Navigation Links
Beach pollution is worst during new and full moon

A new study of 60 beaches in Southern California suggests that water pollution varies with the lunar cycle, reaching the highest levels when tides are ebbing during the new and full moon. The findings could help beachgoers and managers better assess the potential risk of swimming.

The report appears in the Aug. 1 issue of the American Chemical Society's journal Environmental Science & Technology. ACS is the world's largest scientific society.

Coastal water quality is controlled by a number of complex physical and biological factors, including tidal cycles and seasonal rainfall. This complexity makes beach water monitoring difficult, with levels of bacteria in a certain area changing in just a few minutes.

For the new study, the researchers examined monitoring data compiled for beaches throughout Southern California, keeping track of tidal patterns and analyzing them for concentrations of enterococci -- bacteria that allow scientists to estimate the risk of illness from swimming in marine waters. "This is the largest array of beaches examined at the same time for a similar pattern," says Alexandria Boehm, Ph.D., an environmental engineer at Stanford University and lead author of the study.

She and her colleagues at the Southern California Coastal Water Research Project found that in the full and new phases of the moon, levels of enterococci were higher at the vast majority of the beaches studied. Boehm found that during so-called "spring tides," when water levels vary the most between high and low tides, a beach is twice as likely to be out of compliance with water quality standards. Spring tides are exceptionally high or low tides that take place during the full and new moons, but have nothing to do with the season of the year.

The results are of immediate practical use to swimmers and beach managers alike, according to Boehm. "The general public can use the phase of the moon and the tide stage to assess the relative risk o f illness," she says. "It is riskier to swim during spring-ebb tides [receding tide] compared to all other tidal conditions."

Beach managers can now use tides as they currently use rainfall to assess warnings, Boehm suggests. When it rains, managers recommend that swimmers not enter the water for three days. "They could also suggest that during spring tides -- and especially spring-ebb tides -- water quality is more likely to be impaired, and those who are risk-averse should avoid swimming," Boehm says.

The results might also help managers identify potential sources of pollution at beaches. "Most sources of enterococci at beaches are unknown," Boehm says. "Because we found tidal signals in enterococci densities at beaches with no obvious point source, like storm drains and creeks, this suggests that there is a widespread tidally forced source of enterococci at beaches."

Boehm suggests several candidates for this "mystery" source, including beach sands, decaying plant material and polluted groundwater. "Beach sands and wrack [piles of seaweed and animal remains that wash ashore] have been shown at freshwater beaches to harbor fecal indicator bacteria and even pathogenic bacteria," Boehm says. "Beach managers who want to improve water quality at their beaches should investigate the potential of these sources to be contributors of enterococci to marine waters."

Boehm cautions that enterococci from beach sands and wrack may not correlate with health risk the same way as enterococci from runoff or sewage. "We just don't know for sure, since no one has done an epidemiological study to connect human illness to enterococci from non-point sources other than runoff," Boehm says. "We need to do additional work to understand the source of enterococci at all these beaches."


Source:American Chemical Society

Related biology news :

1. UN environmental agency steps up battle against marine pollution
2. Global warming increases oyster sensitivity to pollution
3. Toxic flood lifts lid on common urban pollution problem
4. Study uncovers dirty little secret: Soil emissions are much-bigger-than-expected component of air pollution
5. Sensor web simulation investigates technique to improve prediction of pollution across the globe
6. A radical solution for environmental pollution
7. NCAR analysis shows widespread pollution from 2004 wildfires
8. Researchers show how air pollution can cause heart disease
9. York researchers develop pollution-busting plants to clean up contaminated land
10. Record air pollution above the Arctic
11. High hourly air pollution levels more than double stroke risk
Post Your Comments:

(Date:4/28/2016)... FRANCISCO and BANGALORE, India , ... of EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... provider, today announced a global partnership that will ... way to use mobile banking and payment services. ... is a key innovation area for financial services, but it ...
(Date:4/15/2016)... , April 15, 2016  A new ... make more accurate underwriting decisions in a fraction ... timely, competitively priced and high-value life insurance policies ... screenings. With Force Diagnostics, rapid testing ... lifestyle data readings (blood pressure, weight, pulse, BMI, ...
(Date:3/31/2016)... R.I. , March 31, 2016  Genomics firm ... of founding CEO, Barrett Bready , M.D., who ... members of the original technical leadership team, including Chief ... President of Product Development, Steve Nurnberg and Vice President ... returned to the company. Dr. Bready served ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... 27, 2016 , ... Cancer experts from Austria, Hungary, Switzerland, ... a new and helpful biomarker for malignant pleural mesothelioma. Surviving Mesothelioma has just ... now. , Biomarkers are components in the blood, tissue or body fluids ...
(Date:6/27/2016)... 2016  Liquid Biotech USA ... a Sponsored Research Agreement with The University of ... from cancer patients.  The funding will be used ... with clinical outcomes in cancer patients undergoing a ... be employed to support the design of a ...
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial ... Cary 5000 and the 6000i models are higher end machines that use the more ... the spectrophotometer’s light beam from the bottom of the cuvette holder. , FireflySci ...
(Date:6/23/2016)... , June 23, 2016   Boston Biomedical ... novel compounds designed to target cancer stemness pathways, ... been granted Orphan Drug Designation from the U.S. ... of gastric cancer, including gastroesophageal junction (GEJ) cancer. ... designed to inhibit cancer stemness pathways by targeting ...
Breaking Biology Technology: