Sunday, November 27, 2011

Wave Shield Revisited: Maybe Cell Phones Can Cause Brain Cancer

Over a year ago, I blogged about a product called a Wave Shield, sold to reduce the amount of RF (radio-frequency) radiation reaching one’s head while using a cell phone (“mobile phone” to non-U. S. readers). While I allowed that the existing body of research contained some slight indications that so-called “non-ionizing” radiation such as from a cell phone can have biological effects, the tone of my piece was pretty critical and came close to accusing the Wave Shield people of exploiting false fears. I now have cause to reconsider my words.

Back then, I wrote “The best I can tell from the decades of research is that, if there is any deleterious effect of cell-phone use in terms of causing brain cancer or other serious health problems, it is a very small effect and probably insignificant compared to most other elective hazards of daily life, such as using cell phones while driving.” I still stand by that statement, but I now have more information that makes me question my earlier critical tone.

Last week Mr. Howard Kalnitsky, who is evidently the CEO of Wave Shield, came across my year-old blog and wrote me to protest my treatment of his product. I asked him for solid evidence that cell phones can cause cancer, and he directed me to some websites and a book. The book is Disconnect: The Truth about Cell Phone Radiation, What the Industry Has Done to Hide It, and How to Protect Your Family, by a biomedical researcher named Devra Davis, who has in recent years turned to writing and advocacy in the environmental health area.

Davis’s book is a history of the way scientific research into the question of whether cell-phone radiation can cause biological harm to people has been funded, manipulated, and often suppressed by the cell-phone industry and others whose interests align with that industry. I have to admit that Davis has done her homework. She has interviewed numerous prominent figures such as Om P. Gandhi, professor of electrical engineering at the University of Utah; Franz Adlkofer, a prominent German biomedical researcher; Louis Slesin, editor of the iconoclastic independent publication Microwave News; and Allen Frey, who (according to Davis) published important work about how microwaves can lower the vital blood-brain barrier as long ago as 1975.

The gist of the book is that there in fact are numerous repeatable, verifiable effects that cell-phone emissions have on living tissue. Besides the aforementioned fact that it allows substances to cross the blood-brain barrier that normally protects the brain from a variety of harmful toxins, different researchers in various labs have all demonstrated that RF radiation can break DNA strands. This is one of the hallmarks of X-rays, and is the one of the important causes of cancer in people who are overexposed to ionizing radiation (such as X-rays and radiation from radioactive materials). And though the accepted wisdom was that RF radiation, whose quanta have insufficient energy to directly cause ionization of an atom, therefore could not cause such damage, there is apparently abundant experimental evidence that it does.

Davis doesn’t stop there. She cites numerous epidemiological studies of populations that use cell phones as well, some of which reveal increased rates of brain cancer. Such studies are difficult for a number of reasons. In many advanced countries, it’s hard to find a representative group of people who do not use cell phones to be the control group. And because the technology is constantly changing as people upgrade their phones, you may start out comparing apples but end up comparing oranges, so to speak, especially if the study is a good longitudinal one covering several years. Longitudinal studies are almost necessary in this field, because one of the main illnesses of interest—brain cancer—has been shown to have a long latency period, ten to thirty years, from the initial onset of the disease microscopically until symptoms appear. So it is a nasty problem to tackle.

Nevertheless, researchers have enough evidence to say that heavy use of cell phones can lead to a doubling of your chances of getting brain cancer over the historical normal rate. If you are a young person (under 21, say) and use one heavily for ten years, the risk factor may increase to as much as four times. The Central Brain Tumor Registry of the U. S. says that the incidence of primary malignant tumors in the brain and central nervous system for the years 2003-2007 was 6.5 cases per 100,000 person-years, and about an equal number of non-malignant tumors occurred in that period. To put this in perspective, that is about one-tenth the diagnosis rate of lung cancer, for instance. So if you smoke, don’t worry about brain cancer from your cell phone. You’ve got much worse problems to think about.

On the other hand, doing something that is only 10% as hazardous as smoking, relatively speaking, is not good if you can avoid it without serious inconveniences. Davis has a two-page section at the end of her book describing practical steps you can take to minimize your risk of developing health problems from cell-phone use, short of throwing your phone away. She advises not to keep a turned-on phone next to your body all day. Use a headset so your phone isn’t next to your brain. She is ambivalent about products such as Wave Shield, because they can interfere with the phone’s transmissions and cause it to emit even more energy than otherwise. The amount of energy delivered to the brain falls off very fast with distance, so having the thing even a half-inch away from your ear is a big improvement over clamping it to your head. And Davis notes that in recent years, many cell-phone marketers have inserted fine print in the instruction books telling users not to hold the phone right next to your head. As if anybody reads such stuff except lawyers.

And lawyers are exactly why such language is included, I’m sure. The most telling fact for me in Davis’s book is the news that some insurance companies are no longer willing to insure cell-phone firms against losses due to suits involving cell-phone-related health issues. When that happens, you know things are serious. It is in fact a glimmer of hope, because while the lack of research money has stifled much good work in this area, lack of insurance money may force the phone manufacturers to both acknowledge that their products may be dangerous, and find ways to make them less so. Let’s hope so, anyway.

Sources: Thanks to Howard Kalnitsky for informing me of Davis’s book and other resources on this issue. Devra Davis’s book Disconnect was published in 2010 by the Penguin Group. Her foundation’s website can be found at http://www.environmentalhealthtrust.org/. I used statistics from the websites http://www.cbtrus.org/factsheet/factsheet.html and http://www.cdc.gov/cancer/lung/statistics/. My original blog on Wave Shield was published on Oct. 25, 2010.

Monday, November 21, 2011

Destroying the Engineering Imagination

If our supply of future engineers dries up, nobody will be doing any kind of engineering, ethical or otherwise. So I think it is appropriate for me to address issues relating to engineering education from time to time, including those factors in the upbringing of young people that don’t fit into K-12 institutional studies. For example, as a parent, what could you do to encourage your children to be engineers? Or (what might be just as informative as a bad example), what could you do to keep them away from engineering?

Anthony Esolen has taken the latter approach. A professor of English literature at Rhode Island’s Providence College, he has written a book called Ten Ways to Destroy the Imagination of Your Child. Of course, he is advocating no such thing, but by firmly planting his tongue in his cheek, he indirectly advises parents about what sorts of things will foster and encourage a child’s imagination. He does this through a heavily ironic tone in which current child-rearing practices, systems of public education, and large swathes of the U. S. economy come in for severe criticism.

The part of the book that speaks most directly to the rearing (or discouragement) of future engineers is his Method 3, “Keep Children Away from Machines and Machinists.” With examples drawn from biographies (Edison, naturalist Louis Agassiz, amateur astronomer Charles Messier), older nonfiction books for children (e. g. the electronic hobbyist book series written by the redoubtable Alfred P. Morgan from the 1930s through the 1960s), and fiction (Swiss Family Robinson, the Wallace and Gromit animated films), Esolen shows the vivid contrast between the untrammeled freedom children in past generations had to watch craftsmen at work, read about fascinating machines and the ingenious self-reliant inventors who made them, and play at craftsmanship and invention themselves; and today’s typical childhood, which by contrast is a vast, dreary landscape of scheduled “activities,” indoctrination masquerading as education, and spare time spent in front of computers and video games, indoors, away from anything real that could conceivably be called truly adventurous.

Esolen is not bound by any desire to appear scientific, or particularly even-handed. Accordingly, he paints his picture in vivid, stark colors, leaving the impression that nothing much good has occurred in child-rearing, education, or the economy since about 1970. Mixed in with the more objective material are autobiographical sections in which Esolen recounts the hardscrabble environment of the Pennsylvania coal town where he grew up. So some of the exaggerated contrast between the dismal present and the golden-tinged past can be attributed to insufficiently compensated nostalgia, in my opinion.

This does not detract from the highly useful advice Esolen gives in his backhanded fashion about fostering what I would term the engineering imagination. The best engineers have well-developed imaginations that they use to create new ideas and products in their heads, well before anything exists even on paper, in a computer, or in reality. What Esolen has done is to show us ways that this kind of imagination takes root and grows in children’s minds, and what kinds of experiences and relationships can encourage it.

Structure and discipline are two important ingredients. The parents who would discourage the growth of an engineering imagination should keep their children away from maps, blueprints, and complicated games and stories. Also, people who do intricate skilled tasks with their hands—artists, hunters and fishermen, furniture makers, weavers—should be avoided. In the name of safety, keep children from tinkering with cars, taking things apart, playing with chemicals or fireworks, and using anything in any manner for which it was not intended. Esolen winds up his chapter with a wonderful list that I cannot resist reproducing in part here: “No soldering kits, no ham radios, no transformers, no catapults. No big drills, no routers, no table saws, no axes. . . . No vacuum tubes, no motherboards, no Bunsen burners, no sledges. . . . No gears, no sprockets, no flywheels, no springs, no spools. No trades, no gear, no tackle, and no trim.”

The last sentence is a reference to Gerard Manley Hopkins’ poem “Pied Beauty,” the one that begins, “Glory be to God for dappled things,” and praises the beauty of “áll trádes, their gear and tackle and trim.” Esolen writes from a deeply Christian viewpoint, although most of what he says can be taken seriously by believer and unbeliever alike. However, Christianity furnishes a philosophical framework that gives purpose and meaning to life, and counters the attitude behind sayings like, “Life sucks, and then you die.”

Imagination is closely related to the Christian virtue of hope. We cannot hope for what we cannot imagine, and if our imaginations are stunted and withered, hope suffers as well. At their best, engineers imagine a better future for people and then work to bring it into reality. Anthony Esolen has shown us how to stifle imagination, and therefore hope. But by taking the opposite of his advice, as he intends, we can foster a better future for ourselves and our children.

Sources: Ten Ways to Destroy the Imagination of Your Child, by Anthony Esolen, was published in 2010 by ISI Books, Wilmington, Delaware.

Sunday, November 13, 2011

Phobos-Grunt Flops, or, What’s In A Name?

It is obvious that the Russian Federal Space Agency does not have in its employ one of those multilingual specialists who makes sure that a brand name in one language doesn’t mean something embarrassing in another language. Otherwise the space probe intended to sample a piece of the Martian moon Phobos and return it to Earth would have been called something like Datari or Zeniflex—in other words, “Phobos-Grunt” would sound more like a drug, and less like a psychological problem. Far from being merely psychological, the spacecraft now poses a small but real threat to anyone residing between 51.4 degrees north latitude and 51.4 degrees south latitude—which includes most of the world’s population.

The Russians have not tried to launch a space probe for fifteen years. Phobos-Grunt (the Russian word that is transliterated “grunt” means just “soil”) had a noble goal: to fly to the larger of Mars’s two moons, take a nip out of it, and bring the nip back here so we could figure out why Phobos is the darkest large object in the solar system, among other things. Space probes that don’t use prohibitive amounts of fuel can’t be launched to Mars just any old time. There are fairly narrow launch windows, and the last one came in 2009 amid a near-panic-stricken rush which ended in the Russians concluding they’d better wait till next time.

Next time turned out to be last Wednesday. For a while, all went well as the first stage boosted the seven tons of highly toxic fuel and oxidizer, plus the three tons of spacecraft structure, into a low earth orbit from which it was supposed to take off for Mars. Only, it didn’t. Repeated commands to the rocket engines to fire were followed by attempts to wake up the system, and to receive any telemetry at all from it. Finally, on Saturday (yesterday, as I’m writing this Sunday) the agency admitted that the craft was lost. Its batteries, not designed to last long in Earth orbit, will run down soon, and after that it becomes a hazardous piece of space junk whose orbit will decay inside of a month. NASA is guessing late November will be when the hydrazine and nitrous oxide tanks will (mostly) burn up in the atmosphere before crashing somewhere.

Before you rush out and buy satellite-collision insurance, recall that two-thirds of the Earth’s surface is water. Still, it’s got to come down somewhere, and no one has had to adjudicate a situation in which a spacecraft launched by one nation has caused pain, injury, or the death of residents of another country. In peacetime, that is. Rockets launched as a part of war are a different matter.

It would be easy to criticize the peaceful scientific space exploration efforts of another country, formerly a space-program rival to the U. S. NASA has had its share of space-probe failures, although most of them are at least a decade old. Phobos-Grunt had a number of experiments on board, including an international one to see how well certain kinds of bacteria fared in outer space. It looks like they will get a chance to survive re-entry, but don’t put a lot of money on them making it.

The failure of an unmanned space probe is a different order of business from the failure of a manned flight. What makes this a little disquieting is that for the next several years, the U. S. must rely on Russia—or somebody—to ferry our astronauts to the International Space Station. As a matter of fact, this very night (late Sunday Central Standard Time) a Russian Soyuz is scheduled to take off carrying two cosmonauts and U. S. space veteran Daniel Burbank to the station. An unmanned flight last August using the same type of rocket didn’t work out when the third stage failed to ignite.

Given their complexity, extreme conditions under which they operate, and the onesy-twosy way space hardware is built, orbital spacecraft will probably never be as reliable as a five-year-old American car, for example. But you would think after throwing hardware into space for over half a century, the batting average of one of the major players in the business would be better than it is. Perhaps the Russian agency needs a little more of the famous transparency that has made NASA a favorite with engineering ethics writers. While transparency doesn’t automatically improve performance, it makes things very uncomfortable for bad performers, and that can be a good thing.

Best wishes to the space station commuters, and if you have any good ideas for a hydrazine-proof umbrella, send them my way.

Sources: The news on the Phobos-Grunt failure was carried by the Discovery Channel website at http://news.discovery.com/space/real-russian-roulette-toxic-phobos-grunt-reentry-111111.html, and coverage of the International Space Station flight was carried by CNET at http://news.cnet.com/8301-19514_3-57323809-239/russians-prep-soyuz-for-launch-to-international-space-station/.

Sunday, November 06, 2011

Fresh Water from Salt: The Environment of Desalination

A couple of weeks ago I had the privilege of visiting Doha, Qatar, in connection with an engineering ethics workshop at Texas A&M University Qatar. Qatar is a small nation on a peninsula in the Arabian (Persian) Gulf, almost destitute of natural resources except for oil and gas. These they have in abundance, and exchange for the more mundane necessities of life such as food and water. Especially water.

To support a population of 1.7 million, water desalination plants take seawater from the Gulf and deliver freshwater to the cities and towns, including the capital Doha. I have no statistics on Qatar’s per-capita water use, but Saudi Arabia’s is below the world average. From my very limited perspective, I did not see much in the way of water extravagance in Doha. The city was largely devoid of outdoor greenery except for small patches of grass in front of a few hotels. The larger private homes had gorgeous rose bushes climbing their back walls here and there. But by and large, it’s easy to tell that Doha is built in the middle of a desert.

Desalination is not without its environmental problems. There are two main technical processes in commercial use today: flash evaporation and reverse osmosis. The older flash evaporation method runs the salt water into a partial vacuum, which lowers the boiling point below what it is normally (around 100 C or 212 F). By arranging several stages with heat exchangers and varying pressure between stages, the flash evaporation process can be made fairly economical. But it is still energy-intensive and much more costly than any other kind of water treatment for freshwater sources.

About forty years ago, a lower-energy approach called reverse osmosis was commercialized. Crudely speaking, the salt water is sent through an osmosis membrane with pores so small that even sodium and chlorine ions can’t make it through. Regular “forward” osmosis causes water to flow from a region with lower ion concentrations to higher concentrations, with a resulting pressure difference across the barrier. To make the process run backwards, very high pressures are applied—upwards of tons per square inch. But everything happens more or less at room temperature, and high-pressure pumps use less energy per liter of water than the flash-evaporation technology does.

Both methods produce waste in the form of highly concentrated brine that is typically pumped back into the sea. If this is done carelessly, the dense brine (which also has anti-scaling chemicals added) stays on the sea floor and can harm or kill a wide variety of animal and plant life. At added expense, the brine can be diffused slowly through a large network of perforated pipes so that it doesn’t build up excessively in any one place. Or if there is a large flow of ordinary seawater available from the cooling system of a power plant, for example, the brine can be first diluted with the larger volume of seawater and then released. The second alternative makes sense if the desalination plant is operated in a “cogeneration” fashion, that is, by using waste heat or energy from a power plant (either nuclear or conventional fueled).

So far, desalination has not become a mainstream method of water production except in places that have enough cash to afford it, and don’t have other alternatives for freshwater resources. In the U. S., for example, which has the highest per-capita consumption of water in the world, we also have enough freshwater sources (so far) to avoid desalination altogether, except for a few special situations in California, Florida, and Texas.

Lack of clean drinking water is one of the major challenges in the path of improving the quality of life for billions of poor people around the globe. Unfortunately, unless a population is fairly close to the ocean and not too high in elevation, desalination is usually too expensive to be considered in comparison to simply piping freshwater from somewhere else. And it is not a technology that works well on a small scale, although I am aware of a few experimental projects which tried to develop household-size desalination plants. Even if they work, they are not as efficient as the larger units and produce a relatively large waste stream that has to be dealt with somehow.

As population pressures increase the demand for freshwater supplies, desalination should be considered as one of many options, including conservation, more intelligent utility pricing, and cooperation between private and public entities. In the U. S., the era of grand publicly-financed public works such as dams and aqueducts is mostly over. For one thing, most of the good sites for dams have dams on them already, and for another thing, the political climate in which large areas of land could be taken by eminent domain no longer exists in most places. If an environmentally friendly way can be found to power desalination plants (solar comes to mind), perhaps it will be a viable way to deal with future water crises. Here in central Texas, we are enduring the second year of a severe drought, and we’re considering all kinds of oddball ideas. But I hope the drought breaks before we have to ship desalinated water in from Galveston or somewhere.

Sources: I referred to the Wikipedia articles “desalination” and “reverse osmosis,” and a news article by Emmanuelle Landais in the Gulf News on desalination plants in the Arabian region at http://gulfnews.com/news/gulf/uae/environment/waste-dump-threatens-arabian-gulf-1.72058