Occurrence and photodegradation of typical steroid hormones in surface water of urban lakes in Wuhan, China

The occurrence and distribution of typical estrogenic and androgenic steroid hormones including estrone, 17β-estradiol, estriol, 17α-ethynylestradiol and testosterone in surface water from nine lakes across the Wuhan City, China were investigated. The concentrations of studied steroids in surface water samples from different lakes were ranged from less than detection limits to hundreds nanomolarity and there were significant positive correlations among the concentrations of target steroids, indicating that these chemicals have the common sources and similar environmental behavior. Detection frequencies and abundance of steroids in lakes located in residential area were generally higher than those in remote lakes, and the levels of detected steroids in the identical lake varied in sampling locations with the highest concentration being observed around outlet of wastewater effluent. All these results indicated that anthropogenic factors play important roles in steroids contamination in urban surface water. Photodegradation data of the steroid hormones in natural lake water and deionized water demonstrated that only indirect photosensitive decomposition of steroids occurred in real lake surface water under simulated sunlight irradiation. Reactive species characterization and quenching experimental results revealed that photo-generated triplet 3 DOM⁎, • OH and 1 O 2 contribute to the indirect degradation of steroids in natural lake water. This study provided important reference for better understanding the sources and transformation of steroid hormones in urban lake surface water. • High levels of steroids are detected in urban lake surface water in Wuhan, China. • Steroid hormones in urban lake surface water are mainly from the domestic sewage. • Dissolved photosensitive substances promote the photodegradation of steroids in surface water. • Photo-generated 3 DOM ⁎ and ROS play important roles for indirect degradation of steroids.