(October 29, 1999) The cancer-causing radioisotope Strontium-90 (Sr-90) has been found in the teeth of children born in the 1980's at levels equal to those of the middle 1950's when the US and the former Soviet Union were conducting routine aboveground bomb tests.
(520.5098) RPHP - Directors of the Radiation and Public Health Project (RPHP), who today released an initial report from an ongoing study of baby teeth, said their findings indicate that Americans continued to absorb radiation for years after all atmospheric nuclear testing ended in 1980.
The scientific paper based on the RPHP results has been accepted for publication in the International Journal of Health Services. A second paper has been accepted for presentation later in October at an international meeting of scientists in Italy. "The early results are quite alarming," said Dr. Ernest Sternglass, Professor Emeritus of Radiological Physics at the University of Pittsburgh School of Medicine and co-director of the study which played a key role in the scientific debate that led to the original banning of bomb tests. "The levels of Strontium-90 should have dropped down to near zero once humankind stopped exploding nuclear weapons in the atmosphere. Instead the levels stayed essentially the same as during the bomb-test years, or in some areas they even increased."
The RPHP researchers correlated one increase in Stronium-90 during the 1980's in Suffolk County, New York, to a corresponding rise in childhood leukemia and cancer (which also have been on the rise nationally since the early 1980's). Studies linking Strontium-90 to childhood cancer caused widespread health concerns during the Eisenhower and Kennedy administrations, resulting finally in the historic Nuclear Test Ban Treaty between the US and the USSR in 1963. The Treaty prohibited aboveground testing.
The new higher-than-expected levels of radiation were found in 515 teeth measured thus far, most of them of children born in the states of New York, New Jersey and Florida. Many of the areas where the teeth were collected are near nuclear power plants with a history of unusually large radiation releases. Strontium-90, a man-made element that was first introduced into nature as a byproduct of atomic bomb tests, is also produced by fission in nuclear reactors. It enters the body through drinking water and food, concentrating in bones and teeth.
The largest majority of teeth analyzed by the RPHP researchers were from the 1979-92 period and contained Strontium-90 in the range of 1.1 - 2.0 picocuries per gram of calcium. A few of the teeth were found to have reached levels as high as 16 or 17 picocuries per gram calcium. Baby teeth from the middle 1950's that were tested in a St. Louis-based teeth study contained approximately similar average concentrations. After reaching a peak in 1963, Strontium-90 levels in the US declined steadily but did not disappear entirely due to ongoing French and Chinese aboveground testing as well as releases from US and USSR underground testing and from a growing number of civilian reactors.
With the end of French and Chinese aboverground tests in 1980, the projected rate of decline of Strontium-90 levels should have dropped to about 0.1 picocuries/gram by 1990, according to Dr. Jay M. Gould, an RPHP co-director and statistician who previously served on the US Environmental Protection Agency (EPA) Science Advisory Board. Instead, the levels were still as high as 1.99 picocuries/gram in 1988 and had dropped only to 1.15 picocuries/gram in 1992. "The fact that we're finding numbers at much higher levels than we expected indicates that the dangers from radiation in our diet were not eliminated with the cessation of atmospheric bomb testing," Dr. Gould said. "Strontium-90 is still persisting in the human environment."
The RPHP researchers attributed some of the new radioactive fallout to the accidents at the US Three Mile Island reactor in 1979 and at the Chernobyl reactor in Russia (Ukraine) in 1986. In addition, they noted that state and federal records show a large amount of officially reported airborne emissions during the early 1980's from four nuclear reactors located in the vicinity of Suffolk County, the area from which the majority of the RPHP teeth were collected. "Regardless of the precise source of the radiation, it is clear that more investigation is urgently needed," Dr. Sternglass said. "It is especially urgent given that Strontium-90 is a known carcinogen and a marker for other shorter-lived fission products and simply should not be present at all in our children's teeth."
The private foundations supporting the RPHP study have agreed to assist in financing the collection and analysis of 5000 baby teeth over the next two years. At the same time, the RPHP directors called on the US government to conduct a national-scale study of Strontium-90 in the environment. The US Department of Energy ended a program in 1982 that previously measured the intake of Strontium-90 in adult diets, and the EPA stopped monthly reports of fission products in milk in 1990.
For more information on the RPHP project to collect teeth, see WISE News Communique 509/510: "The Tooth Fairy Project".
Source: Radiation and Public Health Project Press Release, 21 October 1999
Contact: RPHP, 302 W. 86th Street, Suit 118, New York, NY 10024, USA.
Tel: +1-212-496 6787; Fax: +1-212-362 0348
E-mail: JayMGould@aol.com
WWW: www.radiation.org