Environmental chamber studies of eye and respiratory irritation from use of a peracetic acid-based hospital surface disinfectant.

Objective: To characterize personal exposures and measures of eye and respiratory tract irritation in controlled environmental chamber studies of 44 healthy adult volunteers simulating upper-bound use of peracetic acid (PAA)-based surface disinfectant for terminal cleaning of hospital patient rooms. Design: Experimental, within-subject, double-blinded cross-over design. Methods: Objective and subjective exposure effects were assessed for PAA and its components: acetic acid (AA) and hydrogen peroxide (HP). Deionized water was included as a control. Breathing-zone concentrations of PAA, AA, and HP were assessed for 8 female multiday volunteers (5 consecutive days) and 36 single-day volunteers (32 females and 4 males). Wetted cloths were used to wipe high-touch surfaces for 20 minutes per trial. Also, 15 objective measures of tissue injury or inflammation and 4 subjective odor or irritation scores were assessed. Results: Disinfectant trials showed 95th percentile breathing zone concentrations of 101 ppb PAA, 500 ppb AA, and 667 ppb HP. None of the volunteers observed over 75 test days exhibited significant increases in IgE or objective measures of eye and respiratory tract inflammation. Subjective ratings for disinfectant and AA-only trials showed similar increases for odor intensity and nose irritation, with lower ratings for eye and throat irritation. Females were 2.5-fold more likely than males to assign moderate + irritation ratings. Conclusions: Simulated upper-bound hospital use of PAA-based disinfectant led to no significant increases in objective markers of tissue injury, inflammation, or allergic sensitization, and no frank signs of eye or respiratory tract irritation.

PM1 particles at coal- and gas-fired power plant work areas.

With the increased interest in the possible adverse health effects attributed to inhalation of fine particle matter, this study was conducted to gather preliminary information about workplace exposures at coal- and gas-fired power plants to fine particles (PM(1); i.e. <1 µm) and ultrafine particles (i.e. <0.1 µm). Combustion of fossil fuel is known to produce fine particles, and due to their proximity and durations of exposure, power plant workers could be a group of individuals who experience high chronic exposures to these types of particles. The results of a series of real-time instrument measurements showed that concentrations of PM(1) were elevated in some locations in power plants. The highest concentrations were in locations near combustion sources, indicating that combustion materials were leaking from conventional fossil fuel-fired boilers or it was associated with emission plume downwash. Concentrations were the lowest inside air-conditioned control rooms where PM(1) were present at levels similar to or lower than upwind concentrations. Microscopic examinations indicate that PM(1) at the coal-fired plants are dominated by vitrified spheres, although there were also unusual elongated particles. Most of the PM(1) were attached to larger coal fly ash particles that may affect where and how they could be deposited in the lung.

Fungal types and concentrations from settled dust in normal residences.

Analysis of settled dust collected from carpeting and furnishings is occasionally used by investigators to determine whether an environment contains unusual fungi. Little information is available concerning the types and concentrations of culturable fungi present on textile surfaces in normal residential settings not affected by unusual mold reservoirs, such as from fungal growth sites within the built environment. This study presents the results of the collection and analysis of surface dust from 26 residential environments that were prescreened by interview, physical inspection, and air sampling to limit the surface dust collection to structures in which there was no history of water intrusion, flooding, plumbing leaks, signs of mold growth, or evidence of unusual airborne fungal spore types or concentrations. In those structures found to have no history or indications of water events or unusual fungi, surface dust was vacuumed from prescribed horizontal areas on carpet and textile-covered furnishings. These samples were then subjected to fungal culture, from which viable colonies were enumerated and identified. Based on the study results, it does not appear reasonable that the frequently quoted total fungi concentration exceeding 10(5) CFU/g is definitive evidence that a residential surface is contaminated with unusual amounts of culturable fungi. Collocated samples collected from eight side-by-side carpets sections revealed poor reproducibility. While settled dust sampling may be appropriate for determining the fungal status of a localized area, or as a gross screening tool, using settled dust results alone to establish the presence of unusual fungal types or concentrations within a structure appears to be inappropriate, and using settled dust results with other investigative methods, such as visual observations and air sampling, requires cautious interpretation.