[Preliminary study of toxicity of niclosamide ethanolamine salt on wetland creatures along lower reaches of Yangtze River in Nanjing City].

OBJECTIVE: To understand the impact of niclosamide ethanolamine salt on the Yangtze River wetland creatures, so as to provide an evidence for the environmental impact assessment of the Oncomelania hupensis control measures. METHODS: Eriocheir sinensis, Procambarus clarkii, freshwater mysis and Bellamya aeruginosa were chosen as the test organisms from the lower reaches of the Yangtze River in Nanjing City, and they were immersed in the different concentrations of niclosamide ethanolamine salt solution for 24-96 h. The mortality rates and LC50 values were calculated. RESULTS: There was only 1 death (with a mortality rate of 8.33%) of P. clarkia immersed in niclosamide ethanolamine salt with the concentration of 400 mg/L for 96 h. There was no death of the E. sinensis immersed in niclosamide ethanolamine salt with the concentration of 640 mg/L for 96 h. The LC50 values were 2.170 4, 1.303 6, 1.013 1 mg/L and 0.720 5 mg/L respectively when the freshwater mysis were immersed in the solution for 24, 48, 72 h and 96 h. The LC50 values were 1.173 5, 0.642 1, 0.477 3 mg/L respectively when the B. aeruginosa were immersed in the solution for 24, 48, 72, 96 h. CONCLUSIONS: The impacts of niclosamide ethanolamine salt on the different wetland creatures are different. E. sinensis and P. clarkii have high resistance to niclosamide ethanolamine salt. However, niclosamide ethanolamine salt shows heavy toxicity on the freshwater mysis and Bellamya aeruginosa.

[Effect of environmental change in marshland after implementation of Three Gorges Reservoir Project on schistosomiasis in Jiangsu Province].

OBJECTIVE: To investigate the effect of environmental change in marshland after the implementation of the Three Gorges Reservoir Project on schistosomiasis in Jiangsu Province. METHODS: The hydrologic data of Nanjing City in Jiangsu section of the Yangtze River, and the data regarding the marshlands, the snail status and schistosomiasis morbidity in areas adjacent to the Yangtze River in Jiangsu Province were collected, and field snail surveys were performed in typical marshlands. RESULTS: Following the implementation of the Three Gorges Reservoir Project, the water level in Nanjing section of the Yangtze River appeared a year-dependent gradual decline tendency. The mean peak water level on January to March, 2012 (spring) increased by 0.41 m as compared to that before the construction of the project in 2002, while the peak water level on April to December, 2012 decreased by 0.32 m as compared to that before the construction of the project in 2002. The endemic situation of schistosomiasis showed a decline tendency in areas adjacent to the Yangtze River in Jiangsu Province. The area with infected snails along the Yangtze River was 0, the positive rates of serological tests and parasitological tests of the population were 0.73% and 0.004%, respectively in 2012. CONCLUSIONS: Both the schistosomiasis morbidity and snail status appear a decline tendency in areas adjacent to the Yangtze River along the lower reaches of the Yangtze River, Jiangsu Province after the implementation of the Three Gorges Reservoir Project.