Bottled water contains hundreds of thousands of nanoplastics, study shows
A coauthored study is conducted by Columbia University and Rutgers University, to explore nanoplastics in bottled water. The study was published in the journal Proceedings of the National Academy of Sciences.
What are microplastics and nanoplastics?
Microplastics are tiny particles formed when plastics break down into progressively smaller bits while nanoplastics are the spawn of microplastics that have further broken down. Both tiny bits of plastics cause unknown potential health and ecosystem effects.
Microplastics are defined as fragments ranging from 5mm down to 1µm, while nanoplastics, are particles below 1µm.
A study is conducted in exploring nanoplastics in bottled water.
Study on nanoplastics in bottled water
The researchers tested three popular brands of bottled water sold in the United States, analyzing plastic particles down to just 100nm in size.
The study uses a technique called stimulated Raman scattering microscopy, which was co-invented by study coauthor Wei Min, a Columbia biophysicist. This involves probing samples with two simultaneous lasers that are tuned to make specific molecules resonate.
Targeting seven common plastics, the researchers created a data-driven algorithm to interpret the results.
The result revealed that there are 110,000 to 370,000 plastic fragment in each liter, 90% of which were nanoplastics; the rest were microplastics. The researchers also determined the seven specific types of plastics and charted their shapes.
One of the common plastics is polyethylene terephthalate (PET), which is common material for water bottles. PET bits can get into the water when the bottle is squeezed or exposed to heat. Other common plastics the researchers found: polystyrene, polyvinyl chloride and polymethyl methacrylate, all used in various industrial processes.
A tiny particle of polystyrene, about 200nm, imaged by a new microscopic technique.
However, the seven plastic types only accounted for about 10% of all the nanoparticles in the samples, while the rest is unidentified. In the study, the authors explain “indicating the complicated particle composition inside the seemingly simple water sample”.
Further studies
Among other things, the team plans to look at tap water, which also has been shown to contain microplastics, though far less than bottled water. The coauthor Beizhan Yan is also running a project to study microplastics and nanoplastics that end up in wastewater when people do laundry.
The team will soon identify particles in snow that British collaborators trekking by foot across western Antarctica are currently collecting. They also are collaborating with environmental health experts to measure nanoplastics in various human tissues and examine their developmental and neurologic effects.
