Indoor air particles and bioaerosols before and after renovation of moisture-damaged buildings: the effect on biological activity and microbial flora.

Many building-related health problems coincide with moisture damage and mold growth within a building. Their elimination is assumed to improve indoor air quality. The aim of this study was to follow the success of remediation in two individual buildings by analyzing the microbial flora and immunotoxicological activity of filter samples.

Diversity and seasonal dynamics of bacterial community in indoor environment.

Background: We spend most of our lives in indoor environments and are exposed to microbes present in these environments. Hence, knowledge about this exposure is important for understanding how it impacts on human health. However, the bacterial flora in indoor environments has been only fragmentarily explored and mostly using culture methods.

Control of aerosol contaminants in indoor air: combining the particle concentration reduction with microbial inactivation.

An indoor air purification technique, which combines unipolar ion emission and photocatalytic oxidation (promoted by a specially designed RCI cell), was investigated in two test chambers, 2.75 m3 and 24.3 m3, using nonbiological and biological challenge aerosols.

Personal and microenvironmental concentrations of particles and microbial aerosol in relation to health symptoms among teachers.

A total of 81 randomly selected elementary school teachers participated in two sampling campaigns conducted 2 weeks apart during the winter. A 24-h sample collection was performed using personal and microenvironmental sampling from homes, and an 8-h sample collection was performed from workplaces of the studied subjects. Filters were analyzed for particle mass, absorption coefficient of the filter, and for both total and viable microorganisms.

Do N95 respirators provide 95% protection level against airborne viruses, and how adequate are surgical masks?

Background: Respiratory protection devices are used to protect the wearers from inhaling particles suspended in the air. Filtering face piece respirators are usually tested utilizing nonbiologic particles, whereas their use often aims at reducing exposure to biologic aerosols, including infectious agents such as viruses and bacteria.

Methods: The performance of 2 types of N95 half-mask, filtering face piece respirators and 2 types of surgical masks were determined.

Manikin-based performance evaluation of N95 filtering-facepiece respirators challenged with nanoparticles.

Protection of the human respiratory system from exposure to nanoparticles is becoming an emerging issue in occupational hygiene. The potential adverse health effects associated with particles of approximately 1-100 nm are probably greater than submicron or micron-sized particles. The performance of two models of N95 half-facepiece-filtering respirators against nano-sized particles was evaluated at two inhalation flow rates, 30 and 85 l min(-1), following a manikin-based protocol.

Interactions between Streptomyces californicus and Stachybotrys chartarum can induce apoptosis and cell cycle arrest in mouse RAW264.7 macrophages.

Exposure to complex mixtures of bacteria and fungi in moisture-damaged buildings is a potential cause of inflammatory related symptoms among occupants. The present study assessed interactions between two characteristic moldy house microbes Streptomyces californicus and Stachybotrys chartarum. Differences in cytotoxic and inflammatory responses in mouse (RAW264.

Viable fungi and bacteria in personal exposure samples in relation to microenvironments.

Personal exposures to viable fungi and bacteria were compared with the concentrations being assessed by stationary samplers in home and workplace microenvironments. A random sample of 81 elementary school teachers in eastern Finland performed two 24-hour measurement periods in wintertime. Concentrations and prevalences of viable fungi and bacteria on the collection filters were determined by cultivation method.

Mould specific IgG antibodies connected with sinusitis in teachers of mould damaged school: a two-year follow-up study.

Objectives: The aim of this study was to describe the relationship between mould exposure induced by moisture damage and mould specific immunoglobulin G antibodies to 20 common mould species and their association with respiratory diseases.

Materials And Methods: Mould specific immunoglobulin G (IgG) antibodies were monitored in teachers in a follow-up after an extensive mould remediation process in school buildings. IgG antibodies to 20 different microbes were determined from the sera of 26 teachers (19 exposed and 7 references) by enzyme-linked immunosorbent assay (ELISA).

Effect of building frame and moisture damage on microbiological indoor air quality in school buildings.

The effect of building frame and moisture damage on microbial indoor air quality was characterized in 17 wooden and 15 concrete or brick school buildings. Technical investigations to detect visible moisture and mold damage were performed according to a standardized protocol. Viable airborne microbes were determined by using a six-stage impactor (Andersen 10-800).

Inflammatory and cytotoxic potential of the airborne particle material assessed by nasal lavage and cell exposure methods.

Exposure to bioaerosols in moisture-damaged indoor environments has been shown to be a potential health risk. The aim of the present study was to evaluate the inflammatory and cytotoxic potential of airborne particle material using both the nasal lavage (NAL) method and a cell exposure study. A 24-h sample collection for airborne particles was performed using personal sampling and microenvironmental measurements in homes and an 8-h sample collection in the working places of the studied subjects.

Isolation and identification of Aspergillus fumigatus mycotoxins on growth medium and some building materials.

Genotoxic and cytotoxic compounds were isolated and purified from the culture medium of an indoor air mold, Aspergillus fumigatus. One of these compounds was identified as gliotoxin, a known fungal secondary metabolite. Growth of A.

Personal exposures and microenvironmental concentrations of particles and bioaerosols.

The aim of this study was to compare the personal exposure to particles and bioaerosols with that measured by stationary samplers in the main microenvironments, i.e., the home and the workplace.