patterns were found to be more com mon with those having lower MAO levels. So to further screen out some of the variables, the researchers picked a new group of 42 chronic schizophrenic patients. Excluded were any patients with abnormal brain wave patterns as well as any with mental retardation or suffering from severe drug or alcohol abuse. In this second study, chronic par anoid schizophrenics had a platelet MAO activity of 5.97. Nonparanoid schizophrenics had an activity of 9.81. The researchers conclude from their data that chronic paranoid schizophrenia might represent a separate disorder from the other chronic forms of schizophrenia. The correlation between paranoid schiz ophrenia and low platelet MAO ac tivity, they say, suggests at least some degree of biological difference be tween the different subgroups of schizophrenia. D
First TSCA toxicity tests get ACS support In a letter sent last week to Environ mental Protection Agency Adminis trator Douglas M. Costle, the Amer ican Chemical Society voiced its support of the agency's first choice of four individual and six classes of chemicals to be tested for health and environmental effects under the Toxic Substances Control Act. The substances to be tested are alkyl epoxides, alkyl phthalates, mono- and dichlorinated benzenes, chlorinated paraffins, chloromethane, cresoles, hexachloro-l,3-butadiene, nitrobenzene, toluene, and xylenes. To be conducted are tests for carci nogenicity, mutagenicity, teratoge nicity, chronic effects, environmental effects, and epidemiology. Not all items must undergo every test. The letter, signed by ACS presi dent Anna J. Harrison, comments that although "many choices could have been made, there is no uniquely definable list. However, we believe that the choices made appear to be good ones." The letter goes on to say that "the short initial list for priority testing and the selective nature of the testing recommendations indicate that close attention is being given to establishment of priorities and the delineation of the information rele vant to case-by-case regulatory deci sions. We strongly recommend that this emphasis on priority in selection and selectivity in testing be continued and further refined." As ACS points out, the list of 10 is longer than it seems. The cresols,
mono- and dichlorbenzenes, and xy lenes are 10 substances—not three. Thus, "toxicological testing of the chemicals in each category must of necessity be carried forward with specific compounds... and priorities for testing will have to be established within each category." And ACS suggests that in the future dermal and ocular toxicity may deserve more at tention in setting priorities, because skin problems represent about half of the chemically related problems seen by plant physicians. D
Bacterial gene spliced into eucaryotic DNA
added leucine is to make it by using the added gene. "It's the first con clusive evidence of gene transfer from bacteria to a higher organism," ac cording to the Cornell researchers. And the hybrid DNA piece doesn't just sit loosely inside the yeast. In stead, the entire piece with both a yeast and a bacterial portion is glued into place in the yeast. "It suggests that very different organisms may routinely exchange genetic informa tion in nature," according to Fink. The converse observation, that Escherichia coli might take up DNA from higher organisms, is being cited as reason for easing up on the NIH guidelines (C&EN, Jan. 9, page 25). The Cornell group's success with yeast makes that organism more at tractive for other recombinant DNA projects. Such yeasts are not patho genic. Also, they are easy to grow in large quantities—a desirable feature if plans materialize for producing human hormones by the new tech nology. Finally, yeasts are eucaryotes (higher organisms) and thus their genetic apparatus is more complex than bacteia. Some scientists believe that this may make them more suited for some kinds of recombinant DNA work. D
Genes shuttle between organisms nowadays like chemists between seminars. Both carry a new mix of information, which they don't always divulge, and their shuttling is eased by ever-improving techniques. For genes those techniques are a part of recombinant DNA technology in which DNA from one organism is cut, moved, and spliced onto the DNA of another organism. Last week, Dr. Gerald R. Fink in a seminar at Harvard medical school in Boston told of work that he and his col leagues, Dr. Albert Hinnen and Dr. James Hicks, are doing at Cornell Texaco gives details on University in Ithaca, Ν. Υ. That work involves moving a specific yeast gene chemical expansions into and back out of a bacterium, and finally back into a yeast. The yeast Texaco will put more than $500 mil gene carries a bit of bacterial DNA lion into new or expanded capacity to along, and the hybrid piece is taken make chemicals over the next two up by the recipient yeast's chromo years. The added facilities will be at some. There it resides—with the existing plants in three locations in yeast part functioning—without southeastern Texas. gumming up the yeast's genetic This expansion program represents works. a substantial increase in the compa The hybrid DNA piece was put into ny's chemicals capital investment. the yeast using a process called Without details of other future capi transformation that involves treating tal investments for chemicals, this yeast so that it takes up DNA mole project cost exceeds recent capital cules from the medium. It's the first investments for chemicals of $150 time yeast has been transformed, million in 1976 and $72 million in Fink says. The piece contains a yeast 1975. The investments will go for several gene specifying an enzyme that helps make the amino acid leucine. The different plants, all of which are remainder of the piece, called colicin scheduled to be on stream in 1979 or Ei, is a ring of DNA that is one of before. Some of the work already is several plasmids sanctioned for use under way, for example, an olefins by the National Institutes of plant at Port Arthur, Tex., with a capacity of 2 billion lb of ethylene Health. The particular hybrid DNA piece annually due on stream at midyear. Also at Port Arthur, Texaco will used in the Cornell experiments was constructed by Dr. John Carbon and expand its cyclohexane capacity. colleagues at the University of Cali When on stream in 1979, this capacity will be increased 40% to 50 million gal fornia, Santa Barbara. Fink and colleagues put the hybrid per year. Two existing ethylene oxide piece with the leucine gene into a units at the Port Neches, Tex., plant mutant yeast that requires leucine for will be converted to use oxygen in growth. Because the mutant is unable stead of air in their operation and to "revert" (correct its own defect), their combined capacity will be in the only way it can grow without creased to more than 700 million lb Jan. 16, 1978 C&EN
7
per year. The conversion will increase capacity some 220 million lb per year, or about 45%. A new ethanolamines unit will be built at the Port Neches plant. It will have a capacity of 150 million lb a year and be completed in 1979. These expansions of Texaco's petrochemical operations are additional steps of upgrading basic chemical materials. They will provide an outlet for part of the output from the new olefins unit at Port Arthur. However, even if these units provide outlets for ethylene and benzene, both now in considerable oversupply and facing price pressures, their products also face an oversupply situation. Cyclohexane production, for example, likely will be less than 80% of in-place capacity this year. Fortunately, Texaco's cyclohexane expansion of some 14 million to 15 million gal annually will be less than half of the forecast gains in demand. A similar situation exists for ethylene oxide. Production for 1977 annualized from 10 months' production reported by the International Trade Commission could reach 4.4 billion lb. U.S. capacity at year's end was about 6.2 billion lb to give an operating rate of more than 70%. Ethanolamines capacity utilization runs higher than for ethylene oxide, probably reaching about 80% in 1977. Production, about 305 million lb for 1977, would be up 7% over 1976. D
Industrial solvent may deplete ozone layer It's hardly news that a cure can be worse than the disease. Take the latest example: In recent years the use of trichloroethylene, a solvent widely used in industry for degreasing metal, has been restricted by several states on the grounds that its vapors contribute to photochemical smog. It also has been implicated in cancer in rats (C&EN, May 19,1975, page 41). So industry has been turning to 1,1,1 - tr ichloroethane, commonly called methyl chloroform, a more stable solvent classified as safe by the Environmental Protection Agency. Now, however, two Canadian scientists claim that 1,1,1-trichloroethane may be helping to destroy the earth's ozone layer. The scientists, Dr. J. C. McConnell and Dr. H. I. Schiff of York University, Downsview, Ont., reached this conclusion through a computer study of the chemical in a model atmosphere [Science, 199,174 (1978)1. They find that the compound could survive in the troposphere for about eight years before breaking down 8
C&EN Jan. 16, 1978
under attack by OH radicals. During building. A federal district court this time about 15% of the 1,1,1-tri- judge in Michigan dismissed the inchloroethane is transported to the dictment and said that the Clean Air stratosphere, say McConnell and Act of 1970 gave EPA the authority Schiff. Once there, it is rapidly pho- only to set emission standards but not tolyzed to yield CI and CIO radicals, to specify procedures to be used to achieve those standards. The U.S. 6th which can destroy ozone. Overall, the scientists say, 1,1,1- Circuit Court of Appeals later retrichloroethane molecules are not as versed the district court's decision on efficient in effecting ozone destruc- procedural grounds. Writing for the court majority, tion as the widely publicized chlorofluorocarbons. Nevertheless, they Justice William Rehnquist narrowly say, reasonable projections for the interpreted the 1970 law and said that release schedules of 1,1,1-trichlo- Congress had intended to put a roethane lead to a steady-state de- "quantitative limit on emissions" crease in ozone values about 20% as rather than spell out work practices to large as those resulting from the achieve the limits. continuous release of chlorofluoroIn the case of asbestos, EPA recarbons at the 1973 rates. quires that wrecking firms wet down Dow Chemical, the major producer asbestos material that could become of the compound, agrees. "We've airborne before demolishing a buildevaluated Dow's chlorinated solvents ing. But it doesn't spell out acceptable with regard to their ability to harm asbestos emission levels that result the upper atmosphere. We believe from the demolition activity. that at current (and future) producIn a dissenting opinion, Justice tion levels, 1,1,1-trichloroethane John Paul Stevens declared that last could have little, if any, significant week's ruling "has effectively made impact on the ozone layer," a Dow the asbestos standard, and any other spokesman says. D work practice rule as well, unenforceable." EPA had no comment on the decision, saying that agency laware studying the ruling. Supreme Court hits EPA yersLast year Congress amended the on work practice rules 1970 Clean Air Act and gave EPA specific authority to not only set The Supreme Court last week emission standards for industrial acstunned the Environmental Protec- tivity but to prescribe work practices tion Agency, temporarily at least, to be used. But in an apparent legiswhen it ruled five to four that al- lative oversight, according to a though the agency can set emission Washington lawyer who specializes in standards for hazardous air pollu- environmental cases, Congress netants it can't dictate to a firm how to glected to modify the enforcement provisions of the act to reflect EPA's meet those standards. The case was brought to the high newly delegated authority. Nevercourt by Adamo Wrecking Co. of theless, he says, last week's decision Detroit, which was indicted on crim- "probably lacks continuing legal iminal charges in 1974 for violating portance" because Congress doubtEPA's asbestos emission rules when less will act swiftly to correct the legal D the firm demolished a four-story defect in the 1977 law. ing wrecking are among those affected Rules for asbestos emission during bui
