Rapid Analytical Techniques for Drinking Water Security Investigations

Abstract

The events of Sept. 11, 2001, forever changed the climate of the United States and exposed the nation's vulnerabilities. In response, the U.S. Environmental Protection Agency (USEPA) prepared detailed guidance for drinking water utilities to follow in cases of suspected or actual incidents of intentional contamination of public water systems. Under the USEPA protocol, water utility personnel, as the authority onsite, would conduct an initial investigation or site characterization. Key to this preliminary assessment is the use of rapid analytical techniques for field screening. The Pittsburgh, Pennsylvania Water and Sewer Authority and the University of Pittsburgh School of Engineering evaluated a number of analytical methods that utility staff or emergency response teams could use to generate preliminary data during the site characterization phase. The technologies included rapid immunoassays, rapid enzyme tests, rapid polymerase chain reaction methods, field‐deployable gas chromatography‐ mass spectrometry, and acute toxicity screening. Research results indicated that, although analytical capabilities are rapidly improving, field‐screening technologies are not a substitute for standard laboratory analyses and the data such technologies provide should be considered presumptive. The rapid analytical techniques currently available can aid in assessing hazards and directing appropriate operational and public health responses. However, additional studies are needed to determine matrix effects, the influence of interferences, the incidence of inaccurate results, and the limitations of detection capabilities.

Detection

“…Some biosensors can be used for rapid on-site testing (States et al, 2004). Biosensors have been shown to be reliable and to generate reproducible results (Campbell et al, 2007;Hillaker and Botsford, 2004;States et al, 2004). A disadvantage of biosensors is that they may not be suitable for testing drinking water because the organisms used in these tests may be sensitive to disinfectants and to other drinking water constituents (Hall et al, 2007).…”

“…The Microtox test uses Vibrio fischeri as the biological indicator. Some biosensors can be used for rapid on-site testing (States et al, 2004). Biosensors have been shown to be reliable and to generate reproducible results (Campbell et al, 2007;Hillaker and Botsford, 2004;States et al, 2004).…”

“…To measure the effect of potentially contaminated water on the organisms, a metric must be used to measure the biological response; examples of metrics include luminescence of algae, metabolic functions, and respiration rates. Toxicity-based biosensors may use water fleas, mollusks, algae, or fish as the biological organisms (States et al, 2003(States et al, , 2004. Fish ventilatory monitoring is a form of toxicity testing in which the fish response to toxins are observed due to changes in ventilation rate, cough rate, ventilation depth, and movement (van der Schalie et al, 2001(van der Schalie et al, , 2004.…”

“…Several of the preceding tests were also evaluated by van der Schalie (2006). States et al (2004) extensively tested the following rapid field tests: l Bio-Threat Alert ® (Tetracore) test strips that are based on lateral flow immune chromatography.…”

Improved cell sensitivity and longevity in a rapid impedance‐based toxicity sensor

“…One alternative is to use sensors that rapidly evaluate the toxicity of a whole water sample instead of measuring concentrations of individual chemical constituents. Biologically based toxicity sensors can provide rapid assessments of water quality and can contribute to drinking water security investigations (States et al, 2004). Sensors that evaluate cellular cytotoxic responses are well-suited for a broad range of sensing applications, including the detection of unknown agents, and the use of mammalian cells as biosensors can provide responses relevant to human physiology (Pancrazio et al, 1999;Kovacs, 2003).…”