Our exposure to plastic particles from microplastics to nanoplastics starts from the second we sip tap water in the morning. When water boils inside a plastic kettle. When food is prepared using plastic utensils, and when meals are reheated in plastic takeaway containers. At the end of the day, dishwashers and washing machines send millions of these particles into wastewater, which eventually makes its way back into the environment.
Measuring the impacts of these plastics on humans from microplastics to nanoplastics is extremely challenging, says Dr Elvis Okoffo, Research Fellow at the Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland.
Tiny particles present big challenges
“Microplastics are defined as plastic particles smaller than 5 mm in diameter, with many existing in the micrometre size range and often not visible to the naked eye. Nanoplastics are substantially smaller, typically below 1 µm (and often <100 nm), approaching the size of viruses, and require specialised analytical techniques for detection beyond conventional light microscopy.
The behaviour of these particles in biological systems including their potential to cross epithelial barriers, enter the bloodstream, and accumulate in tissues or organs remains incompletely understood. A growing body of research is therefore focused on characterising their transport pathways, bioavailability, and potential health risks associated with micro- and nanoplastic exposure’’.
Exposure in focus
Microplastics and nanoplastics are everywhere inside our homes, in the water we drink, and in the utensils and containers we use. Studying how we are exposed to these tiny particles, how they are released from food contact materials, move through the environment, and potentially affect human health is the focus of Dr Elvis Okoffo, Research Fellow at the Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland.
During his PhD, Dr Okoffo developed quantitative analytical methods to measure plastic residues in Australian wastewater treatment plants and biosolids. Tracking how these particles are released into the environment is central to his work.
Smaller than the eye can see
Detecting, characterising and quantifying micro- and nanoplastics across a large variety of sizes involves applying techniques such as pressurised liquid extraction, ultrafiltration, Vibrational microspectroscopy and pyrolysis gas chromatography–mass spectrometry (Py-GC/MS).
“These techniques allow us to measure plastics from visible microplastics down to nanoplastics that are otherwise impossible to see,” says Dr Okoffo.
“By applying several methods to the same samples, we can cross-check results and gain confidence in our measurements, giving a clearer picture of how plastics move through wastewater, biosolids, and the environment, as well as how we are exposed in daily life.”
In practical terms, Dr Okoffo’s research helps to reveal the origins of plastic pollution, how it spreads, and what strategies can reduce exposure and environmental release, bridging environmental science, analytical chemistry, and public health.
The presence of plastic in drinking water
Dr Okoffo’s preliminary work on plastic particles in drinking water* has already confirmed that plastics are present in tap water.
This finding raises important questions about where these particles originate – for instance from source waters, treatment plants, distribution pipes, or even household taps and their rubber seals and how exposure can be reduced at the source.
To tackle these challenges, Dr Okoffo has been awarded an ARC DECRA Fellowship at the Queensland Alliance for Environmental Health Sciences, where he is leading a project to trace micro- and nanoplastics through drinking water systems.
The research combines advanced analytical methods to detect and characterise plastics, pinpoint their sources, and evaluate practical solutions such as household and point-of-use filtration systems to reduce exposure before water reaches consumers.
“If we detect plastics in tap water, the next step is to test filtration systems to see how effectively they can remove these particles before they reach our homes,” says Dr Okoffo.
By identifying where these plastics come from, and how they travel through water networks, the project aims to close critical knowledge gaps and deliver actionable strategies that protect both human health and the environment.
Coming out in the wash
From dishwashers to washing machines, many everyday household appliances quietly release vast amounts of microplastics into our wastewater. Washing machines, in particular, shed millions of microscopic fibres and fragments from synthetic clothing during each cycle. These particles are often too small to be fully captured by conventional treatment systems, allowing some to pass through into rivers, bays, and coastal waters.
Much of what is captured during treatment ends up in biosolids a nutrient-rich by-product made from treated wastewater and organic matter. These biosolids are frequently applied to agricultural land as fertiliser or otherwise disposed of in the environment, meaning the plastics they contain can re-enter soils, waterways, and potentially even the food chain.
“This shows that plastic pollution doesn’t just disappear down the drain. Rather, it moves through our systems and often returns to the environment in different forms,” says Dr Okoffo.
“That’s why we need prevention at the source, including innovations such as built-in filtration systems in washing machines and dishwashers that can capture fibres and plastic particles before they ever reach wastewater.”
Environmental accumulation
Beyond the household, Dr Okoffo’s research traces where these plastics ultimately accumulate. Supported by the Max Day Environmental Science Fellowship, he has investigated microplastic contamination across Moreton Bay, uncovering historical build-up of plastics in sediments, elevated concentrations in mangroves near industrial areas, and ongoing contamination in water and seafood. The findings show how everyday emissions from homes and cities can accumulate over time in sensitive coastal ecosystems.
At the same time, Dr Okoffo has helped advance how scientists measure these particles. By developing and combining cutting-edge analytical techniques capable of detecting plastics from micro- to nanoscale, his work has improved the accuracy, reliability, and confidence of plastic measurements across complex environmental samples an essential step toward understanding real exposure risks.
“We still have a long way to go in understanding micro- and nanoplastics and what they mean for human health,” he says. “But it’s a rapidly emerging field, and I’m passionate about identifying practical steps people can take every day to lower their exposure and reduce how much plastic we return to the environment.”
It all starts at home
Dr Okoffo applies this philosophy in his own home. Inside his kitchen there are no plastic chopping boards, disposable takeaway cups, plastic kettles, plastic cups or single-use food containers.
Instead, he opts for glass, stainless steel, and reusable alternatives.
“These are small daily changes that, collectively, can make a meaningful difference.”
References
https://www.sciencedirect.com/science/article/pii/S0304389423022975