Potential of Dust and Soot from Air-Filters of Motor Vehicle Engines as a Forensic Tool: First Experimental Palynological Approach in India

Abstract

Dust and soot samples collected from air filters of motor cars and motor boats from three localities, namely Darjeeling, Murshidabad and the Sundarbans, West Bengal, India, each with its own characteristic vegetation type, were analysed for pollen and spore content to investigate their potentials as palynological traps. Pollen grains from high altitude vegetation (Alnus nepalensis, Ilex sp., Pinus sp., Primula sp., Rhododendron sp., Pteris sp., Asplenium sp., Duabanga sp.) were recovered from cars driven through Darjeeling to Kalimpong while pollen grains of mesophytic plants (Mangifera indica, Cocos nucifera, Borassus flabellifer, Parthenium hysterophorus, Azadirachta indica, Lantana camara) and mangroves (Sonneratia apetala, Avicennia sp., Acanthus ilicifolius, Bruguiera sp., Rhizophora mucronata, Heritiera fomes, Phoenix paludosa, Nypa fruticans) were recovered from the vehicles in the Murshidabad district and motor boats in the Indian Sundarbans respectively. Principal Components Analysis (PCA) revealed that pollen spectra from different vegetation zones form distinct groups, while dust/soot samples from areas of similar vegetation zone form a single group while Correspondence Analysis (CA) demonstrates that the dust/soot samples from a distinct vegetation zone and the recovered palynotaxa from these dust/soot samples from a single group. Palynoassemblage analysis, together with PCA and CA data, suggests that dust and soot from air filters of motor vehicle engines may be a reliable trap for palynomorphs, which may help to trace the localities through which vehicles in question have travelled.