STANFORD, Calif., Aug. 1 (UPI) -- A study of 60 Southern California beaches suggests water pollution varies with the lunar cycle, reaching the highest levels during the new and full moon.
The researchers say their findings might help beachgoers and managers better assess the potential risk of swimming.
The scientists examined monitoring data compiled for beaches across 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, an environmental engineer at Stanford University and lead author of the study.
She and her team found that in the full and new phases of the moon, levels of enterococci were higher at the vast majority of the beaches and 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.
The report appears in the current issue of the American Chemical Society's journal Environmental Science & Technology.
