene Association Journal

    (1995)
  • L.K. Dotterud et al.

    Mould allergy in schoolchildren in relation to airborne fungi and residential characteristics in homes and schools in northern Norway

    Indoor Air

    (1996)
  • J. Dutkiewicz

    Bacteria and fungi in organic dust as potential health hazard

    Annals of Agricultural Environmental Medicine

    (1997)
  • Flannigan, B., 1994. Guidelines for evaluation of airborne microbial contamination of buildings. In: Johanning, E.,...
  • Flannigan, B., McCabe, E.M., McGarry, F., 1991. Allergenic and toxigenic micro-organisms in houses. Journal of Applied...
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