Health Effects of Ionizing Radiation
Types of Radiation
When radioactive material decays it gives off one or more of the following types of radiation: Alpha particles, Beta particles, X-rays and Gamma rays, and Neutrons. These rays and particles are called ionizing because as they tear through living tissue, they knock electrons out of their shells. The resulting atoms--called ions--are incomplete and unstable. Their structure and electrical balance have been disrupted.
Alpha particles are relatively large and slow but are also greatly ionized, meaning they can make the atoms they hit lose electrons very easily. They can do a lot of damage in a small area. Alpha particles can be stopped by paper or your skin but are extremely dangerous when inhaled. When inhaled, the smaller particles become stuck in the lungs and continually irradiate the area around them. In contrast, Gamma rays are sparsely ionizing. By not losing much energy knocking electrons around, they can travel farther into human tissue. They don't cause as much damage as an alpha particle per area, but a larger area is affected. Gamma rays penetrate right through the metal sides of the waste and transportation containers and into the human body. Beta particles fall somewhere in between. They are stopped by metal but not by paper or skin and are more energetic than alpha particles.
The radiation in contact-handled transuranic waste is mostly in the form of alpha particles but contains some gamma radiation because the transuranics decay into other elements like americium which do emit gamma rays. DOE is allowed to let 10 millirem per hour of gamma radiation come through the WIPP TRUPACT-II transportation container--measured at about 3 feet. (The maximum dose rate at the surface of the containers inside the transportation container--drums, standard waste boxes, etc.--can be as high as 200 millirem per hour.) Remote-handled waste has to be shielded with lead because most of its radiation is in the form of beta particles and gamma rays and the containers can emit up to 1000 rem per hour (measured at their surface). (The rem or Roentgen Equivalent Man, is a measure of the absorbed dose that takes into account the type of radiation (alpha, beta, or gamma), its intensity and its interaction with human tissue. A millirem is one-thousandth of a rem.)
The nuclear industry tries to keep radioactive exposure As Low As Reasonably Achievable (ALARA). This is not really an encouraging concept since it admits that the industry doesn't have the technical ability to keep exposure to zero. Exposure standards are set by the needs of the industry, not by health effects. Even so, what has been considered a "safe" dose has been steadily decreasing over the years.
In 1934 it was 30 rem.
In 1948 it was 15 rem.
In 1958 (and to the present) it was 5 rem for nuclear workers (the bone marrow equivalent of 1000 chest X-rays) and 0.5 rem for the public (100 chest X-rays).
Even now it is not clear that 5 and 0.5 rem are safe doses. Male nuclear workers in England who were within their safe dosage levels had more children with leukemia than men who were not dosed. This may be another case--all too frequent in the nuclear industry--of making the exposure limits fit the convenience of the industry instead of scientific and health standards. Some time ago the former Chairman of the International Commission on Radiological Protection indicated that if the worker exposure dose had been reduced from 5 to 0.5 rem per year in the early days of the industry, he doubted whether the nuclear power plants of the time could have continued operating. A dose that is "reasonably" or economically achievable may still cause death and disease.
Health Effects from Exposure
If you are acutely exposed to radiation (exposed once for a short period of time) you can expect the following health effects:
50 rem can alter white blood cells.
75 to 125 rem can produce radiation sickness.
400 rem will kill 50% of exposed people.
500 to 600 or more rem will kill almost all exposed people.
Since the dose on the surface of a remote-handled transuranic (RH-TRU) waste canister can be up to 1000 rem per hour, a person in contact with an undamaged canister could experience:
alteration of white blood cells in 3 minutes,
radiation sickness in 5-8 minutes,
death in 35-60 minutes.
Types of Exposure: Acute and Chronic
Some transportation loads will be very hot. The average load coming from the Savannah River Site has 95% of the radioactivity of a fuel assembly (part of the core of a nuclear reactor--very hot!). Shipping waste from there would be like shipping hundreds of fuel assemblies across the country. Other loads would include quantities of powdered plutonium. Powdered plutonium is particularly hazardous because it is so easily spread and so easily inhaled. It can also be resuspended or blown up into the air over and over again. If DOE does not impound food, water or timber contaminated by an accident or clean up radioactive land to the level needed to receive a zero dose from ingestion, people would receive secondary exposure through eating and drinking contaminated food and water and breathing smoke from contaminated wood fires and forest fires.
Even a contact-handled transuranic (CH-TRU) container is like a traveling X-ray machine. Regulations allow the dose 6 and a half feet from a transportation container on the road to be 10 millirem per hour--about the same amount of radiation as in the average chest X-ray. This radiation is penetrating radiation and can go through the sides of a car as well as into and through your body. Again, the nuclear industry does not have the ability to bring the dose down to zero.
Chronic low levels of exposure--like those that would occur during normal transportation and from living in an area contaminated by an accident--have serious effects, though these might not show up for years. There are many questions and much controversy about the effects of chronic, low level radiation exposure. Some scientists, like Dr. John Goffman, former Director of DOE's Lawrence Livermore National Laboratory, believe there is no safe dose and that effects of radiation exposure are cumulative, while others disagree. What is agreed upon, however, is that low dose exposure is much more harmful than was previously thought and that fetuses and infants are both at greatest risk. Radiation exposure has been linked with many different kinds of cancer as well as with immune system problems. If an egg or sperm cell is exposed, genetic mutation may occur. This can result in many different kinds of diseases including Down's syndrome, hemophilia and muscular dystrophy.
The State of New Mexico has studied Los Alamos County cancer incidence (where Los Alamos National Laboratory--LANL--is situated) during the 21 years from 1970 to 1990. Several types of cancer appeared elevated, though it was not possible to say with certainty that this was caused by radioactive exposure because Los Alamos County has so few people. It was certain, however, that "Los Alamos County experienced a sudden and marked increase in thyroid cancer incidence in the mid-1980s. The 1986-1990 county thyroid cancer incidence rate was nearly 4-fold higher than the rate..." for the rest of the state. Counties nearby and downstream from Los Alamos County also showed an elevated thyroid cancer rate.
At the WIPP site, during the operational phase, workers are those most likely to be exposed. They are allowed to receive 5 rem per year, much reduced from previous limits, but as noted above, even this amount may not be safe. EPA standards require that the WIPP project cause no more than one death every ten years or 1000 deaths in 10,000 years. It is not hard to imagine how an accident involving a very hot fire (like a propane truck fire) and powdered plutonium in an urban area like Albuquerque could exceed those figures. This type of low-probability, high-consequence accident caused by human error is often left out of risk assessments by the DOE even though human error has often been the main cause of major accidents. (Chernobyl was caused by human error, as was Three Mile Island.) At WIPP itself, DOE concluded that the possibility of a catastrophic accident occurring with the waste hoist was extremely improbable because it had an annual probability of only 1 in 60 million. Two years after this prediction, an accident did occur--caused by human error. Until DOE includes human error in its health risk assessments, it will be impossible to get a true picture of the actual risk to New Mexicans from the project.