HOOKS
Dioxin's Threat to Human Health Reviewed by Robert A. Neal
During the past decade, no environmental pollutant has generated more public concern, regulatory attention, and press coverage than the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and a trace contaminant of it, 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD). The first association of TCDD with human illness occurred in the early 1950s. Throughout the 1950s and 1960s, there were additional reports of occupational illness resulting from exposure to TCDD present as a contaminant in 2,4,5-trichlorophenol, an intermediate used in the manufacture of 2,4,5-T, other trichlorophenoxy esters, and the bacteriostatic agent hexachlorophene. Concern for the safety of the general public was engendered by a report published in 1969, which indicated that 2,4,5-T contaminated with TCDD causes birth defects in mice. Subsequent research indicated that the TCDD contaminant, not 2,4,5-T, was responsible for the teratogenic effects. This concern for public safety regarding TCDD increased markedly when an industrial accident in Seveso, Italy, in 1976 resulted in the exposure of thousands of people living near a factory involved in making 2,4,5-trichlorophenol. Concern for the potential toxicity of TCDD to humans continues because of periodic discovery of cases of contamination of the environment from past disposal practices involving chemical wastes containing TCDD. In addition, it is now apparent that various chlorinated dioxins, including TCDD, are formed under certain conditions during the combustion of organic materials. In 'The Chemical Scythe: Lessons of 2,4,5-T and Dioxin," Alastair Hay has detailed the history of the public health concern that has surrounded the manufacture and use of 2,4,5-trichlorophenol, 2,4,5-T, hexachlorophene, and related compounds. Hay teaches in the department of chemi-
physicians, scientists, or lay personThus, there is little discriminaThe environmental and nel. tion between information contained in the refereed literature compared health hazards of to that contained in letters to the editor or quoted from public statedioxin contamination ments. For these reasons, the reader continue to be matters unfamiliar with the refereed literature available on this subject will find of wide public concern it difficult to determine the degree to which scientific data currently available support or do not sup"The Chemical Scythe: Lessons of port a correlation between exposure 2,4,5-T and Dioxin" by Alastair Hay, to 2,4,5-T or TCDD and the occurPlenum Press, 233 Spring St., New rence of various toxic effects in huYork, N.Y. 10013, 1982, 264 pages, mans. $27.50 In my view, another unfortunate aspect of "The Chemical Scythe" is Robert A. Neal, president of the Chemical Industry Institute of Toxicology, has the frequent inference that, in some instances involving human exposure written numerous original articles dealing with the metabolism and toxic effects ofto TCDD, industrial managers as well as federal and local officials have TCDD during the past decade been self-serving or have displayed insufficient concern for public health. Hay may have reasons to becal pathology of the University of lieve this is the case, although these Leeds in England. Although he has reasons are not well documented in not contributed to the refereed lit- his book. In any event, the frequent erature on TCDD, he has, during the reference to this premise detracts past few years, published a number from the factual accounts of these of letters to the editor on this incidences of human exposure to TCDD. subject. On the positive side, readers in"The Chemical Scythe" is written in a style that makes it understand- terested in learning of the various able to the ordinary reader. The hope points of views of the threat to is expressed in the foreword that the human health and the environment book also might be useful to "in- that results from exposure to TCDD dustrialists, manufacturers, govern- and related compounds, as expressed ment departments, administrators, by physicians, scientists, and lay planners, and academic scientists." In persons from various backgrounds, addition, Hay thinks the book also will find the book well worth readmay "provide a sound basis for future ing. Considerable detail of the cirhealth and safety plans." Unfortu- cumstances surrounding various innately, it falls somewhat short of cidents of human exposure to TCDD is provided. these goals. Two chapters are of particular inThe book is written in the style of a newspaper account. Therefore, its terest. One describes at length inusefulness to readers interested in dustrial accidents that have resulted determining the validity of scientific in human illness as a consequence of information concerning the toxic exposure to TCDD. These accounts effects of 2,4,5-T and TCDD in ex- provide more detail of these acciperimental animals and humans is dents under a single cover than has limited. Much of the information been available previously. Another cited is anecdotal in nature or con- chapter provides an account of the sists of letters or public statements by military use of defoliants that contain November 14, 1983 C&EN
41
How Exxon developed can double the productivity Guido Sartori's work on hindered amines may impact an entire industry.
Removing impurities such as car bon dioxide and hydrogen sulfide from natural, refinery, and synthesis gases is an expensive, energy-con suming process. But at Exxon Research and Engineering Company a new chem istry discovery, and cross functional teamwork, have led to the development of a new technology-one that signifi cantly decreases the cost and in creases the capacity of commercial gas treating processes.
Research Led to a Discovery Guido Sartori, a chemist in Exxon Research and Engineering Company had been conducting research on amines-organic nitrogen-containing molecules-to increase both the absorption rate and capacity of gas treating solutions. When impurities, such as C0 2 , come in contact with conventional amines, a strong bond is formed be
tween the C0 2 and the nitrogen atom of the amine. This strong bond ties up a disproportionate amount of useful amine. Sartori theorized that both the absorption rate and capacity of the amine would be improved if the bond at the nitrogen site could be weak ened. Continuing research revealed the advantages of a whole new class of amines, which he called hindered amines.
Observing Molecular Behavior Sartori and others began a com prehensive evaluation of the discov ery, utilizing the company's advanced analytical capabilities. To understand the behavior of hindered amines, and to monitor reactions, Sartori employed the results of carbon-13 nuclear mag netic resonance spectroscopy, a
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new molecules that of gas treating plants. state-of-the-art technique not previously used for this purpose. Further research confirmed the hindered amines' capability to substantially increase the rate and capacity of carbon dioxide absorption through the formation of low stability bonds. Low stability was achieved by placing a bulky substituent next to the nitrogen sites, thereby hindering bond formation with CO?· Building on this new understanding, ne synthesized new molecules to meet the performance requirements for specific applications,
Integrated Innovation Other Exxon organizations joined the effort to develop improved gas treating technology. After the hindered amines had been evaluated at the laboratory bench, process develop ment was required on a larger scale. A major pilot plant program confirmed, broadened and extended the bench scale results and helped to define the capabilities of the hindered amines. An engineering program was an inte-
gral part of the research and development required to convert these laboratory discoveries into commercially feasible technologies. Capacity increases of 50% have been achieved commercially using this technology with no added facilities. Through integrated innovation-the combined efforts of the company's basic research, process development, and engineering staffs-hindered amine technologies advanced from scientific discovery through commercial use in less than three years. Further research has enabled ER&E to identify or synthesize other practical hindered amines.
Exxon Research and Engineering Company Research on hindered amines is just one example of the numerous programs underway at ER&E. A wholly owned subsidiary of Exxon
Corporation, ER&E employs some 2,000 scientists and engineers working on petroleum products and processing, synthetic fuels, pioneering science and the engineering required to develop and apply new technology in the manufacture of fuels and other products. For more information on Exxon's hindered amine technology or ER&E, write Dr. Ε. Ε. David, President, Exxon Research and Engineering Company, Room 702, P.O. Box 101, Florham Park, New Jersey 07932. _____ (Z- % >'r-\*7l CIRCLE 13 ON READER SERVICE CARD
Books dioxins as contaminants. It details the. use of herbicides for military pur poses from the time of their general availability in 1941 through their use in Vietnam. It also contains an in teresting description of the activities of scientists and scientific organiza tions, which, at least in part, led to the end of defoliation operations in Vietnam. In summary, "The Chemical Scythe" may have been a more valu able contribution had Hay exercised greater care in indicating what in formation about the health effects of TCDD is conjecture, as compared to that which has been subject to com petent scientific review. However, on balance his book is a useful com pilation of information on TCDD from a variety of sources—informa tion that has been well organized and presented. D Adsorption from Solution at the Solid /Liq uid Interface. G. D. Parfitt, C. H. Rochester, editors, xi + 416 pages. Academic Press, 111 Fifth Ave., New York, N.Y. 10003. 1983. $79.50. Advances in Infrared and Raman Spectros copy. Vol. 10. R. J. H. Clark, R. E. Hester, edi tors, xv + 454 pages. John Wiley & Sons Inc., 605 Third Ave., New York, N.Y. 10016.1983. $110. Annual Review of Nutrition. Vol 3. William J. Darby, Harry P. Broquist, Robert E. Olson, editors, viii + 478 pages. Annual Reviews, 4139 El Camino Way, Palo Alto, Calif. 94306. 1983. $27. The Application of Laser Light Scattering to the Study of Biological Motion. J. C. Earnshaw, M. W. Steer, editors, xiii + 705 pages. Plenum Press, 233 Spring St., New York, N.Y. 10013.1983. $89.50. ASM Handbook of Engineering Mathemat ics. Mamerto L. Chu et al. xiv + 697 pages. American Society for Metals, Metals Park, Ohio 44073.1983. $72. Black Apollo of Science: The Life of Ernest Everett Just. Kenneth R. Manning. 397 pages. Oxford University Press, 200 Madison Ave., New York, N.Y. 10016.1983. $29.95.
Chemistry and Modern Society. ACS Sym posium Series 228. John Parascandola, James C. Whorton, editors, xv + 203 pages. American Chemical Society, 1155—16th St., N.W., Washington, D.C. 20036.1983. $24.95.
Fate of Chemicals in the Environment. ACS Symposium Series 225. Robert L. Swann, Alan Eschenroeder, editors, χ + 320 pages. Ameri can Chemical Society, 1155—16th St., N.W., Washington, D.C. 20036.1983. $44.95.
Chemistry, Man, and Society. 4th Ed. Mark M. Jones et al. xi + 513 pages. Saunders Col lege Publishing, 383 Madison Ave., New York, N.Y. 10017.1983. $27.95.
Ferritic Steels for High-Temperature Ap plications. Ashok K. Khare, editor, χ + 334 pages. American Society for Metals, Metals Park, Ohio 44073.1983. $54.
Chemorheology of Thermosetting Polymers. ACS Symposium Series 227. Clayton A. May, editor, χ + 325 pages. American Chemical So ciety, 1155—16th St., N.W., Washington, D.C. 20036.1983. $44.95.
Finite Element Computational Fluid Me chanics. A. J. Baker, χν + 510 pages. Hemi sphere Publishing Corp., 19 West 44th St., New York, N.Y. 10036.1983. $39.50.
Computational Methods for Turbulent, Transonic, and Viscous Flows. J. A. Essers, editor, vii + 360 pages. Hemisphere Publish ing Corp., 19 West 44th St., New York, N.Y. 10036.1983. $49.95. Computer-Aided Techniques in Food Tech nology. Israel Saguy, editor, χ + 494 pages. Marcel Dekker Inc., 270 Madison Ave., New York, N Y . 10016.1983. $69.75. Controlling In-Plant Airborne Contami nants: Systems Design and Calculations. John D. Constance, xvii + 341 pages. Marcel Dekker Inc., 270 Madison Ave., New York, N.Y. 10016. 1983. $45. CRC Handbook of Chemistry and Physics. 64th Ed. Robert C. Weast, Melvin J. Astle, William H. Beyer, editors. 2393 pages. CRC Press, 2000 Corporate Blvd. N.W., Boca Raton, Fla. 33431. 1983. U.S. $59.95; outside U.S. $69.50. Development and Control of Dust Explo sions. John Nagy, Harry C. Verakis. χ + 279 pages. Marcel Dekker Inc., 270 Madison Ave., New York, N.Y. 10016.1983. $55. Dietary Fats and Health. E. G. Perkins, W. J. Visek, editors, viii + 978 pages. American Oil Chemists' Society, 508 South Sixth St., Cham paign, 111. 61820. 1983. $49. Dopamine Receptors. ACS Symposium Series 224. Carl Kaiser, John W. Kebabian, editors, xiv + 289 pages. American Chemical Society, 1155—16th St., N.W., Washington, D.C. 20036. 1983. $34.95.
Effluent Treatment in the Process Industries. Institution of Chemical Engineers, Symposium Series No. 77. 356 pages. Pergamon Press, Maxwell House, Fairview Park, Elmsford, N.Y. Chemical Reaction Engineering — Plenary 10523. 1983. $59.50. Lectures. ACS Symposium Series 226. James Wei, Christos Georgakis, editors, xi + 202 Engineering Mechanics: Statics and Dy pages. American Chemical Society, 1155—16th namics. Bela I. Sandor. xvi + 992 pages. Pren St., N.W., Washington, D.C. 20036. 1983. tice-Hall Inc., Englewood Cliffs, N.J. 07632. $31.95. $37.95. 44
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Fluid Mixing Technology. James Y. Oldshue. xvi + 574 pages. McGraw-Hill Book Co., 1221 Ave. of the Americas, New York, N.Y. 10020. 1983. $37.50.
Paperbacks Combustion Toxicology: Principles and Test Methods. Harold L. Kaplan, Arthur F. Grand, Gordon E. Hartzell. xv + 174 pages. Technomic Publishing Co., 851 New Holland Ave., Lan caster, Pa. 17604.1983. $22. Glossary of Terms in Heat Transfer, Fluid Flow, and Related Topics. William Begell, editor, xv + 158 pages. Hemisphere Publish ing Corp., 19 West 44th St., New York, N.Y. 10036.1983. $29.95. Glycoproteins. R. C. Hughes. 95 pages. Chapman & Hall, 733 Third Ave., New York, N.Y. 10017.1983. $6.50. Laser Focus Buyers' Guide. 18th Ed. 544 pages. PennWell Publication, 119 Russell St., Little ton, Mass. 01460.1983. $30. The Mass Spec Handbook of Service. Vol. 1. John J. Manura, editor, χ + 302 pages. Scien tific Instrument Services, P.O. Box 159, Pen nington, N.J. 08534.1983. $39.95. Microbiology: A Laboratory Manual. James G. Cappuccino, Natalie Sherman, xiii + 466 pages. Addison-Wesley Publishing Co., Reading, Mass. 01867.1983. $16.95. Microwave Nondestructive Testing Meth ods. Alfred J. Bahr. xvi + 86 pages. Gordon & Breach Science Publishers, 1 Park Ave., New York, N.Y. 10016.1982. $26.95. User Guide on Process Integration for the Efficient Use of Energy. B. Linnhoff et al. v + 247 pages. Pergamon Press, Maxwell House, Fairview Park, Elmsford, N.Y. 10523. 1982. $25. Virology of Flowering Plants. W. A. Stevens, viii + 183 pages. Chapman & Hall, 733 Third Ave., New York, N.Y. 10017.1982. $18.95.
