Writing in the NIH journal Environmental Health Perspectives, Stanford scientists described the biological damage that occurred when they exposed California mussels to synthetic musks--chemical compounds that are used to enhance the smell of detergents, soaps, shampoos, air fresheners, deodorants, cosmetics and other personal care products.

"Synthetic musks can be easily produced and are very cheap," said Stanford postdoctoral fellow Till Luckenbach, lead author of the study. "They get into the environment through sewers and drains, but wastewater treatment plants are not equipped to handle them."

First line of defense

In their study, Luckenbach and Stanford biologist David Epel tested six synthetic musk compounds widely used by industry. Their goal was to determine if these artificial fragrances affected the animals' "xenobiotic defense system"--a biochemical process that allows cells to get rid of poisons and other foreign substances.

"This is the first line of defense used by all cells," said Epel, the Jane and Marshall Steel Jr. Professor of Marine Sciences. "It consists of a special protein, called an efflux transporter, that's embedded in the cell membrane and pumps out toxins that get into the cell."

For the experiment, gills were carefully sliced from living mussels and placed in water containing very low concentrations of synthetic musks--300 parts per billion or less. After two hours, the gills were removed and washed.

To see if this short-term exposure affected the animal's defense system, the gills were placed in musk-free water with a special red fluorescent dye. Under normal con
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Contact: Mark Shwartz
mshwartz@stanford.edu
650-723-9296
Stanford University
28-Oct-2004