Plastic Chemical Research with RTI International

Partnering with RTI International

Coastal Carolina Riverwatch (CCRW) is proud to partner with RTI International (Research Triangle Institute), an independent research institute dedicated to improving the human condition by turning knowledge into practice. RTI brings together scientists, engineers, and policy experts to tackle pressing environmental and public health challenges around the world. Their expertise in chemical analysis and environmental monitoring has been invaluable to our efforts to understand and address pollution in North Carolina’s waters.

Research Leadership: Dr. Imari Walker-Franklin

Figure 1 and 2: Dr. Imari Walker-Franklin at RTI. Photograph by Lisa Rider (2024). Figure 3: Dr. Imari Walker-Franklin at Duke Marine Lab. Photograph by Lisa Rider (2023).

Our work with RTI has been led by Dr. Imari Walker-Franklin, an analytical chemist whose work focuses on uncovering contaminants in our waterways. She specializes in analyzing complex environmental samples, like surface waters, sediments, and biological tissues, using advanced tools such as gas and liquid chromatography paired with high-resolution mass spectrometry. These methods allow her to detect and characterize substances of emerging concern, including PFAS, microplastics, and wastewater tracers. Her research focuses on advancing non-target analysis workflows to identify novel contaminants and better understand their impacts on ecosystems. Through CCRW’s partnership with RTI, Dr. Walker-Franklin is applying this expertise directly to the New River, investigating how tire additives and plastic chemicals may affect coastal waters and fisheries.

Research Results

 

2025:

Water samples were collected from six different locations, each chosen for their public access points, proximity to roadways, and consistent water depth. All sites were located downstream of active roads, reflecting CCRW’s focus on investigating potential roadway-related pollutants. Because these locations fall within the estuary, they are also influenced by tides, which shape how pollutants move through the system.

 

 Maps provided by Riley Lewis (White Oak Waterkeeper).

Research Results:

This round (2025) of sampling identified a variety of chemicals beyond 6PPD that are from anthropogenic sources. Locations 1, 2, and 6 have the highest indication of inputs from human use like: wastewater indicators [caffeine, drugs, etc.], plastic additives, and pesticides. Some other interesting and potentially hazardous chemicals include dyes, colorants and a few pesticides (pentachlorophenol).

Indicators of plastic pollution like microfibers from clothes washing (nylon oligomers) and plastic dumping (UV inhibitor transformation products) and tire runoff (diphenylguanidine) are most prevalent in sites 1 and 2. 

Initial results suggest that New River water quality should not be of immediate human health concern in waters around Sneads Ferry. Further investigations using chemical standards to better understand these compounds would aid in confidence of identification and provide perspective on risk to fisheries. These results are preliminary and more research is needed to determine why the chemicals are present at higher levels at site 1, 2 and 6, and not at 3, 4 and 5.


This research aligns with CCRW’s Water Quality for Fisheries Program which was developed through collaboration with the coastal commercial and recreational fishing community, water quality researchers, and coastal water quality advocacy organizations.  

Through a process of surveying fishers in coastal NC, Industry Working Group meetings and water quality research, Five Water Quality Priorities were identified.

Water Quality Priorities Identified by Coastal North Carolina Fisheries Representatives:

  1. Agriculture and Factory Farm Runoff
  2. Stormwater Runoff from Roads, Highways, and Parking Lots
  3.  Industrial Pollutants
  4.  Plastic Pollution
  5.  Municipal Wastewater Treatment Plants and Septic Tanks