We know these steps because researchers followed the progress of carbon-14 throughout the process.Radioactive isotopes are useful for establishing the ages of various objects.A modified CRS model that uses 137Cs age markers as references improved determination of the sediment chronology.The average sedimentation rates were three to five times higher during the 1957 to 1963 time period than during the 1964 to 2011 period.For instance, leaks in underground water pipes can be discovered by running some tritium-containing water through the pipes and then using a Geiger counter to locate any radioactive tritium subsequently present in the ground around the pipes.(Recall that tritium is a radioactive isotope of hydrogen.) Tracers can also be used to follow the steps of a complex chemical reaction.After incorporating radioactive atoms into reactant molecules, scientists can track where the atoms go by following their radioactivity.
"As the element is decaying it is throwing off radiation, and the radiation, if it hits the DNA in the nucleolus and the nucleus of a cell, can alter that DNA in ways that can produce things like cancer," Hartmann said. "The cesium could cause no cancer, or it could cause cancer in the first cell it irradiates."Now it can also cause simply the cell to die or it can mutate the cell in all kinds of other weird ways, and so it's kind of a numbers game. To say that there is a safe level of radiation is frankly wrong.It's just wrong." VIDEO: THOM HARTMANN REPORTS ON ENVIRONEWS OREGON'S ARTICLE ON FUKUSHIMA PLUME HITTING AMERICA'S WEST COAST Urry said later in a statement, "It's one thing for the media to regurgitate trivial facts on trivial matters, but to blindly repeat that consuming low levels of radiation is 'safe,' is irresponsible reporting and borders on dangerous.Currently, the most accurate atomic clocks first cool the atoms to near absolute zero temperature by slowing them with lasers and probing them in atomic fountains in a microwave-filled cavity.An example of this is the NIST-F1 atomic clock, one of the national primary time and frequency standards of the United States.