University Archives

Rising plastic use has accelerated the release of microplastics (<5 mm) and nanoplastics (<1 µm) into aquatic ecosystems, negatively affecting liver morphology and reducing the capacity of organisms to digest and detoxify. Microplastics are very harmful to the liver of fish because their small size allows them to get embedded in the digestive tract, causing blockage of the absorption of key nutrients. Further, nanoplastics are even more dangerous because they are even smaller and can enter the bloodstream, make their way to the liver, and cause metabolic disruption. To investigate the impacts of micro- and nanoplastics on the liver of fathead minnows, we exposed male and female fathead minnows to polystyrene MPs (30 µm) and NPs (0.5 µm) for 28 days at concentrations of 0 mg/L (control) and 1 mg/L. The liver of these fish was removed, and hematoxylin and eosin staining was performed. Fish livers were evaluated for edema of hepatocytes, dilated sinusoids, and hepatic congestion. This research provides critical insights into how micro- and nanoplastics disrupt liver structure and function in fish, underscoring the urgent need to regulate plastic pollution and prevent long-term impacts on aquatic food webs.