Ecotoxicity of emerging pollutants: Interactive impact of polystyrene nanoplastics and Metanil yellow on Artemia salina

Increasing concern surrounds the impact of pollutants on marine ecosystems, particularly the combined effects of nanoplastics and synthetic dyes. This present study evaluated the toxicity of 100 nm polystyrene nanoplastics (PSNPs) and Metanil Yellow (MY) co-exposure in Artemia salina , a model marine bioindicator. Physicochemical characterization through DLS, FTIR, and Raman analyses confirmed the interaction between PSNPs and MY, indicating dye adsorption on the surface of PSNPs and increased aggregate size after 48 h. The LC₅₀ value for the PSNPs+MY complex, 6.76 mg/L, was significantly lower than that of pristine 14.79 mg/L components, reflecting enhanced toxicity. Mortality rates exceeded 93 % in the complex-exposed group compared to 23 % and 66 % for PSNPs and MY alone, respectively. Co-exposure resulted in elevated ROS levels and enhanced antioxidant enzyme activity, indicating significant oxidative stress. The pristine treatment at 20 mg/L induced 73 % oxidative stress, while the complex exposure at 100 + 20 mg/L increased it to 86 %. Overall, the findings demonstrate that interactions between nanoplastics and dyes exacerbate toxic responses in marine organisms, posing a compounded ecological risk and highlighting the need for stricter monitoring and remediation of such emerging contaminants. • Analytical techniques (DLS, FTIR, UV-spec) confirmed the Metanil Yellow adherence to the PSNPs surfaces. • The PSNPs+MY complex showed higher toxicity compared to individual contaminants. • Elevated ROS levels and altered antioxidant enzyme activities confirmed oxidative stress as a key toxicity mechanism. • The study provides insights into how PSNPs and MY interactions enhance toxicity in aquatic organisms.