Palynological investigation of haze dust in Ayetoro-Itele Ota, Southwest Nigeria
The biological contents of the March 2010 hazy dust in Nigeria deserve verification due to the attendant panic it brought to the public. 3 g of dust deposited on the car bonnet of one of the authors was treated chemo-palynologically and microscopic study of the residue was carried out. The study reveals that the dust was rich in pollen grains, fungal spores and hyphae. No pteridophyte spore was recovered. High proportion of diatoms almost doubling that of the sporomorphs was recorded. Savanna and derived savanna pollen grains and the Sahara desert freshwater diatoms recovered indicate that the dust was still the harmattan borne by the Northeast Trade winds though coming heavily and lately in March instead of the traditional January. This indicates a delay in the northward movement of the Inter Tropical Discontinuity (ITD) with the consequential abnormal hazy atmosphere. Some typical Sudan and Sahel vegetations’ pollen were not recovered inspite of the dust crossing over them, perhaps due tobeing dropped along the way or March not being their flowering periods. Pollen of Vitex cf. doniana dominates the palynoflora along with Isoberlinia doka which might be candidate culprits for clinical conditions in the experimental area.