Monitoring of Metal Deposition by Moss Barbula Constricta J. Linn., from Mussoorie Hills in the India
The moss Barbula constricta J. Linn. was used as an active bio-monitor for estimation of atmospheric metal deposition and its seasonal trend to assess the metal (Zn, Pb, Cu, Cd) status of Mussoorie city and its adjoining areas. Moss transplants were exposed for four months, each period representing winter, summer and monsoon season data at the distances of 0.5, 1.0 and 3.0 km during 2003 to 2007.
Significantly higher levels of Zn, Pb, and Cu were measured in the moss harvested at the end of each season. The values of metals at different distances from the city center were higher than in the background samples treated as control. Patterns of moss analysis for seasonal and annual metal data were closely identical. Values of metals were the highest during summer followed by winter, and the lowest in monsoon. It was found that an increase recorded in the sampling sites in the past 5 years could be due to the rapid economic development and the manifold increase in tourist activities. Results from the present moss surveys make the examination of both spatial and temporal trends of metals possible, and also confirm the validity of moss B. constricta J. Linn. as a reliable bio-monitor, and recommend it for the bio-mapping program. Data from existing surveys of metal concentrations in moss is filling a gap due to very limited information available in this field. In addition, it is an invaluable resource for policy makers in preparing the strategies for mitigation.