Monitoring of Four Trace Metal Levels in the rain Water of Kathmandu Valley

  • K. B. Shahi
  • M. R. Chaulagain

Abstract

Ever increasing urban population and concentration of industry as well as automotive traffic in and around the cities have ultimately resulted in severe air pollution. Trace-metals, one of the pollutants of modern cities, is of major concern today. The history of metal pollution shows that cities are sinks for metals. Particularly, the importation and consumption of materials by city residents tends to enrich cities in metals. The out put of aerosols associated with metals elevates metals into the air. Though the residence time of metals in air is short and the only long-term sink for metals is soil, air borne metals affect the health of city residents severely. Nineteen rain water samples were collected and analysed for four tracemetals at different locations and different times where significant level of trace metals were detected. Elevated level of metals in rain water clearly indicated that valley atmosphere is under the increasing pressure of metallic pollution.