The average liter of bottled water has nearly a quarter million invisible pieces of ever so tiny nanoplastics, detected and categorized for the first time by a microscope using dual lasers.
Scientists long figured there were lots of these microscopic plastic pieces, but until researchers at Columbia and Rutgers universities did their calculations they never knew how many or what kind.
Scientists using the most advanced laser scanning techniques found an average of 240,000 plastic particles in a one-liter bottle of water, compared to 5.5 per one liter of tap water.
University of Columbia researchers tested three popular brands of bottled water sold in the United States and, using lasers, analyzed the plastic particles they contained down to just 100 nanometers in size.
These microscopic particles carry phthalate chemicals that make plastics more durable, flexible, and lasting longer.
Phthalate exposure is attributed to 100,000 premature deaths in the US each year. The chemicals are known to interfere with hormone production in the body.
They are ‘linked with developmental, reproductive, brain, immune, and other problems’, according to the National Institute of Environmental Health Sciences.
The highest estimates found 370,000 particles.
Nanoplastics had been too difficult to detect using conventional techniques, which could only find microplastics ranging from 5mm down to 1 micrometer – a millionth of a meter, or 1/25,000th of an inch.
Groundbreaking research in 2018 found around 300 microplastic particles in a liter of bottled water, but researchers were limited by their measurement techniques at the time.
Research is now underway across the world to assess the potentially harmful effects.
The team used a new technique called Stimulated Raman Scattering (SRS) microscopy, which was recently invented by one of the paper’s co-authors.
The method probes bottles with two lasers tuned to make specific molecules resonate, and a computer algorithm determines their origin.
The results showed that nanoparticles made up 90 percent of these molecules, and 10 percent were microplastics.
