Supplementary Information-Anthropogenic drivers and runoff-mediated transport of microplastics in the Chongqing Section of the Jialing River: A partial least squares regression-based mechanistic study

A total of 14 environmental variables were monitored alongside microplastic concentrations. These variables include geographical distance, water temperature, number of factories, water level, population, industrial energy consumption (IEC), fertilizer use, electrical conductivity (EC), chemical oxygen demand (CODcr), precipitation, discharge, total nitrogen (TN), total phosphorus (TP), and pH.

Descriptive statistics (maximum, minimum, mean, and standard error of the mean) for each variable are provided in Table S1, offering a comprehensive overview of their ranges and central tendencies. Furthermore, a partial least squares regression (PLSR) model was applied to identify key drivers of MP transport. Table S2 reports the variable importance in projection (VIP) scores, loading weights, and the direction of influence (positive or negative) for each environmental factor.