Microplastics in Indian Ecosystems: Environmental Distribution and Human Toxicological Implications

Microplastics (MPs)—plastic particles smaller than 5 mm—have emerged as a pervasive environmental
contaminant in terrestrial, freshwater, and marine ecosystems across India. This review synthesises field data
from major Indian river systems (Ganga, Yamuna, Cauvery, and Brahmaputra), coastal zones (Bay of Bengal
and Arabian Sea shorelines), agricultural soils, and urban air, documenting MP concentrations, polymer types,
and spatial distribution patterns. Findings reveal alarming densities of 1,200–8,500 particles/m³ in riverine
systems and 340–4,800 particles/kg dry weight in agricultural soils of Punjab and Tamil Nadu. Toxicological
pathways examined include ingestion, inhalation, and dermal absorption, with emerging evidence of endocrine
disruption, oxidative stress, neurotoxicity, and genotoxic damage in exposed human populations. Priority
pollutant polymers—polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate
(PET)—serve as vectors for adsorbed heavy metals and persistent organic pollutants (POPs), amplifying
cumulative health risks. Regulatory gaps in India's Plastic Waste Management Rules (2016, amended 2022) are
evaluated, and evidence-based policy recommendations are proposed to address the growing microplastic burden
within the Indian subcontinent.