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Nuclear Radiation: Is There A Safe Dose?

Posted Mar 31 2011 12:00am

Nuclear Radiation: There is No Safe Dose
by Romeo F. Quijano, M.D.
Professor
Department of Pharmacology and Toxicology
College of Medicine, UP Manila


After initially saying that radioactivity from Japan will not reach the Philippines, government officials now admit that radioactive fallout has in fact reached the country but say that levels detected are low and do not pose any health risk. This seemingly authoritative declaration that the Philippines is "safe" from radiation should not be allowed to blind the public to the real dangers brought about by the Japan Nuclear Reactor Disaster which has already surpassed the Three Mile Island incident and is alarmingly approaching the scale of the Chernobyl catastrophe.  Rather than downplaying a very serious catastrophe confronting the entire world and misleading the people, the government should address the full spectrum of public health and environmental problems caused by the release of ionizing radiation from the Fukushima Nuclear Power Plants.

The authorities apparently refer to the so-called standards of permissible or acceptable limits set by the International Commission on Radiation Protection (ICRP) and the US Nuclear Regulatory Commission as basis for declaring that exposure levels of the public are "small" and within "safety" limits and that significant risk of harm is limited to the immediate vicinity of the power plants. These standards, in fact, have been set to accommodate the interests of the nuclear industry and countries with nuclear weapons. The ICRP recommendations of exposure limits are not based on worker and public health criteria, but on value judgements with respect to the acceptability of risk estimates for what it sees as benefits of the activities. Since the decision makers, were either users of ionizing radiation in their employment, or are government regulators, primarily from countries with nuclear weapon programs, the vested interests are very clear.

Government "experts" are actually misinterpreting the standards used world-wide as the common basis for radiological protection standards. Even the ICRP stated that: "The permissible doses can therefore be expected to produce effects [illnesses] that could be detectable only by statistical methods applied to large groups." It further stated that:  "The commission believes that this level [5 rems radiation exposure per 30 years for the general public] provides reasonable latitude for the expansion of atomic energy programs in the foreseeable future. It should be emphasised that the limit may not in fact represent a proper balance between possible harm and probable benefit because of the uncertainty in assessing the risks and benefits that would justify the exposure." Thus, it is quite clear that even the ICRP recognizes that radiation exposure below "acceptable" levels could actually cause adverse health effects.  Yet, 5 rem per year, rather than per 30 years, was permitted for workers in the nuclear industry. The 5 rem per 30 years was set as the average dose to a population, with a maximum of 0.5 rem (5 msV) per year for any individual member of the public.

The concept of "permissible" or "acceptable" level is derived from toxicologic assumptions and extrapolations which do not constitute a valid rationale for a conclusion of "safety". The usual procedure for setting the standard for a toxic substance is to decide the relevant medical symptoms of toxicity and determine a dose level below which these symptoms do not occur. This cut-off point is called the "tolerance level". The tolerance level for a substance, if one can be determined, is then divided by a subjectively derived factor (10-100) to give a so-called "safe" level. This presumably allows for human variability of effects which may occur below the level at which there are no visible signs of toxicity. This rather limited concept, while useful for estimating risks from exposure to certain toxicants in particular situations, does not apply for toxic substances (like radioactive materials) which do not have any "tolerance" level, meaning, even the smallest possible dose can produce a toxic effect. At very low doses, effects are likely to be statistically hidden by normal biological variations, yet these effects are real. Even physicians attending to the affected people are usually not aware that the illnesses they are seeing are connected to the exposure.

For the past several years, health research on the effects of ionizing radiation exposure has focused on estimating the number of excess radiation-induced fatal cancers and excess severe genetic diseases to be expected in a population given the average estimated exposure to radiation for the country. Other radiation-related human tragedies such as earlier occurrence of cancers, endocrine disorders, immune dysfunction, developmental disorders, and other illnesses are not included. This averaging approach also fails to deal with global distribution of air and water with the result that deaths and the cumulative damage to future generations are not limited to one country.

The painful human experience from ionizing radiation since the US dropped nuclear bombs on Hiroshima and Nagasaki in 1945 has stimulated a tremendous growth in understanding the harmful effects of ionizing radiation on the human body, despite the official suppression of independent scientific data by the nuclear powers. Thanks to independent scientists, we now know that radiation has no safe level.
 
As early as 1955, Dr. Alice Stewart. who was head of the Department of Preventative Medicine at Oxford University, discovered that the number of children dying of leukemia had risen 50% in only a few years. She determined that babies born to mothers who had a series of maternal X-rays of the pelvic region during pregnancy were twice as likely to develop leukemia or cancer as babies of mothers who had not been X-rayed. These diagnostic X-rays exposed the patient to extremely low doses of radiation. Other researchers have since verified these findings and have shown the number of mutations to be in direct ratio to the amount of radiation received by the reproductive organs.
 
In 1970, Dr. Thomas Mancuso, a professor of occupational health at the University of Pittsburgh, was commissioned by the Atomic Energy Commission to study the “biological effects, if any, of low-level ionizing radiation among workers employed in atomic energy facilities”. It was expected that Mancuso’s study would find that nuclear work was safe. However, Dr. Mancuso's team found a definite relationship between low levels of radiation and the development of certain types of cancer in spite of the fact that all workers employed were specifically selected for their excellent health. They discovered three kinds of cancers among the workers: lung cancer, pancreatic cancer and cancers of blood-forming tissues, particularly Myeloma. The cancers were occurring at well below the radiation exposure levels of the official limit of five rads per year. This meant that the current standards for nuclear safety might be twenty times too high. However, there were powerful forces who suppressed the research. Mancuso’s funding was cut off and he was ordered not to publish his findings. He was denied further access to the workers’ data. In 1977 he was ordered to give up his files or have them seized.  Practically everyone who sided with Mancuso were subjected to character assassination or lost their funding. The government would only allow studies of workers health records to be performed by labs under them. The data of workers health became the virtual monopoly of a small group of government sponsored scientists and were unavailable to the larger scientific community.
 
Recently, Dr. Rosalie Bertell of the International Institute of Concern for Public Health revealed that there has been an effort to increase permissible doses of ionizing radiation to certain organs such as thyroid and bone marrow in spite of research showing the radiosensitivity of these tissues. This newer trend reflects political and economic, rather than scientific justifications. For example, the ICRP radiation recommendation for workers permits up to the equivalent bone marrow dose of 1,000 chest X-rays per year. ICRP recommended that members of the general public can receive up to one-tenth of the occupational exposure or 0.5 rem per year, the equivalent bone marrow dose of about 100 present-day chest X-rays per year. In 1978, ICRP recommended raising the levels of radiation permitted to humans from man-made sources of radiation, increasing the permitted bone marrow dose from 5 rem to 42 rem with apparently little regard for the increased damage to bones and blood-producing organs. ICRP reiterated the need to allow human exposure in order to "enjoy the economic and social benefits" of the nuclear industries despite the fact that so much new research was available documenting human illness associated with the "permissible" exposure levels.
 
The amount of radioactivity being released to the open environment from the Fukushima nuclear plants are by no means "small". It is difficult to estimate the actual amount of radioactivity released at this time, however, there is ample reason to believe that the seriousness of the accident has already exceeded that of the Three Mile Island incident which reportedly released a total of 13 million curies of radioactivity. A Chernobyl-like scenario is, in fact, more likely.
 
A radioactive substance is not like an ordinary poison that one can dilute to insignificant levels. The lowest dose of ionizing radiation is one nuclear track through one cell. You can't have a fraction of a dose of that sort.  The "small" amount of radiation, claimed to be "safe" by authorities, added to our increasingly fragile environment will cause serious harm to the health of human beings and other living organisms all over the world. Radioactive particles, especially Plutonium, Strontium, and Cesium are bioaccumulative, extremely persistent  and highly toxic. They travel long distances and will contaminate all regions on earth. Particularly devastating would be the inevitable damage to the genetic pool which will lead to an increase in the number of seriously defective offsprings who will be born in future generations. The number of children and grandchildren with birth defects, leukemia, cancer, immune disorders, endocrine disruption and other illnesses due to these officially "safe" levels of radioactivity might seem "statistically insignificant" to some in comparison with other known health hazards, but this is not just another health hazard and it is not just an issue of scientific debate. This is an issue of plain human decency and moral responsibility to our children and grandchildren who deserve to inherit a reasonably habitable earth as their forefathers have enjoyed. 


References:
3. Limitations of the ICRP Recommendations for Worker and Public Protection from Ionizing Radiation by Rosalie Bertell, Ph.D., GNSH, International
   Institute of Concern for Public Health; http://www.ccnr.org/radiatio4
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