Ecotoxicological Evaluation of Poly(<I>ε</I>-Caprolactone) Nanocapsules Containing Triazine Herbicides

Abstract

The triazine class of herbicides includes the compounds ametryn, atrazine, and simazine, which are used to control weeds in plantations of crops such as maize, sorghum, and sugar cane. Despite their acceptance in agriculture, these herbicides can be dangerous to the environment, depending on their toxicity, the degree of contamination, and the duration of exposure. Controlled release systems are increasingly used to mitigate problems of toxicity and minimize environmental impacts, and can also increase herbicide efficiency. The objective of this work was to prepare poly(epsilon-caprolactone) nanocapsules containing ametryn and atrazine, and evaluate their toxicity to aquatic organisms as well as in cytogenetic tests employing human lymphocyte cultures. The PCL nanocapsules were prepared according to the interfacial deposition of pre-formed polymer method. Ecotoxicological assays were performed with the alga Pseudokirchneriella subcapitata and the microcrustacean Daphnia similis. The cytogenetic tests consisted of observing mitotic index alterations after exposing lymphocyte cell cultures to different formulations. Encapsulation of the herbicides in the nanocapsules resulted in lower toxicity to the alga and higher toxicity to the microcrustacean, compared to the herbicides alone. The cytogenetic tests showed that formulations of nanocapsules containing the herbicides were less toxic than the herbicides alone. The findings indicate the potential of the nanocapsule formulations in agricultural applications, where they could help to reduce the quantities of herbicides used as well as impacts on the environment and human health.

Nanotechnology: The new perspective in precision agriculture

“…Herbicides encapsulated in the poly(ε-caprolactone) nanocapsules resulted in lower toxicity to the alga ( Pseudokirchneriella subcapitata ) and higher toxicity to the microcrustacean ( Daphnia similis ) as compared to the herbicides alone [122]. A list of nanoparticles used as herbicides against weeds in different vegetable crops is given in Table 3.…”

Post-Emergence Herbicidal Activity of Nanoatrazine Against Susceptible Weeds

“…In vitro assays demonstrated the high efficiency of encapsulation of atrazine into the PCL nanocapsules and the high stability of the nanoformulation, as well as the controlled release of the herbicide from the nanocapsules (Grillo et al, 2012;Pereira et al, 2014). Toxicity assays conducted with the alga Pseudokirchneriella subcapitata, Allium cepa and human cells showed that atrazine-containing nanocapsules were less toxic to non-target organisms than the free herbicide (Grillo et al, 2012;Clemente et al, 2014;Pereira et al, 2014).…”

Application Of Nanotechnology In Agriculture And Food Industry, Its Prospects And Risks

“…Nanoformulations of poly(ε-caprolactone) containing the herbicide atrazine were found to be effective for the control of the target Brassica sp and showed lower toxicity to the non-target organisms, eg, alga Pseudokirchneriella subcapitata, compared to the herbicide alone [92]. Encapsulated paraquat nanoformulations composed of chitosan and sodium tripolyphosphate, similarly as incorporation of paraquat [93] or clomazone to alginate/chitosan NPs [94] reduced environmental impact with simultaneous preservation of herbicidal effectiveness [95], and treatment with nanoparaquat resulted in less chromosome damage in Allium cepa [96].…”