Hawaii Recycles Ocean Plastic into Roads to Test Microplastic Pollution

Researchers in Hawaii are implementing an innovative recycling method that incorporates marine debris and plastic waste into asphalt for road construction. The project aims to address the islands’ significant exposure to tourist waste, discarded fishing gear, and the Great Pacific Garbage Patch.

The initiative, known as the Nets-to-Roads program, is managed by the Center for Marine Debris Research at Hawaii Pacific University in Honolulu. The program focuses on collecting and sorting marine debris from beaches, specifically targeting durable plastics such as polyethylene, which is commonly found in yogurt containers, milk jugs, and fishing nets.

To date, the project has removed 90 metric tons of plastic trash from the Pacific Ocean. More than one metric ton of fishing nets has been integrated into Hawaiian roads.

Public Health Concerns and Microplastic Monitoring

A primary focus for the researchers is the potential for these roads to shed microplastics into the surrounding environment as the pavement undergoes wear and tear. This monitoring is critical because the release of plastics and associated chemicals can pose significant health risks to both humans and animals.

Chemist Jennifer Lynch, who leads the Center for Marine Debris Research, has highlighted the dangers associated with toxic plastic additives. According to Lynch, these substances can lead to several adverse health outcomes, including:

• Hormone disruption
• Chronic inflammation
• Reproductive problems

Because of these risks, the project includes rigorous testing to determine if the asphalt remains intact or if it releases harmful particles over time.

Preliminary Findings and Methodology

On March 22, 2026, researchers presented preliminary results at the American Chemical Society meeting in Atlanta. The initial data suggests that the asphalt mixed with plastic waste remains largely intact, indicating a potential for the material to be used without immediate widespread shedding of microplastics.

The process involves marine biologist Mafalda de Freitas and her colleagues, who are responsible for the collection and sorting of the debris. By isolating polyethylene, the team ensures that the most durable plastics are used to reinforce the road surfacing.

While other plastic paving initiatives have been implemented in states such as Texas and Missouri, the Hawaiian project is the first to specifically utilize marine debris. This distinction is important given the unique logistical and economic challenges Hawaii faces in recycling plastic waste that lingers in its ocean waters.

Environmental and Health Context

The use of derelict fishing nets and residential plastic trash in infrastructure serves as a dual-purpose strategy: reducing the volume of pollutants in the marine ecosystem and testing the viability of recycled materials in public works. The ability to sequester these plastics in roads could potentially reduce the amount of debris that breaks down into microplastics within the ocean, where they enter the food chain.

However, the transition from ocean pollution to terrestrial infrastructure simply shifts the location of the plastic. The ongoing research by the Hawaii Pacific University team is designed to ensure that this shift does not create new public health hazards through the inhalation or ingestion of microplastics shed from the road surface.