National Geographic News
Synthetic fragrances commonly added to perfumes, soaps, shampoos, and dozens of other personal health care products are proving harmful to the marine environment and potentially to humans as well, according to marine scientists.
Also known as synthetic musks, the chemical compounds reportedly compromise a cellular defense mechanism that normally prevents toxins from entering cells. The mechanism is controlled by efflux transporter proteins embedded in cell membranes.
"Efflux transporters are like bilge pumps in a ship. Another analog is bouncersthese guys at the nightclub," said Till Luckenbach, a postdoctoral fellow at Stanford University's Hopkins Marine Laboratory in Pacific Grove, California.
The transporters recognize and pump out many kinds of toxins from cells, but if too many chemicals are around, the capacity of the transporters can be overwhelmed.
This is a potential danger in the presence of foreign compounds such as synthetic fragrances, Luckenbach said. The fragrances themselves are nontoxic, but by overwhelming the cellular bouncers, the fragrances allow unwanted toxins to slip by and contaminate the cell.
According to Luckenbach, this is a novel mechanism by which a wide range of presumably nontoxic chemicals could have a negative impact on plants and animals.
Together with Stanford biology professor David Epel, Luckenbach demonstrated the effect of these synthetic fragrances in experiments on California mussels.
Mussel cells share properties with some human cells, such as the cells found in a barrier that prevents toxins from entering the brain, Luckenbach said.
"We can't conclude that these [compounds] are having the same effect on humans, but we think it's something we should test," he said.
Luckenbach and Epel published their findings this January in Environmental Health Perspectives, a journal of the U.S. National Institutes of Health.
According to Luckenbach, wastewater treatment plants fail to break down synthetic musks, allowing the compounds to spill into rivers and oceans via sewage discharge.
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