Airborne allergenic pollen grains on a farm in West Bengal, India

Abstract

A continuous two years (July, 1994 to June, 1996) survey of aeropalynoflora on an agricultural farm situated in the suburbs of Calcutta was carried out using a Burkard volumetric spore trap. A total of 46 pollen 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 their degree of allergenicity on adult respiratory allergic patients by means of skin prick tests. A maximum allergenic response was shown to Saccharum officinarum (54.86%) followed by Azadirachta indica (52.93%) and Phoenix sylvestris (44.09%). Among the 46 recorded pollen types, 26 showed a positive skin reaction. Seasonal variations, diurnal periodicities and the vertical profiles of airborne concentrations of these allergenic pollen types were studied to evaluate the extent of exposure. The overall survey confirms the fact that all dominant airborne pollen types do not contribute equally to the aeroallergen load. Some pollen grains, though present in the air in lower concentration, were found to be allergenically significant. © 1998 Taylor & Francis Group, LLC.