is that my father, Lloyd L. Smith, Sr., was a well-known engineer with a national reputation and although h e is now deceased, I like to have my identity kept separate from his. Also, I appear to be the only one of the committee whose title and department were omitted. As you will note from the letterhead, I am a senior professor in fisheries at the University of Minnesota whose work has been devoted for many years to problems of water quality. Lloyd L. Smith, Jr., Professor University of Minnesota Twin Cities St. Paul, Minn. 55101
Radiation Dear Sir: While your recent article, "Environmental Radiation Under Attack" (ES&T, Dec. 1973, p 1104) contains an informative review of some of the highlights of the 3rd Congress of the International Radiation Protection Association, l feel that some comments are in order. My impression of the Congress was that the principal attack, if any, was focused mainly upon larger than necessary medical radiation exposures, rather than on environmental radiation. As the article states, the two leading sources of radiation exposure of the general population are currently natural background and medical usages, both of which now average in the order of 100 mrem per year per capita. The current exposure attributable to nuclear power plants is much less than 1 mrem per year, and even with a large expansion of nuclear power, is anticipated to remain below 1 mrem per year. The prediction of deaths from these exposures by the National Academy of Sciences-Biological Effects of Ionizing Radiation (BEIR) Committee seems to me to be misleading and subject to misinterpretation. Certainly everyone will die sooner or later, so that the relevant issue is not numbers of deaths, but how much sooner as a result of exposure to radiation than without it. Without such judgments, the significance of the BElR Committee predictions cannot be assessed. Furthermore, the BElR predictions seem insufficiently qualified as upper risk estimates, particularly when applied to other than medical radiations, such as natural background and man-made environmental additions which generally occur at much lower dose rates. It is of interest that the 1972 Report of the United Nations Committee on the Effects of Atomic Radiation contains an indication of a reduced effect per unit of exposure for at least some types of radiation, as compared to those for high dose and dose rates from which most of the available experimental data on animals and human epidemiological data are available.
How big is your particulate problem?
GCAs Airborne Particulate Monitors give you direct readout of mass concentration. Based o n the principle of beta radiation absorption, these instruments are n o t significantly affected by variations in chemical composition, size or other particle p r o pert ies. Easy t o use, GCA's advanced line of particulate mass monitors provides direct digital readout of concentration immediately following sampling period. RDM-101 Short term samplingtimes in the order of minutes RDM-PO1 Provides time - averaged concentrations Sampling intervals inthe order of hours
PORTABLE MODELS Safety-approved by the U.S. Bureau of Mines', Models RDM-101 and RDM-201 are 6% Ib. portable instruments designed for monitoring dusts in working environments. RDM-101's digital readout indicates respirable or total dust concentrations in milligrams/cubic meter. The digital readout of RDM-201 indicates mass of total or respirable dust collected during sampling period. C O N T I N U O U S AUTOMATIC MONITOR
Model PMM-1 is designed for continuous unattended or manual monitoring of either ambient particulate concentrations or stationary and mobile source effluents. The instrument provides a direct readout of mass concentrations as low as one microgram/ cubic meter. Readouts can be either digital display or tape printout.
PMM-1
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GCA/TECHNOLOGY-DIVISION e o A CIRCLE 14 ON READER SERVICE CARD
Volume 8 , Number 4 , April 1974
293
Dissolved Oxygen Meter A tough new instrument specially designed for field applications dissolved oxygen ranges 0-5, 0-10 and 0-20 PPM accuracy z!11 yo temperature measurement -5 to -45°C automatic temperature compensation direct dial ocean salinity correction 2 "C" cells provide up to 1000 hours operation sealed, ruggedized meter will withstand 3-foot drop '/s "aluminum case i s watertight carrying handle serves as convenient stand re,corder output provided probes use simple air calibration technique pressure compensated probes for deep water use lead lengths available to 250' submersible stirrer, with built-in power supply, assures proper water flow
Ask for a demonstration o f the YSI Model 57 suitable for dissolved oxygen measurements just about anywhere.
CIRCLE 16 ON READER SERVICE CARD
294
Environmental Science & Technology
The BElR projections are perhaps the most reliable that can be made with present knowledge. However, risk estimates derivable from them should be viewed within contexts of the other risks generally accepted as part of living in a technological society. When this is done, those from man-made environmental radioactivity at current or anticipated levels seem vanishingly small. I t is well established that the principal effect of radiation is the production of leukemia and other forms of cancer. However, it is also obvious that many agents other than radiation must b e included in the current U.S. rate of some 325,000 cases per year. Contrary to the inpression created by the lead sentence in the article, the harmful effects of radiation on the population have been considered in far greater depth than those of any other potentially carcinogenic agent, natural or man-made, and generally abroad in the environment in small concentrations. Andrew P. Hull, Environmental Monitoring Brookhaven National Laboratory Associated Universities, Inc. Upton, L.I., N.Y. 11973 Wind power
Dear Sir: In our search for new sources of energy to meet our present shortage, it seems to m e that we are overlooking one of the most promising possibilities. It is clean, abundant, and inexhaustible. I ' m referring to wind power. Using the wind as a source of power is by no means a crackpot idea as most people obviously think it is, judging from the apparent lack of interest in trying to develop it. Until about 30 years ago, wind power was used on a majority of farms and ranches to pump water and generate electricity for those who had electricity. If it had not been for the money loaned, practically interest-free, by the Federal Government through the Rural Electrification Administration to build electric transmission lines; wind power would probably still be an important source of energy on the American farm and ranch. There are still mahy,windmills in use where electricity is not available and some even where it is. The windmill has always been, and still is, generally considered to be superior to the gasoline motor for pumping water for livestock. The people of Denmark, who have not been blessed with so much oil as the U.S., have been experimenting with wind power. They have built a wind-powered generator which has been successfully operating since 1957, producing electricity at the rate of some 200 kW or nearly 300 hP. A search for information on efforts made to develop the use of wind
power in this country will show that there has been almost none for the past 30 years, until recently. Recently Fairchild Industries has funded a project at Princeton to develop a more efficient windwheel to use on wind-powered generators. Also, a number of utility companies have recently contracted $132,000 with the Oregon State University to try to find a way to use the strong coastal winds to produce electricity. For many years Congress has given the oil industry a large tax incentive in the form of the so-called depletion allowance to encourage that industry to find oil reserves. Why not offer a similar tax incentive in the form of a production tax credit to manufacturers who produce and sell wind-powered equipment? (This is actually what the oil depletion allowance is.) This would be a strong incentive for industry to find new and practical ways to utilize wind power which is pollution-free, abundant, and inexhaustible. Stephen C. Tarver Gillette, Wyo. Disposing the undisposables
Dear Sir: I was much interested in the article (ES&T, Jan. 1974, p 18) which includes a description of Hoechst technology to convert chlorinated waste into carbon tetrachloride. There are a few minor corrections which I would draw to your attention concerning our affiliation and the name of the Hoechst process. The Hoechst-Uhde Corporation is the U.S. affiliate of Friedrich Uhde GmbH, a major international engineering and construction company whose headquarters are located in Dortmund, Germany. Our connection with Farbwerke Hoechst AG results from their 77.5% ownership of Friedrich Uhde GmbH. I can appreciate the difficulties in identifying the various processes that you have covered in your article, especially when it requires a title and generic references in the text of the article. I n any case, you should know that the technology which Farbwerke Hoechst AG developed is "chlorolysis" and this process has been publicized through a paper presented by our Dr. Weber at the ACS meetings in New York. The main purpose of my letter, however, is to alert you to other technologies which our company offers, which are of special interest in the environmental field. One example is our HCI electrolys,is technology which converts waste HCI into chlorine and hydrogen for commercial use. As you can imagine, this technology is receiving considerable attention due to environmental requirements which prohibit waste HCI disposal via deep well, ocean dumping, or into other bodies of water. Furthermore, the process is able to pro-
