Did you know Canadians could ingest several grams of plastic every year? According to the World Economic Forum, plastic could outweigh fish in our oceans and streams by 2050. How does so much plastic get in our ocean (and in our bodies)? Why is it so hard to retrieve?
Problems related to plastic pollution are rising. The Great Pacific Garbage Patch, a floating "island" made of plastic waste and debris located between Hawaii and California, has reached a size comparable to 4 times the province of Newfoundland and Labrador. Moreover, plastic particles are now found in snowfalls, Arctic ice and seabeds. Where does that plastic come from and how does it ends up in the ocean? Why can't we simply fish it out? Single use plastic items contribute to this scourge, but are there other sources?
From your household to …absolutely everywhere
Firstly, the plastic items we discard are often either incinerated, brought to landfills, or sent abroad to be sorted and possibly be recycled. Unfortunately, recycling is not always possible due to multiple factors. Besides, winds, rains, floods and human factors lead some of that plastic to surrounding streams, eventually making their way into bigger bodies of water, until they reach the ocean. Similarly, fishing gear, which is often made of plastic, is commonly lost and never retrieved. Since plastic constantly degrades into smaller pieces called microplastics, it is very challenging to salvage them all using existing filtration and water treatment systems.
Furthermore, the average person releases many plastic particles in the environment, often without even realizing it. For instance, the greywater released in every laundry cycle contains a high number of plastic particles, due to synthetic fabrics shedding plastic. Another example would be antifreeze liquid used in cars which contains polymers. Once these particles make their way into freshwater or marine environments, they are constantly moved by currents and continue to degrade, making them almost impossible to retrieve. Some particles will also sink to the bottom of the ocean, becoming an integrated part of the seabed. Therefore, even if the plastic production and consumption dropped significantly today, high numbers of particles would still make their way into the ocean every day, for a long time. Hence, a key question remains: how can we solve this problem?
Working together towards solutions
Researchers from the National Research Council of Canada (NRC) have developed numerical models and machine learning technologies that enable the prediction of potential sources, pathways and the fate of microplastics in different water settings. With an improved knowledge and understanding of where the particles come from, and where they go once they enter the stream, it will be easier to retrieve them from the bodies of water. By adapting existing modelling techniques that are used to remove other types of pollutants to better study the fate and transport of microplastics, we can build and enable new tools and processes that will support decision-making by water resources managers and policy makers.
In addition to the numerical modelling, NRC experts are developing innovative sensors combining ultrasound and optic technologies for on-site physical monitoring. With these tools and techniques, researchers can gather real-time data, which is crucial to better understand how the particles behave in aqueous environments and therefore, find the best solutions to address this environmental challenge with alarming consequences for future generations.
Novel detection and quantification methods with higher spatial resolution are required for the identification of nanoplastics. These methods, combined with standardized nanoplastic reference materials, which are representative of those encountered in the environment, can help enhance knowledge of how these particles interact with each other and biological organisms. Development of standard measurement protocols further facilitate the monitoring and remediation for nanoplastics that pose an imminent threat to our Canadian marine and freshwater environments.
Microplastics are a growing concern for fish and other animals in aquatic environments. As zebrafish are an accurate and high-throughput model of human and environmental toxicity, they are a valuable tool in the study of the environmental impact of microplastics. The model also provides an internationally recognized high-throughput toxicological testing platform that can be used to test a large diversity of microplastics and potentially associated chemicals. This may be useful for comparing the effects of different types, sizes and chemical profiles of micro and nanoplastics.
To address the issue of plastic pollution at the source, the NRC used its patented thermoplastic starch technology to develop innovative transparent multi-layer sheets for the packaging of perishable foods, produced from Canadian starch. Based on 100% renewable resources, this cost-effective compostable material makes it possible to provide two-fold impact to Canada: significantly reduce plastic wastes, while promoting circular bioeconomy. The research has been completed and the commercial demonstration is currently carried out by Winpak, a Canadian packaging leader.
The NRC is working with other collaborators, including the University of Ottawa, McGill University, the Plastic Lab from Ocean Wise, Photon etc., and Ocean Diagnostics, to further improve knowledge and develop innovative solutions to address this challenge. "When we find a problem we can solve, we make connections with industries and universities and we work together in order to solve issues that affect us," explains Dr. Vahid Pilechi, Researcher and Team Lead at the NRC's Ocean, Coastal and River Engineering Research Centre and an expert in pollution fate and transport modelling. "The environment is one of the most precious things we have and we need to take care of it for it to take care of us."
In addition, in February 2020, the NRC launched a call for proposals through Innovation, Science and Economic Development Canada's Innovation Solutions Canada which called upon Canadian companies to develop new innovative technologies that would support on-site testing for the identification and quantification of microplastics in water, enabling the development of new techniques for monitoring microplastics in Canadian waters.
Making it a Canadian priority
Following the announcement of Budget 2022, in which the Government of Canada announced an investment of $183.1 million over 5 years to reduce plastic waste and increase plastic circularity by developing and implementing regulatory measures and conducting scientific research to inform policy-making, NRC experts are continuing to tackle this challenge alongside academic and industry partners. Together, they are looking at improving detection, tracking and monitoring of plastic particles in aqueous environments, better identifying and characterizing the different types of microplastics found, improving knowledge on how they affect living organisms, and developing sustainable food packaging that does not require petroleum-based plastics.
"The plastic problem needs attention and collaboration from all levels of society. The NRC can provide leadership on science and technology innovation within our fields of expertise, but to solve the problem, we all need to work together," concludes Dr. Pilechi. "We also need to address the problem at the source, by better educating the general public to be mindful on how they use plastic in the first place."