One litre of bottled water contains around one lakh micro-nano plastic particles: Study Premium

A new study reveals that a litre of bottled water can contain over 100,000 micro-nano plastics, with 90% being nanoplastics, highlighting the need for effective analysis techniques.

A litre of bottled water can contain more than one lakh particles of micro-nano plastics, with 90% of those being nanoplastics, a new study has revealed. Nanoplastics are minute in size, with dimensions ranging from 1 nanometre to 1 micrometre. The new findings are way more than the concentration of microplastics previously reported in bottled water.

The study, conducted by scientists at Columbia University in New York and published on January 8, 2024, profiled individual plastic particles with the intention to bridge the knowledge gap that exists in analysis of nanoplastics due to lack of effective techniques. Experts also believe that the study can be instrumental in providing information about plastic pollution at nano level.

Nanoplastics are difficult to analyse, mainly due to their size and plastic-identifying specificity of techniques. The experiment involved addressing these challenges using a custom hyperspectral stimulated Raman scattering (SRS) imaging platform. The platform can take multiple molecular images at different wavelengths to allow for a comprehensive understanding of the composition of the material under study.

SRS microscopy uses Raman Effect – the scattering of molecules depends on the medium it passes through.

The imaging platform was used with an automated plastic identification algorithm that provided detailed information about the chemical makeup at the single-particle level. Once the method was established to detect nanoplastics quickly and accurately, bottled water was used as a model system to study micro-nano plastics.

The investigation revealed the presence of approximately 2.4 ± 1.3 × 105 micro-nano particles per litre of bottled water. The order of magnitude of the result reveals that microplastics are more abundantly present in bottled water than what was previously reported.

Traditional single-particle chemical imaging techniques like Fourier Transform Infrared Spectroscopy (FTIR) or Raman microscopy have lower instrumental resolution and detection sensitivity. They are hence limited to chemical composition only at the microplastic level. On the other hand, particle-imaging techniques, like electron microscopy and atomic force microscopy, with nano-level sensitivity are not suited to differentiate compositions.