The problem with plastic: why the scale keeps growing
Plastic, once celebrated as the miracle material of the 20th century, has fragmented into a planetary problem, literally. Global plastic production was 363 million tons in 2022 and each year, between 19 and 23 million tons of plastic waste leak into aquatic ecosystems [44]. As this plastic degrades, it sheds microplastics — particles smaller than 5 millimeters — and nanoplastics, smaller than 1 micrometer (millionth of a meter).
In the two decades since the term "microplastic" itself was coined in 2004, [24] these particles have been found from the depths of the ocean to the summit of Mount Everest, and have been detected in more than 1,300 aquatic and terrestrial species, from invertebrates at the base of the food web to apex predators, as well as in the blood, lungs, liver, lower limb joints, and brain tissue of humans. [42]
What makes plastic unviable as a waste product is because it does not decompose in the way organic matter does. The half-life of a piece of plastic in the environment can exceed a thousand years, [37] meaning particles released into water systems today will still be present millennia from now. Closing the plastic cycle — reusing what already exists while minimizing new production — is not just preferable but necessary. It is against this backdrop — a miracle material that has become a non-biodegradable pollutant found everywhere on the planet — that a low-cost seed extract capable of pulling 98% of particles from drinking water represents something more than a technical curiosity. [26]
Where microplastics come from
According to a 2025 analysis from The Pew Charitable Trusts, the largest sources of microplastic pollution are from tires and paint, followed by agricultural products and practices and washing of plastic at recycling facilities. [39] Synthetic textiles are another major source, such as polyester, acrylic, and nylon clothing material and cigarette butts — composed largely of cellulose acetate fibers — are the most common plastic litter found on beaches worldwide.
A pervasive environmental presence
Microplastics make up more than 90% of all plastic on the ocean surface. [31]
Microplastics have been shown to slow the growth of phytoplankton, the microscopic marine algae that forms the base of ocean food webs. [28] A recent study found that microplastic exposure reduces plants' ability to photosynthesize, which could mean the significant reduction in certain crops such as corn and rice, as well as in seafood production over the next 25 years. [31]
When ingested by marine birds, fish and mammals, microplastics have detrimental effects such as reduced food intake, suffocation, genetic changes, links to cancer and impaired fetal development. Other research has found that bacteria exposed to microplastics can develop antibiotic resistance, [31] compounding an already serious global health threat.
Microplastics and humans
Scientists estimate that adults ingest the equivalent of one credit card's worth of microplastic per week, largely from seafood intake, and that people inhale an estimated 68,000 microplastic particles every day. [42]
One study found that infants may be exposed to particularly high levels of microplastics through formula prepared in polypropylene feeding bottles. [9]
Disproportionate burdens
The health consequences of plastic pollution fall unevenly. According to the Minderoo-Monaco Commission, exposure disproportionately affects the poor, minorities, marginalized populations and people in the Global South, with people of color, Indigenous populations and children at especially high risk. [4] Island nations bear an outsized burden, with plastics and microplastics washing onto their shores and impacting fisheries and water quality. Fishing communities and populations dependent on seafood diets face the greatest exposure through ingestion.
The Brazilian researchers' emphasis on moringa as a solution suited to small-scale and rural applications, rather than industrial municipal systems, is therefore not a limitation so much as a targeting to those who need it most.
The health questions
The health effects of microplastics in humans are only beginning to be documented, but the emerging evidence is sufficiently alarming to have prompted legislative action in multiple jurisdictions. Researchers exploring potential links between microplastic exposure and human disease have identified associations with male infertility, inflammation, liver disease, metabolic disorders and, in one study published in the New England Journal of Medicine, elevated risk of heart attack and stroke. [45]
What can be done
UNEP's Susan Gardner has emphasized that companies should stop adding unnecessary microplastics to products and that waste collection and recycling systems must improve in preventing plastic from escaping into the environment. [28] The Pew analysis suggests that if these upstream policies — reducing intentional use of microplastics and improving product design — were combined with downstream measures including reduced agricultural use of sewage sludge, together they could potentially cut microplastic pollution from the main sources by 41%. [39]
Plastic Prevention Efforts
While moringa could be a significant part of the solution to the estimated 170 trillion plastic particles floating in the world's oceans, [32] exploring ways to prevent plastics and microplastics from reaching water systems in the first place is also paramount in closing the plastic cycle.
The most visible effort to address this is The Ocean Cleanup (TOC), the Dutch nonprofit founded by Boyan Slat, which uses long U-shaped barriers towed by boats to corral floating debris in the Great Pacific Garbage Patch. [40] The project has collected nearly 200,000 kilograms of ocean plastic. [22] AI-powered cameras continuously scan the surface to calibrate targeting.
Roughly 75 percent of the plastic TOC collects in the open ocean turns out to be abandoned, lost, or discarded fishing gear — nets, buoys, ropes — which could trap and kill marine life long after it drifts out to sea. [35]
Independent researchers have estimated that the system collects between 3.7 and 5.5 times less waste than originally projected. [15] Other critics, including a joint report from the Environmental Investigation Agency and OceanCare, have in turn raised concerns about bycatch — sea turtles, sharks and diverse fish species have been caught in TOC's operations — and feel policymakers and funders should focus more on the upstream measures that would actually stem the flow.
The Royal Society, in a 2024 review of ocean plastic cleanup strategies, put the structural problem plainly: most marine plastic is near shorelines, dispersed in the water column, or buried in sediment. Microplastics, the review noted, are "very challenging if not impossible to remove" once widely dispersed. [33] The conclusion was that a combination of approaches is needed — especially those targeting the sources of marine plastic.
Rivers are the primary sources carrying land-based plastic to the sea. TOC's own research identifies approximately 1,000 rivers as the source of 80 percent of river-borne ocean plastic; [40] its Interceptor program now operates in 11 rivers globally, with ambitions to scale to all 1,000 of the most polluting waterways. A 30 Cities Program extends this to urban areas with multiple polluted waterways, aiming to reduce river-borne plastic globally by up to a third. [36]
In Cambodia, a local NGO called the River Ocean Cleanup (ROC) led by Nou Sovann, in partnership with Germany's Everwave, has been operating a technologically advanced garbage-collection boat on the rivers of Phnom Penh since 2022-2023. [1] According to Sovann, ROC collects 50 to 60 tons of garbage every month, [12] which is then sorted, recycled, and in some cases exported to Europe for processing.
Researchers are also exploring bio-inspired robotic fish designed to adsorb microplastics, autonomous surface vessels capable of operating for eight hours and collecting up to 500 kilograms of waste per charge, [27] and plastic-eating bacteria — among them Ideonella sakaiensis, discovered in Japan, which produces enzymes that break down PET plastic into more benign substances.
The EU's CLAIM project offers a method for evaluating which combinations of technologies yield the best results in different environments, accounting for cost, ecological impact and pollution reduction. Applied to the Mediterranean, it found that for microplastics, a larger number of treatment installations with moderate removal rates outperformed fewer, higher-capacity ones — [6] because microplastic sources are more evenly distributed than macroplastic sources.
What the evidence consistently points toward is a layered strategy to handle the plastics problem: reducing plastic production and use upstream while intercepting it in rivers and wastewater systems before it reaches the sea; targeting coastal and near-shore accumulations where cleanup is most feasible and essential to the health of local citizens and ecosystems; and deploying open-ocean systems for the most concentrated and accessible debris.
The moringa tree — whose seeds are already being tested for microplastic removal from drinking water — shares its name with the garbage-collection boat now operating on the rivers of Phnom Penh. [46] It is a small coincidence, but an apt one: the most durable solutions to the plastic crisis may turn out to combine the ancient and the engineered, the local and the global, in ways that are still being worked out.
