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To read Integrated Environmental Management, Inc.'s (IEM's) response to one of the following questions, simply press the red question number at the left of each question.  When you have read the response, press the "Read Some Answers" category on the left or use your browser's "back" button to return to this list.  Since these 50 questions are recycled with new ones, starting from the bottom and working our way up, you may wish to scan through the list periodically to see what new ones have been posted.  You may also want to press your "re-load" button to be sure you are seeing the most current information.

Question 50:  "Over the past 20 years I have had approx. 90 x-rays, 3 cat scans and 2 mri's, most of the x-rays were from a older machine in a Dr's office. My question is have I been cooked, or overexposed? On a separate matter, I just found out that my new laptop has a embedded lojack recovery chip, in it. What type of radio wave does this chip recieve? and will lead shielding prevent such from getting to my computer? Thank you."

Question 49:  "A friend has lung cancer and received a course of radiation therapy only due to fraility and age (76 years). Since January, she has had a CT scan twice and a PET scan prior to radiation. She has a primary care doctor, a radiologist and an oncologist. I've found out that her primary care has scheduled her for a mammogram, her oncologist has her scheduled for a CT scan, and her radiologist has her scheduled for a PET scan. I have a feeling they don't really talk to each other. I should mention that she is very sensitive to pain and had breast implants done in the early 1970's. Am I right to question whether all these exams are necessary? In particular, the mammogram which I know is very painful."

Question 48:  "To Whom It May Concern, I have a very serious problem in my neighborhod. I live in a small mobile home park in NC and we have just found out that our well is contaminated with Radium. We have been living there for about 7 years. There is one well and it supplies about 30 homes. The owners of the land, and well, were aware of this and have kept it a secret so they would not have to connect to city water. I was wondering what the possible effects could be on me and my family after using the water in all our drinks, foods, and bathing in it? Our water has always been very "hard" and sometimes smelled extremely bad. thank you "

Question 47:   "Hi, a very unusual and scary thing just happened to me and my wife. We opened our microwave door to cook something, and the microwave turned ON! We were both stunned and immediately shut the door after a few seconds. Unfortunately this is a raised (eye and head level) microwave built into a cabinet, so we are concerned about getting to much heat to our brains and cataracts. Have you ever heard of this before, a microwave turning ON when the door opens? I thought microwaves were designed to turn off when the door is opened. I'm hoping it was just the fan, but just in case, what health damage have we done to ourselves?"

Question 46:  "Can you explain how to convert curies to rads?"

Question 45:  "I have a question that has been concerning me and I hope that maybe you could give me some insight. I worked at a veterinary clinic for 5 1/2 years in Oklahoma and my job entailed taking X Rays. X rays were taken on dogs and cats almost every day at least one time, sometimes up to seven times a day. The exposures were up to 14x17 in size. The machines used were the Summit Innovet for approx 2-3 years and before that an older (approx 30 yrs old), portable horse X Ray machine. I'm not sure of the name on the old one. I know where it is stored and could possibly get the name. The whole 5 1/2 years that I took X rays I was totally unprotected as far as wearing an apron or any other gear because there was none supplied. My question is, what kind of health risk was taken, being a 29 year old female, from this amount of radiation exposure? Isn't the employer who owns this clinic violating OSHA regulations on radiation as far as not supplying protective gear and seeing to it that it gets used, not recording the amount of radiation being absorbed with badges (as there is none in use) and not posting radiation warning signs for clients? Thank You."

Question 44:  "Your website has a table of Exposure Rate Constants. Would you mind telling me how the values are calculated? When I use a well established approximation for a common medical nuclide (Tc99m), I do not get the results you have presented (or what I am expecting). It makes me question all your data. The common approximation is G(R m^2 / Ci Hr) = 0.5 * E(MeV) * gamma yield. Your value does not have the 0.5 factor included. Can you convince me your values are correct or will you consider revising calculations to assure accuracy? The common exposure rate constant I am familiar with for Tc99m is about 0.06 Rm^2/Ci hr. (your value is about twice this value). If you want to provide a more valuable table, also present the data in international units of both Gy (J/kg) and C/kg, all at one meter. Indicate that activity may bbe expressed in Ci, Gy or possibly c/kg, the first two being mosst common. It is hard to find a conversion between the different units... I am still searching for the conversion factors (with part-time interest since it hasn't proven to be very straight forward) It lingers as one of those things I haven't yet worked out but I am interested in."

Question 43:   "This is in reference to 10CFR 40.13, exemption for thorium and uranium if less than 0.05% by weight. I wanted to make sure I am calculating the percent weight right. For example Th-230 has a specific activity of 2.06 x 10^-2 Ci/g. If I have Th-230 in water using the density of water 1.0 g/ml, is a solution less than 1 X 10^-5 Ci/ml exempt?"

Question 42:  "Hi folks; We inherited several old boxes (doesn''t every Chemistry Department?) of old instruments from the demolition of a college science class room building . One box contains a Nuclear ––Chicago Model SK-2 Counter of some type from perhaps 1960? The instrument was packed with a few empty bottles that once contained Zn 65, Pb 211, Co 60, C 14, Pr 144, Si 210, and Ce 144. Should we be concerned, 47 years later, with any hazards associated with this? How can we find out?"

Question 41:  "Hi. In an effort to minimize patient transports, it has been suggested all xray procedures be done at the bedside for patients in our hospital. Our state agency regulations require that portables only be done on patients who cannot safely be transported to the xray suite, and that makes sense, given the traditional "control" measures taken to minimize radiation exposure. I know that technology is constantly improving, and we can certainly minimize radiation exposure through distance and shielding on the nursing unit, but I want to be able to explain to the non-clinicians involved in this process change why the image quality from a portable machine is inferior to the image quality on a fixed machine in terms they can understand. I also wonder about the risk to staff, other patients and visitors over time if xrays were routinely taken on the nursing unit without the kind of shielding seen in xray suites. Can you give me a good reference to pull rationale from in a lay-man's terms?"

Question 40:  "I work for a nuclear utility that recently saw a spike in reactor coolant Argon-41 activity. I performed a calculation for specific activity and used that value to determine the mass of Ar-41 present in the coolant. My question is how can I determine the percentage of Argon that got activated to Ar-41? Thanks."

Question 39:  "Hello. I work at a Dental office. We will be re-doing our office, making it bigger. We have x-ray machines, but what do we do with the special wall protection coverings? Do we need Lead Drywall, and if we do, how much do we need (thickness), and where do I find that at? Thank you."

Question 38:  "I had a hemangomia on my chest removed with radiation in 1952 at the age of 3 months. I cannot find my medical records, so I have no idea the amount of radiation used for this treatment. At the age of 50 I had a stroke. I do not suffer with high blood pressure. Cause of the stroke- unknown. I also suffer with peripheral neuropathy. I have been diagnois with fibromyalgia. Also my white blood count has been elavated. The lymphocytes and monocytes are also high. I also suffer with extreme tireness and weakness. Can any of these things be related to the amount of radiation I had as an infant? Thank you for your answer."

Question 37:  "To Whom It May Concern at IEM: I am the RSO for a manufacturer of portable density and moisture testing gauges for construction and agriculture. The sealed sources in each gauge are 10 mCi of Cs-177 and 50 mCi of Am-241/Be. A 40-year history of dosimetry records shows that gauge operators receive no more than 100 mrem total (gamma + neutron) in one year of extensive gauge use. This exposure is only 2% of the NRC allowable limit of 5000 mrem/year for an occupational worker and about 20% of the allowable limit for a female during a declared pregnancy. (At some point during a pregnancy, there are physical limitations to lugging around a 30 lb. nuclear gauge on a construction site, so the actual exposures during a pregnancy are much less than this estimate). I am regularly asked by females who are pregnant, or have confirmed that they are pregnant during gauge use, if their radiation exposure to nuclear gauges can put them at risk of harm to the embryo/fetus. I know that it cannot, but I would like your comments, as a third party expert, to ease their concerns. Also, are there any papers published on this topic, in laymen's terms, that I can refer them to? Thank you for your comments and advise on this matter."

Question 36:  "Dear Madam/ Sir, We got your reference through google search engine. We are stuck up on a question on radioactivity. We need your guidance as we share different opinions on the following question: One sealed (airtight) container contains 100 gm a radioactive element whose half life is 10 min. What would be the weight of the container after 1 hour (60 min)? Though this is a very basic question, we require your help to come to a common conclusion in terms of answer to this question. Please help."

Question 35:  "My company has acquired a small aircraft engine overhaul operation that works with thoriated magnesium alloys (welding and grinding) to a limited extent. Is there any information available on safety programs and licensing requirements?"

Question 34:  "To Whom It May Concern: I work for an industrial gauge manufacturer. Once per month I read the serial numbers engraved on 60, 10 mCi Cs-137 special form sealed gamma sources, i.e., the initial activity for this procedure is 0.6 Curie. It takes me about one hour to read and record the serial numbers and store the sources in lead pigs. I have adequate lead shielding for my mid-trunk and use long-handled tongs for handling the source capsules, assuring that my whole-body and extremity exposures are ALARA. I use a monocular scope to read source serial numbers with my face about 30 inches (76 cm) from the tray of source capsules. Is the above exposure scenario putting me at greater risk of getting cataracts? Several suppliers sell lead glass in various thicknesses. Would it be prudent or beneficial for me to get and use this protective shielding for my head and eyes? Thank you in advance for your response to this question."

Question 33:  "If you started with 1000 grams of radium, how many grams would be left after 3 half lives? A. 125 B. 250 C. 500 D. 1000 E. 2000 Please help with this answer, I haven't a clue. Thanks."

Question 32:  "What would a basic procedure be for clean up of fuel flea in a vehicle? would vacuum and shampooing do it."

Question 31:  "I just found out I''m pregnant and my 1st ob appointment isn''t until 11/21/06; I''m really scared b/c I''m 40 years old and just had a mammogram on 10/26/06. When I went to have the mammogram done she did ask me if I was pregnant or thought I was and of course I explained I couldn''t be. The next week (10/30/06 –– 11/05/06)I was supposed to start my period per my pills which I usually do within the 2 to 3rd day of taking the sugar pills; but I didn''t and I started having the nauseous feeling like when I had been pregnant years before so I took a home test on Sunday which confirmed I was. I had just started the pill on 10/9/06 since being off of it from an insurance change for a couple of months but we were using rubbers. My question is: what kind of harm could I have done to the fetus? I''m so scared."

Question 30:  "We took some air samples and wipe samples on and near an employee Tungsten grinding and had them analyzed for radiation. The results came back in DPM (disengrations per minute). Does this need to be converted to curies or rems? If so, how do you do that conversion and what do we compare the results to? 10 CFR835.202? 5 rems a year? Thanks."

Question 29:  "Dear CHP, I received a pelvic ct scan with iodine and then found out that I was three weeks pregnant when the scan was administered. I am very concerned about the developing fetus. What does the research say and what do you advise? Thank you."

Question 28:  "Thank you for the interesting webpage at http://www.iem-inc.com/prnon3r.html. It's refreshing to see such clear exposition of these important topics, which are so frequently misunderstood. In it, you write: "How much ultraviolet radiation does it take to kill bacteria? Ultraviolet dosage is measured in "microwatt seconds per square centimeter". In essence those units mean that the higher the microwatt level, the higher the dosage. Or the longer the exposure time, the higher the dosage. Finally, the greater the exposed area, the higher the dosage. For your information, the U.S. Public Health Service published a policy stating that the amount of UV necessary to sterilize drinking water is at least 16,000 microwatt seconds per square centimeter." Energy per unit area? What kind of dosage delivery unit is that for a bulk substance? I measure water by volume, not area. Thanks."

Question 27:  "How do I calculate the number of moles of phosphorus in 100uC of P32.?"

Question 26:  "Res. Sir, How much minimum activitity (in RMM) is permissible of a coblat source in Telecobalt unit to treat the cancer patients? Is there any direcetive or document from Competent Authority regrading optimum use of cobalt source? Kindly do the needful. Thanking you."

Question 25:  "We have a house that was previously used by a dentist. The walls in his X-ray room are completely covered with lead panels. If he took many X-rays there, what happens to the radiation that was originally given off? Does the radiation only last as long as the X-ray is being taken, or does it "bounce around" the room forever, or is it absorbed by the lead walls? Also, is it safe for us to remove the lead walls, and should we take precautions such as gloves or face masks? Thank you."

Question 24:  "Is there an "official" source for listing the most commonly accepted Half Lives? I think most professionals in the past used the Radioactive Decay Data Tables by David C. Kocher which was published in 1981, but lately I've seen references to the "Evaluated Nuclear Structure Data File" (ENSDF), National Nuclear Data Center, Brookhaven National Laboratory. The ENSDF has values for Half Lives that are slightly different than what I have been using. One of them, namely I-125 is different enough to lead to some inaccuracies in my data. I would appreciate some help as to what reference I should be using."

Question 23:  "Hello Dear Sir, I enjoyed your answers about radon and methods for measuring its concentration. Would you kindly support me with the equation of calculating indoor radon concentration by using picorad vials & liquid scintillation counters (including the values of : 1- the conversion factor to convert the CPM to Bq/m3 and 2- the adsorption factor for the activated charcoal in the picorad vial). PLS. if you have any paper or document includs these information send it freely through this email. Thank you very much."

Question 22:  "Dear IEM person, I am a graduate student in the Health Physics program at Idaho State University. Recently I did a google search for "specific exposure constant", and the IEM website tool-box was first in the list. The tool-box contained a comprehensive list of "specific exposure constants" in comparison to other websites that came-up in the search. It would be very useful for students like me if you could provide a reference for the 'Exposure constants" in your tool box. Also if possible please e-mail me the reference. Thank you."

Question 21:  "Hi, I have a few basiv questions on how a microwave functions: I was wondering if the radiation emitted inside the cooking compartmant was of alternating frequency or, just generally what type of wave it was! Is the electricity rectified before made into microwaves by the magnetron? When people say the wavelength is roughly 125mm, with a 2.5GHz frequency, is that DC or AC? Cheers!"

Question 20:  "Hello I always read with interest your comments that people should not forsake future medical exams, even if they've had loads of previous radiation exposures, for a fear of cancer related health risks. My question relates to Mr. Lance Armstrong, the bike rider. He has obviously received tons of radiation (assuming you know his history) because he had testicular cancer which spread throughout his body including lungs and brain. But he must still go to the dentist and get x rays I assume. Would you recommend he doesn't do that? What is the real risk of getting dental x rays over and over and how many can you have? Thanks!"

Question 19:  "What are the different standards for disposal and handling for IX resin of different loading capacities? I'm not sure whether to use 1 nCi/g, 2 nCi/g, or 10 nCi/g. I couldn't find any references for any of these values. Thanks and best regards."

Question 18:  "I read your answer to Question 23 on your website. I could not find the referenced question regarding measuring radon. I am a CIH with a bit of a HP background when in the Air Force (base and downrange Radiation Safety Officer) but am certainly not a HP. I have a client with a Rand Earth (?) shell of about 70'x32' made of Portland cement and granite gravel. They want to convert this to a house and would like to find out about the radon that might be present and, if present, how they might control its emission from the walls and floor. What would be the best method for measuring the radon in this case? Do you rent the equipment and do radioanalysis? I appreciate anything you can suggest."

Question 17:  "Dear Sirs, I have a question… How much radiation (in nano curies) does 1 gram of Ra-226 or Ra-228 produce? This related to Na-4-mica absorption of radium: If 1 g of mica can absorb o.2 g of radium from water, how many nano curies did I use up? Thank you very much, Best regards."

Question 16:  "Hi, I really need your help. I'm not a health physicist by education, but I do work for the Radiation Safety Program at the University. I've been tasked to write the reports for research labs who are closing out which we feel should be written up to satisfy decommission and decontamination requirements. For the most part, gathering historical information is not a problem, or figuring out the DCGL's, it's the calculating of the MDC's or MDA's that are giving me the biggest trouble. I know for a fact that my learning style is with examples. A lot of the documents I've looked through will give me the formula used, a count reading, and then the answer. For some reason, whenever I try to plug the numbers into the formula, I don't get the same answer. So, either I'm plugging in the wrong numbers or my calculator is broken or I really don't know what I'm doing (I think this is the answer). I was really hoping you would have or would know where I could get some examples of the calculations done step by step. I've agonized over this for months, approaching a year, of reading and re-reading the manuals off and on depending on the work load. I feel really embarrassed about being so ignorant and un-educated about this. The University is a small school and we don't have much radioactive material, and as each year goes by, we have more labs closing out. Most of the isotopes we worry about is H-3 and C-14. I want to do a good job by my employer and by the school. I'm just worried (anxiety worried) the NRC will call one day to see one of the reports for a lab we closed out, but I don't have a report written up yet. The D & D is just so confusing and daunting. Can you please help? By the way, I've taken a D&D class. It was geared for more reactor type facilities dealing with several isotopes and more complicated decommissions, so that only confused (and freaked me out) more. I feel like I'm in a box with the walls closing in and I can't get out. Thank you so much in advance!"

Question 15:  "Hi, I represent a small granite counter tops producing company. As of the last news, we are concerned our granite slabs would be radioactive safe checked. Our plan is to get a proper certification. Please share your best advice in this situation. Would be very thankful and could share some interest."

Question 14:  "How many millirem is 180 microrem"

Question 13:   "I am trying to find a reference for watts of decay heat per curie of Arsenic-76 (As-76), a usually wonderful resource for many other isotopes (in case you get a question) is at http://ar.inel.gov/images/pdf/200109/2001092100987GSJ.pdf) but alas As-76 is not there. You might consider putting the data there in your Toolbox for Heat of decay (watts per curie). I would love to know the data on As-76. Just realized any other isotopes like 74 would be helpful as well."

Question 12:  "Hello I'm faced with a question and need some guidence. When given count rates cpm vs time in hours how would you ID two genetically independent radionuclides? Both are beta emitters, and they both precipitate in the solution AgNo3. How would you calculate their initial activity with a (DE=40%)?"

Question 11:  "I have just read in The New York Times about granite countertops giving off radon. I am thinking of getting a Safety Siren Pro 3 Radon Detectors, EPA Evaluated. How should I go about measuring my granite countertop, being that it is in the kitchen (very Humid). Also, how would I find hot spots if any existed?"

Question 10:  "Oh my gosh I'm so glad to find your site and this wonderful forum. I am very appreciative to ask you this and look forward to your answer, I had a terribly frightening experience at the doctor's office today and immediately jumped on the internet and found you so I hope you can shed light on this and tell me how much radiation I just inadvertently received. So here's the deal, I am pregnant and unfortunately need to go to bathroom often. I had to take my daughter to the doctor this morning because she broke her arm. We were waiting for the doctor in his office for about an hour until I finally couldn't stand it anymore...I had to go to the bathroom! So I headed down the hall and found a VERY tiny restroom with a wall ADJACENT to the office's x-ray room. The bathroom was SO SMALL, my legs and feet were TOUCHING the adjacent walls of x room WHEN THE X RAYS were being taken! I know there were x rays being taken because I could hear the loud "beeping" noise of each xray as it was taken. (I asked the x ray tech what the noise was and he said it was a beep to let the tech's know the x ray worked correctly and I also saw a person lying on the x ray table.) Anyway now I'm REALLY scared. Do you think my legs and body and feet touching the walls while the x rays gave me radiation? Do you also think the loud beeping noise was harmful? THank you!"

Question 9:  "I am a 27 year old female who has had multiple x-rays (maybe around 45-50), dye during an ASD closure, barium swallow for the GI tract, a hida scan and a CT scan. Do you think I could be over exposed and caused myself damage? I am fretting about it and don't know what I can do except not get any more tests! Thanks."

Question 8:  "Good Morning: I work strictly with non commercial reactors so my knowledge of particles is limited. We recently found one in a paint can removed from the rc which had recently been refueled. Radioanalysis confirmed it was Co60. My reading and studies for the NRRPT made it sound like particles were generally tiny fuel fragments that get irradiated which wouldn't have resulted in Co60. I guess my question is-a tiny particle of just Co60 is not a traditional particle right -but rather the result of a cleanliness problem (e.g. a metal speck that got irradiated intensely?). The whole space was surveyed and no other radioactivity could be found. Your opinion would be appreciated."

Question 7:  "I must be the worst web searcher in the entire world. My company desires to have an in-house radiation safety instructor (which is currently me) that has a certification recognized by the DOE. I have gone through a myriad of search combinations, and cannot find a plan of attack. How does one go about getting this type of certification?"

Question 6:  "What is the principle of liquid scintillation analyser and biological oxidiser"

Question 5:  "Hello, I had a question related to x-ray dose. A particular x-ray tube has an output of 523 mrem of exposure and 1088 mrem of ESE (entrance skin exposure) for a lateral lumbar spine x-ray at 80 kVp and 50 mAs. How would one estrapolate doses to specific organs, such as bone marrow, using these exposures? Would you use tissue weighting factors (Wt), and if so how? Thank you."

Question 4:  "Hello. When my mom bought ahome in included a old blue smoke detector that looked like a spaceship with windows all around it it was metal and has since been thrown away, bad but they did not know any better, my question is since i know nothing baout it except it was quite old perhaps it was a radium type could the cabinet she stored it in, why would you store a smoke detector in a cabinet?? be contaminated by the hot detector?? It was intact."

Question 3:  "I live on the 7th floor of an apartment building. A news truck parks outside our apartment building and broadcasts from the van's microwave antenna on a regular basis. Because I am on the 7th floor, I am at about the same height as the top of the antenna. I am wondering whether this could be exposing me to harmful radiation. Thanks."

Question 2:  "Hello. In search of a potential lump/lymph node in my abdomen I had a CT scan performed October 29, 2007. At that time I took a pregnancy test (home test) and got a negative result. A week after the CT I took another test (missed my period) and it was positive. I'm estimating that conception was October 14-17th time frame putting the fetus as between 14 and 16 days gestation at the time of the CT scan. My HCG levels are rising and things appear to be progressing normally. My question is this. How quickly can they determine the exposure of the fetus (since it was fully exposed) and how quickly would the exposure cause me to miscarry should this be the result. At this point based on some research it seems exposure either has no effect or causes miscarriage at that stage in development. Can you provide any guidance?"

Question 1:  "Our office (orthopaedics) is starting a digital medical records program, they do not want to put a computer IN the xray room because they think the xrays will damage the computer. ( I am a Registered Radiologic Technologist ) (the proverbial "they" is management) What is your take on this? Thanks for a prompt response!"

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