Aldrins (aldrin and dieldrin) and Endrins (endrin and endrin
aldehyde)
Aldrin has been manufactured commercially since 1950 and used to control soil pests and in the protection of wooden structures against termites. It is readily metabolized to dieldrin. There were 18(66.7%) shallow groundwater samples with a higher concentration of aldrin than that of dieldrin, indicating that there may be some fresh input sources
of aldrin in addition to the historical residues, and the application of aldrin may have been one of the main fresh input sources of aldrin in the shallow groundwater of TLR. Endrin is used against a wide range of agricultural pests and as rodenticide. Endrin may be metabolized to endrin aldehyde and endrin ketone. There were 19(70.4%) shallow groundwater samples with a higher concentration of endrin than that of endrin aldehyde, indicating that theremay be some fresh input sources of endrin in addition to the historical residues, and the application of endrin may have been one of the main fresh input sources of endrin in the shallow groundwater of TLR.