ECOLOGY:
Getting out of hand In addition to contributing to the eutrophication of our waters, overuse of phosphates is hastening the arrival of an even more serious problem—running out. That's one conclusion reached in "Man in the Living Environment/' a report on global ecological problems just released by the Institute of Ecology (C&EN, Feb. 1, page 40). The report is intended for presentation to the 1972 United Nations conference on the environment. That finding might seem ironic to phosphate producers struggling to get a decent price for a commodity that seems to be a glut on the market. But of the key elements essential to life, the institute says, phosphorus is the most nearly limited and the least efficiently recycled element in nature. If current trends continue, in 60 years the world's population will have grown to 11 billion, and known reserves of phosphorus will have been used up. New reserves will be discovered, but there is a limit—a "geological upper boundary"—of about 30 billion tons of usable phosphorus. Observing that without phosphate fertilizers world food production could support only about 2 billion people, the institute recommends more judicious use of fertilizer, development of economic methods to recover phosphorus wasted in sewage effluents, and development of "even more intensively managed" systems of agriculture—including aquaculture—"where the cycling of nutrients can be completely controlled." Additionally, the Institute of Ecology's report asserts that "mankind is on a collision course with nature" and calls for efforts to ensure "that the world population stops growing at the earliest possible date." The report, although refreshingly free of shrill polemics, notes increasing evidence that chemical control of agricultural pests "is getting out of hand." The institute urges "that a great deal of effort be put into seeking alternatives" such as crop rotation, biological controls, and "deliberate planning to give the greatest possible amount of species diversity." Industrial pollution is a clear threat, the institute concludes. The effects of some toxic substances may as yet be little understood, but there is ample cause for alarm; it is
essential "to contain these substances within the industrial process." The report recommends an international pollution control commission, with power to set and enforce standards for toxic materials in foods and in the environment. PHEROMONES:
Housefly attractant isolated A sex attractant pheromone of the common housefly has been isolated, identified, and synthesized by a team of entomologists and chemists at laboratories of the U.S. Department of Agriculture's Agricultural Research Service in Gainesville, Fla., and Beltsville, Md. Although not as powerful an attractant as some other insect pheromones, the chemical may be manufactured inexpensively and offers the potential of at least reducing the amount of insecticide needed to control this disease-spreading pest. The sex attractant is cis-9-tricosene, a straight-chain monoolefin with 23 carbons [Science, 174, 76 (1971)]. The name muscalure— after the housefly's name of Musca domestica—has been proposed for the compound by ARS scientists David A. Carlson, M. S. Myer, D. L. Silhacek, and J. D. James in Gainesville and Morton Beroza and B. A. Bierl in Beltsville. Muscalure is found in lipid extracts of the feces and cuticle of the sexually mature female fly. The cuticle is the insect's waxy or oily surface. The pheromone attracts only sexually mature males. The compound thus would not be successful in trapping all the flies in a person's home, for instance. Dr. Carlson and his coworkers isolate muscalure by washing female houseflies with hexane or Houseflies: attraction of muscalure
ether to remove cuticular lipids. The active hydrocarbon fraction is first separated by chromatography on a silicic acid column. Chromatography on a silver nitrate-silica gel column then yields the monoolefin fraction. The three major olefins in this fraction have 23, 27, and 29 carbons. The 23-carbon olefin, muscalure, can be isolated by preparative gas chromatography and is the only compound showing significant activity as a sex attractant. A 23-carbon monoolefin isolated from fly feces is indistinguishable from the cuticular compound. Muscalure can be synthesized by a Wittig reaction starting with 1bromotetradecane and nonanal. The cis isomer is 85% of the product and can be separated by column chromatography. In limited field trials, muscalure doubled the number of flies on test grids. Further field testing lies ahead, as well as development of trapping devices that might include insecticides or sticky paper. RE-REFINING:
Processes avoid polluting U.S. motorists discard about 1.25 billion gallons of oil every year by changing the oil in their automobile engines. More than 75% of this oil is simply dumped or burned, polluting air, land, and water, and wasting a valuable resource. Some of the oil is recycled by re-refining it, but the re-refining process produces an acid sludge that is nearly as great a pollutant as the dirty oil. Now, however, a father and son research team, Louis E. and Edward T. Cutler, maintain that they have perfected three new processes that make it cheaper to re-refine the oil and that eliminate polluting byproducts. The re-refining industry has fallen on hard times during the past decade. Increasing use of additives has forced re-refiners to treat used oil with concentrated sulfuric acid to remove them. This treatment produces a useless acid sludge that must then be disposed of, and increases the difficulty of further treatment of the oil. According to the Association of Petroleum Re-refiners, moreover, the Government's imposition of a 6 cent-per-gallon tax on re-refined oil in 1965 has made re-refining economically noncompetitive. There were about 150 rerefiners in the U.S. in 1965, APR says. Now there are 50. OCT. 11, 1971 C&EN 9
