Researchers led by Columbia Engineering have uncovered why plastic sheds dangerous nanoplastics, shedding light on potential health risks and emphasizing the importance of improved recycling practices.
In a significant breakthrough, scientists led by Columbia Engineering have uncovered the molecular mechanisms that cause plastics to break into potentially harmful nanoscopic particles. This discovery could have major implications for public health, as these tiny fragments are found everywhere from Antarctic snow to human blood, and their presence raises serious health concerns.
The study, led by Sanat Kumar, Michael Bykhovsky and Charo Gonzalez-Bykhovsky Professor of Chemical Engineering at Columbia, explains how the breakdown of commonly used plastics results in the formation of nanoplastics. Published in Nature Communications, the research marks a pivotal step in understanding the environmental and health impacts of plastic pollution.
“We’ve known since the 1950s that the soft stuff is holding the hard stuff together,” Kumar said in a news release. “What we show in the new study is how easily those soft connectors break even under quiescent conditions such as in a landfill. Once that layer fails, the hard segments have nowhere to go — they scatter into the environment.”
Approximately 75-80% of plastics used today are semicrystalline polymers, composed of alternating hard and soft layers. These alternating layers contribute to the plastic’s durability and versatility but also make them susceptible to forming nanoplastics. Over time, the soft layers degrade, enabling the release of hard, crystalline fragments into the environment. These persistent particles can last for centuries and potentially cause significant damage to living organisms, including humans.
“These pieces float around, and some end up in human bodies,” Kumar added. “The smallest pieces pass through cells and into the nucleus, where they can start messing with DNA. Nano- and microplastics, which seem to have similar sizes and shapes to asbestos, raise the potential that they could cause cancer, heart disease/stroke and other diseases.”
The study’s findings could inform future engineering solutions to minimize nanoplastic formation. Kumar suggests that enhancing the resilience of the soft layers could reduce the amount of crystalline fragments produced through normal polymer degradation.
“Our results suggest that engineering the architecture of the soft layers to be more resilient would decrease the amount of crystalline fragments that break off,” he said. “Clearly, focus needs to be placed on this point to reduce the amount of micro and nanoplastics created by normal polymer degradation.”
Improved recycling practices also emerge as a key solution to the problem. Currently, only 2% of plastics are recycled due to high costs. However, Kumar argues that the potential health risks posed by nanoplastics could make recycling more economically viable in the long run.
“If you think about it that way, if you have to choose between the health problems that could be created by the nanoplastics vs. the cost of recycling, then maybe it’s actually cheaper to recycle,” he said.
Source: Columbia Columbia University School of Engineering and Applied Science