Santiago Fernández Rodríguez

Two sampling methods for the Petri dish detection of airborne fungi

Abstract Burkard personal samplers for Petri dishes use two air throughput devices, either with a sieve or with a funnel, for monitoring of airborne fungi concentration. These two different methods have been compared in a comparative study. The two personal traps used for comparison were run simultaneously, one equipped with a sieve and one with a funnel only. Possible correlations with rainfall, temperature, wind speed, and relative humidity were studied. The average concentrations were 74 and 339 colony forming units/m3 (a factor of 4.6 difference) for the funnel and sieve devices, respectively. More than 70 taxa of airborne fungi were identified. The four most important genera in decreasing order of concentration were Cladosporium, Alternaria, Penicillium, and Aspergillus, the last two present in similar concentration. A significant negative correlation with wind speed was detected. Statistical analysis (ANOVA) revealed significant differences between the two sampler types except for Alternaria. In conclusion, the sampler with a sieve provides more colonies than the same sampler with a funnel. Both kinds of samplers are affected by wind speed, with the capture of airborne fungi propagules being reduced as the speed increases.Abstract Burkard personal samplers for Petri dishes use two air throughput devices, either with a sieve or with a funnel, for monitoring of airborne fungi concentration. These two different methods have been compared in a comparative study. The two personal traps used for comparison were run simultaneously, one equipped with a sieve and one with a funnel only. Possible correlations with rainfall, temperature, wind speed, and relative humidity were studied. The average concentrations were 74 and 339 colony forming units/m3 (a factor of 4.6 difference) for the funnel and sieve devices, respectively. More than 70 taxa of airborne fungi were identified. The four most important genera in decreasing order of concentration were Cladosporium, Alternaria, Penicillium, and Aspergillus, the last two present in similar concentration. A significant negative correlation with wind speed was detected. Statistical analysis (ANOVA) revealed significant differences between the two sampler types except for Alternaria. In con...

Use of personal sporetraps to complement continuous aerobiological monitoring

Abstract We analysed pollen and spore data obtained from one continuous and two personal Burkard sporetraps during the spring months of three years (2007–2009). For the statistical analysis, the data was normalised with a log transformation, and then subjected to an ANOVA and a Pearson correlation analysis. The best time to use the personal samplers was determined from 15 years of continuous aerobiological monitoring pollen data to be between 11:00–16:00, when highest concentration was found and in a steady way. Height of sampling was compared at floor level and at 1.1 m with personal samplers; both of them were on a terrace at 6 m above the ground, but no statistically significant differences were found. The results revealed that there were apparently no differences between continuous and personal Burkard samplers for total pollen and spores. Nevertheless, distinguishing the main pollen types (i.e., Poaceae, Quercus, Olea, Cupressaceae, Plantago, and Platanus) revealed that there are some differences for Poaceae pollen only. In conclusion, personal samplers could be used to anticipate continuous monitoring data because their sampling is shorter and the results may be obtained quicker than with a continuous sampler, although they must never be considered as a replacement.

Comparison between two adhesives (silicone and petroleum jelly) in Hirst pollen traps in a controlled environment

Abstract Aerobiological sampling through volumetric pollen traps requires the use of an appropriate adhesive, whose selection is a critical factor in these studies. This study compares the differences between two adhesives that have been widely used in aerobiological studies with the aim of providing a persuasive argument for using petroleum jelly as a viable alternative to silicone diluted with the banned substance carbon tetrachloride. The study was performed using Hirst-type pollen traps in an indoor controlled environment to avoid interference attributed to outdoor meteorological parameters. Furthermore, a gravimetric study was conducted simultaneously as a control. Four different pollen types with different pollen sizes and similar flowering seasons were studied (Acer, Platanus, Quercus and Rumex). Differences between pollen traps were minimised by interchanging the drums in each pollen trap every 24 hours. Gravimetric results showed homogeneous airborne pollen distribution in the study. No statistically significant differences were found between the results for the sample adhesives for Quercus and Platanus, whereas significant differences were observed for Rumex and Acer. In the case of Acer, more pollen grains were recorded using the petroleum jelly, while for Rumex, more pollen grains were recorded with silicone. After this experiment we consider that petroleum jelly can be used as a viable alternative adhesive to the banned silicone diluted with carbon tetrachloride.

Variations in airborne pollen in central and south-western Spain in relation to the distribution of potential sources

Abstract The present study seeks to compare daily and hourly airborne pollen concentrations at eight different stations in Castilla-La Mancha (central Spain) and Extremadura (south-western Spain) and assess pollen distribution sources. Sampling stations were located 69–440 km apart in a straight line in Albacete, Toledo, Talavera de la Reina and Ciudad Real in Castilla-La Mancha, and in Badajoz, Plasencia, Santa Amalia and Zafra in Extremadura. Airborne pollen was collected using Hirst-type volumetric spore traps. Quercus was the most abundant pollen type at all stations except for Ciudad Real, where Olea pollen predominated. Comparisons of daily data between pairs of stations revealed statistically significant positive correlations in all cases for Poaceae and Olea. Comparisons of hourly data between stations indicated greater differences than daily data. Analysis of correlation coefficients and straight-line distances between stations revealed a strong negative correlation. Analysis of total airborne pollen data for the eight sampling stations suggests that airborne pollen concentrations decrease from west to east and from south to north, partly reflecting dominant wind patterns. A clear correlation was observed between airborne pollen concentrations and the surface area covered by olive crops in a 50 km radius around the sampling stations.

Airborne propagules of Phytophthora and related taxa in SW Spain including a predictive model

The airborne sporangia of Oomycota, including Phytophthora species and other species, are usually recorded by volumetric spore traps. The aim of this work was to create a predictive model for the seasonality and weather parameters that may affect sporangia distribution by analysing their presence over the course of a year. Three Hirst spore traps were located in the SW of Spain (Plasencia, Don Benito and Zafra), and the presence of sporangia was recorded throughout 2012–2013. Phytophthora sporangia were recorded on 76–110 days per year. Autumn and spring were the seasons when the highest concentration peaks of airborne sporangia were recorded; these peaks were recorded on the same day in each of the three locations. When analysing weekly sums of the daily concentration of sporangia, there was a statistically significant correlation between the sporangia concentration and amount of rain in the three locations studied; however, this correlation was not observed when comparing the individual daily concentrations. When comparing the daily concentration to the daily rain levels, the highest correlation coefficient and statistically significant correlation was reached on the second day after rain. The proposed predictive model considered the previous rain to be the main environmental factor. Holm oak and cork oak woods in Plasencia may be responsible for a higher concentration of airborne Phytophthora-type sporangia. Rain seems to have a direct influence on the concentration of airborne sporangia, but the highest concentrations appear on the second day after rain.