ment to reduce the amount of chlo rine needed. Dr. Harvey H. Rosen of Union Carbide cites data from several studies by others showing that small doses of ozone are probably the most cost-effective way to reduce trihalomethane precursors. D
Levels of contaminants in water not hazardous The compounds that contaminate U.S. drinking water are not known to be health hazards at the concentra tions at which they are found in water, concludes an 18-month study of drinking water and health just re leased by the National Research Council. Nevertheless, uncertainties about the toxic and carcinogenic ef fects of many of these compounds dictate a cautious approach. The report, mandated by the 1974 Safe Drinking Water Act, reviews the data available on water contaminants and, where possible, proposes maxi mum safe levels for them. It is sup posed to provide a scientific basis for revising the primary drinking water regulations set up by the act. In almost every case, the report finds that information is lacking to establish a definite safe level for a contaminant. This is particularly true in the area of organic contaminants, especially those that may be carci nogenic. Here the report singles out 129 organic compounds, including 55 pesticides, for detailed examination. Of these, 22 are suspected carcino gens, either in animals or humans. The report estimates the human cancer risk based on lifetime expo sures for the 16 of these compounds for which data are available. Effects other than cancer also were evaluated for 45 compounds judged potentially toxic but not carcinogenic. For the latter group, where sufficient data are available, the levels found in water are substantially below the level likely to cause a hazard. Effects of other types of water contaminants also were assessed in the report. Some, such as radioactive materials, are at such low levels compared to natural background ra diation that their risk generally can be ignored, the report finds. Others, such as 22 inorganic materials, were found to be present at such low con centrations as to pose little or no threat to human health. However, the study does recommend re-evaluation of the present water standards for lead, arsenic, and selenium to increase the margin of safety now provided. Water treatment practices greatly reduce the incidence of disease caused by waterborne microorganisms, the
Organics In drinking water are below safety levels Maximum observed concentration in water, microgram/titer
Suggested no adverse effect revels iit water, microgram liter Estimate 1 * Estimate 2*
2,4-D
0,04
87.5
4.4
Alachlor
2.9
700.0
35.0
Butachtor
0.06
Paradichlorobenzene
6.0 1.0
70.0 7
3.5
Hexachforobenzene Atrazirte
5.0
150
7.5
Di-n-btityl phthalate
5.0
770
38.5
30,0
4200
Di(2-ethyl hexyl)phthalate Hexachlorophene
0.01
Methyl methacrylate
1.0
Pentachlorophenol
14
Styrene
1.0
f ί f
93.8
0.35 4.7
210
7 700
0.35 35.0
21 931
46.5
105
a Suggested levels are based on human adults weighing ?0 kg who have an average daily intake of 2 liters of water. Estimate 1 assumes 20% of total acceptable daily intake of the ohemloai in question comes from water. Estimate 2 assumes 1 % of total acceptable daily Intake comes from water.
report states. Chlorine has been the main disinfectant. Concern had been raised by other studies that chlorine, added to water to combat microor ganisms, might be reacting with or ganic contaminants to form possibly carcinogenic organochlorine com-
pounds. However, in 1975 alone, more than 10,000 cases of waterborne en teric disease were reported. This health hazard must be weighed against the possibility of forming carcinogens when evaluating the ap propriateness of chlorination. D
HEW panel recommends improvements for FDA Although the Food & Drug Adminis- I tration is neither pro- nor anti-in dustry, and its new drug approval system "is fundamentally sound," there is room for "substantial im provement," an independent review panel has concluded. Set up more than two years ago by the Depart ment of Health, Education & Wel fare, FDA's parent, the panel last week released its final report on agency "troubles" that began in the late 1960's and early 1970's. The panel and this final report are the result of allegations by FDA employees in 1974 before a Senate health subcommittee chaired by Sen. Edward M. Kennedy (D.-Mass.) that FDA was dominated by the drug in dustry. Chaired by lawyer Norman Dorsen of the New York University school of law, the panel singles out four areas for improvement in the way FDA functions, including: Open FDA's drug review process to public scruti ny; increase the agency's scientific facilities; improve standards for ap proval of drugs, and increase FDA's authority over drugs already mar keted. To this end, the report lists seven basic recommendations. Foremost is the suggestion that Congress rewrite the Food, Drug & Cosmetic Act so that scientific data submitted to FDA would be made public. To a large ex- |
tent this would end trade secrets, though the panel suggests a provision that such data may not be used by a drug sponsor's competitors to support a competing drug application. In addition, the panel recommends that FDA consider risks and benefits in passing on new drug applications. The current requirement that drugs must be shown "safe" and "effective" is "imprecise," according to the re port. FDA also should contract for independent spot checks of any ani mal testing data the agency believes to be incomplete or misleading. At the same time FDA also should take a look at the feasibility of large-scale independent clinical (human) testing of new drugs. Clinical testing now is conducted by drug firms. The internal mechanics of FDA also are addressed by the panel re port. For example, the panel says that the agency should develop a profes sional training program for its staff and relocate on a single, wellequipped campus which has adequate research and library facilities. In dealing with pharmaceutical firms, the panel believes the agency should adopt uniform rules governing communication between pharma ceutical firms and the FDA staff, and written correspondence should be the preferred form of contact. Reaction to the panel's conclusions is mixed. The Public Citizen Health June 6, 1977 C&EN
7
Dorsen: the public needs to know
Research Group, a Ralph Nader affiliate, applauds the report and says "the public needs vigilant, policemenlike scrutiny of industry claims for its products." The pharmaceutical industry's Washington representative, the Pharmaceutical Manufacturers Association, has withheld comment so far. It is still studying the report. D
Laser photochemistry draws research interest The relatively young field called laser-induced infrared photochemistry (LIIP) offers chemists a chance to alter reactions selectively and under mild conditions, says Dr. Robert J. Gordon of the University of Illinois, Chicago Circle. Speaking at the annual Conference on Laser Engineering Applications in Washington, D.C., last week, Gordon explained how this field already is attracting intense research efforts, and where it soon might provide practical dividends—for example, in the field of synthetic chemistry. Unlike conventional photochemistry, which irradiates molecules with either ultraviolet or visible light to excite them electronically, LIIP uses intense infrared lasers to excite molecules vibrationally or rotationally. Thus excited, they show unusual chemical properties. For instance, says Gordon, with lasers that are tuned to highly specific wave lengths, particular chemical bonds can be made to vibrate, and hence become more reactive than those between even nearby atoms. With this fine control, it's possible to react one or two compounds within a complex mixture by selectively exciting them, Gordon says. For example, trimethyl boron can be bromi8
C&EN June 6, 1977
nated stepwise to form boron tribromide. Conventionally, the successive intermediate reactions take place at increasingly higher temperatures. But, with appropriate laser excitation intermediate steps occur at ordinary temperatures. By tuning to the right frequency, individual steps can be singled out without affecting the other reactions. As a straight research tool, LIIP offers information on how increased vibrational energies affect reaction pathways. Gordon's group, for example, is studying the reactions of nitric oxide with ozone—a model system that bears on atmospheric chemistry. By exciting these two gases with a carbon dioxide laser, Gordon finds that vibrational energy is "50% effective in lowering activation energy." Whether similar effects occur in the upper atmosphere is open to speculation, adds Gordon, though it's known that molecules there are constantly bombarded by radiation. D
Industry employs fewer chemists and engineers It's been confirmed. Industrial employment of scientists and engineers declined 5% between 1970 and 1975, the first such decline in more than a decade. Employment among the group had risen 14% in the 1965-70 period and showed a 19% gain from 1960 to 1965. The largest decrease, 18%, occurred in employment of scientists and engineers by the manufacturers of durable goods, such as steel, transportation equipment, and electrical machinery. Employment of scientists and engineers among manufacturers of nondurable goods, such as chemicals, textiles, and petroleum, was down 8.6%. This trend was partially offset by an 11% rise in scientific and technical employment among nonmanufacturing industries. These are the conclusions drawn by the National Science Foundation from a nationwide survey of employers conducted by the Bureau of the Census in 1975. The last such survey was done in 1970. According to the NSF data, engineers accounted for 72% of the 1.03 million scientists and engineers employed by private industry in 1975. Of these, 34% were electrical engineers, 23% mechanical/aeronautical, 10% civil, 8% industrial, and 6% chemical engineers. The largest group of scientists was the 143,000 computer scientists, which was also the largest group of scientists employed by nonmanufacturing industries. Among the
104,000 physical scientists, chemists were the largest group at 65,000, more than three quarters of whom were employed in nondurable goods manufacturing industries. In 1975, according to NSF, 329,000 scientists and engineers were engaged in R&D activities, a decline of 12% from 1970 levels. R&D employment among manufacturers of durable goods was down 35%, to 172,000, and was down 10%, to 60,000, among manufacturers of nondurable goods. However, R&D employment in nonmanufacturing industries increased 31%, to 97,000. D
Argentine scientists' repression assailed U.S. scientists' concern over mistreatment of colleagues abroad continues to grow. In the latest step, "repression" of scientists in Argentina was assailed at a press conference in Washington, D.C., organized by the American Association for the Advancement of Science's Committee on Scientific Freedom & Responsibility, in cooperation with the Federation of American Scientists, American Physical Society, and National Academy of Sciences. Dr. Maximo Victoria, an Argentine physicist now in Belgium, described how he was "kidnapped" in April 1976, jailed without charge for seven months, and tortured. Arrested at the same time and undergoing similar treatment were nine fellow workers at the Argentine Atomic Energy Commission. Victoria explains that action against scientists is part of a general purge of thousands of intellectuals and opinion leaders in Argentina following a military coup in March 1976. Mass dismissals of scientists— most of them, like Victoria, politically inactive—have decimated research, he charges. For example, 62 of a staff of 100 at one institute were fired. AAAS also arranged for Victoria to testify before the Organization of American States' Inter-American Commission on Human Rights. AAAS is urging OAS to make an onsite investigation of human rights violations in Argentina, particularly the cases of 11 currently missing or imprisoned scientists. Five physicists on this list also are the object of NAS efforts (C&EN, May 2, page 8). Two further ideas under discussion: a visit to Argentina by a U.S. scientists' delegation; partial diversion by Congress of funds cut off from Argentina and other human rights violators to aid resettlement of their émigré sciD I entists and intellectuals.
