Identification of factors affecting Oncomelania hupensis density in Eastern Dongting Lake regions / 中国血吸虫病防治杂志

Objective To evaluate the impact of water pollutants, water levels and meteorological factors on the Oncomelania hupensis density in Eastern Dongting Lake regions, so as to provide insights into schistosomiasis control. Methods O. hupensis snails were surveyed using a systematic sampling method in snail-infested marshlands in Eastern Dongting Lake regions from 2007 to 2014, and data pertaining to water pollutants, water levels and meteorological factors were collected. The duration of submergence and the date of the start of submergence were calculated. The snail density and its influencing factors were descriptively analyzed, and a linear mixed model was generated to examine the impacts of variables on the snail density. In addition, smooth curves were fitted to investigate the relationship between snail density and variables. Results The snail density appeared a fluctuation in Eastern Dongting Lake regions during the period from 2007 to 2014, with the highest density on October, 2010 (52.79 snails/0.1 m2) and the lowest density on January 2009 (2.15 snails/0.1 m2). Linear mixed-model analysis showed that permanganate index, total phosphorus and the date of the start of submergence affected the snail density (t = 6.386, −2.920 and −3.892, all P values < 0.01). Smooth curve analysis revealed that the associations of the snail density with the permanganate index and total phosphorus appeared an approximately quadratic curve. After the end of April, the earlier date of the start of submergence resulted in a higher snail density. Conclusion Permenganate index, total phosphorus and the date of the start of submergence affect the O. hupensis snail density in Eastern Dongting Lake regions.

The Application of Macroreticular Resins to Concentrate Organic Contaminants in Water / 环境与健康杂志

Concentration of the trace organic contaminants in water by high adsorption capacity macroreticular resins, have been introduced to physical, chemical and biological analysis of organic compounds from surface water, underground water, tap water and different kinds of wastewaters, and runoff water. This review summarized the techniques and conditions for the application of macroreticular resins to concentrate the organic compounds in water, including purification of resin, column preparation, solvents extraction and elution, concentration of eluate and resin regeneration. It is suggested that it is necessary to set the technique criteria for the application of macroreticular resins.