JUDY WOODRUFF: Marine scientists say they have identified in the Pacific Ocean more
than 25,000 barrels that they believe contain the toxic chemical DDT.
A massive underwater toxic waste site dating back to World War II has long been suspected
off the shore of Southern California, given industrial companies had used the ocean as
a dumping ground there until 1972.
But, as Stephanie Sy, the magnitude of this problem was not previously known.
STEPHANIE SY: That's right, Judy.
Staggering, overwhelming, that was how researchers describe the amount of these potentially toxic
barrels they mapped in a survey last month. The Scripps Institution of Oceanography team
used autonomous underwater vehicles and sonar to survey 36,000 acres of a dump site that
lies between the coast off Los Angeles and Catalina Island.
For decades, researchers have detected high levels of DDT in marine mammals, including
dolphins. Sea lions in the area have died of an aggressive cancer.
For a deeper look at the impact of the discovery, I'm joined by U.C. Santa Barbara professor
of microbiology David Valentine, who first identified dozens of these DDT barrels nearly
a decade ago.
Professor Valentine, thank you for joining the "NewsHour."
So, what do you make of these new findings? Do they further validate your suspensions
about this dump site, from dozens of barrels that you found 10 years ago to tens of thousands?
DAVID VALENTINE, UCSB Marine Science Institute: Thank you, Stephanie, for having me.
And, yes, this is an important piece of information that we simply lacked before, now knowing
that 27,000 barrel-like objects were present in a survey area that is still not the full
scope of where dumping likely occurred.
So, to me, this is an indication that we have a real problem going on down on the seafloor
there.
STEPHANIE SY: You shared photos with us. And you can see that some of the barrels are corroded.
Could some, Professor Valentine, still be leaking? And what do we know about how these
old chemicals are still impacting the environment and animal life?
DAVID VALENTINE: Yes, when we were working at the site in 2011, and then again in 2013,
we observed all sorts different barrels of different shapes and sizes, and some of them
were heavily decomposed.
Some of them appeared to be at least somewhat intact. And so we don't know that proportionality.
What we do know is some of the material, these DDT wastes, did escape containment and were
present in the sediments even away from barrels at concentrations that were extremely high.
So, we know that there's this escape of containment. And we know that these materials are there
and can potentially get back into animals in the ecosystem.
STEPHANIE SY: You said we don't even know now the full extent of this dump site. One
of the Scripps scientists said it was more than twice the size of Manhattan that they
surveyed, and it continued.
I have read that there could be hundreds of thousands of these barrels. Other than studying
all of this, Professor Valentine, is there anything that can be practically done to address
it?
DAVID VALENTINE: Well, I think you touch on an important point.
You know, we know that there's now at least tens of thousands, and likely hundreds of
thousands, of objects down there, many of which are barrels. And there is quite a bit
of study that we do have to do in order to get to the point where we can really address
the question of, what can we do to clean this up?
And I think, until we understand the full scope of the problem, we can't really lay
out all of our options, because there are things that happen naturally in the ocean.
Microbes can break these things down under the right circumstances. They can get buried
long term.
We don't know the extent to which those things may or may not be happening with these wastes.
And I think we need to know that before we can really chart the path forward.
STEPHANIE SY: But you and other researchers did meet with Senator Dianne Feinstein to
brief her on the data just yesterday. What is your ask from her and others in Congress?
DAVID VALENTINE: Well, our ask is that we need the support from the federal government
to really understand what is happening in this environment.
You know, I think we're seeing the tip of the iceberg right now. We know there's 27,000
barrels, but we don't know what's in each and every one of those barrels. We know there's
DDT, but we don't know quite what else is down there.
So, we need to figure out, just how much are we dealing with, how much is there, and what
are the processes that are active in moving this stuff around, in the transport and transformation,
and then what are the effects?
And those are -- that's the ask, is to work with the scientific community, to have the
federal government work with the scientific community, in order to push this forward and
get that understanding that we can use to chart the path forward.
STEPHANIE SY: Marine biologists have detected DDT in animal life around the Los Angeles
area off the coast there for decades.
They have seen require aggressive cancer among sea lions, and yet the attention seems relatively
recent. You have been trying to get people to care about this issue for a while. Why
the sudden attention?
DAVID VALENTINE: You know, I think a lot of it has to do with the release of images and
video.
And we came across this site back in 2011, and it took us years to work up and understand
what we were really seeing and to publish something in the scientific peer-reviewed
literature that really paved a way for our understanding. And in doing that, we also
released the video and images to go along with it.
That all triggered an investigative report by Rosanna Xia of The L.A. Times. And I think
that has created the public interest, now that we have knowledge to back up that imagery
and we can say something about what's really going on down there.
STEPHANIE SY: A toxic legacy that we are only now beginning to fully grasp.
David Valentine with U.C. Santa Barbara, thank you so much for sharing your expertise with
us.
DAVID VALENTINE: Thank you for having me, Stephanie.