Notably, 90 percent of these particles were identified as nanoplastics, while the remaining 10 percent were classified as microplastics, according to a study
A recent study conducted by researchers from Columbia University has brought to light findings about the presence of plastic particles in bottled water. Contrary to previous estimates primarily focused on larger plastic sizes, the study reveals that an average litre of bottled water may contain around 240,000 plastic pieces. This figure is significantly higher, ranging from 10 to 100 times, than earlier assessments.
The study specifically analysed three popular bottled water brands in the United States. Plastic particles were measured down to 100 nanometers in size, with results indicating the presence of 110,000 to 370,000 plastic fragments per litre. Notably, 90 percent of these particles were identified as nanoplastics, while the remaining 10 percent were classified as microplastics. The study sheds light on a previously unexplored aspect of plastic pollution.
The research employed stimulated Raman scattering microscopy, a technique that involves probing samples with two simultaneous lasers tuned to make specific molecules resonate. Algorithms were then used to analyse and interpret the data. The study not only quantified the presence of plastic particles but also identified the types of plastics in the bottled water.
Polyethylene terephthalate (PET), commonly used in water bottles, was identified among the plastic types detected. Another plastic type found in greater quantity was polyamide, a type of nylon, which the researchers speculated might have originated from plastic fibres used in water purification processes before bottling.
The study also identified other common plastics used in various industrial processes, including polystyrene, polyvinyl chloride, and polymethyl methacrylate. However, these seven plastic types only accounted for approximately 10 percent of all the nanoparticles found in the bottled water samples.
The researchers acknowledged that the remaining 90 percent of nanoparticles present in the water samples remain unidentified, indicating a complex composition of particles within what appears to be a simple water sample.
Lead author Naixin Qian, a graduate student in chemistry at Columbia University, emphasised that the study's results highlight "the complicated particle composition inside the seemingly simple water sample." The team used this study as a platform to develop a technique called stimulated Raman scattering microscopy to delve deeper into the world of nanoplastics.
While the study focused on bottled water, researchers emphasised that nanoplastics pose a broader concern, and further exploration is needed to understand their prevalence and potential impacts beyond this specific context. The study highlights the necessity for continued research into the presence and effects of nanoplastics on human health and the environment.