Ultimate fate and possible ecological risks associated with atrazine and its principal metabolites (DIA and DEA) in soil and water environment

Abstract

Atrazine (AT) is a triazine herbicide widely used to control weeds in several crops. De-isopropylatrazine (DIA) and de-ethylatrazine (DEA) are two of the eight primary metabolites produced by AT breakdown in soil and water. The physico-chemical properties of the soil determine their final fate. So, this study aimed to assess the function of clay loam and sandy loam soils in determining their ultimate fate and the potential ecological risks to non-target species during their persistence in soil and transportation to water bodies. The soil in pots was spiked with standard solutions of AT, DEA, and DIA at 0.3 and 0.6 mg/kg for the persistence study. The leaching potential was determined by placing soils in Plexi columns and spiking them with 50 and 100 µg standard solutions. Liquid-liquid extraction was used to prepare the samples, which were then analyzed using GC-MS/MS. The dynamics of dissipation were first-order. AT, DEA and DIA disappeared rapidly in sandy loam soil, with half-lives ranging from 6.2 to 8.4 days. AT and its metabolites had a significant amount of leaching potential. In sandy loam soil, leaching was more effective, resulting in maximal residue movement up to 30–40 cm soil depth. The presence of a notable collection of residues in leachate fractions suggests the potential for surface and groundwater contamination. In particular, DEA and DIA metabolites caused springtail Folsomia candida and earthworm Eisenia fetida to have longer and greater unacceptable risks. If the residues comparable to the amount acquired in leachate fractions reach water bodies, they could cause toxicity to a variety of freshwater fish, aquatic arthropods, amphibians, and aquatic invertebrates. Future studies should take a more comprehensive approach to evaluate ecological health and dangers to non-target species.