Residue and behavior of HCH from surface soils in Hanoi and BacNinh

Abstract

    Selected HCH isomer residues (α, β, γ and δ-HCH) were analyzed in the soil samples of Hanoi and Bacninh. The soil samples were collected from agriculture areas as well as from urban and industrial areas with an attempt to get them evenly distributed over selected regions. Results show that total HCH concentrations ranged from <0,05 to 20,57 ng g-1 . In general, the distributions of low level contamination of ΣHCH from Hanoi and Bacninh are displayed (mean concentration >< 12 ng g-1 ). However, the HCH presence in the most soil samples (76/100 samples) is remarkable. Assessment of HCH isomeric percentages indicated that there is little recent input of HCH. Technical HCH was the main source of HCH contamination in comparison with lindan in the past.