Effect of Wastewater Treatment Plants on Microplastics in Mussels and Their Surrounding Environment

Microplastics are a growing concern, especially in the context of aquatic systems. Microplastics are small (<5 mm) particles of plastic that have been broken down and can carry toxic chemicals as well as bioaccumulate in the environment. All over the world, microplastics are being studied and considered a current threat. Especially with the consumption of aquatic animals, microplastics are entering the human food chain and causing damage to the human immune system. Even rural areas with fewer human populations, such as Upstate New York, are seeing the bioaccumulation of freshwater mussels. Specifically looking at wastewater treatment, mussels are a good indicator of the microplastics present in the outflow of wastewater treatment plants. This study aimed to collect mussel samples from three sites in the Adirondack region: the Grasse River, the Raquette River, and the Saint Regis River, to determine how these areas are affected by microplastic pollution. Mussels, water, and sediment samples were collected from the upstream and downstream of three wastewater treatment plants that discharge into these rivers to understand the effect of wastewater treatment plant effluents on the mussels and their surrounding environment. Results from this study should provide an important indication of the type of microplastics released from wastewater treatment plants as well as the dominant microplastic type ingested by an important aquatic biota, mussels. Furthermore, this study also builds a relationship between microplastics in organisms (mussels) and their living environment (water and sediment).