DISTRIBUTION CHARACTERISTICS AND RISK ASSESSMENT OF ANTIBIOTICS AND HEAVY METALS IN THE YUDONG RIVER BASIN

Despite rivers being crucial to human civilization human activities have introduced increasing amounts of pollutants.The combined contamination of river waters by antibiotics and heavy metals has receiving growing attention.However, little is known about the co-occurrence of these contaminants in rivers affected by mining wastewater.By collecting and analyzing water samples from the Yudong River basin, we investigated the distribution patterns of antibiotics and heavy metals, assessed their respective risks, and explored potential relationships between them.Our findings revealed that sulfamethoxazole (143.68 ng/L) had the highest concentration, and the combined risk quotient of all antibiotics ranging from 10.17 to 33.54, which indicated severe antibiotic contamination.None of the heavy metal concentrations exceeded regulatory limits, and the single-factor and Nemero pollution indices suggested the river was nonpolluted for heavy metals.Significant spatial variation was observed, with concentrations of oxytetracycline and roxithromycin increasing in the lower reaches, and Zn, As, and Cd concentrations increasing significantly in the middle reaches.A complex correlation between heavy metals and antibiotics was observed across different sections of the river.This study provides novel insights into the co-occurrence of antibiotics and heavy metals in river systems, offering valuable data to inform management strategies.