Photo: Michael Macor, SFC
New
UC Davis study finds significant amount of synthetic clothing fibers in
fish caught off Northern California and sold at markets for public
consumption.
A significant amount of synthetic clothing fibers have been
found inside fish caught off the Northern California coast and ending up
on local dinner plates, according to a new study by environmental
scientists at UC Davis.
About a quarter of the 64 fish purchased at fish
markets in Half Moon Bay and Princeton and analyzed for the study turned
out to have bits of synthetic clothing in their guts, said lead
researcher
Chelsea Rochman, of the
UC Davis School of Veterinary Medicine.
The study, published Thursday in the journal of Scientific Reports, came on the heels of research by the
San Francisco Estuary Institute
that found the surface of San Francisco Bay to be heavily contaminated
with plastic microbeads from cosmetics and plastic fibers from clothing.
In the UC Davis study, scientists randomly bought
locally-caught fish at markets and dissected their guts at a laboratory
in Davis. Plastic clothing fibers were found in the guts of about
one-fourth of the smelt, anchovy, rockfish, bass, salmon, sanddab, cod
and oysters.
Inadequate filtering by home laundry users and sewage
treatment plants is suspected of being the source of the contamination,
Rochman said.
“This shows we have a waste management problem that is coming back to haunt us,” Rochman said.
Plastic fibers, Rochman said, were only one of many
contaminants that get inside fish and were probably less hazardous than
mercury, PCBs and other known fish contaminants.
“This study doesn’t make me afraid of eating fish,”
said Rochman, a fish fan who dined on oysters twice last week. “The
health benefits outweigh the hazards of my being contaminated with
microplastics.”
The scientists also analyzed fish purchased at a
market in Indonesia and found that they were contaminated with plasic
debris fragments but not with synthetic fibers.
A study released Wednesday by the San Francisco
Estuary Insitute found that the San Francisco Bay is hundreds of times
more contaminated than the Great Lakes with small plastic particles from
cosmetics and synthetic clothing.
The report also found the small
microbeads and other pollutants are gobbled up by fish, whose guts
contain far more of the toxic stuff than their fellow Great Lakes fish.
In January, researchers took water samples from
different spots in San Francisco Bay and analyzed the results. They
found that the waters of the South Bay contained 2.6 million
microplastic particles of 5 millimeters or smaller per square mile,
compared with 285,000 in Lake Erie, 13,000 in Lake Superior and 7,800 in
Lake Huron.
The two studies were released shortly after the
California legislature passed a bill to regulate microplastics in
cosmetics. That bill is awaiting action by the governor.
Steve Rubenstein is a San Francisco Chronicle staff writer. E-mail: SRubenstein@sfchronicle.com Twitter: @SteveRubeSF