Aeropalynological study of two selected locations in North-Central Nigeria

Pollen and spores have been found as major biological sources of morbidity among individuals sensitive to respiratory disorders. The aim of the present study was to analyse the deposition rate of atmospheric pollen and fern spores at selected sites in Benue and Plateau states of the North-Central Nigeria between July 2015 and June 2016. This was accomplished by: (1) determining the pollen and fern spore content of each monitoring station; (2) establishing the relationship between total pollen count and meteorological parameters; and (3) comparing the recovered airborne pollen spectra with identified plants in the surrounding vegetation types of the sampling sites. The collection of atmospheric pollen was done using a modified Tauber sampler and plants in the surrounding environment of the sampling sites were enumerated. The residual solution was collected monthly and acetolysed, after which slide preparation and microscopy of the treated residue were done. Meteorological data were obtained from the Nigerian Meteorological Agency, Lagos. The results obtained reveal seasonal distribution patterns of various airborne pollen grains in the study locations. The most abundant pollen types recovered in Plateau State were produced by Syzygium guineense, Tridax procumbens, Alchornea sp., Terminalia sp., Poaceae and Amaranthaceae. Pollen types of Casuarina equisetifolia, Syzygium guineense, Tridax procumbens, Poaceae and Cyperaceae were preponderant in Benue State. Pteris sp., Nephrolepis sp. and a trilete fern spore were also represented in this study. The recovered airborne pollen spectra correspond favourably with some identified plants in the study locations. There was no significant correlation between monthly total pollen count and mean monthly values of meteorological parameters in Benue State. Air temperature and wind speed correlated significantly with monthly total pollen count in Plateau State. It is suggested that the allergenic effect of these abundant pollen types on humans should be further examined.