PCDDs and PCDFs in soil and river sediment samples from a rural area in the United States of America

In 1994, we collected 36 soil samples and 61 sediment samples from southern Mississippi, USA. Each sample was analyzed for PCDDs and PCDFs by HRMS using either a polar or a non-polar HRGC column. Although most Cl4 --- Cl8 PCDDs and PCDFs were detected in each sample, PCDD levels (particularly Cl7 --- Cl8) were higher in sediment than soil samples. The PCDF pattern in two sediment samples indicated a possible PCB source. The concentrations of 2,3,7,8-tetra CDD and 2,3,7,8-tetra CDF were somewhat higher upstream of a pulp mill than downstream from the mill.