Photo: 123RF
Scientists say microplastics are silently spreading from soils to salads to people.
A review from Murdoch University in Western Australia has stressed that agricultural soils now hold around 23 times more microplastics than oceans or waterways.
PhD candidate Joseph Boctor, who led the study, said the results were "scary" and "quite concerning".
"It's not just abundant in soil, it gets uptaken by plants as well and that means our salad contains microplastics."
Both microplastics and nanoplastics have now been found in lettuce, wheat and carrot crops
"The problem with the soil is, because of agriculture we use a lot of plastic in agriculture as well. It depends on the country but a lot of countries use main agricultural practices that introduce more plastic into the soil.
"These plastics are almost impossible to collect back because of weathering and conditions in the soil. So what happens is it breaks into smaller pieces and we have more microplastics in the soil."
Boctor said common practices which could lead to plastic pollution included plastic mulching and fertiliser use.
He said microplastics weren't just impacting plant and crop growth, but also increased the risk of exposure to toxins.
"These microplastics are turning food-producing land into a plastic sink [for toxic compounds]."
Boctor found the plastics in soil may be exposed to up to 10,000 chemical additives, most of which he said were unregulated in agriculture.
"The problem is microplastics and nanoplastics are not just particles. They also attract additives. Think of it as small magnets attracting other toxic compounds."
Alongside endocrine disruptors, the review pinpointed other additives in soil such as Phthalates (linked to reproductive issues), and PBDEs (neurotoxic flame retardants).
These additives have been linked with neurodegenerative disease, increased risks of stroke and heart attack and early death.
He said the review highlighted the urgent need for coordinated scientific and regulatory efforts.
"These are not distant possibilities - they are unfolding within biological systems - silently and systematically," he said.
Boctor is working alongside his colleagues at the Bioplastics Innovation Hub to create a type of plastic that is not only safe, but also decomposes in soil, land and water.
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