Abstract

Antibiotics are widely used and ubiquitous in the environment, which in turn poses potential threat to human health. However, the effects of agricultural activities and river input on the fate and ecological risks of antibiotics in shallow lake are still poorly understood. Surface water, overlying water and pore water, sediments and aquatic plant samples in the historical planting subarea (PA), historical aquaculture subarea (AU), inflow subarea (IW), discharge subarea (DC), and conservation subarea (CK) of Baiyangdian Lake were collected and analyzed. Our results revealed that the total antibiotic concentrations ranged from 85.33 ng/L to 1631.47 ng/L in waters and from 66.90 ng/g to 177.03 ng/g in sediments. Generally, the total antibiotic concentrations introduced by planting activity in surface water, overlying water and sediments were higher and the levels of total antibiotics in pore water were more affected by river input. In addition, three quinolones (QNs) and two tetracyclines (TCs) were dominant antibiotics in almost five subareas. The pseudo-partitioning coefficient kd(pw) and bioaccumulation factor (BAF) of antibiotics varied according to the ef-fects of river input and historical agricultural activities. The ecological risk (RQ) of antibiotics from agricultural activ-ities was higher than that from river input. The norfloxacin (NOR) in pore water showed high RQ, which contributed to a large proportion (>50 %) of the combined ecological risks ( n-ary sumation RQs) except for surface water. Therefore, NOR should be used as the primary ecological risk control index for antibiotic contamination management in the BYD. n-ary sumation RQs showed high risk in water in the five subareas. This study can act as a reference for governments to formulate effective man-agement strategies for protecting the ecological health of lakes.