Showing papers on "Bioaerosol published in 1996"

Environmental Assessment of Aerosols, Bioaerosols, and Airborne Endotoxins in a Machining Plant

Abstract: Bioaerosol monitoring was undertaken in a 185,000 m2 engine plant employing 900 production workers and 300 in the skilled trades. Sampling was performed across four seasons in nine locations: four sites were on an older (1970s) engine line, four sites on a new engine line with improved engineering controls, and one site was in assembly. The machining sites represented areas supplied with three different metal-working fluid (MWF) formulations from eight separate sump systems. Bulk in-use MWF samples were collected at the machining sites and compared with air measurements at the same sites. Gravimetric concentration of aerosol averaged 1.24 mg/m3 on the older engine line and 0.74 mg/m3 on the new line. The inhalable fraction was 87% of the aerosol and 57% was respirable. Formaldehyde yielded from biocides averaged 0.22 mg/m3 and was as high as 0.62 mg/m3. Endotoxin concentration ranged from 39 to 166,000 endotoxin units (EU)/mL in the bulk MWF and from below detection (<4 EU/m3) to 790 EU/m3 in air. Airborn...

Evaluation of Four Bioaerosol samplers in the Outdoor Environment

Abstract: Introduction A comparative evaluation of four air samplers was performed using bioaerosol collection in the outdoor environment. Methods Test samplers used included a Rotorod, a Kramer-Collins suction trap, an all-glass impinger (AGI-30), and a high-volume cyclonic liquid impinger (Spin-Con). All samples were analyzed microscopically for spores and pollen. The two collectors providing a liquid sample (AGI-30 and SpinCon) also were analyzed for specific allergen content by enzyme-linked immunoassay. Results The SpinCon collected a larger number of spores than the other devices. The number of spores collected by this unit per volume of air sampled was comparable to the AGI-30. The Rotorod and Kramer-Collins collected a lower number of spores per unit of air but collected a larger number of pollen grains per volume sampled. Alternaria allergens Alt a I and GP70 were collected by both liquid impingers; however, the SpinCon collected more Alt a I and the AGI-30 collected more GP70. Conclusions The SpinCon is a device that is capable of efficiently sampling a high volume of air and concentrating it in a form that can be analyzed for the presence of spores and fungal allergens. It is less useful for collecting intact pollen grains. Pollen allergen quantitation has not yet been performed on the SpinCon effluent.

Diarrhoea among waste collectors associated with bioaerosol exposure

Abstract: Gastrointestinal problems such as diarrhoea have previously been reported in small studies among waste collectors. The present nationwide study relates self-reported diarrhoea symptoms to self-reported working conditions and estimated levels of bioaerosols. A questionnaire based survey among Danish waste collectors (n = 2303) and a comparison group of male municipality workers (n = 1430) collected data on occupational exposures, present and past working environment, psychosocial work environment, and health status. Estimated exposure was related to self-reported working conditions. Prevalence Proportion Ratios (PPR) adjusted for relevant confounders were estimated by generalized linear models. The group with high exposure to fungal spores reported most diarrhoea symptoms (PPR = 5.60 (2.39;13.08)), medium exposure was associated with fewer diarrhoea symptoms (PPR = 3.45 (2.24;5.31)), and the low exposure was associated with the fewest diarrhoea symptoms (PPR = 3.02 (1.86;4.92)). Test for trend was significant. The group with high exposure to either total count of fungi or total count of microorganisms reported fewest symptoms compared to the low exposed. No positive trend was found. This study reported an association between level of exposure to fungal spores and self-reported diarrhoea among waste collectors. Address for correspondence: Ulla I. Ivens, Department of Occupational Medicine, National Institute of Occupational Health, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. E-mail: uii@ami.dk

Method and apparatus for collecting airborne biological particles

Abstract: A bioaerosol collection device (BCD) includes a housing with a first opening, a second opening, and a plate positioned between the first opening and the second opening. When a vacuum is applied to the second opening, the resulting air flow through the BCD causes bioaerosols to collect on a medium positioned on a surface of the plate. The collected bioaerosols are incubated and the resulting bacterial colonies can then be counted to determine a level of bioaerosol contamination in the air.

The sea to air bacteria transfer from the coastal waters.

Abstract: Bacteria transfer from the water into the air may play an important role in bioaerosol cycle. Bubbles raising through the water column collect bacteria but also other suspended material and transport them towards water surface. When the bubble burst at the water surface collected material are skimmed off the bubble to become highly enriched in jet and film drops. After ejection airborne droplets can evaporate and as small droplets can be transported even to remote locations. Such a stream of aerosol droplets may carry stream of bacteria scavenged from the water column. The fate of bacteria in the air may possibly depend on the environmental conditions like intensity of sunlight or ambient air humidity. In addition the wind speed might be responsible for both wave/bubble mediated production of marine originated droplets and their transport in the atmosphere. The evidences that bacteria are transferred from the breaking waves, in particular in the coastal zone, were observed during several field experiments conducted in 1994 and 1995 over the Gulf of Gdansk and the Baltic Sea coast. Enhanced sea to air bacteria transfer were noticed over the polluted waters where in addition gas supersaturations in the water were recorded. Further laboratory investigations of bacteria scavenge via bubbles produced by single capillary and by plume of bubbles produced by ceramic stone indicated high enrichment within both mesophile and psychrophile bacteria categories.

The Use of an Experimental Room for Monitoring of Airborne Concentrations of Microorganisms, Glass Fibers, and Total Particles

Abstract: An experimental room was used as a microcosm for studies of airborne particles and microorganisms in indoor environments. The interior of the room measures 4 by 4 by 2.2 m high and has a hardwood floor and the walls and ceiling are sheetrocked and coated with interior latex paint. Exterior walls are 11.4-cm thick plywood panels consisting of two outer sections of plywood insulated with fiber glass batts. The ceiling is of similar construction with 17.1-cm thick panels. Attached to the room entrance is an anteroom equipped with a HEPA-filtered air shower to reduce mixing of air resulting from entering and exiting during experiments. The room is equipped with a computer-controlled heating, ventilation, and cooling system. Temperature, relative humidity, air flow, and room pressure can be continuously monitored by probes located in the room and air handling system components. Several research projects have been conducted using this room including monitoring the potential for airborne glass fibers released from rigid fibrous ductboard, comparisons of commercially available samplers for monitoring of airborne fungal spores, and a study on the efficacy of vacuum bags to minimize dispersal of particles, including fungal spores from fungal-contaminated carpet. During studies designed to monitor airborne fiberglass, airmore » samples were taken in the room serviced by new rigid fibrous glass ductwork, and the results were compared to those obtained in the room with bare metal ductwork installed. Monitoring of airborne fungal spores using the Andersen six-stage sampler, the high flow Spiral Biotech sampler, the Biotest RCS Plus sampler, and the Burkard spore trap sampler was performed following the release of Penicillium spores into the room through the supply register. Dispersal of carpet-associated particles and fungal spores was measured after vacuuming using conventional cellulose vacuum bags in comparison to recently developed bags.« less