Research

Our collaborative team works on answering questions about the amount of debris that enters the environment, where it comes from, and how it subsequently moves between land and water. Within our waterways and the surrounding land, we investigate how the debris breaks down and how it impacts ecosystems. Our work aims to understand the risk of anthropogenic debris, especially plastic, to organisms (including people) and to develop data-backed solutions. Below are stories explaining how the members of our collaborative are addressing important questions about plastic pollution. Publications related to all of our projects can be found on the publications page. 

In a 2017 paper by scientists in our collaborative, it was estimated that 9,887 metric tonnes of plastic debris enter the great lakes per year. The paper also estimated that around 1,400 tonnes of plastic enters Lake Ontario per year. Where is all that plastic coming from? 

The Collaborative for Plastics and the Environment has been working on answering that question by assessing the various routes that plastics can take to enter the lake. We have identified several main pathways into the environment such as littering and illegal dumping, wastewater, stormwater runoff, industrial waste, agricultural runoff, food waste, and the disposal of personal protective equipment. Microplastics can also enter the lake via atmospheric deposition.

Our research group is working on understanding how and what types of plastics enter Lake Ontario. We’re collecting data through our LittaTraps and Seabins, through field sampling, and through our litter audits. Some of the most common plastic items that we find in all our samples and in all locations include cigarette butts and food wrappers. We hope that by understanding how plastic enters the lake, we can inform interventions to help stop the flow of plastic to the lake. 

We are using some of this data to estimate the composition, quantity, and sources of plastic emissions into the environment. We have worked on estimating the plastic pollution emissions in Toronto and, while this work was completed in Toronto, there are likely similar sources in other cities like Rochester. Some of these sources included littering, industrial plastic production, construction waste, washing and drying machines, house paint, road marking paint, tires, artificial turf, fishing gear, and boats.

Though plastic has likely been accumulating in the Great Lakes since plastic entered widespread consumer use in the 1950s, awareness of plastic debris as a problem in the Great Lakes picked up following the publication of the first large-scale sampling of surface microplastic in 2013. In that paper (which sampled Lakes Erie, Huron, and Michigan), Great Lakes microplastic concentrations were reported that were similar to those found in the Atlantic Ocean garbage patch.

Even higher concentrations of plastic were later reported in Lake Ontario. Time-averaged currents in Lake Erie have a gyre pattern similar to the oceans, which led to speculation that there might be garbage patches in the Great Lakes. To see whether circulation should support the formation of a persistent garbage patch, we have used computational models to simulate the movement of microplastic particles through the waters of the Great Lakes. This modeling indicates that there is likely no sustained garbage patch in the Great Lakes, with plastic instead accumulating near or on the shore and in the sediment. Sampling and analysis that has been conducted by members of our collaborative have confirmed the presence of plastic in nearshore sediment and wetlands of Lake Ontario.

Microplastic transport is affected by a range of different factors, many of which are still unknown. We are working on experiments to understand what factors may affect the transport and fate of microplastics. Plastic pollution in the great lakes is widespread but it also varies spatially because plastic transport is affected by many different factors. Microplastics can sink into sediments and be trapped including entering wetlands. They can stay in sediment or be resuspended afterwards. The rate that microplastics move depends on lots of factors including the biofilms attached to them and the depth of the lake. We have been conducting experiments to understand how plastic accumulates biofilm and how this changes their transport. Microplastics can also be beached to end up on shorelines. This may even be the fate of a majority of the microplastics that enter a lake.

Previous research has shown that there are plastics in stormwater, and stormwater runoff can have especially high concentrations of microplastics. After finding that stormwater can be an important pathway for plastics to enter the environment, RIT worked with NY Sea Grant to install LittaTraps through a program called CASCADE. 

We use these LittaTraps to understand how much plastic enters the environment by emptying them and quantifying the plastic found inside. CASCADE is also actively doing community science and outreach around plastic litter using the LittaTraps. Using this data, we can create models that describe the movement of plastics to Lake Ontario and estimate how much is entering the lake. 

Once plastic enters the environment it can go through a lot of processes and be transported through the environment. One thing that can happens is that plastics can break down into smaller pieces. Macroplastics can break down to become microplastics and microplastic can breakdown into smaller microplastic and even nanoplastic. Both micro- and macroplastics accumulate biological growth, called a biofilm, on them when they are in the environment. Our team has run experiments that put common plastic in different environments to see how the biofilms are different in different locations and on different products. We use genome sequencing to identify different species on the plastic and track how it changes over time and differs with location.

In addition to accumulating biological growth, plastic can also absorb chemicals (even potentially toxic chemicals) that are already present in the environment. As plastic gets transported through the environment, it carries with it any accumulated biological growth and chemicals. In this way, plastic has the potential to transport things like pathogens and antibiotic resistant bacteria.  

While scientists have been working on understanding the effects of plastic pollution on organisms and the environment, there is still a lot that is unknown. Our research group has been investigating the effects on organisms. So far we have found that the effects of plastics depend on the polymer used to make them and that plastics can impact microbial diversity and community function. We’re continuing to explore the impacts of plastics on microbial communities.

If different kinds of plastic have different effects, we also want to understand how those effects vary. The research group has also worked on experiments using PPE which was commonly littered during the COVID-19 pandemic. Looking at the effects of face masks and gloves on benthic worms, we found that both affected the worms. 

To further understand the effects of plastics, some of our team are part of a lake mesocosm and full-lake experiment that is being carried out in Ontario at the International Institute for Sustainable Development Experimental lakes Area (IISD-ELA) to understand how microplastics impact freshwater ecosystems including on zooplankton and fish. The project is still ongoing.

Microplastics have been found in the human body as well as in the environment. Our group at RIT is working with the University of Rochester to try to understand how humans are exposed and affected by these microplastics as well as how these particles impact the environment. The Lake Ontario MicroPlastics Center was created to address these questions. 

We are especially interested in how climate change could influence microplastics. Climate-related changes could alter human and environmental exposure to these particles or affect the plastics themselves, such as through accelerated degradation, potentially changing their impacts. 

RIT is also involved in studying how microplastics can end up in food waste and how that might be an important consideration in the processing of food waste.