A secondary data–driven framework for screening microplastic risk in wastewater-affected water bodies of the baddi industrial region, India

ABSTRACT

Microplastic pollution is an increasing concern in wastewater-affected aquatic systems, yet direct monitoring remains limited in many industrial regions. This study presents a secondary data-driven screening framework for assessing relative microplastic risk in wastewater-affected water bodies of the Baddi–Barotiwala–Nalagarh industrial belt, India. A dataset of 24 sites was compiled from regulatory reports, published literature, hydrological information, and indicators of industrial activity. Because direct microplastic measurements were unavailable for most locations, relative microplastic loading potential was estimated using a proxy-based approach informed by total suspended solids, chemical oxygen demand, flow conditions, industrial density, treatment-related context, and retention characteristics. Descriptive statistics, exploratory correlation analysis, and a composite Microplastic Risk Index were used to identify priority locations. The results indicated higher relative risk in industrial drains, stagnant ponds, and low-flow wastewater receiving waters near dense industrial activity, while upstream and better-flushed sites ranked lower. Estimated loading patterns were positively associated with particulate-rich wastewater conditions and industrial pressure, and negatively associated with flow velocity. The framework is intended as a screening and prioritization tool rather than a substitute for direct field measurement. It may help regulators and industrial managers target limited monitoring resources toward likely hotspot locations in data-limited industrial regions.