It seems that everywhere scientists look for plastic, they find it: from the ice in Antarctica to the first bowel movements of newborn babies.
Now researchers are discovering that the amount of microscopic plastic floating in bottled water is much higher than previously thought.
Using advanced imaging technology, scientists from Columbia University’s Lamont-Doherty laboratory examined water samples from three popular brands (they won’t say which) and found hundreds of thousands of pieces of plastic per liter of water.
Ninety percent of those plastics were small enough to qualify as nanoplastics: microscopic specks so small that they can be absorbed into human cells and tissues and cross the blood-brain barrier.
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The research, published Monday in the journal Proceedings of the National Academy of Sciences, raises new concerns about the potentially harmful health effects – and prevalence – of nanoplastics. The researchers found that the amount of such particles was 10 to 100 times greater than previously estimated.
“For a long time before this study, I actually thought it contained bottled water [in terms of] nanoplastics consisted of just a few hundred PET particles,” said Naixin Qian, a chemistry student at Columbia and lead author of the study. “It turns out to be much more than that.” PET, or polyethylene terephthalate, is a type of clear plastic often used for single-use water bottles.
Microplastics – particles ranging in size from 1 micrometer to 5 millimeters – have been documented in bottled and tap water for years. But the identification of nanoplastics – particles that are only a billionth of a meter in size – is raising alarms.
The incredibly small size of nanoparticles allows them to behave differently from larger pieces of matter Beizhan Yanan environmental chemist from Columbia and co-author of the study.
Pollutants and pathogens can be carried on the surface of a particle, and the smaller a particle becomes, the greater the surface area to volume ratio becomes.
As a result, Yan said, “even if they are not as toxic at a larger particle size, they become toxic as they get smaller, because they can interfere in the cells, in the tissues, in the organelles.”
Research into the effects of plastic on human health is still in its infancy. It is only recently that scientists have identified the presence of plastic in people’s bodies and organs.
But research in other animals suggests a strong, negative impact on health. Laboratory research in fish and rodents has shown that microplastics disrupt development, reproductive capacity and health, gut health, hormone levels, immune responses, the heart and more.
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The study authors used a new type of microscope that uses lasers to image the vibrations of molecules to analyze the nanoparticles against a library of seven common plastics. They were not surprised when they found small pieces of PET, because that is what the bottles were made of. However, the amount of PET was dwarfed by the amount of polyamides, a form of nylon used in the reverse osmosis filters through which water is passed before bottling.
Other plastics found in microscopic amounts in water include polystyrene, polyvinyl chloride and polymethyl methacrylate, also known as plexiglass. But only 10% of the nanoparticles analyzed could be classified as one of the seven known plastics, the researchers found. The origin of the rest is unknown.
In recent years, researchers have identified microplastics from the deepest oceanic waters to the snow-capped peaks of the planet’s highest mountains. They have found it in human blood, lung tissue and in the brain, and in organisms ranging from worms and zooplankton to whales and polar bears.
In some cases, the particles are ingested with food and water. In other cases, they are inhaled – scientists have found them in indoor and outdoor air, as well as in clouds – or absorbed through the skin.
Laundering synthetic clothing and breaking car tires are two of the biggest sources of plastic in the air.
“As humans, we find ourselves in environments where there is plastic everywhere,” Yan said.
There is also evidence that these small particles bioaccumulate, or become more concentrated, as they move up the food chain from one organism to another.
Although the Columbia study did not analyze tap water samples, previous studies of microplastics have found much lower concentrations of those particles in tap water than in bottled water.
Food packaging is also a known source of plastic pollution in food. On January 4, Consumer Reports published the results of its study research in plastic chemicals in common processed foods commonly available in the US
Plastic chemicals and nanoplastics “are part of the same problem, but they are two completely different animals,” says James E. Rogers, a microbiologist and acting director of product safety at Consumer Reports. “One is a chemical and one is a physical part, even if it is micro-sized.”
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Of the 85 food products tested, 84 contained traces of phthalates, the most common chemical used to make plastic more durable. Nearly 80% of the foods contained bisphenols, another industrial chemical.
Both phthalates and bisphenols are known endocrine disruptors, meaning they disrupt the body’s hormonal systems. Exposure to these chemicals over time is associated with higher risks of diabetes, obesity, cancer and fertility problems, Rogers said.
“You may not be able to reduce your exposure to zero, but you can at least reduce your risk by reducing your exposure,” Rogers said. “Eliminate the fast food. Eat less processed foods. Eat less fatty foods.”
Now that they’ve finished talking to us about bottled water, the Columbia team is exploring how they can use even more stimulated Raman scattering microscopy to detect nanoplastics in other areas of life.
One project examines the nanoplastics in exhaust and wastewater from commercial and residential washers and dryers. A few British adventurers currently traveling through Antarctica are collecting snow samples for the team to analyze. The Columbia team is also working with other research institutions to measure nanoplastics in human tissues and understand their effects on health.
And a group at the University of Waterloo, in Canada, is using artificial intelligence to help sort the plastic bits they find in wastewater – providing a new, and potentially more powerful and accurate way to identify different and often difficult-to-identify variants of plastic in water samples.
“It’s an example of how we can use AI for good,” said Wayne Parker, professor of civil and environmental engineering at the school.
Methods such as AI, or the technology used by the Columbia team to identify micro- and nanoplastics, will allow researchers to better identify and assess “the risks posed by these particles” in the environment and in ourselves, Parker said .
This story originally appeared in the Los Angeles Times.