{Yet another reason to be a vegetarian, or a vegan. Rick.}
Waiting for the DDT tide to turn
Federal study shows that fish caught off L.A. County still contain the
world's highest levels of the pesticide 35 years after it was banned.
By Marla Cone, Times Staff Writer
January 28, 2007
Many fish caught off Los Angeles County still contain extremely high
levels of DDT, a sign that anglers and consumers remain at risk and that
the ocean's ecosystem may be far from recovery 35 years after the
pesticide was banned.
Newly released data from a federal survey indicate that fish caught in
the area contained the world's highest-known DDT concentrations. Among
1,200 fish caught from Ventura to Dana Point, white croaker off San
Pedro and the Palos Verdes Peninsula were the most highly contaminated.
Fish off Orange County and areas north of the Redondo Beach Pier had low
concentrations.
The data, collected primarily in 2002, offer the most comprehensive
look at the scope of contamination from a 100-ton deposit of DDT that
still covers several square miles of the ocean floor decades after the
pesticide flowed into county sewers beginning in the late 1940s.
More recent annual sampling by Los Angeles County, far less extensive
than the federal survey, suggests that the DDT levels in fish may be
improving but still far exceed safe levels.
In response to the new federal findings, the state's environmental
health agency is reevaluating the risks of eating locally caught fish,
which could result in updates to a health advisory and a commercial fishing
ban that have been in effect since 1991.
Fish from local waters are often eaten by recreational anglers and
subsistence fishermen, who catch them from piers and boats. Some highly
contaminated white croaker is still showing up in a handful of Asian
markets in Los Angeles and Orange counties.
The levels "are lower than what we historically have seen" in the 1970s
and '80s, "but they are still levels of concern to us," said Sharon
Lin, a Superfund project manager at the Environmental Protection Agency's
San Francisco office.
Banned in the United States in 1972, DDT is classified as a probable
human carcinogen and has been linked to liver disease, reproductive
damage and altered hormones in lab animals and wildlife. So much DDT remains
in bald eagles on Santa Catalina Island that their chicks die unless
the weakened eggs are removed from the island to hatch.
The data from the federal survey by the National Oceanic and
Atmospheric Administration and the Environmental Protection Agency suggest that
there has been no improvement since the late 1980s, when the last
regional fish survey was conducted. Some scientists have long theorized that
the DDT on the ocean floor has been breaking down into less-toxic
compounds and would soon disappear from marine life.
Yet at least through 2002, when most of the fish were caught for the
survey, the DDT â as well as industrial compounds called PCBs, or
polychlorinated biphenyls â remained a threat to people eating white
croaker and several other species of local fish, particularly in waters off
the Palos Verdes Peninsula and in San Pedro Bay.
"Things have not changed a whole lot in the last decade or so," said
David Witting, a National Oceanic and Atmospheric Administration fish
biologist who directed the survey. "The biggest concern is still lower
Santa Monica Bay, Palos Verdes Shelf and much of San Pedro Bay. The
species that is consistently the most highly contaminated is still white
croaker."
Manufacturing pesticides at a plant near Torrance from 1947 to 1971,
the Montrose Chemical Co. released about 2,000 tons of DDT into county
sewers, which empty into the ocean via an outfall off White Point on the
Palos Verdes Peninsula. The pesticide adheres to sediment and continues
to seep into marine creatures.
Mark Gold, executive director of the Santa Monica-based environmental
group Heal the Bay, said the scope of the contamination revealed by the
new fish data was worse than he thought.
"Not only have things not improved for contaminated fish off Palos
Verdes, but this data shows that the concern is more far-ranging than we
originally thought," Gold said. "Hot fish off Palos Verdes is no
surprise, but we're finding hot fish all the way from the Redondo Pier
throughout San Pedro Bay, and it's for a wide variety of species, not just the
bottom-dwelling ones."
The goals of the survey are to update health advisories on which fish
are unsafe to eat and to help the EPA decide whether to attempt to seal
off the ocean deposit with a thick cap of sand, which could cost tens
of millions of dollars.
In addition to white croaker â which feeds on the ocean floor â
kelp bass, barred sandbass, scorpionfish and rockfish also contained some
high levels above half a part per million.
The highest readings were in white croaker from the middle of San Pedro
Bay â about 1.5 miles offshore in an area called Horseshoe Kelp â
and near the Cabrillo Pier, half a mile beyond the breakwater. The
average at Horseshoe Kelp was 3.2 parts per million of DDT, with one fish
reaching almost 13 ppm.
Generally, 10% of the white croaker caught in San Pedro Bay were highly
contaminated while the rest had lower levels. The "hot" ones probably
migrated from the DDT deposit off White Point, Witting said.
Waters at the southern end of Santa Monica Bay, between Redondo Beach
and Palos Verdes Estates, also had some highly contaminated croaker and
barred sandbass. Pacific mackerel, opaleye and jacksmelt had the lowest
concentrations.
All fish caught off Ventura County â even white croaker â had
little contamination, and low levels also were found in fish off Long Beach,
Seal Beach and Huntington Beach.
Derek Muir, a global contamination expert at Canada's National Water
Research Institute, said the amounts found in the white croaker were
"definitely the highest DDT that I have seen in any fish." He suspects they
are so high that the fish have liver damage. In a new U.S. sampling of
fish in 500 freshwater lakes and reservoirs, the worst DDT level was
just under 1.5 ppm, about eight times lower than the peak found in San
Pedro Bay.
In the past, the state has used 100 parts per billion of DDT as the
threshold for acceptable cancer risk from eating fish. One of every
100,000 people who regularly eat such fish could contract cancer. The amount
found in the average San Pedro Bay croaker was 30 times higher than
that threshold.
Some of the most contaminated fish finds its way into local residents'
kitchens, despite 15 years of health advisories and fishing
restrictions.
One white croaker sold in an Asian market in Monterey Park contained
nearly 12 ppm of DDT, virtually the same as the most contaminated fish
caught in the federal survey.
But outreach programs spearheaded by the EPA and Heal the Bay
apparently are working.
Ten years ago, a survey by the environmental group found that
contaminated white croaker was plentiful in all Asian markets. But of 68 Asian
markets in Los Angeles and Orange counties that the EPA surveyed in 2004
and 2005, only six sold white croaker. "The availability has gone down
markedly, but the bad news is: The levels are just as high as they were
in 1997," Lin said.
The last comprehensive fish survey prompted the state in 1991 to issue
a health advisory for people eating local fish and a no-take zone for
commercial fishing.
Most local fish are healthy to eat, but the advisory warns people to
watch the types eaten and where they are caught.
People should never eat white croaker from near White Point or the Los Angeles
and Long Beach harbors, particularly the Cabrillo Pier, the
advisory says. Other fish from the San Pedro and Long Beach harbor area
â including surfperch, rockfish, queenfish, scorpionfish and kelp bass
â should be eaten no more than once or twice a month, depending on
the location.
Commercial fishing of white croaker is banned in a relatively small
area, a 15-mile stretch off the Palos Verdes Peninsula.
Robert K. Brodberg, chief of fish and water quality evaluation at the
Office of Environmental Health Hazard Assessment, said the agency will
launch a reevaluation of the health risks this year, as soon as a
federal report detailing the new data is complete. The aim is to develop new
fish consumption recommendations and advise the Department of Fish and
Game in updating its commercial no-fishing zone.
The recommendation is expected to come next year. Brodberg would not
say what levels of DDT and PCBs would be considered safe, because, he
said, it would require complex formulations involving how much people eat.
In the meantime, he said, anglers and consumers should follow existing
health advisories.
County sanitation officials, who annually test fish off the Palos
Verdes Peninsula, said conditions may have improved at the DDT deposit in
the four years since the federal survey was conducted. For two straight
years, average DDT concentrations in white croaker there declined
dramatically, from 33 ppm in 2002 to 4 ppm in 2005 â still a worldwide
high.
David Montagne, supervising environmental scientist at the Los Angeles County
Sanitation District, said that at least another year of data is
needed before officials could be confident that the drop was permanent
and not a temporary flux.
"The trend we see â and we don't know if it's real or not â
suggests that concentrations over the area of greatest DDT contamination are
dropping," he said. If that proves to be true, Montagne said, it
supports the theory that the pesticide is degrading to less toxic compounds.
*
--------------------------------------------------------------------------------
[EMAIL PROTECTED]
*
(INFOBOX BELOW)
Toxic fish
A new federal survey of 1,200 fish shows that white croaker caught off
San Pedro and the Palos Verdes Peninsula are highly contaminated with
the pesticide DDT from a decades-old deposit on the ocean floor. Fish
caught off Orange County and north of the Redondo Beach Pier had low
concentrations.
DDT concentrations in white croaker
(in parts per million of fish tissue)
Readings from individual sites*
1.
Median: 0.28
Maximum: 0.87
2.
Median: 0.80 Maximum: 3.6
3. Median: 1.8 Maximum: 6.8
4.
Median: 0.74 Maximum: 1.4
5. Median: 3.2 Maximum: 11.1
6.
Median: 0.07
Maximum: 0.17
7. Median: 2.5 Maximum: 12.7
---
Averages by decade**
1970s Median: 11.5
Maximum: 51.5
---
1980s Median: 7.4
Maximum: 101
---
1990s Median: 8.6
Maximum: 135
---
2000s Median: 5.8
Maximum: 78.8
---
* Measurements from fish mostly collected in 2002
** Averages for each decade are for fish tested next to the DDT deposit
off Palos Verdes Peninsula, the most contaminated area. Covers 1971 to
2005. Different testing methods were used in the 1970s and 1980s, so
comparisons to later years are approximate.
Which locally caught fish are safe to eat:
oehha.org/fish/so_cal/socalpddp.html
Sources: EPA, NOAA, Los Angeles County Sanitation District
---------------------------------
TV dinner still cooling?
Check out "Tonight's Picks" on Yahoo! TV.
