Assessing the Biodistribution and Toxicity of Fluorescently Dyed Nano-Polystyrene in Artemia salina Nauplii

Plastic pollution is a growing environmental crisis, with millions of tons of plastic entering the ocean each year and breaking down into microplastics and nanoplastics. These tiny particles pose a serious threat to marine life, particularly to zooplankton, which are essential to aquatic ecosystems. This study investigated the distribution and toxicity of polystyrene nanoplastics in Artemia salina (brine shrimp), a key model organism in ecotoxicology. Using specialized imaging and spectroscopy techniques, we tracked the presence of nanoplastics in A. salina and examined their effects on survival, behavior, and body structure. The results showed that nanoplastics accumulated in the gut and, at higher concentrations, caused gut deformities. The toxicity assay revealed that after 48 h of exposure, lethal concentrations decreased by nearly half compared with 24 h, demonstrating a time-dependent toxic effect. The estimated concentration that caused 50% mortality was 30.21 ± 6.44 mg/L. Additionally, these findings suggest that nanoplastics may impair the salt gland, affecting osmoregulation and energy allocation, leading to reduced feeding and pigmentation. These results highlight the potential risks of nanoplastics to marine organisms and emphasize the need for further research to understand their broader ecological and health impacts.