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Selected tag(s): BP Oil disaster

No disappearing act: Dispersant ingredient lives on months after BP oil disaster

By / Published: January 31, 2011

Richard Denison, Ph.D., is a Senior Scientist.

Remember that old naïve saw, “Dilution is the Solution to Pollution”?   When it comes to the dispersants used last year to address the Deepwater Horizon disaster in the Gulf of Mexico, that axiom appears to be the operative mechanism.

Last week, researchers at Woods Hole Oceanographic Institute published data showing that a key component of the Corexit dispersant used by BP to address the oil spill, did not degrade – as had been predicted by just about everybody, including BP, the Coast Guard, the dispersant manufacturer Nalco and EPA.  In fact, it was still detectable when last looked for in September, 5 months after the spill began and at least two months after use of dispersants had ceased. Read More »

Posted in Environment, Health science / Also tagged | Comments are closed

New EPA data: Dispersant likely not increasing acute lethality of oil in BP oil disaster

By / Published: August 2, 2010

Richard Denison, Ph.D., is a Senior Scientist.

I had reported in an earlier post – based on data provided to EPA by Nalco, the maker of Corexit® 9500, the main dispersant being used in the Gulf – that the dispersant appeared to increase the acute aquatic toxicity of oil.

At a press conference today, EPA released data from the second round of its own testing on Corexit 9500 (and seven other dispersants), and concluded that the acute toxicity of the dispersant-oil mixture is about the same as the oil by itself.

What explains the discrepancy?  To put it most simply:   It’s not that the dispersant-oil mixture was less toxic in the EPA tests, it’s that the oil EPA used – which is the actual oil that has been leaking into the Gulf – was more toxic than the fuel oil Nalco had used.  Here’s a cartoon illustrating what I’m saying (the arrow shows the biggest change):

So the good news is that the dispersant doesn’t appear to be increasing the acute aquatic toxicity of the oil released into the Gulf.  The bad news is that the oil is pretty toxic, and the dispersant certainly doesn’t help directly with that.  And of course, the bigger questions about longer-term effects of dispersants and dispersed oil are not addressed by the new data.   Read More »

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Exceptions swallow the rule: “Rare cases” turn into daily approvals for dispersant use

By / Published: July 7, 2010

Richard Denison, Ph.D., is a Senior Scientist.

What the EPA hath sought to take away from BP, the US Coast Guard hath given back.

Remember the May 26 Directive that, well, directed BP to “eliminate the surface application of dispersants” except in “rare cases when there may have to be an exemption” and where BP submits a written request and receives an exemption in writing from the Federal On-Scene Coordinator (FOSC, currently Admiral James Watson of the Coast Guard)?

Naturally, I was curious about the nature and number of such exemptions, given that, as I noted earlier, surface application of dispersants has continued since the May 26 Directive.  After I (and others, I expect) made inquiries a couple of weeks ago to get copies of the written requests from BP and written approvals from the FOSC, the Coast Guard has informed me that it has posted these documents on the Deepwater Horizon response website.

These documents reveal that, as of June 30 (the last day for which a document has been posted as of this writing), more than 40 exemption requests have been submitted – and approved.  These exemptions have allowed surface application of dispersant to occur virtually every day since the Directive was issued.

The documents also hold some other interesting details as to the rationales offered for the exemptions and the nature of the approvals.  Read More »

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Not so fast: Why dispersants EPA ranks as “practically non-toxic” are still a concern

By / Published: July 2, 2010

Richard Denison, Ph.D., is a Senior Scientist.

To judge by the headlines and leads of stories that ran on the websites of the New York Times (“The E.P.A. on Dispersants: Cure Is Not Worse Than the Disease”) and the Washington Post (“Oil dispersant does not pose environmental threat, early EPA findings suggest”) reporting on an EPA conference call held Wednesday, you’d think the first round of test results on dispersants conducted by EPA answered all outstanding questions and gave their use a clean bill of health.

Hardly.  (Despite the misleading headlines and leads, the rest of these stories were more nuanced and more accurate.)

As I reported in a post Wednesday, the new acute toxicity data were from tests conducted on the dispersants by themselves, rather than mixed with oil – which is what the environment sees.  Moreover, the new data did little more than confirm already available data showing that currently listed dispersants exhibit relatively low acute toxicity to fish and shrimp, and that by themselves they are less toxic than oil by itself.

So despite the hoopla, the new data from this first round of testing are of very limited utility in answering any of the more profound questions surrounding the use of dispersants.  Read More »

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Katrina chronicles meet the BP oil disaster: Formaldehyde-laced trailers are back in the Gulf

By / Published: July 1, 2010

Richard Denison, Ph.D., is a Senior Scientist.

In another truly bizarre collision between recent Gulf coast disasters (on top of Hurricane Alex), Ian Urbina of the New York Times reports on the front page today that those toxic trailers – sold at auction by FEMA back in March – have been reincarnated once again, this time as housing for Gulf cleanup workers.

I had blogged about the sale at the time, questioning the viability of FEMA’s assurance that “wholesale buyers from the auction must sign contracts attesting that trailers will not be used, sold or advertised as housing, and that trailers will carry a sticker saying, ‘Not to be used for housing’.”  In that post, I had cynically asked:  “Think that’s likely to be enough?”

With good reason, it turns out.  Read More »

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Hurry up and wait: Not much new revealed by EPA’s initial round of dispersant toxicity testing

By / Published: June 30, 2010

Richard Denison, Ph.D., is a Senior Scientist.

EPA held a press call today to discuss the initial results of its own testing of oil spill dispersants.  The testing by EPA was initiated after BP resisted complying with an EPA-Coast Guard Directive issued May 20 that directed the company to identify and switch to dispersants that are less toxic and more effective than the two Corexit® dispersants on which BP has exclusively relied to mitigate the effects of the oil disaster unfolding at Deepwater Horizon.  In expressing disappointment with BP’s response to the Directive, EPA indicated it would initiate its own toxicity and effectiveness testing of Corexit and other dispersants.  Today’s call reported on round 1 of that testing.

First let me say I applaud EPA for taking on the unglamorous task of conducting further testing and seeking to answer questions that would have been nice to have had answers to well before this mess developed.  Second, I understand that testing takes time, that this is only round one and EPA says more is coming, so that at least partially compensates for the distinctly anticlimactic feeling I had listening in on today’s call.

So, what did we learn today?  Not too much new. Read More »

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