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 results often are not ready until the next day. With such a delay between sampling and results, the results may no longer be relevant due to the dynamic nature of water quality in beach environments.
The new rapid method represents a field-portable alternative to more expensive procedures, particularly where larger-scale, expensive equipment is not readily accessible. To decrease the time to determine results, the researchers have outfitted a portable kit to test samples for bacterial concentrations.
"We envision a tool that can be used by lifeguards to collect and analyze water samples throughout the day, providing beachgoers with up-to-date, near-real-time data on water conditions," Lee said. "This could also be useful in determining persistence of a bacterial contaminant after a pollution event, such as a sewage spill or a septic tank leaking."
"We are currently applying this method, in a new approach, to identifying contamination sources in which we can adaptively sample the environment in order to hone in on hotspots," Jay said.
The process uses magnetic beads conjugated to specific antibodies that identify and bind fecal bacteria that are used as standards for determining the safety of recreational waters, such as E. coli and Enterococcus.
After a few filtration and isolation steps, the sample organisms are lysed and treated with an enzyme that catalyzes a light-emitting reaction with target ATP, the energy currency of a cell. Cells break down ATP to obtain energy important for cellular processes.
Scientists can then determine bacterial concentrations based on how much light is released by using a luminometer, a device that detects light emissions.
The process is called covalently linked immunomagnetic separation/adenosine triphosphate quantification technique (Cov-IMS/ATP).
The paper's other co-authors are UCLA electrical engineering professor William Kaiser and John Griffith, Ph.D., a senior microbiologist with the Southern California Coastal Water Research Project.
For the Southern California coast, using this detection method could significantly inform source-tracking practices.
"UCLA's rapid-method work is very exciting," said Mark Gold, D.Env., president of the environmental group Heal the Bay. "It could result in faster notification of the public on the health risks of swimming at contaminated beaches and better protection of public health."
Jay's research group has also applied Cov-IMS/ATP in drinking and source waters in Dar es Salaam, Tanzania, as part of the Environmental Protection Agency's People, Planet, Prosperity (P3) initiative, which promotes innovative designs for sustainabe resource use. The Tanzania project, which focuses on waterborne illness, contamination and hygiene behavior, is being conducted in partnership with Stanford University civil and environmental engineering professors Alexandria Boehm and Jenna Davis. Recent and future work for Jay's group also involves application of this method in beach water samples in Tijuana, Mexico.
The UCLA Henry Samueli School of Engineering and Applied Science, established in 1945, offers 28 academic and professional degree programs, including an interdepartmental graduate degree program in biomedical engineering. Ranked among the top 10 engineering schools at public universities nationwide, the school is home to eight multimillion-dollar interdisciplinary research centers in wireless sensor systems, nanotechnology, nanomanufacturing and nanoelectronics, all funded by federal and private agencies.
For more news, visit the UCLA Newsroom and follow us on Twitter.
Matthew Chin | EurekAlert!
Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel
Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences