LONG-TERM RESIDUE OF DDT COMPOUNDS IN FOREST SOILS IN MAINE

Soils in forests sprayed aerially with DDT in 1958-1967 have been samp led for persistence of residues at intervals since then and most recen tly in 1993. Results of all the samples are presented and show persist ence through 30 years, with evidence of decline of residue only in the third decade. The metabolites of DDT-DDE and DDD-increased over time, each comprising about a third of total residue in 1993. Residue conti nues to be held in the organic mat with little evidence of movement do wnward to the inorganic soil horizons. Copyright (C) 1996 Elsevier Sci ence Ltd.