AIRBORNE ALLERGENIC POLLEN GRAINS ON A FARM IN WEST-BENGAL, INDIA

A continuous two years (July, 1994 to June, 1996) survey of aeropalyno flora on an agricultural farm situated in the suburbs of Calcutta was carried out using a Burkard volumetric spore trap. A total of 46 polle n types were identified. The dominant pollen types recorded originated from Poaceae, Trema orientalis, Cyperaceae and Cocos nucifera. These pollen types were subjected to clinical investigation to determine the ir degree of allergenicity on adult respiratory allergic patients by m eans of skin prick tests. A maximum allergenic response was shown to S accharum officinarum (54.86%) followed by Azadirachta indica (52.93%) and Phoenix sylvestris (44.09%). Among the 46 recorded pollen types, 2 6 showed a positive skin reaction. Seasonal variations, diurnal period icities and the vertical profiles of airborne concentrations of these allergenic pollen types were studied to evaluate the extent of exposur e. The overall survey confirms the fact that all dominant airborne pol len types do not contribute equally to the aeroallergen load. Some pol len grains, though present in the air in lower concentration, were fou nd to be allergenically significant.