Estimating levels of human exposure to nanoplastics
Nanoplastics, extremely small pieces or particles of plastic that can find their way into the environment, have become the focus of a great deal of academic research. Much of this work however has tended to focus on their potential impact on ecosystems rather than the risks they pose to human health. The EU-funded PLASTICHEAL(opens in new window) project was launched to redress this imbalance. “We set out with the aim of better understanding what happens to us,” explains PLASTICHEAL project coordinator Alba Hernández from the Autonomous University of Barcelona(opens in new window) (UAB) in Spain.
Techniques to identify nanoparticles in humans
The project had two distinct objectives. The first was to achieve a clearer picture of the levels of human exposure to nanoplastics – a critical first step in understanding the extent of the problem. The second was to better understand the potential health impacts that certain exposure levels might trigger. Hernández notes that in assessing human exposure levels, taking account of the size of nanoparticles was crucial. “It is only the smaller nanoplastics that are able to move from air or food into the body and into the bloodstream,” she says. “From there they can be distributed and accumulate in organs.” New technologies were developed to identify these nanoplastics in food and beverages as well as air, and to detect them in blood and urine. Plastics industry workers were tested, as they were thought to be more likely to have been exposed to nanoplastics. “No one before had really been able to do this for plastic particles below one micrometre in size,” adds Hernández. “This helped us to better understand concentration levels inside the body.”
Potential effects of nanoplastics in the body
Next, in vitro tools were developed to examine the potential effects of nanoplastics in the body. “We wanted to see what happens when plastics enter cells, and whether this generates stress, changes in DNA or inflammatory responses, etc.,” explains Hernández. “We also wanted to see if we could predict long-term effects including carcinogenicity and assess any changes in the microbiome.” To achieve this, the project developed nanoparticles that were as representative as possible of those found in nature. The goal here was to ensure that any results were as accurate as possible. “We obtained information that we feel is sufficient grounds for concern,” notes Hernández. “There is much more that needs to be understood though, and we still don’t know what safe limits would be.”
Developing and harmonising analytical technologies
The consortium is currently preparing a new proposal that will continue this work, building on the knowledge gleaned and technologies developed. “We know a lot more now than we did before,” says Hernández. Next steps include further developing and harmonising the analytical technologies. “These need to be usable not just within our project group but by the whole scientific community,” adds Hernández. “We need to discuss various protocols with standardisation bodies.” A huge effort was made during the project to involve industry and regulators, to ensure that the data gathered was as useful as possible to society. The ultimate goal, remarks Hernández, is that this will help in accurately assessing risk and regulating safe limits.
