Biological Monitoring of Roadside Plants Exposed to Vehicular Pollution in an Urban Area

Study was carried out to assess the impact of automobile exhaust on some selected plant species grown in Madurai city, world famous tourist spot in southern India. The plant species selected for the study were Azadirachta indica, Pongamia pinnata, Delonix regia, Polyalthia longifolia and Ficus religiosa. Reduction in chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll content and carotenoid was recorded in the leaf samples of all selected plant species collected from polluted site when compared with samples from control area. Experiments on air and biomonitoring were conducted to evaluate pollution impact on the vegetation along the road in the city. For biomonitoring, chlorophyll ‘a’ and ‘b’ and total carotenoid were analyzed to study the impact of air pollutants. It was observed that vegetation at roadside with heavy traffic and markets was much affected by vehicular emission. Significant decrease in total chlorophyll and carotenoid was observed with reduced leaf area. It is concluded that plants can be used as indicators for urban air pollution, and there is need to protect the roadside plants from air pollution.