California scientists hope studying 180 black mussels pried from algae-covered rocks in San Francisco Bay will provide clues into how many drugs and chemicals are polluting waters across the nation.
Mussels filter water and store contaminants in their tissue, providing a record of pollution in the environment. The creatures are being culled from 80 sites in California as part of a pilot study by the National Oceanic and Atmospheric Administration to see how pervasive the substances have become.
"We haven't measured mussels for these compounds, so there's not a lot of data," said Dominic Gregorio, a senior environmental scientist with the State Water Resources Control Board. "So this is really a first step to be proactive and get ahead of the curve on this."
Regulators are concerned about an array of chemicals and pharmaceuticals — synthetic estrogen used in birth control pills, anti-bacterial agents in hand sanitizers and a flame retardant used on computers, furniture and cars — that can accumulate in the tissue of animals and people. Recent studies found levels of PBDEs, or polybrominated diphenyl ethers, a flame retardant used in the manufacture of a wide range of consumer products, in waters off of every U.S. coast.
The chemicals are being detected more often in surface water, state water quality officials said, but little data exists about how these substances negatively effect the health of humans and animals.
After conducting tests on the mussels, the data will help guide the study of emerging contaminants in other states, said Gunnar Lauenstein, program manager for NOAA's Mussel Watch, which has tested mussels since 1986.
Traces of PBDEs have also been found in human breast milk, aquatic birds and fish in North America, Europe and Asia, according to the U.S. Environmental Protection Agency.
Until now NOAA's Mussel Watch has tested the bivalves for pollutants like the pesticide DDT. This pilot study could help guide regulators in determining what new pollutants in mussels should be regularly monitored.
"What we're trying to do now is focus on a newer generation of consumer products," Lauenstein said.
The California mussels will also be tested for bisphenol A, or BPA, a chemical used to harden plastics and line the cans of baby formula and other foods.
Scientists are concerned that BPA exposure may harm reproductive systems and promote prostate and breast cancers, though the Centers of Disease Control and Prevention says human health effects of BPA exposure are still unknown.
Gregorio said the data collected from around the state will include mussels from a wide range of areas including cities, agricultural regions and open spaces.