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.     

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.     

An evaluation of two methods used for microscopic analysis of airborne fungal spore concentrations from the Burkard Spore Trap

The Burkard Volumetric Spore Trap is a common and efficient instrument used to collect outdoor air samples. In North America, two slide counting methods have been widely used by aerobiologists: the single longitudinal traverse method and the twelve transverse traverse method. The purpose of this study was to compare the two counting methods by assessing fungal spore concentrations of ascospores, basidiospores, smut teliospores, Cladosporium, Alternaria, Epicoccum, Curvularia, Drechslera, Pithomyces, other spores, and total spores at two metropolitan Tulsa, Oklahoma sites (Tulsa and Hectorville) during September 1996. Results showed that both methods were sensing parallel fluctuations in average daily spore concentration, although the twelve transverse traverse method usually resulted in higher concentrations. At the Tulsa site, the twelve transverse traverse method gave statistically higher concentrations than the single longitudinal traverse method except for Epicoccum, Pithomyces, smut teliospores, and other spores. At the Hectorville site, however, only Cladosporium and basidiospores showed that the twelve transverse traverse method was statistically higher than the single longitudinal traverse method. Comparison with concentrations obtained by counting the total slide surface of two slides indicated that neither method was equivalent to the total slide spore count, although the twelve transverse traverse method gave a lower absolute percent difference from the total slide surface concentration. While the twelve transverse traverse method gave slightly better approximations of the spore concentration, the increase in accuracy may not justify the extra effort required to analyze with this method.     

Performance of the Coriolis air sampler,a high-volume aerosol-collection system for quantification of airborne spores and pollen grains

The Coriolis δ air sampler manufactured by Bertin Technologies (France) is a continuous air sampler, dedicated to outdoor monitoring of airborne spores and pollen grains. This high-volume sampler is based on patented Coriolis technology delivering a liquid sample. The air is drawn into a conical vial in a whirling type motion using suction; particles are pulled against the wall by centrifugal force. Airborne particles are separated from the air and collected in a liquid medium. This innovative solution allows rapid analysis by several techniques including PCR assay and serological assay in order to measure the antigenicity/allergenicity of pollen grains and fungal spores. Also, traditional counting of pollen grains or taxa identification by optical microscopy can be done. A study has been carried out by the Health Protection Agency (HPA), Porton Down, UK, to measure the physical efficiency of the Coriolis air sampler. The physical efficiency of the sampler for collection of micro-organism-laden particles of various sizes has been compared with that of membrane filter samplers using the techniques described by ISO 14698-1. The Coriolis was operated simultaneously with membrane filter samplers in a controlled room where they were challenged with uniform-sized particles of different diameters containing bacterial spores. For the larger particle sizes, it was found that the physical efficiency of the Coriolis was 92% for 10-μm particles. The biological performance of the Coriolis in the collection of airborne fungal spores and pollen grains was evaluated in comparison with a Hirst spore trap (one-week tape-on-drum type sampler) which is one of the most frequently used traps in the measurement of outdoor pollen grain concentrations. The advantages and limitations of both technologies are discussed. The Coriolis was operated simultaneously with a Hirst spore trap in the sampling station of Réseau National de Surveillance Aérobiologique, France (RNSA); the pollen grain and fungal spore counts were analysed by optical microscopy. The pollen grain count m⁻³ collected was compared for both devices. The dispersion values were obtained and statistical analysis was carried out. This study shows that the Coriolis air sampler provided equivalent recovery of pollen grain and fungal spores compared with the volumetric trap standard method (not significantly different, W test, α = 0.05). Nowadays, the French-led project, acronym MONALISA, with financial support from the European Commission––Life-Environment (LIFE05 ENV/F/000068), is testing this innovative air sampler in order to measure the antigenicity/allergenicity of the main aeroallergen particles, i.e. Betula (birch), Poaceae (grasses), Parietaria (pellitory), Olea spp (olive tree), and Artemisia (mugwort) pollen grains, and Alternaria (fungal spores) to validate a new approach of monitoring instead of quantifying pollen grains by their morphology. The robustness and efficiency of the MONALISA system is being demonstrated at a national level throughout Europe in eight different countries with different bio-climatic and topography characteristics: France, UK, Finland, Poland, Spain, Portugal, Switzerland, and Italy.     

A new sub-sampling method for analysis of air samples collected with the Andersen single-stage sampler

A protocol for bioaerosol collection was developed that provides not only accurate predictions of fungal concentration, but also improves species recovery. Random transfer of a subset of 50 of the 400 impaction points from Andersen single-stage bioaerosol sampling plates results in subcultures that are accurate predictors of fungal concentration (CFU/m³), when compared to duplicate untouched Andersen plates. A linear regression model was developed to estimate CFU/m³ from the colonies counted on the Random-50 plates. The random transfer to five plates (“Random-50” plates), allows large numbers of fungi to be recovered and identified, including slow-growing fungi that otherwise would be masked by fast-growing fungi.     

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.     

Simulation of the interactions of predatoryTyphlodromus mites with the European red mite,Panonychus ulmi (Koch)

Interactions of Typhlodromus mites and their prey, the European red mite, in orchard settings were examined through computer simulation. In particular, the consequences of very slow dispersal by the predators, compared with the weather-dependent higher rates of prey dispersal, were elucidated. In simulations of the interactions of the predator and its prey, both dispersal and temperature strongly affected the available supply of juvenile prey, and thus could determine whether the predators on an individual tree survived or perished.     

Inhibition of quantitative PCR analysis of fungal conidia associated with indoor air particulate matter

Environmental samples analyzed by quantitative PCR (qPCR) are subject to interference by inhibitors present in the environment being sampled. A controlled determination of the effect of inhibitors associated with sampling indoor air and the ability of internal standard controls to detect inhibition was carried out by filter collection of air samples followed by spiking of the filters with green fluorescent protein-expressing Aspergillus fumigatus conidia. Microscopic conidial counts were compared with qPCR results and correlated with levels of particulate matter and viable airborne microorganisms. Our data showed that PCR can be inhibited by masses of particulate matter as low as 50 μg and that the amount of inhibition was positively correlated with the mass of particulate (r = 0.75) and the number of non-filamentous organisms (r = 0.73). The use of internal standard DNA identified the presence of inhibitors and indicated the need for additional sample processing or qualification of sample results.     

Characterization of actinomycetes isolated from the indoor air of the church of Saint Katherine Monastery, Egypt

Actinomycetes were isolated from the indoor air of the church of Saint Katherin Monastery during different visiting hours. Fifty air samples collected over one year by using automated air sampler were plated on four different media. The low nutrient-content medium 1/10 SC was significantly effective in recovery of actinomycetes compared to the other formula of rich media. Average counts of bacteria, actinomycetes and fungi were 487, 65 and 90 cfu/m³, respectively. Fifty-six morphologically different actinomycetes isolates were recovered during this study assigned into five different genera, in addition to three unidentified isolates. Tentative identification of the isolates indicated predominance of genus Streptomyces, representing 59% of the isolates. Isolates were screened for resistance to 11 antibiotics, antimicrobial activities towards seven microbial strains, Growth on 12 different carbon source, acid production and pigmentation. About 77% of actinomycete isolates were resistant to the antibiotics with different resistance patterns. 12.5% of the airborne actinomycetes exhibited antinmicrobial activities. The isolates showed wide variation in carbon source usage. Forty percent of the isolates were able to utilize all tested carbon sources while 80% were acid producers. Melanin production was produced by 34% of the isolates. While 45% of the isolates were able to produce other diffusible pigments, the majority of the pigments were brown in color however; yellow, orange and green pigments were produced by a number of isolates. The impact of these activities on the historical objects of the church and the tourist’s health is discussed.     

Hydrogen sulfide concentrations in indoor air of thermal springs

This study aimed to assess hydrogen sulfide (H₂S) concentrations in the pool indoor air of hot springs and its link to some physicochemical properties of the springs in Ardabil province. Twenty-two hot springs from different regions were selected and monitored for H₂S concentrations using a portable gas meter. Respective mean concentrations of H₂S in hot springs indoor air were 9.11 ± 11. Ghotour Souei hot springs had the highest concentration of H₂S with a mean concentration of 29.4 ± 7.7 and 25.2 ± 8.16 ppm at the source and general pool areas, respectively. Oxidation-reduction potential and pH of the water were the most important factor influencing H₂S concentrations in the hot springs. H₂S concentrations in indoor air of Ardabil hot springs were noticeably higher than OEL-TWA and OEL-STEL, and therefore may pose important risks for human health on both short-and long-term exposures.     

Chemical characterization of indoor air quality in Parisian homes

Summary Air quality inside 9 homes in the Paris region was evaluated by measuring several atmospheric pollutants. In these homes interior emissions of ammonia and volatile organic compounds were obvious. Regarding other pollutants such as sulphur dioxide, nitrogen dioxide, particles, polycyclic aromatic hydrocarbons, sulphate and metals, the influence of external surrounding air remains predominant.     

Levels of formaldehyde in residential indoor air of Gonabad,Iran

Abstract

Human health has been identified to be affected more significantly by indoor air quality. Among numerous pollutants present in indoor air, formaldehyde (FA) is of great concern because of its highly hazardous nature. The concentrations of FA were determined from 20 newly decorated homes in the city of Gonabad, Iran during 2015. It was found that the indoor air levels of FA in all the sampled houses were exceptionally high in the range of 21 to 360 µg/m³ (mean of 149.3 µg/m³). If the 24-h average concentrations of FA measured from those sites were concerned, nearly 40% of them were seen to exceed the WHO guideline values (i.e., 100 µg/m³). One of the important reasons for the high concentrations could be low air exchange rates in those houses (e.g., from 0.18 to 0.37?h^?1), high levels of humidity in the newly decorating houses and stronger sources in the indoor environment. Furthermore, its pollution in homes with natural ventilation was seen to be much higher than those of mechanical ventilation. Due to high levels of indoor FA, more effective control procedures should be developed and employed to reduce the risk associated with formaldehyde exposure.     

Methods for estimating the number of the Cryptomeria red mite,especially with the removal by solutions

We compared the removal by solution, the represented count-area method and the beating, for the purpose of estimating the number of the Cryptomeria red mite. Among them the solution procedure provided the smallest standard error as per cent of the mean. 0.25 per cent unheated solution of sodium hydroxide is used for the summer generation, and also 0.25 per cent boiling one for the winter eggs. The mean proportion removed±standard error for the summer eggs and the winter eggs were 0.8770±0.0316 and 0.7920±0.0281 respectively, while 0.9894±0.0050 for the mites.     

Methods and techniques for sampling and analyzing gases and particles present in indoor air: take into account the experience acquired with outdoor air

Summary This paper highlights the common points of indoor and outdoor air; the range of pollutant concentrations, the questions that must be asked prior to making any measurements, the aim of measuring and the state of the art. The detailed study of the sampling and analysis methods and techniques used, prompted us to build an experimental chamber designed to stimulate the phenomena under investigation and the first findings are presented here.     

Impact of indoor air pollution on health,comfort and productivity of the occupants

In this special report, the possible causes of indoor air pollution and its impact on the health, comfort and productivity of the building occupant are discussed. The causes and symptoms of sick building syndrome, allergy and environmental-illnesses and building related illnesses are discussed in the context of building environments. The remediation and prevention measures examine the solution to the problems caused by indoor air pollution in buildings     

Impact of indoor air pollution on health,comfort and productivity of the occupants

In this special report, the possible causes of indoor air pollution and its impact on the health, comfort and productivity of the building occupant are discussed. The causes and symptoms of sick building syndrome, allergy and environmental illnesses and building related illnesses are discussed in the context of building environments. The remediation and prevention measures examine the solution to the problems caused by indoor air pollution in buildings.     

Biological treatment of indoor air for VOC removal: potential and challenges

There is nowadays no single fully satisfactory method for VOC removal from indoor air due to the difficulties linked to the very low concentration (microg m(-3) range), diversity, and variability at which VOCs are typically found in the indoor environment. Although biological methods have shown a certain potential for this purpose, the specific characteristic of indoor air and the indoor air environment brings numerous challenges. In particular, new methods must be developed to inoculate, express, and maintain a suitable and diverse catabolic ability under conditions of trace substrate concentration which might not sustain microbial growth. In addition, the biological treatment of indoor air must be able to purify large amounts of air in confined environments with minimal nuisances and release of microorganisms. This requires technical innovations, the development of specific testing protocols and a deep understanding of microbial activities and the mechanisms of substrate uptake at trace concentrations.     

Deployment of a threshold activated pump sampler in an industrial shock load impact study

Shock loading of toxic substances into natural waterways is apervasive practice which has substantial impacts on their biota.This paper describes the effects of shock (pulse) pollution loadingfrom two major industries on a river and wetland system in southernOntario, Canada. The assessment of shock loading frequencyindicated that sporadic discharges of polluted water occurred onaverage once every other day during the 38 days of monitoring inthe period April, 1986 to November, 1987.To estimate the frequency and intensity of the shock loads, anautomatic pump sampler that was activated by a thresholdconductivity was constructed and deployed. Samples were withdrawnfrom the river when the specific conductivity of the streamexceeded a threshold value of two times background. Backgroundspecific conductivity ranged between 200–250 S cm^-1The impact of these shock load discharges on a downstream aquaticplant community in a Class One (Provincially Significant) wetlandwas examined. The area of Thompsons Creek upstream of the CyanamidChemical Company displayed a normal complement of aquatic organismswhile downstream of the companys main discharges for a distance ofnearly 2 km, the stream was barren of nearly all aquatic life.A reef-like structure in which nickel, chromium, and lead reachedrespectively 2900, 2100 and 2210 mg kg^-1 dry weight ofsediment was located in the Welland River near the outfall of theAtlas-Mansfield storm sewer adjacent to the Atlas Specialty SteelsCompany. The average flow rate at the outfall of theAtlas-Mansfield storm sewer into the Welland River wasapproximately 28400 m³ day-¹ in 1986 (MOE 1987). Asmall area referred to as the Atlas reef because of the high ironconcentrations giving the sediments a cement-like condition, wasdevoid of all higher aquatic plants.