New insight into the spatiotemporal distribution and ecological risk assessment of endocrine-disrupting chemicals in the Minjiang and Tuojiang rivers: perspective of watershed landscape patterns†

This study evaluated the pollution characteristics, spatiotemporal distribution, and ecological risks of eight endocrine-disrupting chemicals (EDCs) in the Minjiang and Tuojiang rivers. Utilizing 3S technology (ArcGIS, remote sensing, GPS) and Fragstats, the research calculated eight landscape pattern indices related to land use types along the Minjiang river and established correlations between landscape factors and EDC distribution through stepwise multiple regression. The results indicated that bisphenol A (BPA) and nonylphenol (NP) were the most concerning EDCs, with detection frequencies of 97–100% and peak concentrations up to 63.35 ng L⁻¹, primarily located in the middle and lower reaches of the Minjiang river and the upper reaches of the Tuojiang river. There was a significant correlation between the spatial distribution of pollutants and landscape patterns, where increased fragmentation, a higher number of patches, and complex patch shapes within a 10-kilometer buffer zone were associated with elevated levels of river pollution. By integrating four classical mathematical models to fit curves for acute and chronic toxicity data of BPA and NP, the findings suggested that BPA posed a higher ecological risk. This interdisciplinary research provided essential theoretical insights for investigating river pollution and its influencing factors, offering a new perspective on simultaneous river pollution control, urban functional zoning, and adjustment of watershed landscape spatial patterns from an urban planning standpoint.