Clean water can still yield polluted sand
Sand Can Be Polluted Even with Clean Water
May 24, 2006 By Associated Press
LOS ANGELES Beach sand can be teeming with bacteria even
when the ocean water is clean, according to a study
released on Tuesday.
Health officials have long known that urban runoff
pollutes ocean water with microbes including E. coli and
enterococci bacteria found in fecal material. The study by
University of California, Los Angeles researchers found
microbes can grow in the sand as well, and remain there
long after the ocean has flushed itself clean.
“Even on days when the water is very clean, bacteria is
still in the sand for a week,” said Jennifer Jay, a UCLA
environmental engineering professor who headed the study.
“We feel it can be an important exposure route” for
contamination.
Jay and a graduate researcher tested three beaches —
Surfrider Beach in Malibu, Santa Monica Beach and Mother’s
Beach in Marina del Rey — during a storm in February
2003. They also surveyed sand at 13 Santa Monica Bay
beaches from Malibu to Redondo during the summer, focusing
on wet sand near the water’s edge.
They found that sand bacteria concentrations at sheltered
beaches favored by parents with toddlers were 1,000 times
higher than at beaches that were open to the ocean.
However, Jay said it’s hard to evaluate the health risk
these bacteria pose because health standards for beach
sediment have not been developed.
