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

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.