Spore Concentrations In Air Research Articles

Fungal spore involvement in the resuspension of radiocaesium in summer

We observed the atmospheric resuspension of radiocaesium, derived from the Fukushima Dai-ichi Nuclear Power Plant accident, at Namie, a heavily contaminated area of Fukushima, since 2012. During the survey periods from 2012 to 2015, the activity concentrations of radiocaesium in air ranged from approximately 10−5 to 10−2 Bq per m3 and were higher in the warm season than in the cold season. Electron microscopy showed that the particles collected on filters in summer were predominantly of biological origin (bioaerosols), with which the observed radiocaesium activity concentration varied. We conducted an additional aerosol analysis based on fluorescent optical microscopic observation and high-throughput DNA sequencing technique to identify bioaerosols at Namie in 2015 summer. The concentrations of bioaerosols fluctuated the order of 106 particles per m3, and the phyla Basidiomycota and Ascomycota (true Fungi) accounted for approximately two-thirds of the bioaerosols. Moreover, the fungal spore concentration in air was positively correlated with the radiocaesium concentration at Namie in summer 2016. The bioaerosol emissions from Japanese mixed forests in the temperate zone predominately included fungal cells, which are known to accumulate radiocaesium, and should be considered an important scientific issue that must be addressed.

Health hazards related to conidia of Cladosporium—biological air pollutants in Poland, central Europe

The spores of Cladosporium Link. are often present in the air in high quantities and produce many allergenic proteins, which may lead to asthma. An aerobiological spore monitoring program can inform patients about the current spore concentration in air and help their physicians determine the spore dose that is harmful for a given individual. This makes it possible to develop optimized responses and propose personalized therapy for a particular sensitive patient. The aim of this study was to assess the extent of the human health hazard posed by the fungal genus Cladosporium. For the first time, we have determined the number of days on which air samples in Poland exceeded the concentrations linked to allergic responses of sensitive patients, according to thresholds established by three different groups (2800/3000/4000 spores per 1m3 of the air). The survey was conducted over three consecutive growing seasons (April–September, 2010–2012) in three cities located in different climate zones of Poland (Poznan, Lublin and Rzeszow). The average number of days exceeding 2800 spores per cubic meter (the lowest threshold) ranged from 61 (2010) through 76 (2011) to 93 (2012), though there was significant variation between cities. In each year the highest concentration of spores in the air was detected in either Poznan or Lublin, both located on large plains with intensive agriculture. We have proposed that an effective, science-based software platform to support policy-making on air quality should incorporate biological air pollutant data, such as allergenic fungal spores and pollen grains.

Comparison of Several Optical Methods for an Automated Fungal Spore Sensor System Concept

Molds and their spores are important to the global ecosystem. Thus, the thousands of different mold species are present worldwide and their spores can be found almost everywhere. Dangerous fungal contaminations that pose threats to the economy and human health are problematic especially in the areas of public buildings (hospitals), food industry (food transport), and private residences. A simple and cost-effective sensor system for the detection of fungal spore concentrations in air would minimize this risk. This paper presents an optical sensor system developed for the detection of airborne spores. Results from both this paper and the functional tests of the fabricated parts were used to develop a concept for a fully automated fungal spore sensor system, which can detect a contamination within minutes. This sensor system is based on a commonly used manual technique, in which the pictures of particles in air samples are analyzed. In the first step, the particles in an air sample were collected and fixed onto an adhesive surface. Afterward, the images were captured using a color camera and a microscope objective. The system allows images to be captured under three different microscopy methods: bright-field, dark-field, and fluorescence microscopy. The images were subsequently analyzed by software, and the analysis results from the three microscopy methods were compared. The results showed that the system was able to detect, differentiate, and count spores within minutes. This system also offers the major advantage of not requiring any prior incubation. Furthermore, based on the innovative use of adhesive tape that can serve as an automated microscopy surface, the system can be made simple and cost-effective to operate.

Effective protection of allogeneic stem cell recipients against Aspergillosis by HEPA air filtration during a period of construction--a prospective survey.

High incidence of aspergillosis on transplant units or hematological wards without HEPA air conditioning during periods of demolishing or construction has been reported by several investigators. Here we report monitoring of fungal air contamination during a period of construction on a stem cell transplantation ward using the gravity air-setting plate (GASP) method. Fungal air contamination in HEPA-conditioned patient rooms was constantly low, independent from construction activity. Outside of the patient rooms at the ward's corridor, the fungal load was significantly higher with some peak values. Outside the transplant unit measures of construction led to a significant increase of fungal spore concentration in air. Transplant activity was not reduced during construction and patients were nursed strictly under HEPA conditions. Patients were monitored prospectively for incidence of infections since 1990 and data of patients grafted during construction (n = 28) were compared to those grafted outside building activity (n = 652). An increase of aspergillosis during construction could be clearly excluded. It can be concluded: Nursing of patients undergoing stem cell transplantation in HEPA-conditioned rooms is an effective protection against acquisition of aspergillus-infection, even under environmental conditions with increased air contamination by conidia. The gravity air-setting plate (GASP) method is not expensive and easy to use and allows reliable and quantitative aerobiological spore monitoring.

DEPOSITION OF AIR‐BORNE LYCOPODIUM SPORES ON PLANE SURFACES

The deposition of Lycopodium spores on sticky surface traps, including vertical and horizontal microscope slides and Petri dishes as used in routine aerobiological survey, was studied in a small wind tunnel at wind speeds from approximately 0.5–9.5 m./sec.Deposition results from several processes acting singly or in combination. The pattern of deposit on a microscope slide orientated at angles varying from o to 90° to the wind, with gravity either positive, neutral or negative, indicates that, except on a surface parallel to the wind at the lowest wind speed, sedimentation under gravity plays a minor part in deposition on plane surfaces. As the wind speed is increased the deposit is decreased because of ‘edge shadow’. At the highest wind speed the deposit is as large on the lower as on the upper surface of the horizontal slide, which suggests deposition by turbulence. Deposition by impaction against a vertical strip increases with wind speed, and efficiencies observed are lower than for cylinders of the same diameter. The deposit on slides inclined at angles of 45° or less to the wind direction is increased by impaction of an ‘edge drift’. The interaction of these various deposition processes on mean deposition at different angles and wind speeds gives a series of curves with a maximum at 90° at 9.5 m./sec. and with minima at 0, 90 and 180° at wind speeds lower than 9.5 m./sec. At these lower wind speeds there are two maxima in the range 20–70° and 135–150° respectively.Deposits on Petri dishes show rim effects differing at different wind speeds. These can be eliminated by sinking the dish below a flat surface.Blow‐off from non‐sticky surfaces is least at about 45°, and greatest at 0°.Spore concentration in air is difficult to estimate from the deposits on planesurface traps, because horizontal traps under‐record at medium wind speeds, and because vertical traps are very sensitive to changes in wind speed. Power‐operated suction traps are to be preferred when data on spore concentrations are required.