Immunoblotting of mite aeroallergens collected with an indoor Burkard air sampler

We examined the kinetics of airborne levels of mite allergen particles in a house by combined use of an indoor Burkard air sampler and immunoblotting. Airborne mite allergens collected on the Burkard sampling tape were transferred onto a nitrocellulose membrane, reacted with mouse monoclonal anti-mite allergen (Der pI) antibody, then treated with alkaline phosphatase conjugated anti-mouse IgG. Finally, the blotted allergen on the membrane was reacted with BCIP/NBT phosphatase, and purple spots visible by the naked eye were produced. The shape of the spots was observed under a microscope, and the spot area was measured by an image processor. This technique might be useful for analyzing the behavior of airborne allergen particles in indoor environments.     

Sampling in aerobiology. Differences between traverses along the length of the slide in Hirst sporetraps

Two years of data from four longitudinal traverses along each day's slide prepared from a continuously running Burkard sporetrap have been analyzed statistically. Using the Friedman test, a statistically significant difference was found between the four traverses, with a greater than 7% loss of pollen grains in the two outer traverses in relation to the inner. Four slides were then selected for more detailed analysis, using 18 longitudinal traverses with a 1-mm separation from the upper to the lower edge of the Melinex tape. There was found to be a progressive decline from the centre to the outside, and more than 4% of pollen grains were found outside the typical 14 mm width of the impaction orifice. There was no correlation between pollen grain size and the decline in counts from the centre to the outside. For the complete data set, there was a general rise in the diversity of pollen types with increasing sample counts, but above about 1000 pollen grains per sample there were no more than 27 pollen types found, often even fewer. A discussion is presented of whether four traverses really should be a fixing sample size, or whether it might be better to fix the total pollen count beginning with a traverse in the middle of the slide and ending with a variable number of traverses when that count is reached.     

Comparison between pollen counts at ground and at roof level in Basel (Switzerland)

Measurements of pollen frequency were made using two identical pollen traps, one situated at ground level and one at the height of about 30 m. There was no special difference between the results for the two traps in 1995, apart from an excess of pollen in the ground level trap originatinig from trees growing near the trap. In 1996 there was also a greater amount of birch pollen, this time at the roof level. There was also a great difference in the time at which the pollen first appeared between the two years, especially in the early spring.     

Comparison of the Rotorod to other air samplers for the determination of Ambrosia artemisiifolia pollen concentrations conducted in the Environmental Exposure Unit

The Environmental Exposure Unit (EEU) is a 924 m³ facility (Kingston General Hospital, Ontario) in which uniform concentrations of various pollens in HEPA-filtered air at known rates of laminar airflow can be maintained. This facility provided a unique opportunity to compare several air samplers without the environmental variation inherent in outdoor comparisons. The purpose of this study was to conduct a quantitative comparison of pollen measurements using the Rotorod, Burkard™ Personal Volumetric Air Sampler, Air-O-Cell™ and a 37 mm open-faced filter cassette with a microporous filter in the EEU. Pollen samples were taken during clinical trials being conducted in the Unit. Raw pollen counts/m³ obtained using the different methods were corrected using published particle collection efficiencies for the particle size (∼ ∼20 μm) and airflow. Data were analyzed by ANOVA/Tukey HSD. No statistically significant differences were found between pollen concentrations determined by Rotorod, Air-O-Cell and filter cassette. Pollen levels determined by the Burkard were up to 2 times higher than the other sampling methods. Relative standard deviations were similar for the Rotorod, Burkard, and filter cassette and higher for the Air-O-Cell. This study demonstrated that, under our conditions, the Rotorod sampler provides consistent and reliable measurements of ragweed pollen concentrations.     

The air spora close to a compost facility in Northeast Oklahoma: Part I—spore trap sampling

A compost facility in northeast Oklahoma is located relatively close to a residential area and is the focus of complaints about smell and concerns about health effects. Several species of Aspergillus have been known to cause health problems, and at least one of these species is dominant in compost. The atmosphere surrounding the compost facility was monitored for 1 year using Burkard spore traps to determine if there was a significant difference in Penicillium/Aspergillus type spores concentration between a test and control site. Samplers were situated 710 m downwind for the test site and 6,085 m upwind at the control site. There was no significant difference in mean concentration of Penicillium/Aspergillus type spores between the two sites (t = 0.576 P > 0.05). The mean concentration of total spores was significantly higher at the upwind control site (t = −7.64, P < 0.01). Wind direction was examined to determine if the compost facility was a possible source for any spikes in concentration. No clear relationship was found between wind direction and mean Penicillium/Aspergillus concentration at the test site, but peak concentrations of Penicillium/Aspergillus seen at the test site were on days when it was downwind from the composting facility. However, these concentrations were no higher than those seen at the control site on other days. If the compost was releasing large amounts of Penicillium/Aspergillus type spores into the atmosphere they were generally diluted to background levels by the time they reached the test site.     

MonitoringAspergillus fumigatus aerosols from a composting facility

The large, outdoor Islip Yard Waste Composting Facility on Long Island, New York was investigated as a source of airborne fungus spores. The Burkard-Hirst volumetric spore trap was used for the first extensive sampling of small mold spores for this application. Samplers were operated continuously from 21 August to 30 November 1992 in the facility and in a suburban community about 540 m from the facility. A control site approximately 10 000 m from the facility was also sampled to establish background levels of fungus spores. The facility site had higher average readings ofAspergillus fumigatus spores than did the community and both were higher than the control.A. fumigatus was the only fungus among 30 categories tracked that differed significantly between the facility and control sites. It was also isolated repeatedly from the compost. Higher average levels ofA. fumigatus were measured in the community when winds blew from the facility, and also during times when the compost was moved or mixed at the facility. No correlation was found between wind direction or work times andA. fumigatus conidia at the control site. The study shows that this compost facility can produce a measurable increase in the number of airborneA. fumigatus conidia both at the edge of the facility and at 540 m downwind. It also demonstrates that the Burkard spore trap can be used for monitoring small, airborne mold spores, but it is a difficult and labor intensive task.     

Enumeration of airborne molds in some indoor environments of Madras city (India) by cultural and non-cultural volumetric samplers

The air mycoflora of six indoor environments in Madras city (India) has been investigated by sampling air with an Andersen sampler and a Burkard personal sampler. Forty-eight species assignable to 24 genera were recorded by Andersen sampler. Spores belonging to 14 genera in addition toPenicillium andAspergillus were identified from Burkard trap slides. Species ofAspergillus, Penicillium, Mucor andRhizopus were most frequently isolated in considerable numbers. As a single genusAspergillus ranked first followed byPenicillium at some sites, andCladosporium at some other sites. The predominance ofPenicillium andAspergillus was also confirmed by Burkard trap data. Spores belonging toGanoderma, Nigrospora, Epicoccum, andTetraploa were recorded only by Burkard sampler, thereby suggesting the necessity of using two complimentary spore traps, cultural and non-cultural, in any aerobiological investigation.     

Sampling in aerobiology. Differences between traverses along the length of the slide in Hirst sporetraps

Two years of data from four longitudinal traverses along each day's slide prepared from a continuously running Burkard sporetrap have been analyzed statistically. Using the Friedman test, a statistically significant difference was found between the four traverses, with a greater than 7% loss of pollen grains in the two outer traverses in relation to the inner. Four slides were then selected for more detailed analysis, using 18 longitudinal traverses with a 1-mm separation from the upper to the lower edge of the Melinex tape. There was found to be a progressive decline from the centre to the outside, and more than 4% of pollen grains were found outside the typical 14 mm width of the impaction orifice. There was no correlation between pollen grain size and the decline in counts from the centre to the outside. For the complete data set, there was a general rise in the diversity of bollen types with increasing sample counts, but above about 1000 pollen grains per sample there were no more than 27 pollen types found, often even fewer. A discussion is presented of whether four traverses really should be a fixing sample size, or whether it might be better to fix the total pollen count beginning with a traverse in the middle of the slide and ending with a variable number of traverses when that count is reached.     

Palynological characterization of honeys from the Andean Patagonia (Chubut,Argentina)

The pollen content of 58 honey samples of Apis mellifera L. from the Andean region of Chubut (Argentinian Patagonia) was analyzed. The samples were provided by beekeepers between 1999 and 2004. Eighty‐eight pollen types were identified, 30 of them are not reported in Argentinian honeys. Identified types belong to 47 families, of which the most diverse were Asteraceae (15 pollen types), Fabaceae (13 pollen types), and Rosaceae (four pollen types). From the samples analyzed, 47% were monofloral and corresponded to the following taxa: Trifolium spp. (16%), Rosaceae (10%), Aristotelia chilensis (Molina) Stuntz (7%), Discaria‐Colletia (5%), Escallonia spp. (3%), Schinus patagonica (Phil.) I. M. Johnst. (2%), Phacelia secunda J. F. Gmel. (2%), Myrtaceae (2%). The results of this study show a high level of utilization of native flora by Apis mellifera. Four new types of monofloral honey were recognized: Aristotelia chilensis, Discaria‐Colletia, Phacelia secunda, and Schinus patagonica. The high representation of native flora distinguishes these honeys geographically.     

Preliminary studies on the effect of the Burkard alternate orifice on airborne fungal spore concentrations

The Burkard 7-day spore trap with standard orifice is commonly used by researchers in sampling outdoor air. The alternate orifice is reported to have higher efficiency in collecting small airborne fungal spores; however, no previous studies compared Burkard samplers with different orifices. This study was conducted to study the effect of the alternate orifice on the concentration of airborne fungal spores. Air samples were collected from July to October 2005 with two Burkard spore traps, one had the standard orifice and the second had the alternate orifice. The two spore traps were located on the roof of a building (12 m height) at the University of Tulsa, Oklahoma. Burkard daily slides were analyzed for airborne spores by light microscopy. The data from the two samplers were statistically analyzed using t-tests. The results indicated that the alternate orifice had significantly higher concentrations of Penicillium/Aspergillus-type spores and basidiospores than the standard orifice. By contrast, the standard orifice had significantly higher concentrations of Alternaria, ascospores, and other spores than the alternate orifice. The alternate orifice can be used to increase the efficiency of trapping small spores, which can be underestimated by using the standard orifice. However, additional comparison in other months of the year is recommended.