Abstract:
In order to study long distance atmospheric transport of persistent organic pollutants (POPs), and regional distribution and origins of POPs in remote mountain areas, both surface soil and passive air samples were collected along an altitudinal transect (1242-4475 m above sea level) on the slope of Balang Mountain in Wolong Nature Reserve in the western mountain area of Sichuan from April 2005 to April 2008. GC-HRMS data revealed that concentrations of HCB, HCHs, and DDTs in the air and surface soil at sites higher than 2800 m were low and evenly distributed, and could be attributed to long distance atmospheric transport, while at lower sites where anthropogenic activities existed, abnormally high concentrations of HCHs and DDTs were found and regarded as local contamination. Contributions from long distance atmospheric transport and local source emissions could be distinguished based on integrated analysis of concentration levels, relative composition, spatial distribution and seasonal variations of organochlorine pollutants (OCPs) of interest. Passive air sampling turned out to be useful in providing information on POPs levels and spatial and temporal distributions in remote mountainous areas. Integrated observation and characterization of abnormal concentrations of POPs in mountain areas could be performed based on field data of both air and soil samples.