RESUMO

In order to determine the sequential prevalence of pollen grains and fungi spores in the city of Caracas by the volumetric method of collection and its effect on the population at risk, the first multidisciplinary team of aerobiological research was structured through a protocol designed for five experimental stages namely: a) Determination of the climatological parameters: temperature, relative humidity, speed and wind direction, precipitation and atmospheric stability, through simultaneous records of meteorological status located in the metropolitan area of Caracas; b) Collection, identification, classification and determination of the local distribution of the most important pollen grains existing in the zone under study; c) Collection, identification and classification of the most important fungi spores in the area; d) Preparation of the first pollinic calendar of Caracas and e) Evaluation of possible implication of the environment and the response through the IgE antibody in the selected patients in the area under study. Our results show: 1) The climatic conditions existing during the sampling period coincide with the analysis of the last 20 years in the Valley of Caracas. 2) The Venezuelan Central University (UCV) station was elected as the most representative point for permanent sampling. 3) An ideal statistical method is obtained in order to determine the spatial arrangement in the sampler rod of a dense type of fungi spores typical of the area under study. 4) The first pollinic calendar of Caracas was structured and 5) A seasonal tendency of the IgE response is shown. These results suggest an evident interrelation between the suggested concept of polyseasonality and antigenic polysensitization, and between individual seasonality with a specific reactivity and, finally, between tropical mixed seasonality with the expression of combined respiratory pathologies in our environment.

Assuntos

Microbiologia do Ar , Ar/análise , Pólen , Esporos Fúngicos/isolamento & purificação , Especificidade de Anticorpos , Asma/epidemiologia , Asma/etiologia , Asma/imunologia , Humanos , Imunoglobulina E/imunologia , Conceitos Meteorológicos , Prevalência , Rinite Alérgica Perene/epidemiologia , Rinite Alérgica Perene/etiologia , Rinite Alérgica Perene/imunologia , Rinite Alérgica Sazonal/epidemiologia , Rinite Alérgica Sazonal/etiologia , Rinite Alérgica Sazonal/imunologia , Estações do Ano , População Urbana , Venezuela/epidemiologia

RESUMO

In order to search an uniform criteria for sampling aerobiological particles, three sites were selected along the valley of Caracas. The distribution of vegetation, topographical and meteorological parameters were monitored. Pollen and spores were collected at each site during 24 hr at 6 min-intervals with a Rotorod sampler. Pollen counts were similar in all sites and much less abundant than spores. Cladosporium was the most abundant spore and grass pollen represented more than 50% of the pollen grains. Results showed that the three sites could be selected as suitable sampling area for airborne pollen and spores. Nevertheless, we recommend the selection of the most accessible and central site for a long-term sampling.

Assuntos

Ar/análise , Pólen/análise , Esporos , Geografia , Venezuela

RESUMO

Chemical, paleontological, and mineralogical analyses of a 7.5-meter core from the middle of Lake Valencia, Venezuela, have provided information on the paleoclimatic history of this low-elevation, low-latitude site for the last 13,000 years. The data show that dry climates existed in this region from 13,000 years before present (B.P.) until about 10,000 years B.P. The Lake Valencia Basin was occupied by intermittent saline marshes at that time. About 10,000 years B.P., a permanent lake of fluctuating salinity formed and arboreal plant communities replaced the earlier dominant xeric herbaceous vegetation and marsh plants. By 8500 years B.P., Lake Valencia reached moderate to low salinities and discharged water; the modern vegetation became established at that time. After 8500 years B.P., the lake twice ceased discharging as a result of reduced watershed moisture. The second of these drying episodes is still in progress and has been aggravated by human activities in the watershed.