An automated biomonitoring system for early warning of pollutants in aquatic environments is described and characterized. The system uses sublethal changes in the movement behavior of the flagellate Euglena gracilis as biological endpoints. The movement is determined by real time image analysis. All parameters describing motility, velocity, orientation, and form of the cells are calculated during measurement, and changes of these parameters are interpreted as effect. By automatic dilution of the water sample, dose-effect relationships can be recorded automatically. A total measurement procedure, including control and sample measurement and filling and rinsing of the system, typically requires 8 min. Measurements with different organic and inorganic toxic compounds were performed and the calculated EC(50) values compared with literature data for the bioluminescence test with Vibrio fischeri. Also, measurements with waste water samples from different industrial plants were performed. The fast response time, the small size, the reliable image analysis system, the calculation of several endpoints, and the automatic measuring procedure are major advantages compared to other biological test systems.
Copyright 2001 Academic Press.