Decomposition of Diethylstilboestrol in Soil

The rate of decomposition of DES-monoethyl-1-C14 in soil was followed by measurement of C14O2 released. From 1.6 to 16% of the added C14 was recovered as C14O2 during 3 months. After six months as much as 12 to 28 per cent was released as C14O2.Determination of C14 in the soil samples after the experiments showed that the amount extractable with benzene decreased to a greater extent than would be expected from the production of C14O2 and that the amount extractable with water was increased when compared with that found shortly after the addition of DES.Addition of large amounts of DES (8%) did not inhibit the CO2 production from the soil.Experiments with γ-sterilized soil indicated that enzymes present in the soil are able to attack DES.