Pesticides Levels in Water, Soil, and Sediment of the Wheeler Lake Basin.

Bioaccumulation, biomagnification, and environmental persistence are among the disadvantages associated with organochlorine pesticides (OCPs) in the environment.  In fact, the persistence of OCPs in terrestrial and aquatic ecosystems of the Indian Creek (ICW) and Huntsville Spring Branch (HSBW) Watersheds is a major concern for North Alabama.  This study reports the concentration levels and distribution patterns of OCP residues found in water, soil, and bed sediment of these two watersheds.  Concentrations for 22 OCPs were determined through dual-column analysis using GC-ECD (EPA Method 8081A).  Interestingly, the OCPs were found to be widely distributed in the watersheds.  Detected OCP residues in water and soil/sediment of the ICW and the HSBW ranged from 0.0133 to 0.0712 μg/kg and 0.96 to 5080 μg/kg, respectively.  Overall, the highest concentrations observed were for the DDTRs (DDT, DDE, DDD), more specifically DDT.  Its predominance was followed by DDE (57%), dieldrin (20%)  DDD (16%) and endrin ketone (11%).  Results also indicated that the ∑DDTR concentrations were significantly higher in the HSBW.  These findings were attributed to variations in absorption, volatilization, plant uptake, microbial degradation, and other processes affecting the retention of these pesticides at the various locations. 

Keywords:  water, soil, sediment, pesticide, gas chromatography, DDT