Environmetal Science & Technology (Vol. 40, Iss. 5)
March 1, 2006

THE CLOUDY SIDE OF SUNSCREENS

Tasha Eichenseher

In a study published in this issue of ES&T (pp 1427-1431), a team of
scientists report high concentrations of two sunscreen ingredients in
fish tissue samples taken from rivers in northern Switzerland. The
findings imply that on a hot summer day, chances are that if people
are wearing sunscreen, it's also likely to be in their drinking water
or fish dinner.

Both Europe and the U.S. have consumer-protection guidelines for many
UV-inhibitor products, such as sunscreen lotions, lip balms, and
cosmetics. However, regulatory agencies are well behind the curve on
the environmental risks they pose. Many of the lotions, lip balms, and
other cosmetics that we slather on to protect us from the deleterious
effects of too much sun exposure contain chemical compounds that
absorb ultraviolet (UV) radiation. When people swim, the UV filters in
these products can be transferred from their skin into lakes and
streams. The chemicals also wash off in the shower and are funneled to
wastewater treatment plants, where traces can escape via treated
effluent into the environment. However, although consumer-protection
guidelines are in place for many of these UV-inhibitor products in
both Europe and the U.S., regulatory agencies have placed less
emphasis on the environmental risks that they pose.

Annual production figures for UV filters are estimated in the hundreds
of metric tons, according to a previous study on the chemical contents
of wastewater by the new study's corresponding author Marianne Balmer.
She conducted this latest study with a team of chemists at the Swiss
agriculture department's federal research station (Agroscope FAW) in
W├ndenswil and the Swiss Federal Laboratories for Materials Testing
and Research's Laboratory of Organic Chemistry in D├╝bendorf.

All of the 19 fish tested in the recent study had traces of 2 of the
most commonly used UV filters in Europe: 4-MBC (4-methylbenzylidene
camphor) and OC (octocrylene). Both chemicals biodegrade slowly and
can bioaccumulate, according to the researchers.

Compared with another FAW study that analyzed fish from remote Swiss
mountain lakes, the river fish accumulated much higher concentrations
of both chemicals. Lipid-weight-based concentrations of 4-MBC in the
lake species whitefish (Coregonus) and roach (Rutilus rutilus) ranged
from 20 to 170 ppb. The brown trout (Salmo trutta fario) from the
rivers tested in the current study had concentrations ranging from 50
to 1800 ppb. OC was mostly absent in the lake fish but was found in
the river fish at concentrations from 40 to 2400 ppb.

The nearly 10-fold difference in concentrations among lake and river
fish sheds light on the environmental transport and fate of these
chemicals. "The study shows that UV filters were present in fish from
rivers that receive inputs of wastewater," says Hans-Rudolf Buser, one
of the report's coauthors. "One might argue, therefore, that aerial
transport is not a major pathway for the presence, or the
distribution, of UV filters in the environment and fish."

The Swiss government's work takes research on pharmaceuticals and
personal care products (PPCPs) in the environment to the next level in
the U.S., says Dana Kolpin, a hydrologist with the U.S. Geological
Survey (USGS). Although the U.S. EPA does not regulate any personal
care products and 4-MBC and OC are not currently on USGS's monitoring
list, Kolpin says that Balmer's work will help USGS decide how to
prioritize further study on specific PPCPs. USGS is modifying its
sediment analysis method to include some UV inhibitors and will soon
establish a new monitoring protocol for these substances in water, he
adds.

4-MBC is a known endocrine disrupter and was detected in human milk in
a 1997 study in Germany, according to Margret Schlumpf, a toxicologist
at the University of Zurich's Group for Reproductive, Endocrine, and
Environmental Toxicology, which researches the health effects of UV
filters. In studies with rats, Schlumpf has shown that some UV
filters, including 4-MBC at levels as low as 7 mg per kg of body
weight each day, can alter reproductive function and affect birth
weight and postnatal survival rates. The significantly higher
concentrations in river fish reported in the new study are shocking,
she says, and will help further her research.

But industry sources maintain that UV filters do not produce harmful
endocrine-disruption effects. Industry studies on the health impacts
and environmental fate of both 4-MBC and OC, which are currently under
review by EU officials, have shown that there is no risk of these
chemicals contaminating the food chain at harmful levels, according to
Gerald Renner, director of science and research at the European
Cosmetic Toiletry and Perfumery Association.