Decomposition of diethylstilboestrol in soil

Summary 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 -sterilized soil indicated that enzymes present in the soil are able to attack DES.