Fears Raised Over Nanoplastics In Bottled Water
Over the last few years, there has been much research carried out into microplastics and the impact they have on the natural environment, with most of the plastic produced finding its way into landfills, where it can take up to 1,000 years to biodegrade.
This leads to toxic substances potentially making their way into soil and water sources, putting plants, animals and human life at risk as a result. For people, interacting with microplastics can result in undesirable immune responses, hypersensitivity, cytotoxicity (cell damage) and acute responses like hemolysis (the destruction of red blood cells).
Recent studies show that around a third of all plastic waste enters the ground or freshwater, where it then disintegrates over time into microplastics (less than 5mm in size). These microplastics then break down even further into nanoplastics (less than 0.1 micrometre in size)… and these then enter the food chain, causing further problems for one and all.
Unlike microplastics, nanoplastics are so small that they’re able to enter our bloodstream through the intestines and lungs, before travelling to our other vital organs, including our brains and hearts.
They can also enter the bodies of unborn babies via the placenta, with research published back in 2020 in the Environment International journal revealing that particles were detected on both the foetal and maternal sides of the placenta, as well as in the membrane in which the foetus develops.
And now new research from the University of Columbia has revealed that bottled water contains tens of thousands of identifiable nanoparticles in each container, with stimulated Raman scattering microscopy techniques probing samples with two simultaneous lasers that have been tuned to make certain molecules resonate.
It was found that, on average, a litre of bottled water contained 240,000 detectable fragments of plastic, between ten and 100 times greater than previous estimates.
In all, seven common plastics from three popular brands of bottled water sold in the US were targeted in this latest study, with a data-driven algorithm designed to interpret the results.
Plastic particles were analysed down to 100 nanometres in size, with 110,000 to 370,000 fragments identified per litre. Some 90 per cent of these were nanoplastics, with the remainder microplastics.
One of the most common plastics identified was polyethylene terephthalate (also known as PET), perhaps unsurprising given that this is what a lot of plastic bottles are made of. It’s thought that it enters the water as fragments come off when the bottle in question is exposed to heat or when it is squeezed, or when the cap is opened and closed repeatedly.
However, polyamide was found to be the most common plastic identified, a type of nylon that is thought to come from plastic filters that are used to purify the water before bottling. Other plastics identified in the study included polymethyl methacrylate, polyvinyl chloride and polystyrene, all of which are used in a range of different industrial processes.
Even more disturbingly, the seven types of plastics that were searched for in the study only made up around ten per cent of all the nanoparticles found in samples – and the researchers currently do not know what the rest are.
In fact, they could be almost anything, which suggests that there is “complicated particle composition” contained within what looks like a simple sample of water.
Plastic production around the world is now fast approaching 400 million metric tonnes per year, with over 30 million tonnes dumped annually in water or on land. Furthermore, many plastic-manufactured products, including synthetic textiles, actually discard particles while they’re still in use.
And unlike natural organic materials, the majority of plastics don’t break down into relatively harmless substances. Instead, they divide and redivide to get smaller and smaller, while retaining their original chemical compositions – and there is no theoretical limit to how small they can break down, beyond single molecules.
Co-author of the study and Columbia biophysicist Wei Min said: “It is one thing to detect, but another to know what you are detecting. There is a huge world of nanoplastics to be studied. It’s not size that matters. It’s the numbers, because the smaller the things are, the more easily they can get inside us.”
The plan now is to take this study one step further and investigate tap water, which has also been found to contain microplastics, although in smaller volumes than in bottled water.
Research is already underway looking into microplastics and nanoplastics that find their way into wastewater when laundry processes are carried out. Thus far, it has been found that there are millions of these particles released per ten-pound load of synthetic materials.
The team are also currently designing filters to help reduce the amount of pollution created by both commercial and residential washing machines.
And they’ll also soon be testing samples of snow that British collaborators are currently collecting in western Antarctica, while working alongside environmental health experts to measure nanoplastic levels in human tissue to determine their developmental and neurologic effects.