Detection of chemical threat agents in drinking water by an early warning real-time biomonitor.

Having a safe water supply for civilian organizations and military personnel is an important objective to avoid toxic contamination of civilians and soldiers. Chemical warfare (CW) agents, especially organophosphorous nerve compounds, are the most toxic of known chemical agents. The Daphnia Toximeter system is a continuously working test system that uses Daphnia magna as a sensitive organism for monitoring drinking water. Both small doses (allowable for short-term water ingestion) and graduated higher concentrations induced toxic reactions in the Daphnia Toximeter system, leading to alarms sounding. The system is sensitive to a wide range of CW agents and their hydrolysis products. Concentrations below acute human toxicity can be discovered in a very short time, with the actual time depending on the concentrations applied. In every case alarms were triggered within 2 h at concentrations in water low enough for that water to be allowed for use as drinking water in exceptional conditions. Copyright 2003 Wiley Periodicals, Inc.