From snowfall on remote mountaintops from the Arctic to the European Alps to the deepest depths of the ocean, microplastics have been documented in virtually every corner of the world. Now, scientists have found a way to detect microplastics in every organ of the human body.
So far, the scientists have only shown chemical traces of plastic in human tissues, but expect they will discover particles in human organs. The work was presented at a meeting of the American Chemical Society on 17 August.
Whereas larger plastics can be visibly seen polluting oceans, waterways, and land, these eventually break down into smaller fragments called microplastics – minuscule plastic particles that often go undetected. In the oceans, fish and other sea creatures mistake plastic particles for prey. Moreover, these minuscule plastic particles have been linked to infertility, inflammation and cancer in animals.
Scientists have previously shown that microplastics are contaminating the air we breathe and the food we eat. “It would be naive to believe there is plastic everywhere but just not in us”, senior author Prof Rolf Halden, a senior sustainability scientist in the Global Institute of Sustainability at Arizona State University, told the Guardian. But to what extent they accumulate inside the human body and the impacts they may have on human health remain a mystery.
In a statement, co-author and PhD student Charles Rolsky said: “You can find plastics contaminating the environment at virtually every location on the globe, and in a few short decades, we’ve gone from seeing plastic as a wonderful benefit to considering it a threat”.
“There’s evidence that plastic is making its way into our bodies, but very few studies have looked for it there. And at this point, we don’t know whether this plastic is just a nuisance or whether it represents a human health hazard”.
To test out their new methodology, the researchers added plastics to 47 tissue samples taken from lung, liver, spleen and kidney tissue obtained from a tissue bank originally set up to study neurodegenerative diseases like Alzheimer’s. They focused specifically on these organs because they are likely to be exposed to microplastics or collect them. Then, they used a technique called mass spectrometry to analyze the samples.
They were able to detect the microplastics in every tissue sample. Moreover, various types of plastic could be identified, including those used in widely used in plastic drink bottles – polyethylene terephthalate (PET) – and plastic carrier bags – polyethylene. In addition, all of the samples contained bisphenol A (BPA), a chemical commonly used to make plastics.
However, the researchers emphasise that they have not yet identified microplastics in these tissues since this is not what they were looking for but have demonstrated that their method works on plastic components. The next step will be to use their approach to screen multiple organs from multiple cadavers in a bid to determine the abundance of plastics in humans.
The team also created a computer program that converts information on plastic particle count into units of mass and surface area that will allow these results to be shared in a standardised way. Halden says the new platform “will help build a plastic exposure database so that we can compare exposures in organs and groups of people over time and geographic space”.
The new shared resource will be available online so that other scientists around the world can study the extent of microplastics in the human body and the potential impact on human health.
“We never want to be alarmist, but it is concerning that these non-biodegradable materials that are present everywhere can enter and accumulate in human tissues, and we don’t know the possible health effects,” said Varun Kelkar, another co-author and PhD student.
“Once we get a better idea of what’s in the tissues, we can conduct epidemiological studies to assess human health outcomes. That way, we can start to understand the potential health risks, if any”.