The Accumulation and Dissipation of Residues Resulting from the Use of Aldrin in Soils1

Data are presented to delineate (1) the rate and extent of aldrin conversion to dieldrin and (2) the rate of residue (aldrin + dieldrin) dissipation in Illinois soils. Formulae were developed to estimate with reasonable accuracy accumulated residues resulting from repeated annual applications of aldrin. It is concluded that under corn belt conditions in Illinois the probability that annual applications of aldrin over a period of 10 or more years will result in accumulations in excess of the annual application rate is remote. A study of 35 fields with well-documented case histories supports this conclusion.