Complex sentence: The concentration and location of some natural isotopes (such as 238 U) can be affected by human activity, for more details of uranium and radium please see Uranium in the environment and radium in the environment.
Split into simpler sentences: The concentration and location of some natural isotopes (such as 238 U) can be affected by human activity. For more details of uranium and radium please see Uranium in the environment and radium in the environment.