Microplastic Contamination in Groundwater Aquifers along the Ganga River Basin: A Comprehensive study from Devprayag to Gangasagar, India

Microplastics are tiny plastic particles, less than 5 millimetres in size and their access to food chain have a significant hazard to ecosystems and environmental health. Their concern also extends to drinking water and our limited understanding of their occurrence in groundwater aquifers poses a potential research gap. Our preliminary investigation suggests the presence of microplastics in groundwater samples from near vicinity of Ganga Channel and subsequently, 60 groundwater samples were collected for the detailed study from Devprayag (Uttarakhand) to Gangasagar (West Bengal), India. This is the first study that investigates the distribution and quantification of microplastics from the groundwater aquifers influenced by Ganga River water, the largest fresh water source in Northern India. The water samples are filtered through 0.45-micron size nitrocellulose filter membrane and the residue is visually inspected under a stereo microscope. Further, the abundance, type, and size of MPs were determined by micro-Raman spectroscopy following a well-established and quality-controlled analytical route. The findings indicate the presence of microplastics (MPs) in all samples, with Polyethylene (PE), Polypropylene (PP), and Polyvinyl chloride (PVC) identified as common types in each sample. Various shapes of microplastics, such as fibres, fragments, films, and foam, were detected. MPs with size less than 150 µm are significantly abundant, likely owing to their mixing in ground water through the infiltration from surface waters. Contamination of groundwater with microplastics (MPs) poses a significant health risk, especially given its importance as a crucial source for drinking and irrigation. If this problem left untreated or if concentrations of MPs continue to rise, this has the potential to evolve into a man-made disaster.