Toxicological impacts and environmental risk of atrazine in the presence of graphene family nanomaterials (GFNs) on Chlorella sp.

Abstract

Atrazine is a widely used chlorine herbicide, but recent studies raised concerns about its environmental and human health risks. Graphene family nanomaterials (GFNs) have various applications and are often released into aquatic environments, impacting marine microflora. However, the combined effects of atrazine and GFNs on marine organisms like Chlorella sp. have not been thoroughly assessed. The physicochemical interactions between atrazine and GFNs were examined using Raman spectroscopy, electron microscopy, contact angle measurements, surface charge analyses, and chromatography. The contact angle analysis revealed a decline with increasing atrazine concentration, indicating enhanced hydrophilicity of the mixture. Key toxicity parameters, including growth inhibition, total reactive oxygen species (ROS) production, malondialdehyde (MDA) generation, photosynthetic efficiency, and antioxidant enzyme activity, were assessed for individual contaminants and their binary mixtures. ROS and antioxidant enzyme activity exhibited the most significant modulation in response to atrazine concentration. Low atrazine levels exacerbated toxicity by elevating oxidative stress markers (ROS and MDA) in mixtures with GFNs, whereas higher concentrations mitigated these effects by reducing ROS and MDA generation compared to individual exposures. The study also uses statistical tools to evaluate the interconnection between the biochemical parameters and the treatment groups. The results clearly show how the GFNs can reduce the harmful effects of atrazine in marine ecosystems. GFNs provide a surface for the adsorption of the atrazine molecules, thereby reducing their availability to the algal cells and reducing their toxic potential. This deepens our understanding of the environmental applications of the GFNs for mitigating the risk of emerging pollutants like atrazine.