Currently, beachgoers are informed about water-quality conditions based on results from the previous day's sample. Scientists must collect samples in the field, then return to a lab to culture them for analysis a process that takes a minimum of 24 hours.
Now, engineers from the UCLA Henry Samueli School of Engineering and Applied Science have sped up the process of analyzing bacterial concentrations to under one hour, through the development of a new in-field, rapid-detection method.
Since bacteria levels can change quickly in the water column, a one-day turnaround time simply isn't fast enough to adequately protect swimmers or prevent unnecessary beach closures, the engineers say.
This issue is especially pertinent in California, where gastrointestinal illness that can result from contact with contaminated beach waters has been estimated to cost Orange and Los Angeles county beach visitors between $21 million and $51 million per year in sick days and related issues.
Furthermore, California coastlines are subject to chronic water pollution problems due to sewage spills and urban runoff. Rainstorms in Southern California can further exacerbate this problem, as pollutants that have accumulated over time on street surfaces are suddenly flushed into our waterways and into the ocean.
Jenny Jay, UCLA associate professor of civil and environmental engineering, and Ph.D. student Christine Lee have advanced and tested a rapid method in marine and freshwater samples from beaches in Malibu and Santa Monica. To their knowledge, it is among the first viable in-field methods for rapid, portable fecal bacteria analysis. This research will be published in an upcoming issue of the Journal of Applied Microbiology and is currently available online.
Even for areas like the Southern California coast, which are close to state-of-the-art laboratories, transportation time, coupled with lab work, may mean that result
|Contact: Matthew Chin|
University of California - Los Angeles