Comparative study of seasonal and intradiurnal variation of airborne herbaceous pollen in urban and rural areas

The content of herbaceous pollen in the atmosphere depends on the vegetal cover, climate and the weather and geographical conditions. The aim of the study reported here was to compare aerobiological data obtained from pollen monitoring stations located at sites differing with respect to their flora and microclimate – i.e. a town and a rural area. A volumetric method was used for sampling. In each microscopic preparation 12 vertical strips corresponding with 2-h intervals were analysed. A 90% method was used to determine the pollen season. The results were statistically verified using the u test and the Kolmogorov-Smirnov, Spearman and Wilcoxon tests. Higher values of the Seasonal Pollen Index (SPI), higher daily average concentrations and higher peak values were recorded in the rural area. An analysis of intradiurnal variations of airborne pollen showed that apart from the Poaceae the number of pollen grains in the air began to increase earlier in the day in the rural area; in the case of Rumex and Ambrosia, the maximum values also appeared a few hours earlier. For all the taxa investigated, the analysis of correlation showed a significant association between the daily average concentrations at both sites. The weakest association occurred for Plantago lanceolata; for all other taxa, the determination coefficients (R ²) were high. The results of the Wilcoxon test showed that, despite the strong positive association between daily concentrations of the pollen types investigated, there were differences in mean pollen concentrations in the overlapping pollen season. Mean concentrations of Poaceae and Rumex airborne pollen were significantly higher in the rural area in both years, and those of Urtica and P. lanceolata were significantly higher only in 2002.     

Airborne fungal spores in urban and rural environments in Poland

The concentrations of airborne fungal spores were measured during 2001–2002 in two sites in Poland—one in the city and the other in the countryside. The sites differed in habitat characteristics, such as urbanisation level, vegetation and microclimate. The aim of the study was to determine if, and in which way, land use type would affect spore occurrence. The volumetric method was used, and ten easily identifiable spore types were sampled and anyalysed: Alternaria, Botrytis, Cladosporium, Epiccocum, Ganoderma, Pithomyces, Polythrincium, Stemphylium, Torula and Drechslera. The season of spore occurrence was determined using the 90% method. The fungal spores studied were very frequent in the air (in most instances at a frequency higher than 50%). The most common spores were those of Cladosporium, with a frequency range of 83.1–90.5%. In both years the proportion of Cladosporium spores was statistically significantly higher in the city. In both 2001 and 2002 the total seasonal sum of all the spores was higher in the countryside than in the city as was the Seasonal Fungal Index (SFI) values and average concentrations of Botrytis, Ganoderma and Torula. These latter three genera are usually represented as pathogens of plants. The mean spore concentrations of most taxa were significantly higher in the rural environment. Correlation coefficients between daily concentrations at both sites for most of the taxa studied were significant, but with lower correlation values between variables. Such results indicate that the values from the sites are weakly interdependent. The study confirms that land use type may very likely have an impact on the course of spore occurrence, the mean daily concentrations of spores as well as SFI values.     

Airborne fungal spores in an industrial area: seasonal and diurnal periodicity

Qualitative and quantitative studies of atmospheric fungal spores at a chloralkali factory, Jayashree Chemicals. were made during 1993 employing culture plate and rotorod methods. A total of 57 sporulating fungal types, including three sterile mycelial forms, were recorded by the culture plate method and 51 spore types, including the hyphal fragments and unidentified spores, were recorded by the rotorod method. As to the seasonal variation, winter was found to be the greatest contributor of fungal spores as compared to the summer and rainy season. Instead, when considering the hour of the day, the peak number of fungal propagules was recorded at noon (12.00 h) followed by evening and morning values, an exception being recorded in winter months, when maximum CFUs ofCladosporium were monitored in the morning. The seasonal variation in fungal concentration and composition was found to be influenced by temperature, rainfall and relative humidity, whereas diurnal incidence was the effect of varying temperature and relative humidity during day time only. Moderate temperature and relative humidity favoured the maximum fungal spore load in the atmosphere.Cladosporium, Nigrospora, Alternaria, Lasiodiplodia, Drechslera, Pestalotia, Curvularia, Epicoccum, Aspergillus, Penicillium andChaetomium were the commonest fungal spores in the factory area.     

Gravimetric survey of airborne fungal spores in Milan

Knowledge of airborne viable particles is basic to every study of respiratory allergies and an understanding of airborne fungal spores is particularly useful because they are harder to detect than other inhalant allergens such as pollens, which can be predicted seasonally. The gravimetric method is the simplest way to search for fungal spores.     

Airborne fungal spores in the coastal plain of Israel: A preliminary survey

Airborne spores were monitored during the years 1993–1995 in three cities along the coastal plain of Israel: Ramat Gan, Tel Aviv (Ramat Aviv) and Haifa. Seasonal fluctuations in the concentration of airborne spores were recorded. The following genera of fungi were identified:Alternaria, Cladosporium, Coprinus, Curvularia, Drechslera. Diplococcum, Epicoccum, Fusarium, Leptosphaeria, Pithomyces, Puccinia, Sphacelotheca, Stemphylium andUstilago. Unidentified spores were very rare and in negligible numbers. The dominant airborne fungal spores wereCladosporium andAlternaria. The monthly variations in airborne spores, observed among the three cities, seem to be rather minor. The recorded levels of airborne spores were below the concentrations that are accepted as threshold levels for provocation of clinical responses.     

Detection of fungal spores from contaminated surfaces by the polymerase chain reaction

A method has been developed to detect fungal spores in dust samples collected from internal surfaces of air-conditioning ducts. The method is based on the utilization of the polymerase chain reaction (PCR) with specific primers for fungal species. PCR amplification is carried out directly in boiled samples avoiding time-consuming DNA preparation steps. The presence of bovine serum albumin in the reaction mixture overcame the inhibitory effect of the humic acids present in the dust.     

Aerobiological monitoring for fungal spores in a rehabilitation hospital in Northern Italy

In the setting of an aerobiological study of confined environments and environmental prevention of nosocomial infections, aerobiological monitoring of 22 areas in Montescano Medical Rehabilitation Centre (Pavia) was performed in three different months: February, May, and August, 1994. A Lanzoni 3000 spore trap was used for the monitoring. Examination of the results showed that, in the environments monitored, the indoor presence of fungi increased progressively over the three periods considered. The behaviour of individual genera of fungi differed. In the winter periodPenicillium andAspergillus were the most commonly encountered genera.Cladosporium was the dominant genus from the spring to the summer while the yeasts had their maximum counts in the spring morning. The use of air conditioning, combined with the low air exchange between outdoors and indoors in some of the environments certainly played a part in the low concentrations of these latter aerofungi.     

Aerobiological monitoring for fungal spores in a rehabilitation hospital in Northern Italy

In the setting of an aerobiological study of confined environments and environmental prevention of nosocomial infections, aerobiological monitoring of 22 areas in Montescano Medical Rehabilitation Centre (Pavia) was performed in three different months: February, May, and August, 1994. A Lanzoni 3000 spore trap was used for the monitoring. Examination of the results showed that, in the environments monitored, the indoor presence of fungi increased progresively over the three periods considered. The behaviour of individual genera of fungi differed. In the winter periodPenicillium andAspergillus were the most commonly encountered genera,Cladosporium was the dominant genus from the spring to the summer while the yeasts had their maximum counts in the spring morning. The use of air conditioning, combined with the low air exchange between outdoors and andoors in some of the environments certainly played a part in the low concentrations of these latter aerofungi.     

Airborne fungal spores in 80 homes in the Latrobe Valley, Australia: levels, seasonality and indoor-outdoor relationship

Airborne viable and total fungal spores were sampled inside and outside 80 houses in the Latrobe Valley, Victoria, Australia as part of a larger indoor environmental study. Each residence was visited six times over a period of 1 year for sample collection, and fungal spore samples were collected from at least three indoor sites and from an outdoor site. Viable spores were sampled using an Andersen sampler, while total spores were assessed using a Burkard spore trap. Identification of fungal colonies to genera level was performed in two seasons; winter and late spring. The most common fungal genera/groups wereCladosporium, Penicillium, and yeasts, both indoors and outdoors in winter and late spring. Outdoor levels were higher than those indoors throughout the year, and a significant seasonal variation in spore levels was seen both indoors and outdoors with overall maxima in summer. Contrary to this trend, the levels ofAspergillus, yeasts,Cephalosporium andGliocladium were higher in winter. Most fungal genera were found in greater concentrations outdoors compared to indoors, butPenicillium was more common indoors. Outdoor spore levels were a significant influence on indoor levels, but seasonal differences suggest that other influences are important.     

丛枝菌根真菌种群的孢子季相动态研究

以草坪为研究对象,研究草坪土壤中丛枝菌根真菌种群的孢子组成、孢子密度、物种丰富度、多样性及其季相变化规律。结果表明,丛枝菌根真菌孢子密度、物种丰富度和多样性指数在一年内随季节变化表现出一定的季相变化规律,三者均在冬季达到最高,在时间节律上与植物群落季相变化不同步;同时分析了气候因素(平均温度、降雨量和日照时间等)对丛枝菌根真菌的影响。结果表明,气候因素对孢子密度、物种丰富度和多样性指数均有显著影响。     

Differentiation of allergenic fungal spores by image analysis, with application to aerobiological counts

The ability of an image analysis routine to differentiate between spores of eleven allergenic fungal genera was tested using analysis based on seven basic and up to 17 more complex features, extracted from digitised images. Fungal spores of Alternaria, Cladosporium, Fusarium, Aspergillus, Penicillium, Botrytis, Epicoccum, Exserohilum, Ustilago, Coprinus and Psilocybe were examined in a series of experiments designed to differentiate between spores at the genus and species level. Linear and Quadratic Discriminant Analysis of feature measurements, recorded for 100 to 1600 spores per taxon, differentiated between genera and species with a high level of accuracy. Genus comparisons using only seven basic features resulted in 98% accuracy for the recognition of conidia belonging to Cladosporium, Fusarium and Epicoccum. Differentiation between conidia of Aspergillus and Penicillium was the least reliable, with 56% of Aspergillus conidia correctly identified and 41% misidentified as Penicillium. At the species level, conidia of Cladosporium macrocarpum, Fusarium moniliforme (microconidia), F. oxysporum (microconidia), F. solani (macroconidia), Alternaria helianthi and A. brassicae were consistently identified with 86--100% accuracy. Reduced levels of accuracy in the identification of spores by image analysis reflected similarities between species in their spore morphology. The application of image analysis to aerobiological counting methods is discussed in relation to the results obtained.     

The effects of meteorological factors on airborne fungal spore concentration in two areas differing in urbanisation level

Although fungal spores are an ever-present component of the atmosphere throughout the year, their concentration oscillates widely. This work aims to establish correlations between fungal spore concentrations in Porto and Amares and meteorological data. The seasonal distribution of fungal spores was studied continuously (2005–2007) using volumetric spore traps. To determine the effect of meteorological factors (temperature, relative humidity and rainfall) on spore concentration, the Spearman rank correlation test was used. In both locations, the most abundant fungal spores were Cladosporium, Agaricus, Agrocybe, Alternaria and Aspergillus/Penicillium, the highest concentrations being found during summer and autumn. In the present study, with the exception of Coprinus and Pleospora, spore concentrations were higher in the rural area than in the urban location. Among the selected spore types, spring-autumn spores (Coprinus, Didymella, Leptosphaeria and Pleospora) exhibited negative correlations with temperature and positive correlations both with relative humidity and rainfall level. On the contrary, late spring-early summer (Smuts) and summer spores (Alternaria, Cladosporium, Epicoccum, Ganoderma, Stemphylium and Ustilago) exhibited positive correlations with temperature and negative correlations both with relative humidity and rainfall level. Rust, a frequent spore type during summer, had a positive correlation with temperature. Aspergillus/Penicillium, showed no correlation with the meteorological factors analysed. This knowledge can be useful for agriculture, allowing more efficient and reliable application of pesticides, and for human health, by improving the diagnosis and treatment of respiratory allergic disease.     

A 3-year airborne pollen and fungal spores record in San Carlos de Bariloche, Patagonia, Argentina

Airborne pollen in San Carlos de Bariloche was sampled from September to March 2001–2004 with a Hirst-type volumetric spore trap placed at a height of 15 m in a city extending from the humid forests, through the mesic forests, to the steppe. The total amount of pollen recorded varied widely from year to year. The pollen index was 4,395 in the sampling period 2001/2002; 9,055 in 2002/2003 and 2,756 in 2003/2004. The main pollen period extended from October to January. In October, pollen concentration was the highest. Sixty-six pollen types were identified. Cupressaceae and Nothofagus were the major contributors. Betula, Prunus, Pinus and Populus, the most abundant ornamental taxa in the city, also contributed to the pollen record. Pollen of Maytenus and Lomatia was representative of the mesic forest, while pollen in the lower layers of the humid forest was present in trace amounts. Cupressaceae, Nothofagus and Betula prevailed during spring (September–December), and Plantago, Rumex and Poaceae during summer (December–March). The association of daily pollen concentration and meteorological variables, temperature (mean, maximum, minimum), dew point, rainfall and wind speed, was significant. Correlations showed to be negative, with the exception of that to wind speed. The total sum of fungi spores increased from 1,771 in 2001/2002; through 8,441 in 2002/2003 to 13,782 in 2003/2004. Relative concentration rose to 29%, 48% and 84% of the total number of pollen and fungal spores recorded during each sampling period.     

Seasonal variation of denitrification rate in Lake Suwa sediment

The seasonal variation of denitrification rate in sediments in the central station of Lake Suwa, Japan, was estimated by the acetylene-inhibition technique from March 20 to December 10, 1994. The denitrification rate ranged from 0 to 1800µmolNm^–2day^–1 and showed a distinct seasonal trend, i.e., relatively high rates in spring and winter, and low or negligible rates in summer. The denitrification rate was well correlated with NO^–₃ concentration in overlying water, suggesting that NO^–₃ in overlying water was the primary controlling factor for denitrification. The annual rate of denitrification was 0.15molNm^–2year^–1. Denitrification removed 5% of the annual nitrogen load from the lake, and this fraction was relatively small compared to the values reported for a variety of aquatic environments. In Lake Suwa, NO^–₃ in the water column was depleted during summer, and this suppressed effective removal of nitrogen from the lake by denitrification.     

Seasonal variation of airborne fungal spore concentrations in a vineyard of North-West Spain

Conidial types collected daily in the air above a vineyard in northwest Spain were identified and counted. A total of 26 fungal spore types were recognised; ten of which (Cladosporium, Botrytis, Fusarium-Leptosphaeria type,Torula, Puccinia, Alternaria, Uncinula, Helminthosporium type,Agrocybe andStemphylium) gave a seasonal total concentration exceeding 1000 spores. Seasonal patterns are shown for 12 of the identified taxa.     

Seasonal nutrient variation in trembling aspen

Summary Variation in concentrations of N, K, Mg, and Ca in vegetative-buds, leaves, twigs, and male catkins of trembling aspen (Populus tremuloides Michx.), determined throughout a growing season in central Minnesota, reflected the different physiological roles of the nutrients. Practical implications are discussed.     

The daily variations of airborne fungal spores in Mexico City

The daily and seasonal distribution of airborne fungal particles was recorded in a high altitude tropical zone. Sampling was carried out in the southern part of Mexico City. An Andersen air sampler was used over a period of six months. Ten minutes sampling for each set of plates was done at fixed schedule: 07:30, 14:00 and 19:00 hours. The sampler was placed 10 m above the ground. Daily variation was found to be associated with the season, weather and atmospheric stability. The highest value of mold counts (3195 CFU m⁻³) was recorded in the evening on October, a transitional month between the rainy and the dry seasons, the lowest (45 CFU m⁻³) at noon during the rainy season. Mold counts were significantly correlated with temperature, having negative signs both in the morning and at noon, and being positive in the evening. The abundance of only three genera was recorded.Cladosporium, was isolated more frequently, and its abundance at 14:00 h was of 38%;Alternaria represented 4.0%, at 14:00 h, andAspergillus 3.0% at 7:30 h. Fifteen species belonging to the latter genera were identified and most of them are considered as opportunistic molds of clinical significance.     

Seasonal and age-related variation in the needle quality of five conifer species

Summary Age changes of foliage resource quality (water, nitrogen, fibre, phenolics and toughness) were studied in five species of conifer (Pinus sylvestris L.), Picea abies (L.) Karsten, Tsuga heterophylla (Rafinesque) Sargent (all Pinaceae), Chamaecyparis lawsonian (Murray) Parlatore and Thuja plicata D. Don (both Cupressaceae) over a 2-year period in an English forest.Mature foliage of Pinus sylvestris was characterized by higher levels of nitrogen, fibre and toughness, and lower phenolics, and that of Tsuga heterophylla by higher levels of phenolics, and lower fibre and toughness levels, than the mature needles of the other species studied. Immature needles had higher levels of water and nitrogen, and lower levels of fibre and toughness, than older needles. Immature needles of Picea abies and Tsuga heterophylla had a high concentration of phenolics, which decreased with needle maturity. By mid-August, the levels of most of the foliar constituents in current-year needles had stabilized at levels maintained for the next year. Sampling revealed a fall in the concentration of phenolics, fibre and water in mature needles between March and June. Possible reasons for this seasonal trend are discussed. The levels of conifer foliar constituents were compared with levels recorded in broadleaf trees. Conifers had greater concentrations of all measured foliar constituents, but, with the exception of the six fold greater toughness of conifer needles, the differences between broadleaves and conifers were less than those between the immature and mature conifer needles. Previous studies have related the abundance of Lepidoptera on conifers to hostplant taxonomic relationships. However, the foliar constituents measured in this study were poor predictors of taxonomic relationships between the conifers. It is suggested that the abundance of Lepidoptera on conifers is not determined by levels of general foliar constituents and the role of other hostplant factors in shaping lepidopteran utilization of conifers is discussed.     

Body fat in urban and rural male college students of Eastern India

Male college students (N = 381) residing in several districts of Eastern India, classified into two groups, urban (N = 193) and rural (N = 188), were studied by anthropometric measurements of skinfold thicknesses in several sites of the body to determine their body fat content. The mean value of percentage of body fat was found to be significantly higher (P < 0.001) in the urban group of students (12.07 ± 3.04) than in the rurals (11.04 ± 2.63). The mean values of skinfold thicknesses of the biceps, triceps, and subscapular regions were also found to be higher in urbans (P < 0.01), but no such significant differences in mean values of supra-iliac and abdominal skinfolds were found between the two groups of students. Most of the subjects of both the groups had a greater thickness of the abdominal skinfold compared to thickness of the biceps, triceps, and suprailiac skinfolds. It was found that the college students of Eastern India were leaner than the youths of North America, Europe, Japan, and Northern India.     

Seasonal variation in the properties of titania photocatalysts produced from Ti-salt flocculated bioresource sludge

Ti-salt flocculation of biologically treated sewage effluent (BTSE) was carried out on monthly basis during one year to trace the seasonal variation in the properties of BTSE, Ti-salt flocculated BTSE and titania photocatalysts. Titania photocatalysts were produced from incineration of Ti-salt flocculated sludge at 600 °C. The physio-chemical properties of BTSE, Ti-salt flocculated BTSE and titania photocatalysts were investigated. The photocatalytic activity of titania was examined using different substrates of rhodamine B and humic acid under UV light irradiation. Results indicated that the flocculation performance of Ti-salt was not affected by the seasonal variation of BTSE. BTSE characteristics resulted in marginal effect in titania characterisation and photocatalytic activity. Titania photocatalysts produced from Ti-salt flocculated sludge in different seasons showed constant anatase phase, high BET surface area and high photocatalytic activity.