P. O. Box 929
Upton NY 11973
Tel: 516-344-3100
Fax: 516-344-2887
Sidney H. Kahana, Vice President
George R. Hendrey, Secretary
Alfredo U. Luccio, Treasurer
Flawed Study of Strontium-90 in Deciduous Teeth
Dentists of Suffolk County have been asked to participate in a study supposedly intended to examine
Brookhaven National Laboratory. This study is inherently flawed for a number of reasons, as outlined
below. It is being conducted by anti-nuclear activist and self-proclaimed epidemiologist Jay M. Gould,
who claims, among other things, that ionizing radiation from nuclear weapons tests, reactors, and x-rays
plays an important role not only in breast cancer, but also AIDS, infant mortality, low-birthweight, and
the decline in SAT scores.
Dr. Gould hypothesizes a link between strontium-90 in the population, releases from BNL, and breast
cancer rates on Long Island. While elevated breast cancer rates on the East End are a concern to all
Long Islanders and need to be investigated, Dr. Gould would have us believe that these cancers are
attributable to BNL. Ostensibly as a test of this hypothesis, he has initiated a project to collect
deciduous teeth for measurement of their strontium-90 content and subsequent examination of links
between strontium-90 burden, location of residence of the individual, and perhaps cancer incidence.
Our first concern with this study is that it makes no recognition of the fact that strontium-90 is already
widespread in the environment. Strontium-90 is present at trace levels in food and surface water as a
legacy of above-ground nuclear weapons tests from 1945 to the late 1970's. (The buildup of strontium-
90 in the environment was one of the reasons that led to the Test Ban Treaty, which ended atmospheric
testing by the signatory countries.) Food, especially dairy products and leafy vegetables which are major
sources of dietary calcium, contains small amounts of strontium-90, which behaves chemically in the
body as an analog of calcium and hence localizes in bone and teeth. Every person alive today has
ingested some strontium-90 from food and water, and every developing tooth since 1945 has
incorporated some strontium-90. Therefore, teeth samples taken anywhere in the world, from anyone
younger than about 52 years, will contain strontium-90. The amount of strontium-90 present in a tooth
will be related to the individual's intake of strontium-90 associated with dietary calcium, during
gestation and early childhood, and not by where the person lives.
Any study to correlate enhanced strontium-90 levels with other variables must take into account
sources of dietary calcium. Very little of the food basket we Long Islanders consume is produced
locally, and because Long Island no longer has any commercial dairy farms, we consume milk from
New Jersey and upstate New York, and cheese and ice cream from as far away as Wisconsin and
Vermont. This means that any interpretation of strontium-90 in deciduous teeth from Long Islanders is
necessarily confounded by multiple source terms. Sorting out these confounding variables requires
careful identification of controls, quality assurance not just of the analytical procedures but also of the
diet of individuals, including any differences associated with economic status or change of residence,
and peer review. All these essential elements are absent from the Gould study.
A further concern with the Gould study is the assumption of guilt by association. The most likely
cancer to be caused by strontium-90 is not breast cancer, a solid tumor, but leukemia, resulting from
irradiation of the bone marrow. This health effect is well known from animal studies and epidemiology
of the Hiroshima and Nagasaki populations. Yet there is no indication of excess incidence of leukemia
on Long Island.
The radiation dose to Long Islanders from natural background and man-made sources is about 360
millirem per year. Of that total, 0.3% about 1 millirem per year comes from the legacy of atmospheric
nuclear weapons tests. Strontium-90 accounts for a fraction of that 1 millirem. Contrast this with dental
x-ray exposures. A dental x-ray examination results in approximately 10 millirem to the active bone
marrow. Thousands of dental patients on Long Island receive this radiation dose every year.
In conclusion Brookhaven Organization of Scientists urges dentists of Suffolk County not to
participate in the Gould study and thereby lend support to Gould and his activities.