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Characterization of colloid-size copper-based pesticide and its potential ecological implications.
Citation:
Tegenaw, A., G. Sorial, E. Sahle-Demessie, AND C. Han. Characterization of colloid-size copper-based pesticide and its potential ecological implications. ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, 253:278-287, (2019). https://doi.org/10.1016/j.envpol.2019.07.036
Impact/Purpose:
The colloidal stability of a Cu-based commercial pesticide, was studied to characterize its fate, transport and environmental implication. The wide use of Cu-based and other inorganic pesticides could also increase the quantity of Cu that could potentially reach to the biotic and abiotic compartments of the ecosystems. The co-existence of several pesticides residues and heavy metals like Cu in environmental samples and crops may also cause synergistic and complicated adverse impacts on ecosystems and human health.
Description:
The intensive use of Cu-based pesticides in agriculture could have an unintended impact on the ecosystems and human health via different exposure pathways. This paper presents the results of experiments involving colloidal stability, aggregation, and dissolution of Cu2O commercial pesticide under various environmental conditions in view of ecological implications. The investigated pesticide contains ∼750 g kg−1 Cu (75% weight of product), Cu2O particles with sizes < 1 μm, and nominal size fraction of Cu2O nanoparticles. The co-presence of Ca2+ (20 mM) and humic acid (HA, 15 mg L−1) significantly modulates (p < 0.001) the colloidal stability and mobility of particles. The dissolution of Cu at pH 5.5 was about 85%, 90%, and 75% weight more than the dissolution of Cu at pH 7.0, pH 8.5, and pH 7.0 and pH 8.5 combined, respectively in all dispersions. However, increasing HA content from 0 to 15 mg L−1 reduced the dissolution of Cu by 56%, 50%, and 40% weight at pH 5.5, 7.0, and 8.5, respectively. Thus, pH below 7.0 is a critical factor to control the dissolution and bioavailability of Cu that may pose ecotoxicity and environmental pollution, whereas pH above 7.0 and the presence of HA attenuate the pH effect. These findings provide insight into how the potential mobility and bioavailability of Cu is modulated by the water chemistry under various environmental scenarios and media.
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DOI: Characterization of colloid-size copper-based pesticide and its potential ecological implications.
Free access through PubMed Central
Free access through PubMed Central