Barium is interchangeable with strontium in the crystal structure; there is a gradation between celestine and barite.
The tests looked at an element called strontium in the tooth enamel, which can identify where an individual lived as the tooth formed.
The goal is to see a rise in concentrations of strontium in the wall, and a drop in the ground water downstream.
The latest discovery of strontium in the groundwater could signal that water is leaking from the tanks, or from the damaged reactor buildings themselves.
On Wednesday, the plant's operator, the Tokyo Electric Power Company, said it had detected high levels of radioactive strontium in groundwater at the site.
In addition, the Nuclear Regulatory Commission calculated that the doses from radioactive strontium in the environment add only about 0.3 percent to the average American's background exposure.
Dissolved strontium in the oceans today has a value of 0.709 that is dependent on the relative input from the continents and the ridges.
Unlike rubidium, which is enriched over strontium in the crust, samarium is relatively enriched with respect to neodymium in the mantle.
The study's authors had previously tried to link strontium in the teeth of children growing up near nuclear power plants to releases from those plants, but those findings have not met with much scientific acceptance.
As a farmer who had moved to the city himself, he spoke the language of the peasants forced from their plots by landslides, the fishermen whose stocks were dead, the weeping, terrified villagers whose livers had been enlarged by strontium in the river water.
Tokyo Electric Power, the operator of the stricken nuclear power plant at Fukushima, said Wednesday that it had detected high levels of radioactive strontium in groundwater at the plant, raising concerns that its storage tanks are leaking contaminated water, possibly into the ocean.
