Document DDzwzn3dJQqdN6r2rKwaBo834

Tgid' (polychlorinated biphenyl*), a group of Industrial chemical*, have been found In tliiue* of wildlife In many parts of the world (Environment, January/February 1970). Like DDT they have been Implicated In the decline of some bird population*. Now, a group of sclentlat* In the Netherlands has Identified two highly toxic contaminants In each of two PCS preparations, but failed to find them In a third. The contaminants may cause birth defects In man, and are chemically similar to tha dioxins, contaminants found In the weed-killers 2,4-Dand 2,4,5-T. The two compounds most heavily contaminated, Phenodor DPS and Clophen A60, are produced In Prance and Germany, respectively, while the third, Aroclor 1260, the uncontaminated compound, la formulated in the United State* by Monsanto Chemical Company. The contaminant compounda, chlorinated dlbenaofurans, were Isolated from the two European PCB compounds and Infected Into the air cells of chicken eggs at a calculated maximum dose of 0.2 microgram par egg. All of the embryos died within the first four days of Inoubatlon. Earlier studies of these compounds confirm their extreme toxicity. Single oral doses as low as 0.5 to 1.0 milligram per kilogram of body weight have produced severe and often fatal liver damage in rabbits. A spokesman for the Monsanto Chemical Company, the sol* producer of PCB compounds In this country, told Environment that because of differences in the manufacturing proeesa, chlorinated dlbenaofurans are not part of the company's final PCB product. Tha potential haxard of PCB was underlined by an action of the New York State Department of Agriculture, which condemned 130,000 spent laying chickens In Sullivan, Orange, and Holsten counties when the department found that PCBs In the fdt of the birds ranged from five to twenty parts per million. The chickens were to be used in food products. The source of the PCBs was traced to wafer-meal feed, a diet composed of stale bakery products. So far New York State officials have been unable to explain how the contaminant got into the feed, but they are Mr 1S1I continuing their Investigation. A spokesman for the Food and Drug Administration told Environment that the FDA is now conducting toxicity tests on PCB compounds In order to set guidelines for levels In food products. Until levels are set, the FDA will handle each case Individually. DDT MAY BE AFFECTING fertility in women, according to Drs. W.L. Heinrichs and R. J. Gellert, of the University of Washington Medical School. In a paper delivered at an Amerioan Cancer Society seminar, April 4, Heinrichs and Gellert explained that because DDT Is known to produce effects similar to those caused by the hormone estrogen, they treated newborn rats with fairly high levels of DDT on the second, third, and fourth days of Ufa to see If reproduction would be Impaired. The rats seemad to develop normally, wars fertile for a time, and than all of the treated rats became prematurely Infertile. The scientists felt that the DDT affected the brain of the newborn In such a way as to produce a permanent defect In the secretion of hormones that regulate fertility. Because DDT has been shown to be capable of entering the fetus in humans, Heinrichs and Gellert warned that "the possibility exists that some forma of Infertility or menstrual Irregularity In adults are associated with the presence of this ubiquitous chemical." NITROGEN, not phosphates. Is the limiting factor In eutrophication (overgrowth of algae) In the coastal marine environment, according to John H. Ryther and William M. Dunstan of the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts (Science, March 12). Ryther and Dunstan found that In the surface waters of the ocean there Is always a small, ubiquitous excess of phosphate, relative to the amount of nitrogen available for nutrient use by algae. Normally, the nutrient moat quickly consumed by a system , Is the one that limits the growth of that system. Ryther and Dunstan noted that although phosphatss are tha critical nutrient in many freshwater lakes. In coastal waters and estuaries, "It Is unquestionably nitrogen that MOWS 032543 25 limit* and controls algal growth and autrophloatlon." They further note that removing phosphates from detergents would at best be useless to the coastal waters that receive roughly half of the country's sewage. At worst, replacing phosphates with a nitrogen-containing compound (such as NTAI would probably Increase eutrophication along the nation's coastlines. The situation in freshwater lakes and streams may be quite different, however. THE FEDERAL Environmental Protection Agency (EPA) announced at a press conference March 18 that It was Initiating an administrative review of three pesticides--aldrln, dleldrln, and mlrex. EPA also disclosed that it was continuing its revlaw of DDT and the herbicide 2,4,5-T; not having found these substances to present an Imminent hasard to public health, EPA has not suspended the use of the chemicals. Aldrln, dleldrln, and mlrex may still be sold during the review process. Aldrln is used as an insecticide for com and citrus, and both aldrln and dleldrln are used for seed treatment and for termite control. Dleldrln Is a persistent ohemloal in the environment. (Aldrln quickly breaks down to dleldrln.) Dleldrln has been shown to be concentrated In the fatty tissues of a number of animals, Including man, and at low doses Is more toxic to warm-blooded animals than Is DDT. Mlrex, a persistent chemical known to be toxto to a variety of animals, Is used primarily by the U.S. Department of . Agriculture to control the fire ant (see. "Ant War," Environment, December 1970). . Following the administrative review, EPA .may cancel the registrations of the ohemlcala under consideration, or It may continue.their present registrations. More likely, though, a limitation will be pimped on the use of the chemicals. William Di Ruckelshaua,. . administrator of EPA, noted In this regard, "We are considerably strlctured by existing laws. We have asked Congress for a change In the law to permit us to exercise finer Judgments regarding the use of pesticides." MEASUREMENTS made by Dr. Robert W. as Rlsebrough, of the University of California at Berkeley, show that PCB and DDT compounds In urban sewage outfalls in California range from none detected to 220 pounds per day for PCBs and from none detected to 213 pounds per day for DDT. The highest figures, for both PCBs and DDT, were found at the White Point Sewage Treatment Plant, located In the Los Angeles area. The PCB outflow there was SO times more than at any of the other nine sampling stations; and the DDT outflow was more than one thousand times greater than that at any of the other stations. The White Point plant Is downstream from the Montrose Chemical Corporation, against whom the Environmental Defense Fund has filed a suit for discharging DDT into the Los Angeles sewer system. Although the White Point plant discharges a larger total quantity of PCBs than any of the other sampling stations, the concentration of PCBs In the effluent was found to be greatest at the Hyperion sludge plant (also In the Los Angeles area). The source of PCB compounds In the sewage Is not known. TESTS FOR the presence of seven metals In the nation's surface waters have revealed that although most of the water surveyed met U.S. Public Health Service (PHS) drinking water standards, some localised areas contained excessive amounts of arsenic, cadmium, chromium (hexavalent), cobalt, lead, zinc, or mercury. The U.S. Geological Survey, which conducted the testing, reported In a news release (March 31) that 4 percent of the 720 samples taken contained cadmium In excess of the PH8 standards. Two percent of the samples exceeded the PHS standard for arsenic. A few samples contained excess lead or mercury. No sample exceeded the PHS standard for chromium, and no standard has yet been set for either cobalt or sine In drinking water. Dr. William T. Pecora, director of the Geological Survey, noted that values obtained for individual samples mey not be typloal of the sampling sites because concentrations of contaminants may vary significantly. Pecora also pointed out that background levels of the seven metals In HONS 0325A4 Environment, Vol. 13. No. 4