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September 6, 2004 | A version of this story appeared in Volume 82, Issue 36

Producing success

I took notice of one part of your review of "Knowledge and Competitive Advantage" (C&EN, July 12, page 31), which referred to the growth of the chemical industry in 19th-century Germany: "German universities educated a surplus of chemists, and the dye companies began to employ chemists in production jobs. The chemists experimented with plant processes to improve yields, giving the German companies cost advantages."

My experience suggests that this would be a rare occurrence in present-day America, because chemists are commonly regarded as overqualified for production work. Maybe there is something here to be learned from history.

Richard V. Cartwright
Essex Junction, Vt.

Solar shortfall

"Power From The Sun" was an interesting update on solar energy but misleading with regard to its real (that is, free of taxes and subsidies) costs and more anecdotal than scientific (C&EN, June 21, page 25).

When you ask power companies for an interruptible service rate, they will charge you about 90% of the full power rate. This is their "avoided fuel rate." It applies when you want to generate your own power but want network power part of the time or on standby. Typically, this means if you pay $0.13 per kWh, you can only reduce your bill by $0.013 per kWh. Your total real electric cost is nearly doubled. If you use a tax to promote large-scale solar power utilization, U.S. manufactured goods will be priced out of nearly all their markets.

The utilities are not being backward or arbitrary or mean-spirited; they want you to pay for your fair share of the fixed cost of the transmission lines, boilers, and generators and their maintenance so they can deliver the power when and if you need it. There are slightly lower rates available if you avoid their peak demand periods.

The biggest roadblock to photovoltaic (PV) use is a lack of storage systems with a low initial cost, deep cycles, and a long life for self-sufficient, continuous electric service. Perhaps the use of hybrid cars will stimulate the battery research needed to free solar power from the network. In addition, we need research to lower costs and improve the efficiency of PV cells. Both solar cells and batteries have been around for some time and extensively studied, so new developments are likely to be slow.

Robert O. Lindblom
Walnut Creek, Calif.

The sustainability problem

Your editor's pages "A Challenge We Must Meet" (C&EN, March 15, page 3) and "When Is Enough, Enough?" (C&EN, July 12, page 3) featured a thoughtful and tasteful selection of two excellent books: "Out of Gas: The End of the Age of Oil" by David Goodstein and "Red Sky at Morning: America and the Crisis of the Global Environment" by James G. Speth. The subjects discussed in the books are not new, but they are foremost issues that urgently deserve the society's full attention.

During the entire 20th century, the profit-driven capitalism and free-market economy have created an unprecedented vast amount of wealth at an unprecedented rate of rearranging Earth's resources, especially energy in the form of fossil fuels. In this human endeavor, the U.S. has emerged as the world leader due to a century of technological and economic development. Along with the successful development of the world, the human population has also been growing exponentially for decades, and as a result, the readily available natural resources on Earth are becoming gradually less available.

The most important challenge to us now, among others, is the relationship between humankind and Earth in terms of global energy and the environment, as renowned authors Goodstein and Speth and other prominent scientists have argued. The healthy, long-lasting relationship that we desire to establish depends on a sustainable world economy that further depends on sustainable energy. While we are enjoying the "seemingly abundant" fossil fuels as Nature's one-time gift, we should consciously and soberly keep in mind that complacency coupled with the lack of a sense of crisis eventually would not help us in pursuing sustainability for the future. Facing the greatest challenge of the 21st century, we need--more than ever before--a courageous, knowledgeable, and visionary leadership.

ACS, the world's largest scientific society, is well positioned to actively advocate the implementation of sound scientific recommendations regarding sustainability and to continue to reach out to the public and policymakers. Educating the public is always hard work, but as ACS members we have the right profession to educate ourselves and the people around us with respect to the issues of sustainable energy and environment. This is our inescapable duty and obligation to fulfill--we owe our future generations a clean global environment and a sustainable civilization since, according to Goodstein, "our children and grandchildren will not inherit the riches that we inherited."

Charles Rong

Regulation required

Michael J. Haas, in his letter on dietary supplement regulation, absolves the supplement/nutriceutical industry of the need for regulation a little too quickly by claiming herbal medicine has been relegated to the sidelines by modern medicine and therefore shouldn't be held to the same standards as pharmaceuticals (C&EN, July 26, page 6). A multi-billion-dollar industry is not a sideline, and millions of Americans use nutriceuticals and alternative medicine either alongside, or in place of, modern medicine. But there are good reasons to regulate dietary supplements that are neither the economic nor the cultural ones he dismisses.

First, although that industry is not permitted to claim to cure a disease with any of its products, anyone who sees TV commercials or Web popup ads knows that the herbal/nutriceutical ones often come close enough to such claims to fool a lot of people. How many people get proper treatment too late or even die because they rely on one of these products instead of consulting a physician? This was always the problem with "snake oil" products, and while many supplements may promote health and even contribute to ameliorating some conditions, others are no better than a placebo.

Second, even when the supplement does contain a genuinely potent and useful ingredient, there is the problem of uncertain content/dosage. This was always the problem with real herbal drugs; witness the loss of life when digitalis (foxglove) was part of the prescribed pharmacopeia before digoxin replaced it. It killed from both over- and underdosing. While most supplements will not be nearly so potent as this, we read constantly of analytical surveys that find the concentration of a substance in a commercial supplement is often far from the amount claimed on the label. When it is on the very low side, the consumer is essentially being defrauded. When it is on the high side, the supplement may indeed be dangerous.

Third, because the supplement industry is not required to demonstrate safety or efficacy as the pharmaceutical industry must, there is often knowledge neither of the therapeutic ratio (ratio of the therapeutic dose to the toxic one) nor of interactions with other drugs or supplements. Haas in effect plays down the hazard of ephedra by linking its dangers to co-consumption of caffeine, but with caffeine a nearly omnipresent food ingredient, should not the suppliers have been required to put a warning about co-consumption on their label? And even when the data are available, they are rarely given to the consumer. Vitamins A and D are quite toxic in too high doses, but I do not see any warnings on the innumerable brands of these in every supermarket, drugstore, and nutritional supplement emporium. (The Eskimos learned centuries ago to remove the liver from a slain seal and toss it in the sea because both dogs and humans could be poisoned by it. They had not heard of vitamins, but it is vitamin D that is the problem. How many dogs and Eskimos died before they had enough empirical data to eliminate the livers?)

If every consumer were a knowledgeable chemist, the dietary supplement industry could be left safely unregulated. We know all too well that most people are abysmally ignorant of chemistry and even biology. Smaller government may be a desirable goal in general, but it would be unethical to continue to leave supplements so loosely controlled under current circumstances.

Barry M. Jacobson
Ann Arbor, Mich.

Promising too much?

The article on embryonic stem cell (hESC) research mentioned several strong proponents but did not quote any skeptics (C&EN, July 19, page 16). However, it did admit that the promise for treating Alzheimer's disease was uncertain. Indeed, since Alzheimer's is caused by a flood of ß-amyloid (Aß)-killing neurons, a relatively small amount of introduced stem cells would also be expected to be overwhelmed by Aß.

Fortunately, several drugs are in the pipeline to inhibit the production of Aß. A vaccine has been developed that was successful in reversing the symptoms in a mouse model of Alzheimer's. Although a few adverse reactions caused the first clinical trial to be halted, work is continuing to develop an improved vaccine. Omentum transposition has been effective in treating not only Alzheimer's but also stroke and spinal cord damage.

I would expect that any introduction of hESC into a person would produce a massive immune reaction. At best, powerful immune-repressing drugs with attendant side effects would be needed. Even in the case of Alzheimer's, the blood/brain barrier is often defective, which would permit an adverse immune reaction. Successful development of adult stem cells could avoid this serious problem.

I am afraid that 50 years from now, hESC research will have proven to be a cul-de-sac as far as useful medical applications is concerned, but that a number of people will have gotten grants and publications doing research not requiring much creativity. In this case, the biomedical concerns of President George W. Bush are not even in conflict with good science.

Dean C. Luehrs
Sun City, Ariz.

A history of the actinides

K.M.Reese quotes a letter from John H. Marburger supporting a posthumous award to Gilbert Newton Lewis and notes significant later accomplishments of his most outstanding student, Glenn Seaborg (C&EN, June 28, page 96). With due respect, I address here a statement about Seaborg: "In 1944, he developed the 'actinide concept' of heavy-element electronic structure, probably his single greatest contribution to science."

Beginning in 1943, W. H. Zachariasen joined the wartime effort at the Metallurgical Laboratory at the University of Chicago to do chemical and X-ray powder diffraction studies leading to the structures of more than 70 compounds of the heavy elements from actinium on, often at the 10-g scale of material. An example is a sample of NpO2 that confirmed its existence and formula; his study also established the ionic radius, slightly larger (by 0.015Å) than that of Pu4+, slightly smaller (by 0.016Å) than that of U4+, and very near that of Ce4+. On June 22, 1944, Zachariasen stated, "I believe that the persistent valence is four and that thorium is to be regarded as the prototype of the regular rare-earth elements." These data indicate the lanthanide type of contraction.

Seaborg then, on July 14, 1944, dictated a memorandum that includes the sentence, "I suggest that the elements heavier than actinium be placed in the periodic table as an 'Actinide series.''' However, Zachariasen wrote, "The name actinide is not acceptable because thorium in solution is never actinide-like," and that only beginning at elements 95 and 96 were the elements rare-earth-like. Actually, some 20 years earlier, Niels Bohr predicted the transuranium elements as a 5f series beginning at element 95, and he also suggested that early valences of the 5f group are expected to be higher than those of the 4f group because the electrons would be less firmly held in the 5f group [Fysisk Tidrskrift, 19, 153 (1921); N. Bohr, "Theory of Spectra and Atomic Constitution," 1922, pages 109­113, 70 (Fig. 1)]. It is now known that localized electrons first appear at 95 (americium); moreover, in curium (96), the 5f shell is half-filled.


Zachariasen's 1948 papers [Phys. Rev., 70, 116 (1946); 73, 1104 (1948)] state that many investigators had predicted that a 5f series of elements would begin at the end of the then periodic system and that his crystal structures prove these earlier predictions. However, there are two prominent valence states. The trivalent state is known for actinium, uranium, neptunium, plutonium, and americium, but not for protactinium. The tetravalent state has been observed for all the elements from thorium to americium. "Accordingly, one should speak of the thoride series for the tetravalent state, and of an actinide series for the trivalent state." (See table III, crystal radii, in this 1948 paper.)

An outstanding account of the truly remarkable contributions of Zachariasen are well presented in Sidgwick's two-volume series (N. V. Sidgwick, "The Chemical Elements and Their Compounds, Vol. II," Oxford Clarendon Press, 1950, pages 1092­1096.) In 1946, Zachariasen summarized his crystal structures of 32 plutonium compounds and 13 neptunium compounds from X-ray diffraction of samples that at that time were too small for microchemical methods of analysis. A later account appeared in 1956 from the Proceedings of the International Conference on the Peaceful Uses of Atomic Energy Held in Geneva August 1955.

William N. Lipscomb
Nobel Laureate in Chemistry, 1976
Cambridge, Mass.


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