NATURALLY DANGEROUS: Surprising Facts About Food, Health, and the Environment.
By James P. Collman, Professor of Chemistry, Stanford University
Chapter 10. We Are All Radioactive!
© James P. Collman, 2003. All rights reserved
The poisoning of Alexander Litovinenko, a former Soviet KGB agent, in November 2006 has been ascribed to an exotic radioactive isotope, Polonium-210. Litovinenko died 22 days after he was hospitalized, apparently from ingesting polonium in a London sushi bar. His assassins have not yet been identified, but the trail of this deadly radioactive material seems to lead back to Russia . Traces of polonium have been found on aircraft that flew between Moscow and London , suggesting a possible link to Russian agents.
The history of polonium is interesting. This rare element was isolated and identified in 1898 by Marie and Pierre Curie. It was named after Marie’s native country, Poland . The major isotope, polonium-210 is extremely toxic. It is estimated that one gram of polonium-210 could kill 100 million people! Polonium is also very rare; there are only 100 micrograms of polonium in one ton of uranium ore. In spite of its formidable toxicity, polonium is used in tiny amounts alloyed with other elements to reduce static charges and in larger amounts to provide heat on moon rovers. Polonium-210 is an alpha emitter with a very short half-life - about 138 days. Such a short half-life means that polonium-210 decomposes very rapidly. For example, one nanogram of polonium produces as many alpha particles in one second as do five grams of radium! Recall from Chapter 10 that alpha particles are helium nuclei and that alpha particles cannot penetrate a sheet of paper. Thus to kill, polonium-210 must enter the body of its victim by being ingested or breathed in. Chemically, polonium behaves like tellurium, a cousin of sulfur. Polonium concentrates in the spleen and liver of its victims, destroying these vital organs.
Because of its intense radioactivity, tiny amounts of polonium are easily detected; thus Litovinenko’s trail, after he was exposed to polonium, was easily followed. Even some of Litovinenko’s associates, and perhaps his assassins can also be identified because of their minor exposure to this deadly, radioactive element. Since polonium is a very rare element, nuclear reactors must be used to produce even small quantities of this material. For this reason, it seems likely that a national agency must have been involved in making the sample used to poison Litovinenko. Of course, Russia has such reactors and has manufactured this toxic, rare element.
Since President Jimmy Carter forbade processing spent fuel from nuclear power plants about 30 years ago, research on this method of reducing nuclear wastes and capturing new nuclear fuel has been ignored in the U.S. Now with rising interest in creating energy without generating the greenhouse gas, carbon dioxide, nuclear power is being reexamined. But a major problem is how to deal with radioactive wastes from nuclear power plants. Some scientists are proposing to resolve this problem by reprocessing radioactive wastes from power plants. This will require developing new reprocessing plants and new nuclear power reactors. The idea is to separate nuclear wastes into a mixture of uranium isotopes (approximately 93%), actinides such as plutonium (about 2%), and dangerous unusable radioactive wastes such as cesium and strontium (roughly 5%) by using an electroplating technique. The first two categories would be used as fuel in a new type of nuclear reactor; the third waste category would be stored in repositories such as Yuka Mountain, where the smaller bulk and lower temperatures would be easier to handle. There are problems and controversy. The plutonium waste could be stolen and used in atomic bombs. The new reactors would employ fast neutrons as opposed to the slow neutron reactors now used to generate nuclear power. These fast neutron reactors generate higher temperatures such that they cannot be cooled with water, but require other heat exchangers such as molten sodium. As political pressure builds to deal with the Global Warming phenomenon, expect new research focused on solving this promising, but difficult method of solving the nuclear waste problem. (The New York Times, December 27, 2005, page D3)
The August issue of Consumer Reports analyzes irradiated meat with mixed results. Irradiated ground beef and chicken have begun to appear in supermarkets and restaurants. The tone of this Consumer Reports article is skeptical; there is more bad new than good news. The good news is that irradiated meats are safe to eat and they contain much lower levels of harmful bacteria compared with comparable, non-irradiated meat. But irradiated meat is not completely safe; it contains some bacteria and if not properly handled, it can become just as contaminated and dangerous as ordinary meat. The relative bad news is that a staff of experienced taste testers noted a slight off-taste and smell in irradiated beef. Even ketchup did not completely disguise this off-taste or smell – likened to singed hair (ugh).
It has been estimated that irradiating only half of all ground beef, poultry, and pork in the U.S. each year would prevent 900,000 instances of infections related to eating contaminated meats and would prevent 6,000 serious illnesses and 350 deaths. The CDC (center for disease control) estimates that 20% of illnesses from eating food that is contaminated with bacteria can be traced to poor hygiene by food handlers. An alternative inexpensive solution would be to spray blocks of beef with lactic acid before grinding hamburger. No taste tests of such ground beef were reported. In January 2004, the USDA will permit school districts the option of using irradiated ground beef for school lunches; naturally, the politically correct Berkeley, CA school board has prohibited this practice. After all, that city is a “nuclear free zone”.
Which consumers, if any, should purchase irradiated meats? If you want your hamburger rare (your Author does) this might be an option, but for a higher price, one can buy meat that is ground by your butcher in a reliable butcher shop. The issues are taste, safety and price.
The Consumer Report stresses that powerful gamma rays are used, 15 million times the energy of a typical chest x-ray and 150 times the dose that would kill an adult, but of course the cow is already dead! Another objection, which has been raised by Germany’s Federal Research Centre for Nutrition, is that unique chemicals called 2-alkylcyclobuanones are formed during irradiating the fat in meat. They suggest, but apparently have not established that these byproducts might act as tumor promoters in rats. On the other hand, three United Nations agencies, including the World Health Organization have had five committees study the safety of irradiated food and each has concluded that such foods are safe. In the end the market place and the taste will decide whether irradiated foods will be a commercial success.
In Chapter 10 the concept of hormesis is introduced by stating that small doses of radiation increase health and longevity. This controversial topic is developing legs and breadth. An article by Will Hively, published in Discover, December 2002, page 74 describes in lay terms statistical evidence supporting hormesis and connects it to a well accepted biological concept, homeostasis, as well as a very controversial European medical practice, homeopathy. If a broad concept of hormesis including toxic chemicals were to be widely accepted, this could have a substantial impact on environmental regulations. Hively’s article is centered around the findings of a mainstream toxicologist, Edward Calabrese, on the faculty of the University of Massachusetts in Amherst. The main idea behind hormesis is that poisons that injure or kill at high doses, are beneficial at low doses. Many reproducible statistical studies involving low dose exposure to radiation, and toxic chemicals such as arsenic, and even dioxin, appear to support this paradoxical idea. As these studies are published in refereed scientific journals, such as BELLE (Biological Effects of Low Level Exposures), this controversial concept will be discussed in the mainstream media. Hormesis has been sharply criticized in physicist Robert Ehrlich’s recent book: Nine Crazy Ideas in Science. To gain credibility a concept such as hormesis should have a plausible explanation. The rationale supporting hormesis may be found in a widely-accepted biological principle, homeostasis – the tendency for an organism to keep itself on balance by resisting a change. For example, when our bodies overheat, we sweat to cool ourselves. When bacteria invade us, the immune system is stimulated and remembers that danger so it can respond to a later invasion. One way of thinking about hormesis is: what doesn’t kill you makes you stronger. Even exercise falls under this rubric. Don’t carry these ideas too far; most scientists still scoff at homeopathy. However, we may need to reevaluate our standards for arsenic in drinking water, but hormesis should not become a license to pollute. Another difficulty is that these positive responses to dilute toxins may vary with age groups, among individuals, and different races.
In late 2002, irradiated beef and chicken began to come on the market in many parts of the country, but progress is slow in Northern California, especially in politically correct Berkeley, where organic food is popular. Omaha Steaks irradiated gourmet beef is being sold nationwide, even in the San Francisco Bay area. Twelve chains of supermarkets in Eastern and Midwestern states began to introduce irradiated meats following the recall of 19 million pounds of raw hamburger because of possible contamination with E. coli. Schools may soon be allowed to serve irradiated meat for lunch, previously, this was not allowed.
Most irradiation is done with accelerated electrons, or in a few cases with gamma rays. Spices and tropical fruits such of papayas have long been irradiated; most people have eaten these irradiated foods without realizing it. The FDA is being petitioned to change labeling requirements by substituting cold pasteurization for treated by irradiation. These changes would be cosmetic but are necessary because scientific illiterate consumers fear and avoid irradiated food. This public health issue in which consumers have the choice of avoiding bacteria free food, is being resisted by anti-irradiation activists, who want to impose their sense of morality on the general public. (See also Chapter 6.)