Back in late September, the press had a field day with a mathematical model developed by CDC that estimated that if left unchecked, the Ebola outbreak in West Africa could wind up infecting over 1.4 million people. Almost missed in the hysteria over that high number was the fact that this same model predicted that even with key public health measures (patient isolation, monitoring of at-risk population who had contact with infected people and safe burial practices) falling short of 100% implementation, the outbreak could be brought under control around January of next year.
Word has been leaking out for a while now that the rate of new Ebola infections in Liberia is falling. Reports in the Washington Post on October 29 and November 3 told us as much. A chart in the WHO Situation Report for November 5 drives home just how dramatic the decline in new cases has become:
As can be seen in the chart, the rate of new infections for the two most recent weeks is less than one fourth the rate at the peak of the outbreak. Unfortunately, the news for Sierra Leone is not as good. While the rate of new infections may be leveling off, it is not yet falling appreciably:
Digging into the WHO report a bit further, we can find some evidence for how this dramatic drop in new cases has been brought about. We see that 52% of cases are now isolated. The WHO target for December 1 has been set at 70%, with a target of 100% by January 1. When it comes to management of dead bodies, though, the December 1 target has already been surpassed. WHO reports that 87% of the dead are being “managed in a safe and dignified manner” while the targets were set at 70% for December 1 and 100% for January 1. Also, although no benchmarks are reported, WHO states that 95% of registered contacts were reached daily (although in the text of the report, there are suggestions this number may be somewhat overstated).
It should come as no surprise that progress in implementing these basic measures has had a huge impact on bringing down the rate of new infections. It fits perfectly with the CDC mathematical model and it also addresses the known biology of Ebola infections. Patients are most infectious at or near death, so establishing safe burial practices is vitally important. Conversely, identifying infected individuals through daily monitoring of the at-risk population and then isolating infected individuals once symptoms begin means that far fewer people are exposed to people producing large amounts of virus.
Sadly, those who remain exposed are the health care workers who are providing care to those who are infected. Despite shortages of equipment and supplies, WHO and other organizations are doing their best to overcome those shortages and to beef up training to reduce risk to these brave people on the front lines in the work to control the virus. As of this November 5 report, 546 health care workers have been infected, with 310 of them dying. Only four new infections were reported for the week ending November 2, so it is hoped that this rate is also dropping.
Had the alarmists who insisted that this was a new super-strain of Ebola capable of airborne transmission (or even a strain developed in a bioweapons laboratory), it is doubtful that these basic public health measures would have had such a dramatic impact on the rate of new infections. Perhaps those folks can go back to railing about chemtrails or the evils of vaccines, because basic boring science appears to be on the road to controlling the current outbreak before all of mankind succumbs.
In the meantime, we are at about two weeks into the three week incubation period both for anyone “exposed” by Craig Spencer or for Kaci Hickox (or anyone she “exposed”) to show symptoms. No reports of transmission so far, and the odds of any cases showing up are dropping very rapidly from the already very low levels where they started.
See the update below, as of about 2:45 pm, the Times has changed the wording of the erroneous paragraph without adding a note of the correction. Oops. I got off on the wrong paragraph when I checked back. See the comment from Tony Papert below.
For someone who has written on a range of technical issues for many years, the error committed last night by David Sanger could not be worse nor come at a worse time for the important events he is attempting to cover. In an article put up last night on the New York Times website and apparently carried on page A1 of today’s print edition, Sanger and the Times have garbled a key point at the heart of the negotiations between Iran and the P5+1 group of nations as they near the critical November 24 deadline for achieving a full agreement on the heels of last year’s interim agreement.
The article ostensibly was to announce a major breakthrough in the negotiations, although Gareth Porter had worked out the details of the progress last week. Here is what Porter deduced:
The key to the new approach is Iran’s willingness to send both its existing stockpile of low enriched uranium (LEU) as well as newly enriched uranium to Russia for conversion into fuel for power plants for an agreed period of years.
In the first official indication of the new turn in the negotiations, Iranian Foreign Ministry spokesperson Marzieh Afkham acknowledged in a briefing for the Iranian press Oct. 22 that new proposals combining a limit on centrifuges and the transfer of Iran’s LEU stockpile to Russia were under discussion in the nuclear negotiations.
The briefing was translated by BBC’s monitoring service but not reported in the Western press.
Undersecretary of State Wendy Sherman, who heads the U.S. delegation to the talks, has not referred publicly to the compromise approach, but she appeared to be hinting at it when she said on Oct. 25 that the two sides had “made impressive progress on issues that originally seemed intractable.”
As Porter goes on to explain, such an arrangement would allow Iran to maintain a large number of centrifuges continuing to enrich uranium, but because there would be no stockpile of low enriched uranium (LEU), the “breakout time” (time required to highly enrich enough uranium for a nuclear weapon) would remain at about a year. By having Russia convert the LEU to fuel rods for Iran’s nuclear power plant, that LEU would be removed from any easy pathway to a weapon. This would provide Iran the “win” of maintaining its present level of around 10,000 operational centrifuges but give the P5+1 its goal of a longer breakout time. The key here is that unlike a proposal in 2005 where Russia would take over enrichment for Iran, this new proposal would allow Iran to continue its enrichment program while shipping virtually all of of its LEU to Russia for conversion to fuel rods.
Sanger appears to start off on the right track with his article:
Iran has tentatively agreed to ship much of its huge stockpile of uranium to Russia if it reaches a broader nuclear deal with the West, according to officials and diplomats involved in the negotiations, potentially a major breakthrough in talks that have until now been deadlocked.
Under the proposed agreement, the Russians would convert the uranium into specialized fuel rods for the Bushehr nuclear power plant, Iran’s only commercial reactor. Once the uranium is converted into fuel rods, it is extremely difficult to use them to make a nuclear weapon. That could go a long way toward alleviating Western concerns about Iran’s stockpile, though the agreement would not cut off every pathway that Tehran could take to obtain a nuclear weapon.
But about halfway through the article, Sanger displays a shocking ignorance of the real points of recent negotiations and somehow comes to the conclusion that Russia would be taking over enrichment for Iran rather than converting LEU into fuel rods:
For Russia, the incentives for a deal are both financial and political. It would be paid handsomely for enriching Iran’s uranium, continuing the monopoly it has in providing the Iranians with a commercial reactor, and putting it in a good position to build the new nuclear power reactors that Iran has said it intends to construct in the future. And it also places President Vladimir V. Putin at the center of negotiations that may well determine the future of the Middle East, a position he is eager to occupy.
Somehow, Sanger and his New York Times editors and fact-checkers are stuck in 2005, suggesting that Iran would negotiate away its entire enrichment program. Such a drastic move would never be contemplated by Iran today and we are left to wonder whether this language found its way into the Times article through mere incompetence or more nefarious motives meant to disrupt any possible deal by providing false information to hardliners in Iran.
At the time of this writing (just before 9 am on November 4), the Times still has not added any correction or clarification to the article, despite the error being pointed out on Twitter just after 10:30 pm last night (be sure to read the ensuing Twitter conversation where Laura Rozen and Cheryl Rofer work out the nature of the error).
And now, around 2:45 in the afternoon, I see that the Times has changed the erroneous paragraph. So far, I don’t see a note that a correction has been made. Here is the edited paragraph:
Russia’s calculus is also complex. It stands to gain financially from the deal, but it also has an incentive to see the nuclear standoff between Iran and the rest of the world continue, because an embargo keeps Iranian oil off the market. With oil prices falling, a flood of exports from Iran could further depress prices.
Will they ever get around to adding a note? I’ll keep an eye out. Well dang, this is embarrassing. I went to the wrong paragraph when I looked back. The article is still unchanged. Thanks to Tony Papert in comments for catching my bone-headedness.
Yesterday evening, an Antares rocket built and operated by Orbital Sciences Corporation exploded shortly after liftoff. The rocket was intended to ferry supplies and equipment to the International Space Station. Orbital and Spacex have taken over some of the duties supplying the space station since the termination of NASA’s shuttle program.
In the early aftermath of the explosion, word came out that the crash site had to be secured because sensitive cryptographic equipment was on board:
The Cygnus mission was non-military, but the company’s Antares program manager, Mike Pinkston, said the craft included “some classified cryptographic equipment, so we do need to maintain the area around the debris in a secure manner”.
That initially struck me as odd. The International Space Station has a large number of cooperating countries, including Russia. It’s hard to imagine that the US would put sensitive equipment into the hands of cosmonauts right now, given the cool state of US-Russian relations. Of course, it would make sense for ISS communications to be encrypted in order to prevent meddling by hackers, but movement all the way to classified (and presumably military or NSA-level) encryption seems to be excessive.
This morning, we are seeing walk-back on the presence of classified equipment:
Shortly after the explosion, CNN quoted a launch director as saying that the spacecraft contained classified “crypto” equipment, but early Wednesday a NASA spokesman said by email that “We didn’t have any classified items on board.”
In trying to make sense of what could have been behind these strange statements, I ran across this interesting announcement of a new cryptographic technology that European scientists have proposed evaluating in an experiment on the space staion:
A team of European researchers have proposed a series of experiments that, if successful, could turn the International Space Station into a key relay for a quantum communications network.
The key basis of physics underlying quantum communications is entanglement. Entangled particles are connected in a way that pretty much defies common sense. If you change the spin of one of the particles, the spin of its entangled counterpart will change – even if they’re miles apart. And that change happens nearly instantaneously – at least four orders of magnitude faster than the speed of light, according to a recent experiment.
Another remarkable aspect of this technology that sounds almost too good to be true is its potential security. After noting that quantum networks are quite fragile, the Forbes article continues:
But why bother with these networks at all if they’re so fragile? The answer is pretty simple – because they’re almost perfectly secure. Here’s how it works. Let’s say that I want to send a message to New York City. My message is going to travel through normal channels, but it will be encrypted with a key. That key is transmitted via the entangled photons – so the changes I make to entangled particles on my end almost instantly show up in the particles in New York. We then compare the measurements of what I changed in my photons to those states in New York City.
Those measurements then comprise an encryption key for our communications. So even if our communications are bugged, nobody can read them without knowing that encryption key. And here’s the important thing: if somebody were to try to eavesdrop on the quantum entanglement, they would alter the spin of the photons. So the measurements I make and the measurements made in New York would be out of sync – thus letting us know that we have an eavesdropper. It also prevents us from creating an encryption key, so we don’t send any communications. Theoretically, a quantum encrypted network is almost perfectly secure. (That said, they’re not perfect, and there are some exploits.)
The announcement from the European group that they wished to carry out the experiment based on what Einstein called “spooky action over a distance” came last April. Then, in June, it was announced that China had carried out a key demonstration of concept experiment back in 2010 but waited four years to publish the result.
With China announcing progress on the technology, one would think that the West would want to accelerate its work in the area, so it would not be at all surprising if equipment for the European experiment was among the items lost when the rocket exploded. Further, one would expect that Orbital would have been told that security for that equipment would be of the very highest level. In discussing the issue of sensitive equipment among the Antares wreckage, PCWorld this morning mentioned the incident of China perhaps examining the wreckage of the US stealth helicopter that was left behind after the mission to kill Osama bin Laden. It could well be that for this crash site, keeping the debris away from prying eyes from China is behind the call for security. Note also that the experiment quite likely would have been coordinated by the European Space Agency on behalf of the European scientists, so NASA’s claim that “We didn’t have any classified items on board” could be parsed as not applying to any classified items that ESA might have had on the rocket.
It’s really difficult to say which poor response to Ebola has done more damage to the public health system in the United States. First, we had the series of unforgivable errors at Texas Health Presbyterian Dallas that resulted in Thomas Duncan being sent home with Tylenol and antibiotics when he first presented with Ebola symptoms. This was followed up after he was admitted by Nina Pham and Amber Vinson coming down with the disease after they treated him. Now, we have Kaci Hickox, who treated Ebola patients in West Africa, confined to an unheated tent in a New Jersey hospital for 21 days even though she is asymptomatic and has tested negative for Ebola. Twice.
The hysteria over retracing the steps of Craig Spencer in New York City just before he developed his fever illustrates the way the US press has misled the public about when and where Ebola risk exists. Abundant evidence from this and previous Ebola outbreaks demonstrates clearly that there simply is no risk of transmission from asymptomatic patients and that transmission risk grows through the course of the infection.
We see that principle demonstrated very clearly in Duncan’s case history. See this terrific ABC timeline for relevant dates quoted below. Duncan arrived in Dallas September 20. No passengers on any of the flights he took have developed Ebola. The incubation period has elapsed, so we know that no transmission of the virus occurred during any of his flights. Duncan had symptoms on his first hospital visit on September 26 but was sent home. He was later admitted on September 28. No patients or personnel from the hospital became infected from his visit September 26. The incubation period has expired, so we know for certain that transmission did not occur for anyone near Duncan that day. Similarly, even though they were in the apartment with him for days after he developed symptoms, none of the residents of or visitors to the apartment where Duncan was staying in Dallas became infected. The incubation period for that exposure also has expired. From this timeline developed by the New York Times, it appears that Pham and Vinson treated Duncan on the day before he died, which would be at the time when the amount of virus being produced by his body was nearing its maximum.
I had really hoped I wasn’t going to have to write this post. Yesterday, Marcy emailed me a link to a Washington’sBlog post that breathlessly asks us “Was Ebola Accidentally Released from a Bioweapons Lab In West Africa?” Sadly, that post relies on an interview with Francis Boyle, whom I admire greatly for his work as a legal scholar on bioweapons. My copy of his book is very well-thumbed. But Boyle and WashingtonsBlog are just wrong here, and it takes only seconds to prove them wrong.
Shortly after getting the email and reading the blog post, I sent out tweets to this summary and this original scientific report which describe work on DNA analysis of Ebola isolated from multiple patients during the current outbreak. That work conclusively shows that the virus in the current outbreak is intimately related to isolates from previous outbreaks with changes only on the order of the naturally occurring mutation rate known for the virus. Further, these random mutations are spread evenly throughout the short run of the virus’s genes and there are clearly no new bits spliced in by a laboratory. Since I wasn’t seeing a lot of traction from the Washington’sBlog post, I was going to let it just sit there.
I should have alerted last night when I heard my wife chuckling over the line “It is difficult to describe working with a horse infected with Ebola”, but I merely laughed along with her and didn’t ask where she read it.
This morning, while perusing the Washington Post, I saw that Joby Warrick has returned to his beat as the new Judy Miller. Along with the line about the Ebola-infected horse, Warrick’s return to beating the drums over bioweapons fear boasts a headline that could have been penned by WashingtonsBlog: “Ebola crisis rekindles concerns about secret research in Russian military labs“.
Warrick opens with a re-telling of a tragic accident in 1996 in a Soviet lab where a technician accidentally infected herself with Ebola. He uses that to fan flames around Soviet work in that era:
The fatal lab accident and a similar one in 2004 offer a rare glimpse into a 35-year history of Soviet and Russian interest in the Ebola virus. The research began amid intense secrecy with an ambitious effort to assess Ebola’s potential as a biological weapon, and it later included attempts to manipulate the virus’s genetic coding, U.S. officials and researchers say. Those efforts ultimately failed as Soviet scientists stumbled against natural barriers that make Ebola poorly suited for biowarfare.
The bioweapons program officially ended in 1991, but Ebola research continued in Defense Ministry laboratories, where it remains largely invisible despite years of appeals by U.S. officials to allow greater transparency. Now, at a time when the world is grappling with an unprecedented Ebola crisis, the wall of secrecy surrounding the labs looms still larger, arms-control experts say, feeding conspiracy theories and raising suspicions.
Enhancing the threat is the facilities’ collection of deadly germs, which presumably includes the strains Soviet scientists tried to manipulate to make them hardier, deadlier and more difficult to detect, said Smithson, now a senior fellow with the James Martin Center for Nonproliferation Studies, a research institute based in Monterey, Calif.
“We have ample accounts from defectors that these are not just strains from nature, but strains that have been deliberately enhanced,” she said.
Only when we get three paragraphs from the end of the article do we get the most important bit of information to be gleaned from the Soviet work on Ebola:
Ultimately, the effort to concoct a more dangerous form of Ebola appears to have failed. Mutated strains died quickly, and Soviet researchers eventually reached a conclusion shared by many U.S. biodefense experts today: Ebola is a poor candidate for either biological warfare or terrorism, compared with viruses such as smallpox, which is highly infectious, or the hardy, easily dispersible bacteria that causes anthrax.
Note also that, in order to make Ebola more scary, Warrick completely fails to mention the escape of weaponized anthrax from a Soviet facility in 1979, infecting 94 and killing 64, dwarfing the toll from the two Ebola accidents.
And lest we calm down about Ebola and the other bioweapons the Soviets worked on, Warrick leaves us this charming tidbit to end the article: Continue reading
I’m either a lone voice in the wilderness or just another angry old man shouting at clouds on this, but, to me, the issue of personnel flow inside a facility treating a patient for Ebola is critical. Texas Health Presbyterian Dallas got that issue terribly wrong in the case of Thomas Duncan, and now, although they provide very good guidance on the issue of personal protective equipment and its use, new guidelines just released by CDC sadly fall short of correcting the problem I have highlighted.
The issue is simple and can even be explained on a semantic level. If a patient is being treated in an isolation ward, that isolation should apply not only to the patient but also to the staff caring for the patient. As I explained previously, National Nurses United complained that health care workers at Texas Health Presbyterian Dallas treated Duncan and then continued “taking care of other patients”.
Allowing care providers to go back to treating the general patient population after caring for an isolated patient is in direct contradiction to one of the basic recommendations by WHO in a document (pdf) providing guidance for treatment of hemorrhagic fever (HF, includes Ebola):
Exclusively assign clinical and non-clinical personnel to HF patient care areas.
By exclusively assigning personnel to care of the isolated patient, then the isolation is more complete.
The new CDC guidelines, released on Monday, offer updated recommendations on the types of personal protective equipment (PPE) to be used and how it is to be used. The guidelines also stress the importance of training on effective PPE use prior to beginning treatment of an Ebola patient. Unfortunately, though, the guidelines still leave open the possibility of health care workers moving between the isolation area and the general patient population.
In the preparations before treatment of an Ebola patient commences, the guidelines state:
Identify critical patient care functions and essential healthcare workers for care of Ebola patients, for collection of laboratory specimens, and for management of the environment and waste ahead of time.
And then once treatment begins, we have this:
Identify and isolate the Ebola patient in a single patient room with a closed door and a private bathroom as soon as possible.
Limit the number of healthcare workers who come into contact with the Ebola patient (e.g., avoid short shifts), and restrict non-essential personnel and visitors from the patient care area.
So the facility is advised to identify the “essential” workers who will provide care to an Ebola patient and to limit the number of personnel coming into contact with the patient. And even though the patient is to be in an isolated room, the guidelines still fall short of the WHO measure of calling for the Ebola treatment staff to be exclusively assigned. Precautions for safely removing the PPE are described, but once removed, the workers presumably are free to go back to mixing with the general patient population. Hospitals are cautioned against allowing large numbers of care providers into the room and to avoid “short shifts”, but there still is no recommendation for workers to be exclusively assigned to the isolation area.
The first thing that comes to mind in this regard is to question whether the CDC recommendations fall short of the WHO call for exclusive assignment in order to allow US hospitals avoid the perceived expense of dedicating a handful of personnel to treatment of a single patient. Is the ever-constant push to reduce personnel costs responsible for this difference between CDC and WHO guidelines? In the US healthcare system, it appears once again that MBA’s can carry more weight than MD’s on critical issues.
The incompetence of Texas Health Presbyterian Hospital Dallas is staggering. In following today’s rapidly developing story of a second nurse at the hospital now testing positive for Ebola, this passage in the New York Times stands out, where the content of a statement released by National Nurses United is being discussed (emphasis added):
The statement asserted that when Mr. Duncan arrived by ambulance with Ebola symptoms at the hospital’s emergency room on Sept. 28, he “was left for several hours, not in isolation, in an area where other patients were present.” At some point, it said, a nurse supervisor demanded that Mr. Duncan be moved to an isolation unit “but faced resistance from other hospital authorities.”
The nurses who first interacted with Mr. Duncan wore ordinary gowns, three pairs of gloves with no taping around the wrists, and surgical masks with the option of a shield, the statement said.
“The gowns they were given still exposed their necks, the part closest to their face and mouth,” the nurses said. “They also left exposed the majority of their heads and their scrubs from the knees down. Initially they were not even given surgical bootees nor were they advised the number of pairs of gloves to wear.”
The statement said hospital officials allowed nurses who interacted with Mr. Duncan at a time when he was vomiting and had diarrhea to continue their normal duties, “taking care of other patients even though they had not had the proper personal protective equipment while providing care for Mr. Duncan that was later recommended by the C.D.C.”
From the context of both the New York Times article and the nurses’ statement, it seems most likely that this movement of nurses from treating Duncan to treating other patients took place during the period after Duncan was admitted to the hospital and before the positive test result for Ebola was known. However, from the nurses’ statement showing that at least some of the personnel on duty realized Duncan almost certainly had Ebola, proper isolation technique should have been initiated immediately.
And that movement of nurses from a patient who should have been in isolation back into the general patient population is a huge, and obvious, error. Consider this publication (pdf) put out in August by the World Health Organization, summarizing precautions to be taken in care of Ebola patients. The very first page of actual content, even before the section labeled “Introduction”, is a page with the heading “Key messages for infection prevention and control to be applied in health-care settings”. The page lists nine bullet points about dealing with ” hemorrhagic fever (HF) cases” (hemorrhagic fever diseases include Ebola). Here is the third entry on that list:
Exclusively assign clinical and non-clinical personnel to HF patient care areas.
There really is no point in saying a patient is isolated if staff are freely moving back and forth between the isolation area and the general patient population. I’m wondering how long it will be until there is a whole new management team at Texas Health Resources, the parent firm for the hospital.
Not long after we learned that a health care worker treating Thomas Duncan has tested positive for Ebola, I ran across this terse tweet from Mackey Dunn, the pen name of Don Weiss, who is “a medical epidemiologist with the New York City Department of Health and Mental Hygiene”. The tweet linked to this short but incredibly important blog post. In the post, Weiss notes the baffling development that a health care worker, who wore full personal protective equipment (PPE), contracted Ebola from Duncan even though at this point, none of his family or other close contacts, who did not have full PPE, have developed symptoms of the disease.
That set of facts prompts Weiss to pose the question “So, what does this tell us about Ebola and how we can attain control?” His answer begins:
One, that Ebola patients become more infectious as the illness progresses. The newly reported case in a healthcare worker had onset on October 10th. If we take 9 days as the mean incubation period for Ebola this means the healthcare worker’s exposure was sometime around October 1, which was day 8 of Mr. Duncan’s illness. This is similar to what was seen with SARS, that patients become more infectious (and dangerous) with time.
In setting up the circumstances for his question, Weiss had noted that Duncan was hospitalized, ending exposure to family members, on day 5 of his disease.
Although he doesn’t mention it, this aspect of Ebola, where patients produce more virus and become more infectious during the course of a fatal infection, also accounts for why burial practices are so important to containing the spread of Ebola. Patients produce the most virus and are thus at their most infectious at death.
The converse also appears to be true. Duncan was symptom-free when he flew from Liberia to Dallas on September 19 to 20. At 24 days since the end of that trip, we have now passed the incubation period, commonly given as 2-21 days, for Ebola to develop in anyone who could have been exposed during the flights. No infections among those airline passengers have been reported. I have yet to see a major media outlet mention this point, though.
We are now at 16 days since Duncan was hospitalized, ending his family’s direct exposure, so we have passed the two-thirds point of the incubation period for them (and well past the 9 days that Weiss gives as the average incubation period for Ebola).
The second part of Weiss’ musings on the infection of the nurse is extremely important:
Second, that only hospitals that are well prepared to care for highly infectious patients should be allowed to do so. Standard practice is to have a staff person dedicated to observing the donning (putting on) and doffing (taking off) of PPE. This observation should continue throughout the period of clinical care (from an ante-room with a window). Perhaps gentle reminders during the doffing can avoid the presumed situation in Spain where the nurse may have touched her face with a gloved hand.
When a patient presents to a hospital early in the illness there is time to transfer to such a facility. That’s the plan here in NYC. Bellevue hospital has a specially equipped ward to care for Ebola patients. Their staff are well trained. The number of healthcare workers entering the room should be kept to a minimum, especially after day 7 of the illness.
Weiss was prescient in his push for an observer for workers putting on and taking off PPE. In today’s New York Times, we have this on the CDC’s thoughts regarding improving practices for health care workers treating Ebola patients: Continue reading
Yesterday, I described what was known at the time about a mysterious blast near the Parchin military site in Iran. I postulated that satellite imagery would soon be available to help sort out the mystery of what took place. A tweet this afternoon from @dravazed alerted me to this article at the Times of Israel, which, in turn, linked to this story posted at israeldefense.com.
Satellite imagery described as from Sunday night’s blast at the Israel Defense site shows several buildings destroyed. The article claims that the blast looks like an attack on a bunker:
Satellite images obtained by Israel Defense and analyzed by specialist Ronen Solomon clearly show damage consistent with an attack against bunkers in a central locality within the military research complex at the Parchin military compound.
Because of the unique shape of the large building adjacent to those destroyed by the blast, I was able to find the location of the blast on Google Maps. Also, with the help of this article from 2012 in The Atlantic, I was able to locate both the area inspected by IAEA in 2005 and the site of the disputed blast chamber where it is alleged that research to develop a high explosive fuse for a nuclear weapon has been carried out. None of these three locations, the blast site, the chamber site or the area inspected in 2005, lies within the boundaries marked as Parchin on Google Maps. The blast site looks to be near a populated area of what is marked on Google Maps as Mojtame-e Maskuni-ye Parchin (which appears to translate as Parchin Residential Complex A if I used Google Translate appropriately). In fact, the blast site appears to be just over a mile from an athletic field. On the map below, #1 is the disputed blast chamber location, #2 is the blast site and #3 is the area inspected in 2005. Note that both the blast chamber site and the area inspected in 2005 are more removed from what appear to be the populated areas.
I am far from an image analysis expert, but the blast site looks to me to be more like an industrial site than a cache for storing explosives. If a bunker were indeed located here, that would put the local planning in this area on a par with West, Texas.
It will be very interesting to see how US officials describe the damage and the site where it occurred.
Detailed information is not yet available, but by all accounts there was a very large explosion east of Tehran Sunday night, around 11:15 local time. Many believe that the explosion took place at Parchin, the military site that has been at the center of controversy raised by those who accuse Iran of carrying out work there to develop an explosive trigger for a nuclear bomb. Some of the most detailed information comes from Thomas Erdbrink of the New York Times:
A mysterious explosion at or near an important military complex rocked the Iranian capital on Sunday, lighting up the skies over the city.
Iranian official sources denied the explosion had taken place at the complex, the expansive Parchin military site east of the city, where international monitors suspect Iran once tested triggers for potential nuclear weapons. But the enormous orange flash that illuminated Tehran around 11:15 p.m. local time clearly came from that direction, several witnesses said.
Officials at Iran’s Defense Industries Organization, though also denying that the explosion took place at Parchin, confirmed that two people were missing after “an ordinary fire” caused by “chemical reactions of flammable material” at an unspecified production unit, according to the semiofficial Iranian Students’ News Agency. There was no word on the location of the fire.
Witnesses in the east of Tehran said that windows had been shattered in the vicinity of the military complex and that all trees in a hundred-yard radius of two villages, Changi and Hammamak, had been burned. The villages are on the outskirts of the military site.
The map below shows the area in question:
As seen on the map, Changi is very close to Parchin, but Hammamak is on the other side of Parchin and the two villages are over three miles from one another. A blast fireball that scorched trees over three miles apart must have been quite spectacular.
Many factors go into calculating the strength of blasts, including the type of explosive and what type of containment might have been present. However, FEMA provides (pdf) this rough guideline (via DTRA) of the radius over which various types of damage might be expected to occur as a function of the amount of explosive material used:
Because it relates to assessing damage from terrorist bombs, the FEMA figure breaks the amounts of explosives down into the amounts that can be carried by cars, vans and large trucks. The Times story doesn’t report on how far away from the complex windows were shattered, but the effect of burned trees in villages over three miles from one another suggests that such damage would reach quite a ways. At the very least, it would appear that the blast had the equivalent of more than 10,000 pounds of TNT, and perhaps significantly more than that.