ISSN:0017-3134    

DOI:10.1080/00173139409427832

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This short account describes the beginnings of aerobiology at Rothamsted and the development of studies of airborne dispersal of insects and fungal spores in relation to diseases of plants, animals and man.

ISSN:0017-3134    

DOI:10.1080/00173139409427833

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Grasses form the most important source of airborne pollen in the United Kingdom. This article reviews the ecological, geographical and historical features of grassland utilization relevant to pollen production. During the past half century extensive agricultural management, with botanically diverse swards and late (post anthesis) mowing for hay, has been progressively replaced by more intensive management with more reliance onLolium perenneand early mowing for silage. The role ofDactylis glomerataandPhleum pratensehas declined. A decrease in the June pollen catch supports the hypothesis that these changes have affected the quantities of pollen released. Incidence of hay fever shows geographical variation with climate, topography and vegetation type. Recent policy changes intended to decrease agricultural production and to meet environmental objectives may, in future, further affect the types and quantities of pollen produced.

ISSN:0017-3134    

DOI:10.1080/00173139409427834

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Fungal spores and pollens can be dispersed in a number of ways: by animals and insects; by water; by wind or by rain. This paper concentrates on the effects of wind on the dispersal of spores and pollen grains and the effects of rain on spore dispersal. For dispersal to be successful particles must complete three phases: removal, dispersal through the air and deposition. The biology of the organism and its environment can affect all three phases, however, once released the fate of all airborne particles largely depends on the laws of physics which govern the motion of the air. Many types of spore are actively ejected into the air while others are simply blown from the host surface. Particle size and shape affects dispersal and deposition phases. Local environmental factors such as temperature, humidity and light, as well as wind or rain, can play a key role in the removal of spores. Wind speed and turbulence or rainfall, largely determine spore dispersal, but, the size and shape of the particle, the nature of the plant canopy and the way the particles are released into the air may also be important. Particle deposition depends on both environmental and biological factors. This paper briefly considers these processes using examples and how they can be modelled.

ISSN:0017-3134    

DOI:10.1080/00173139409427835

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Asthma and allergic alveolitis account for about one third of the total number (2000 plus) of cases of work-related respiratory disease reported annually in the U.K. The majority of cases of occupational asthma are caused by chemical agents, but a significant number of the remainder result from inhalation of biological agents, such as those encountered in agriculture. A wide range of activities can result in exposure to organic dusts and associated microorganisms. These include handling mouldy hay and grains, fruit and vegetables, processing wastes, including compost making for mushroom growing and tending animals in confined facilities. To determine the incidence of occupational respiratory allergy in agriculture, to study aetiology and risk factors and, ultimately, to establish dose response relationships, requires input from a wide range of disciplines including clinicians, immunologists, microbiologists and aerobiologists. The link between what a farm worker breathes in and development of disease needs to be established. This paper reviews the role of microorganisms in the aetiology of disease with examples of typical exposures in agriculture and outlines the role that aerobiology can play in risk assessment.

ISSN:0017-3134    

DOI:10.1080/00173139409427836

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Concentrations of microorganisms, dust and bacterial endotoxin were determined in the air of 18 animal houses (four cowsheds, nine horse stables and five piggeries) in eastern Poland. Total mesophilic bacteria numbered 568.7–1480.7 colony forming units (CFU)x103m-3in piggeries, 43.9–280.5 CFU×103m-3in cowsheds, and 26.2–150.1 CFU×103m-3in horse stables. Corynebacteria (Corynebacteriumspp.,Arthrobacterspp.) predominated. Concentrations of Gram-negative bacteria, thermophilic actinomycetes and fungi were smaller (mostly in the range of 102-104CFU m-3) except for one cowshed and two stables where concentrations of thermophilic actinomycetes exceeded 100 CFU×103m-3.Thermoactinomyces vulgarisandSaccharopolyspora rectivirgula, both known to be strongly allergenic, were the predominant actinomycetes. Concentrations of airborne dust were 0.15–14.05 mg m-3. There were large concentrations of bacterial endotoxin in the air of piggeries, in the range 1.88–75.0 μg m-3, but concentrations were much smaller in other houses and mostly did not exceed a safe level of 0.1 μg m-3. The results show that the farm workers and housed animals can be exposed to large quantities of airborne microbes and their products that pose a potential risk of respiratory disease resulting from the immunomodulatory action of these organisms.

ISSN:0017-3134    

DOI:10.1080/00173139409427837

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Bracken (Pteridium aquilinum, L.) is a fern which mostly reproduces vegetatively although it also produces large numbers of spores that are dispersed by wind. Spore production was monitored using a Burkard spore trap, operated continuously, from August to October 1990 and 1991, with the intake about 20 cm from a clump of bracken fronds. Changes in spore concentration with height were also measured using five rotorod samplers placed downwind of a stand of bracken at the edge of a Field of wheat stubble. Between 20th August and 20th October 1990 and between 30th September and 14th October in 1991, daily average spore concentrations often exceeded 750 spores m-3. Daily mean concentrations exceeding 1,750 spores m-3air were observed on 13th September 1990 and 1st October 1991. Spores were mostly dispersed singly and nearly half were released between 08.00 and 11.00 hrs GMT.

ISSN:0017-3134    

DOI:10.1080/00173139409427838

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The start of the grass pollen season is compared over a network of standard sites for the six year period, 1987–1992. Five sites have records for the whole of this period, and a further four joined the network at different times since 1987. Two definitions of the start of the season were compared; those defined by the sum75 method tend to be later than those defined by the 98% method. Differences in the start dates were analysed in relation to cumulative temperatures above 5.5°C and monthly total rainfall from February to the end of June. Where comparisons can be made, seasons often start simultaneously in the south and the west. The variation in start dates shows a close relationship to cumulative temperatures and to rainfall in May and June but the patterns are complicated. Future work will analyse the data from the full geographical range of the network now that more sites are operating.

ISSN:0017-3134    

DOI:10.1080/00173139409427839

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Pollen data from three Burkard volumetric samplers, running simultaneously on buildings at heights of 12, 24 and 30 metres above ground level from 23rd June to 21st July 1992, were used to investigate vertical differences in pollen abundance, and correlations with six different weather parameters. Regression analysis was used to investigate the relationship between Gramineae andUrticapollen levels and the weather variables. Pollen concentrations from the 30 m trap were consistently smaller than those from the 12 and 24 m traps for all types examined. It was concluded that pollen from local sources was not sufficiently mixed in the air to reach the 30 m trap. A delay was observed in the peak concentrations of bothUrticaand Gramineae pollen between the three traps, with the maximum occurring approximately four hours earlier at 12 m than at 24 and 30 m. Circadian rhythms were also more prominent at the lower trap than at the two higher ones.Urticaand Gramineae concentrations at 12 and 24 m were correlated significantly to all the weather variables examined. Only sunshine and relative humidity were significantly correlated with pollen concentrations ofUrticaand Gramineae recorded at 30 m. Climate also affected the vertical variation in pollen concentration between the three traps. Rainfall, high wind speeds and high relative humidity reduced vertical variation, whilst warm sunny weather increased it.

ISSN:0017-3134    

DOI:10.1080/00173139409427840

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The mainDidymellaascospore season in Derby is June-September. 10 day running means for the years 1986–1988 have been compared with 10 day running means of rainfall and maximum temperatures. The high temperatures reached in 1987 together with substantial rainfall were very favourable forDidymellaascospore release. Diurnal periodicity showed that the expected night time pattern was only occasionally disturbed by day time rainfall.Didymellaascospore liberation is greatly increased when both temperature and rainfall are high. Temperatures of about 20° in the period before rainfall appear to greatly increase the numbers ofDidymellaascospores liberated.

ISSN:0017-3134    

DOI:10.1080/00173139409427841

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor