Firefighters in Cambridge, Mass., practice decontaminating victims by carrying them through water sprays during a simulated dirty bomb attack.
Firefighters in Cambridge practice decontaminating simulated victims by carrying them through water sprays while simulating a "dirty bomb" attack drill in Cambridge May 16, 2004.
The Department of Homeland Security is set to issue guidelines that will likely change the way emergency workers would respond to a dirty bomb attack. NPR received a preview of the new safety standards, which significantly increase the level of radiation exposure considered safe for emergency workers and residents.
For instance, the guidelines advise that residents should only be evacuated if they are in danger of getting a radiation dose greater than 1,000 dental X-rays; that's about four times the exposure a person gets each year from natural resources.
In case of exposure to a dirty bomb attack, the Centers for Disease Control and Prevention advises the following steps:
• Leave the immediate area on foot. Buses, subways and cars may be contaminated.
• Go inside the nearest building. Staying inside will reduce exposure to any radioactive material that may be on dust at the scene.
• Remove clothes as soon as possible, place them in a plastic bag, and seal it. Removing clothing will remove most of the contamination caused by external exposure.
• Saving the contaminated clothing would allow testing for exposure without invasive sampling.
• Take a shower or wash as best you can. Washing will reduce the amount of radioactive contamination on the body and will effectively reduce total exposure.
As NPR's David Kestenbaum reports, the new guidelines suggest that a dirty bomb does not pose as great a risk as the guidelines drawn up by many emergency services have suggested.
An overview of the new draft "protective action guidelines" recommended by the Department of Homeland Security:
First Responder Exposure: Over the course of the initial event, the new guidelines say it's safe for firemen, police and EMTs to receive a total exposure of five rem. That's the equivalent of 5,000 dental X-rays, or 20 times the radiation people normally are exposed to in a year from natural sources.
Evacuation: Residents do not need to be evacuated in the days immediately following the attack unless exposure surpasses one rem, or the equivalent of 1,000 dental X-rays. In some cases, exposure as high as five rem may be allowed.
Relocation: More permanent relocation would only be ordered if over the course of first year the total additional dose to a resident would be two rem — eight times the radiation dose people normally get in a year. For subsequent years, the allowable additional radiation dose would be 500 millirem, which is twice the average annual background radiation dose from natural sources.