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Chapter X: U.S. Reversal on Detergent Phosphate
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in the united states, in mid-1971, the continuing need was to control cultural eutrophication. The scientific, governmental, and public view was that it could be controlled by reducing phosphorus inputs. Under governmental and public pressure, the detergent industry reluctantly had begun to reduce the phosphate content of detergents while continuing to maintain, however, that a satisfactory way of controlling detergent phosphate was to remove it, together with all the other phosphate in municipal wastewater, at wastewater treatment plants. Keenly aware of the intense antiphosphate sentiment, yet denied the use of NTA as a substitute for phosphates and finding themselves without a second satisfactory substitute , the leading U.S. detergent manufacturers, particularly Procter and Gamble, hoped that Surgeon General Steinfeld could soon be persuaded by new evidence to withdraw his disapproval of NTA. In the U.S., as in Canada, the National Institute of Environmental Health Sciences’ (NIEHS) studies of NTA were repeated by several parties. Early in 1971, data obtained from a series of studies by industrial and university scientists negated the NIEHS results.1 However, these new data were not accepted by the government as conclusive, and a joint government /industry review and analysis was initiated. General toxicological 157 U.S. Reversal on Detergent Phosphate C H A P T E R X studies were reviewed with an eye to possible mutagenic, teratogenic, and carcinogenic potentials of NTA. By June 1971, the joint study had concluded that NTA was not a mutagen. NTA did appear to enhance the teratogenicity of methylmercury under certain circumstances; but since methylmercury was itself a potent teratogen, U.S. Public Health Service scientists did not consider the enhancement significant. In 1972, the NIEHS director, David P. Rall, in testifying before Congress would say of the ChernoffCourtney studies: “As these were studies done .l.l. on a crash basis, the answers were looked for in a very short time line.l.l.l. Now, later, when much more careful studies were performed, it turned out that .l.l. the experiments were probably unrealistic; that is, there would be very, very much less NTA present in the environment than had been used in these studies.”2 That is what Canadian scientists had concluded in December 1970. Given the favorable outcome of the studies of NTA during the first half of 1971, and the fact that NTA continued to be used in detergents in Canada and Sweden, the U.S. industry believed that the government should cease to oppose its use in U.S. detergents. Furthermore, the industry had also found NTA not to be carcinogenic. In late August 1971, at a joint meeting of industrial and government scientists, data from a two-year Procter and Gamble study of rats fed NTA were examined for carcinogenic effects, and the following conclusions reached. Except for mammary tumors (to which the strain of rat used was susceptible), there was a low incidence of all types of tumors in both control and test animals. There was no significant increase in either the incidence of specific organ tumors or the total number of tumors in test animals. The tests were such that if NTA were an active carcinogen, it was most likely that such activity would have been detected . These same data were reviewed by many other scientists, including Samuel Epstein for the Senate Committee on Public Works.3 He reported that the incidence of tumors in test and control groups were in similar ranges. Any signs of carcinogenicity would have shown significant increases in tumors in the test animals. Subsequently, Surgeon General Steinfeld had the National Cancer Institute (NCI) conduct an independent review of the Procter and Gamble study. In its report of September 1, the NCI concluded: 158 U.S. Reversal on Detergent Phosphate [34.237.245.80] Project MUSE (2024-03-19 08:40 GMT) A. The [Procter and Gamble study] contained major weaknesses in both experimental design and execution. This resulted in a large loss of animals and tissues from many animals, which severely limited the degree of confidence in which it must be viewed. B. The study .l.l. is inadequate to provide evidence that NTA is not carcinogenic . C. Based upon the lack of large significant differences in the tumor incidences of treated and control animals, there is a reasonably high probability that NTA is not a very strong carcinogen under the conditions of the test. D. A general trend was observed in the treated groups toward increased incidence of non...