Influence of land cover, point source pollution, and granularity on the distribution of metals, metalloids, and organic matter in the river and stream sediments in the Republic of Korea

Abstract

With increasing anthropogenic activities, rivers and streams have become vulnerable to pollution; therefore, monitoring potential contaminants and the pollution status of surface sediments is essential. This study analyzed the concentrations of organic matter, metals, and metalloids; indices for organic, metal, and metalloid pollution; and ecological risk in river and stream sediments at 82 stations across Korea in 2017, 2018, and 2020. We performed bootstrapped analysis of variance, principal component analysis, and cluster analysis and used a structural equation model (SEM) to investigate spatiotemporal changes in the pollution status, main pollutant chemicals, and the exogenous factors affecting pollution status. The results suggest no significant differences in any of the twelve single chemical parameters and three pollution indices across the surveyed years. Metals, metalloids (Cu, Zn, Pb, and Hg), and organic matter with nutrients were identified as the main pollutants. The SEM demonstrated the significant influence of pollution sources—water used for industrial purposes, landfill wastewater discharge, and industrial wastewater discharge—on organic pollution, metal and metalloid pollution load, and environmental toxicity. This study identified consistently polluted areas, proposed additional management policies and stricter regulations on major point pollution sources rather than on broader land-use types, and suggested the combined consideration of metal toxicity risk with nutrient accumulation for future risk assessments. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-023-27080-4.

Fish Tissue Contamination with Organic Pollutants and Heavy Metals: Link between Land Use and Ecological Health

“…The final scores were calculated by aggregating all scores for individual metrics to quantify each riverine site's overall biotic integrity. The final health status of the study sites was ranked based on the final IBI score as excellent (36)(37)(38)(39)(40), good (28)(29)(30)(31)(32)(33)(34), fair (20)(21)(22)(23)(24)(25)(26), poor (14)(15)(16)(17)(18), or very poor (8-13).…”

“…This method comprehensively assesses the functional relationships, species abundance, fish population density, and diverse functions and structures of fish communities that are affected by ecological disturbances in aquatic ecosystems [23,24]. Land-use patterns have multiple impacts, including heavy metal pollution and agricultural intensification, which promote the accumulation of harmful substances, such as pesticides, in riverine ecosystems [22,[25][26][27][28][29][30]. Therefore, evaluation of the major links among ecological health assessment, land-use patterns, and various contaminants is necessary to elucidate how fish assemblages are impacted by anthropogenic threats.…”