Spatial variability, source identification and risks assessment of antibiotics in multimedia of North China's largest freshwater lake using positive matrix factorization and Monte Carlo simulation.

Antibiotics are widely found in aquatic ecosystems and pose a serious threat to human and the ecological system. Samples of surface water (SW), overlying water (OW), pore water (PW) and sediments (Sedi) were collected to investigate the spatial variability, potential sources, ecological risk (RQs) and health risks (HQs) of nine common antibiotics in Baiyangdian Lake using positive matrix factorization (PMF), and Monte Carlo simulation. Significant spatial autocorrelation of most antibiotics were observed in PW and Sedi samples rather than in SW and OW samples, and higher antibiotic levels were found in the northwest of waters and the southwest of sediments. Livestock (26.74-35.57%) and aquaculture (21.62-37.70%) were identified as primary sources of antibiotics in the water and sediments. Norfloxacin and roxithromycin showed high levels of RQ and HQ in more than 50% of samples, respectively. The combined RQ (ΣRQ) in the PW can be used as a sign of across multimedia risk. Notably, appreciable health risks were observed for the combined HQ (ΣHQ) in about 80% of samples, indicating the importance of taking health risk of antibiotics into consideration. The findings of this work provides a reference for antibiotics pollution control and risk management in shallow lake.

[Risk assessment for emergency events of infectious disease in outlying areas of large-scale activities].

OBJECTIVE: To identify and assess the potential public health risks of emergency events of infectious disease in the surrounding areas of Hangzhou during the 11th G20 summit, and to assess their impacts on the G20 summit. METHODS: The surrounding cities of Hangzhou included Ningbo, Wenzhou, Jiaxing, Huzhou, Shaoxing, Jinhua, Quzhou, Zhoushan, Taizhou and Lishui. Background information on infectious diseases in Zhejiang province was collected, and the brainstorming and expert consultation methods were used to identify the risks. The local risks and the impact of local risks on the G20 summit were assessed. RESULTS: The criteria for public health risk was first established. Through the assessments,a total of 27 kinds of infectious diseases in 4 types of public health risks were identified. The impact of these risks on Hangzhou G20 summit was divided into 1 item of high-risk, 12 items of medium risk and 14 items of low risk.According to the results of risk assessment, the recommendations for risk management of respiratory infectious diseases, intestinal infectious diseases, imported infectious diseases like Middle East respiratory syndrome and other infectious diseases were made. With risk management, Middle East respiratory syndrome was not occurred during the G20 summit, and the epidemic situation of other infectious diseases with middle or low risks was almost the same with that of past years. CONCLUSIONS: sThe public health risks of Hangzhou G20 summit from sudden infectious diseases in outlying areas are mainly medium and low risks. The recommendations on risk management provide a basis for reducing the adverse consequences of public health risks in the event of an outbreak of infectious diseases, avoiding the impact of various risk factors in the outlying areas on G20 summit.