The source of DDT and its metabolites contamination in Turkish agricultural soils

Abstract

The concentration and impact of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) and its metabolites (DDE: 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene) on the environment was expected to decrease after its ban in the mid-1980s. Unfortunately, DDT contamination via its presence as an impurity in dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol) has led to a new source of contamination. This is particularly true especially in cotton production in Söke Plain, Turkey, where difocol-based pesticides are being used. The aim of this research was to investigate the extent and source of DDT contamination in cotton soils. Söke Plain soil samples were collected from 0-30, 30-60, and 60-90-cm depth and analyzed by GC/MS/MS. o,p'-DDT and p, p'-DDE were detected at 16.2 % and 17.6 % of the sites in the 0-30-cm depth of soils. In the 30-60 cm, p, p'-DDT (14.9 %), o, p'-DDE (8.1 %) and p, p'-DDE (2.7 %) were found in soil samples, and p, p'-DDT was the most prevalent with 9.5 % of the sampling sites. The dominant source of DDT particularly in the 60-90-cm depth was due to historic use of DDT. The presence of p, p'-DDE, o, p'-DDE and p,p'-DDT in the topsoil was attributed to recent dicofol applications.

The uptake modeling of DDT and its degradation products (o,p′-DDE and p,p′-DDE) from soil

“…DDT and its degradation products were detected in soil samples collected from the Soke region of Aydin, Turkey [26]. The crop-specific models result showed that DDT and its degradation products primarily accumulate in the root, potato tuber, leafy vegetables with soil and cereals compared to leaves fruits, and water.…”

“…0-30 cm, 30-60 cm, and 60-90 cm. The study results indicated that p,p′-DDT, p,p′-DDE, and o,p′-DDE levels were varied from 0.17-1.92 µg kg −1 , 0.003-0.24 µg kg −1 , and 0.018-0.48 µg kg −1 in different soil layers [26]. Sum values of the levels for p,p′-DDT, p,p′-DDE, and o,p′-DDE were used in crop-specific model which created by Legind and Trapp [10] to estimate plant uptake of p,p′-DDT, p,p′-DDE, and o,p′-DDE and their possible levels.…”

“…The chemical and physical properties of DDT permit it to highly accumulate in soils with lipophilic characteristics. In soils, environmental conditions support DDT degradation to its primary and secondary degradation products [26]. Turgut et al [26] sampled soil samples from 74 locations in Soke, Aydin with different soil layers (depth) i.e.…”

“…DDT and its degradation products are persistent in the environment and can cause detrimental effects to humans, plants, and animals that contact with it in the soil, air, and water [26]. DDT can be taken up via plant roots and accumulate in lipophilic plant parts such as waxes and seeds [5,6].…”

“…The present study aimed to evaluate the levels of DDT and its degradation products (i.e. o,p′-DDE and p,p′-DDE) contamination on root, potato, leaves, fruit, cereal, and water by applying crop-specific models including root, potato, leafy vegetables, cereal, fruit-tree models [10] on analyzed soil samples collected in Soke, Aydin, Turkey [26] where intensive agricultural practices and past DDT applications have taken place in the production of a broad range of products such as olive, wheat, cotton, and tomato.…”