The Atomic War at Home 1
In the 1500s, pitchblende miners in the Erz Mountains complained of a chest disease called mountain sickness later identified as lung cancer 2
Following the discovery of X-rays, many scientists tested radiation on themselves, eventually resulting in a number of early deaths. The mechanisms of illness were not understood. 3
In the 19 th and early 20 th centuries, X-rays were touted for medical treatment & healing 4
Radium beguiled consumers during the early 20 th century 5
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Radium was also used in a number of consumer and industrial products with sometimes deadly results 7
Casual uses of radiation continued until well after WW II: Kids could get their feet X-rayed for shoe fitting I remember the foot X-ray machine. I'm 62 now. Back about 1950 we lived in Miami Florida. Mom use to take my sister and me to the neighborhood "Stride- Rite" shoe store on Flagler Boulevard about twice a year. After we had our feet measured and picked out a pair of shoes we'd march right over to the X-Ray machine followed by mom and the shoe salesman. I'd step up on the platform, stick my feet in the recessed area and peer through the scope. The shoe salesman and mom would look through their own scopes while he pointed out the growth area in the toe. I got a real thrill looking at the bones in my feet. I doesn't seem to have done me or my sister any harm. http://www.spittingimage.net/archives/000497.html 8
The health benefits of radon are still touted today; see http://www.radonmine.com/ 9
Eventually, the deleterious health effects of radiation came to be widely recognized 10
The penetrating power of radiation is of particular concern 11
Different forms of radiation have different penetrating power 12
The effects of high doses are relatively wellknown and understood 13
Low-level effects are much less certain: How much radiation are people exposed to & what are its sources? 14
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What are the physiological effects of low doses of radiation? Is it good for you? Is it bad for you? What do the data say? There is still controversy 16
Natural background varies greatly, according to local geology and altitude 17
Average annual exposure from background is about 360 millirem which may contribute to some level of illness 18
The U.S. Atomic Energy Commission was particularly interested in determining the biological effects of low-levels of exposure Determine safe levels of exposure to atomic workers Assess exposure of public to test fallout for public health purposes Reassure public that exposures were not harmful Support nuclear power industrty AEC s safety standard for the general public of 100 sunshine units, the AEC-named unit for one picocurie of radioactivity from Sr-90 per gram of calcium (as, for example, in the body), determined by Edward Lewis. 19
On the one hand, radiation in low & controlled doses has therapeutic effects & diagnostic uses 20
On the other hand, sustained exposure to low doses poses serious problems, especially ion in the case of ingestion & inhalation of small quantities of radioactive materials 21
Sustained damage to cells may result, and can trigger cancers after a long latency period Diagram of the leukemia frequency among atomic bomb survivors by age at exposure, latent period, and city (Hiroshima, black; Nagasaki, hatched). ATB, at time of bomb. 22
There are a number of sources of data, but great uncertainty in measurements Radium Girls Navajo miners Human subjects Downwinders Atomic bomb survivors and other nuclear events (e.g., Chernobyl) 23
Epidemiology is probabilistic and depends on large N data sets 24
And there are multiple steps in estimating exposure and risk 25
Total external and internal radiation dose (mgy) to the thyroid of adults in the United States from all tests at the Nevada test site (background is about 3.6mGy/yr.) Exposure data are inferred from monitoring of fallout patterns, estimates of time spent in places, location relative to detonation: all of this is very uncertain 26
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The radium watch dial painters who ingested high amounts of Ra-228 tended to contract cancer; others did not 28
The incidence of excess cancers is highest among the youngest Hiroshima survivors (in excess of background rate) 29
Uranium miners show elevated levels of cancers and mortality due to radon exposure but effects depend on length of employment underground 30
The vulnerability of young children to Iodine 131 is clearly visible in this graph Some other malignancies have shown higher-thanexpected rates, but the exposure data are very unreliable 31
1997 Nat l Cancer Institute summary suggests that from 25,000 to 50,000 additional cases of thyroid disease and 2,500 deaths would be likely in fallout areas as diverse as New Mexico, New York, Massachusetts, Iowa, Oklahoma and Wisconsin. 32
Organ NRC Limit (mrem/year) University investigati on level (mrem) Comments Whole Body 5000 100 Lens of the Eye 15,000 300 Includes dose from both internal and external sources. The Whole Body limit applies to exposure of the torso and head when the radiation is penetrating enough to irradiate tissues at a depth of 1 cm where the deeper blood-forming tissues are located. The Lens of the Eye limit applies to exposure of the eye to radiation penetrating enough to irradiate the lens, at a depth of 0.3 cm. Legally permissible exposure limits are fairly low Extremities 50,000 1000 The extremities include the arm or leg below the elbow or knee. The Extremities limit applies to exposure of the extremities when the radiation is penetrating enough to irradiate tissues at a depth of 1 cm. Skin 50,000 1000 The Skin limit applies to dose deposited in the skin when the radiation is penetrating enough to irradiate tissues at a depth of 0.007 cm. Embryo/Fet us 500 (for the entire pregnancy) 50 Applies only when a Declaration of Pregnancy has been submitted Occupationa l exposure of a minor 10% of the limits above 50 Applies to anyone under 18 years of age Member of the general public 100 50 33
According to some research, low levels of radiation can have beneficial effects, and some groups, such as the American Nuclear Society, are calling for a re-evaluation of this point. 34
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