Answer to Question #1898 Submitted to "Ask the Experts"

Q

I'm in a location that I'm told might have radium deposits from 80 years ago. What is the acceptible background for radium? What is a level that may be considered dangerous? If I tore down the old structure and built a new one, would that get rid of the radioactivity? Who do you suggest I speak to who's an expert in radium? Who in Los Angeles sells radium Geiger counters?

A

1.  What is the acceptable background for radium? Please refer to the response to Ask the Expert Question 1899. 2.  What is a level that may be considered dangerous? Radium is primarily an internal hazard. Loose material that could be ingested or airborne material that could be inhaled would be more of a concern than spots of radium that are fixed in concrete or under many feet of soil. Unless purified radium was being handled inside an occupied area, the quantities of loose (removable) radium that would be encountered are unlikely to be an issue. The main consideration is probably the radon that the radium generates as part of radioactive decay. For the type of situation you describe, the hazard from external radiation (gamma rays) would be low. In general however, radium is not to be treated lightly. If you have reason to believe your site is contaminated, you should have it assessed (characterized) by someone who is experienced in this area. Please note that in all but extreme cases, the risk due to radioactive contamination is chronic, not acute. One would have to have a considerable exposure for long periods of time before the hazards might be considered "dangerous." Sites can generally be released to the public without any further controls if the potential dose to the public after the cleanup is less than a set limit (above background). Depending on the situation, the appropriate dose limit will be established by a state or federal agency. However, California's decommissioning rule was recently challenged in court and so it is not clear as to what is a level that you could clean up to. In general, if the potential dose to the public after cleanup is between 15 and 25 mrem per year (from all possible pathways, external and internal), then it can be considered for release without any further restrictions, however, that may not stand up after the courts have finished their review. 3.  If I tore down the old structure and built a new one, would that get rid of the radioactivity? Maybe. Contamination might exist either on building surfaces or in soil. It depends on how the radium was handled and stored. Contamination could be limited to spots on the benches, walls, and floors, but it could be in the soil beneath or around the building foundations. For that matter, it might be in the soil anywhere on the property. Keep in mind that in addition to radium, there might be other members of the uranium decay series that might need to be evaluated. It is not recommended that you just tear down the structure. If the building is contaminated, you could not just take it to a local landfill. That might cause some problems for you, the landfill, and the state health department. Instead, the contaminated portions would likely be segregated from the rest of the material and then disposed of in a licensed facility. If the radium was loose and in a form that could get into the soil, there could be the need for cleanup of soils around the structure. Do not attempt to handle the decontamination yourself. Have it dealt with by folks who are properly trained and have the equipment to work safely around radioactive contamination. 4.  Who do you suggest I speak to who's an expert in radium? We cannot recommend one consultant or engineering firm over another, but look for one with plenty of radiological experience, preferably one with experience characterizing and handling naturally occurring radionuclides. Radon testing companies may not have the expertise to characterize for radium. Check with the people at the State of California Radiologic Health Branch to see if they have a contractors list. If your site is contaminated, you will be talking to them eventually, so it is better to open a dialogue with them sooner rather than later. The World Wide Web has some good information on natural radioactivity; try the TENORM site. 5.  Who in Los Angeles sells radium Geiger counters? There are a variety of instruments that can be used to detect radioactivity. Although radium is primarily an alpha emitter, radium and its progeny emit enough gamma radiation such that a gamma scintillometer or dose rate meter may be useful for finding elevated areas of radiation. To find discrete deposits of radioactivity on fixed surfaces, either a pancake detector or a gas-proportional detector are recommended. The use of these instruments is not necessarily intuitive, and the data analysis requires potentially complex calculations to arrive at the final units of measure that are compared to the guidelines. One company in the Los Angeles area that sells radiation detection instrumentation is Technical Associates in Canoga Park; another is Far West Technology, but it is in the Santa Barbara area. One can occasionally find detectors for sale on e-Bay. Other vendors are available through the World Wide Web. You might also consider renting an instrument or borrowing one from a university or local health department. A final comment:  Much of this discussion may be premature since it is not certain that contamination actually exists. Please contact the State of California Radiologic Health Branch, which might be able to visit your property, perform a quick "scoping" survey, and conclude that you have nothing to worry about. Phil Egidi