Science Notebook: Transcript of Interview with Ron Fraass
EPA Science Notebook Coordinator Dr. Dale Haroski recently interviewed Ron Fraas, the Director of EPA's National Air and Radiation lab in Montgomery, Alabama. Listen to a discussion between EPA Science Notebook Coordinator Dr. Dale Haroski and Ron, as he discusses EPA's RadNet program and the 2 a.m. phone call he received last year.
DMH: We all know what it's like when your phone rings in the middle of the night and your heart starts pounding and you immediately worry that something bad has happened but imagine if that phone call is alerting you to an increase in radiation in a major city.
Ron Fraas, the Director of EPA's National Air and Radiation lab, had this very experience last year.
DMH Q: Ron, can you describe what happened that night for me?
Ron: I woke up thinking what's that noise? I keep my blackberry beside the bed; it was 2:07 AM on a Friday morning and my Blackberry was ringing and trying to vibrate off of my night stand. Normally not a good thing-but in this case, I had hoped it would happen. One of the RadNet air monitoring stations had sensed an increase of radioactive material near it or on its filter.
DMH: When you say a RadNet air station is calling you, what is that? Is it voicemail? Is it an email? What happened actually?
Ron: In this case we have the system set up to send an e-mail, it can be sent to me or one of the other scientists at the laboratory. In this case we were testing out the email system. So in this case my blackberry pops up and says "you have an email" from Station XXX and it has had a radiation alert.
DMH: Before we go on can you just briefly tell me what RadNet is and what the monitors are and what they look like?
Ron: Yes. RadNet is EPA's nationwide radiation monitoring system that tracks radioactive material in the nation's air, drinking water, precipitation and pasteurized milk. RadNet tracks trends in environmental radiation, so we know what is "normal" or "average" for an area - this is commonly referred to as background radiation. At this time approximately 100 RadNet air monitors have the ability to measure and transmit data real-time to our laboratory here in Montgomery. When a monitor reads something outside of that background range, the system sends an alert. The 2 AM alarm is continuing evidence that the system works correctly.
DMH: And what do these monitors look like? Am I likely to notice one walking or driving down a street?
Ron: You probably will not see a monitor from the street. In most cases they tend to be on the tops of local, state, or federal buildings. They are about the size of a post office box. Except our monitors are plain aluminum with an antennae up the back and a little air monitoring station on the top that gives us information about the weather such as temperature and direction of the wind.
DMH: Ok, so now that we know what RadNet is let's go back to that night or what led up to that night.
Ron: A few weeks prior to my awakening in the middle of the night, RadNet staff detected an unusual increase in some of the readings for one of the RadNet air monitors in a major US city. When staff confirmed the increases in the hourly reports, they downloaded a full spectrum of data from the detector. Analysis clearly showed the presence of Cobalt 60, a radioactive version of Cobalt. Later reports showed that the readings went back to background levels. This told us two things. 1) The Cobalt-60 wasn't on the air filter and 2) The cobalt source must have been somewhere nearby. Because the counts dropped to background during later hourly reporting periods, the material was clearly not on the air filter that is directly below the detector. That was why we knew it must have been nearby.
DMH: Ok, so basically the radiation source was there, but then it disappeared.
Ron: That is correct. That's what made us realize that it was probably nearby. Our first call went to the operator that morning asking if they had been up on the roof at 2am with the source and that answer was clearly no.
DMH: Did you have any idea where the Cobalt radiation might have come from?
Ron: Actually we did have some pretty good ideas. If the Cobalt 60 had been on it we would have known it was on the filter, but once it wasn't we presumed it had been shielded or moved away from the area. So at that point our assumption was a radiographer. Cobalt 60 is a radiation source often used by radiographers around the country. They use radioactive material to take the equivalent of X-rays of metal parts and welds to check for flaws.
DMH: You used the term radiographer. Can you tell me what a radiographer is?
Ron: A radiographer is trained to use radioactive sources rather than an X-ray machine to inspect a variety of metal parts or welds in the field locations that make it unwieldy to bring an X-ray machine. While inspections of oil and gas pipelines are the most common tasks for radiographers, they also inspect major welds in building structures to ensure they have been properly accomplished. In this country all radiographers are licensed by either the Nuclear Regulatory Commission or state radiation protection programs.
A few calculations showed that a radiography source could be sensed by the detector from a few blocks away. Plus the fact that the earlier events had occurred during the night gave more reason to suspect a radiography source. Radiographers are required to rope off the area where they are working to protect the public and other workers from unnecessary radiation exposure. Performing radiography at night reduces the number of persons who might be exposed even to low levels of radiation.
The levels detected at the RadNet monitor site were well below any regulated limits. The events were detected because the RadNet monitor is very sensitive.
DMH: It is great that you had an idea of what have might caused the spike. But were you able to confirm your suspicions?
Ron: That next morning we contacted the volunteer operator who used that particular site and we asked them if they knew about any nearby construction. Our RadNet operators are volunteers from local, state, or federal agencies who maintain the RadNet monitors. They replace the air monitoring filter twice a week, do an initial check for radioactive material on the filter, and then send the filter to NAREL for further analyses.
Although illegal activities were not suspected, local federal investigators were asked to make inquiries as well. A few days after the initial event, a contactor confirmed that they had been doing radiography about two blocks from the detector site. The mystery was solved.
DMH: Ron, I am a little confused. Did all this happen before or after your alarm went off in the middle of the night?
Ron: The confirmation that it was a radiographer all happened before the alarm. The cobalt-60 we found during our review of the reports wasn't at levels high enough to set off an alert. After the earlier events, staff reduced parameters on this particular monitor. If any of the levels were slightly exceeded, it was to send a message to my Blackberry. The key was we knew that we could do this, but since we do not normally have radioactive events occurring around the United States we hadn't had a chance to practice it. Normally, we only review data during the work day but wanted to confirm that our system could alert staff 24/7 if needed.
That brings us back to our early morning event. My blackberry woke me up, I got up and booted my home computer and accessed the restricted user site for RadNet data to see if we had again detected another use of radiography equipment. It was the middle of the night, but we had hoped the radiographer still had some work to do.
When I reviewed the basic data, there were three areas that appeared higher than normal, but not as high as we had seen in prior radiography events. The next morning, I asked the staff to analyze the data. They found that it was just an increase in natural radioactive material.
Apparently there had been rain showers in the area during the night. That brought down more of the natural radioactive dust particles that are always in the air and deposited them on the roof near the detector. The system worked just as planned, even though I lost an hour of sleep and did not see another radiography event.
DMH: Natural radioactive dust particles? Can you just explain this a little bit more? I don't know that many people assume there is radioactive dust floating above our heads!
Ron: Good question! Many rocks and soil on or near the Earth's surface contain uranium and thorium. Both of those elements are radioactive. Over time, uranium and thorium atoms become more stable through radioactive decay (emitting radiation and changing into other elements.) At one point in the decay process, they change into the element radon which is a radioactive gas. As the radon decays, it changes into non-gaseous elements that attach themselves atom by atom to dust particles in the air. Every air filter we check across the United States has some amount of radioactive dust on it. Our normal exposure to radon and its decay products accounts for approximately 40% of our annual background radiation exposure in the United States.
DMH: So since then has RadNet picked up on any more radiography sources?
Ron: Since that time, we have seen a different radiography source (Iridium 192) and two medical isotopes (Technetium 99m and Iodine 131) because of activities and persons near the RadNet monitors.
DMH: And when you say "activities or persons near the monitors" I assume you mean there was a reason they were using radiation and that it was nothing to be concerned about?
Ron: Yes, we were able to find the radiographer who used the Iridium source and two employees who had undergone recent medical procedures involving Technetium and Iodine. Nuclear medicine procedures account for 12% of our annual collective dose in the United States while less than one tenth of one percent of our annual dose is from industrial activities such as radiography.
DMH: when you say nuclear medicine procedure, can you give an example of what that may be?
Ron: Yes, nuclear medicine procedures are methods that use radioactive isotopes. We either swallow them or have them injected into our bloodstream so the physicians can use a variety of detectors to determine where that radioactive material collects in the body or is used in the body. We can get excellent images of the heart, information on the lungs, we can look for thyroid cancer, some of the newer methods are even being used to detect things like breast cancer.
DMH: Wow, so it is pretty amazing that a RadNet sensor on a building is able to pick up someone who has undergone a medical test. But what would happen during a radiological emergency?
Ron: RadNet is really not meant to pick up those localized things, but is there to provide a national level set of data from large scale (multi-state), such as Chernobyl, radiation events for which we will normally have warning or other indications they have happened. RadNet is not meant to provide our first indication of a release of radioactive material into the air. However; due to its high sensitivity, we are confident that any release of material significantly above background levels will be detected. If we suspect an event may happen or has happened, we would put staff on 24 hour operations to review any increases in count rates.
RadNet is there to help protect our citizens and the environment. Our software and staff review over 2,000 hourly reports each day to ensure that only environmental background levels of radioactive material are being detected in the air. We use these background values to set limits that are used to flag high values.
DMH: You mention that the staff review over 2,000 hourly reports, what type of review is that? Is it something they have to do by hand or is it something that gets done on a computer?
Ron: We are very fortunate that by setting those limits we are able to have the computer do the initial review so when the staff arrives in the morning they are looking at only things that are flagged. So if a monitor sees a little higher count on one of the channels of the detector the staff can download the data from the detector, review it and if they need to the can download the spectrum to confirm whether or not it is just an increase in background or a potential event.
DMH: So, if there is an emergency, who has access to the data?
Ron: A lot of folks, primarily state and federal agencies with an expertise in radiation detection may obtain restricted access to the RadNet data via a password protected site.
Members of the public always have access to fully verified RadNet data through EPA's CDX web site.
Data that has not been fully verified and approved is not posted on the public site. There are currently 96 near-real-time RadNet air monitors operating in cities across the United States.
DMH: Has RadNet ever been used to collect data during an emergency?
Ron: The precursor to the current RadNet system was called Environmental Radiation Ambient Monitoring System (ERAMS) and data are available on the Envirofacts web site. Early ERAMS operators collected air filters each day and sent them to NAREL or another laboratory for analysis.
During the Chernobyl incident, ERAMS systems clearly detected the plume of radioactive material as it passed over the United States. Although the levels of radioactive material were easily detected, they did not pose a health threat to the public.
Well, Ron thanks so much for taking the time to chat with us today, I know I'll sleep better at night knowing there are people like you and other EPA emergency responders out there monitoring for these things. I'm also glad that I'm not the one picking up that blackberry at night with a radiation alert!
Thanks so much for sharing your story Ron and thanks for all the work that you and your staff do!