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.
Researchers will next examine whether viruses are present in the sand,
she said.
Mark Gold, executive director of Santa Monica-based Heal the Bay, said
the study adds urgency to beach cleanup efforts and could lead to more
health warnings posted along the shore.
Heal the Bay on Wednesday plans to release a list of the most polluted
California beaches.
Source: Associated Press
|