Microplastic contamination and environmental risks in the Beas River, western Himalayas

Area of Science:

• Environmental Science
• Ecotoxicology
• Environmental Chemistry

Background:

• The Western Himalayas harbor fragile riverine systems, including the Beas River, vital for local ecosystems and indigenous populations.
• Microplastics (MPs) are pervasive environmental contaminants, but their presence and ecological risks in the Beas River remain understudied.
• Tourism and urbanization contribute to significant plastic and MP release into the Beas River.

Purpose of the Study:

• To investigate the extent of microplastic pollution in the Beas River's water and sediment.
• To assess the associated environmental and ecological risks of microplastic contamination.
• To identify MP types, polymers, and their correlation with population density.

Main Methods:

• Sampling of water and sediment along a 300 km stretch of the Beas River.
• Quantification of microplastic abundance, morphotypes, and polymer identification.
• Calculation of pollution load index, polymer hazard index, and potential ecological risk index.

Main Results:

• Microplastics were abundant in both water (46-222 items/L) and sediment (36-896 items/kg), widely distributed across sampling sites.
• MP abundance in water significantly correlated with population size, with higher concentrations in populated areas like Kullu.
• Fibers and films were common morphotypes, predominantly polyethylene, with extreme ecological risk indicated by high hazard and risk indices.

Conclusions:

• The Beas River faces significant microplastic pollution, posing an extreme ecological risk.
• Findings highlight potential threats to human health, as the river is a primary water source for local communities.
• The study provides critical data for policymakers to develop eco-friendly strategies for vulnerable Himalayan regions.