继续查证,发现维基百科中有这么一段:In the United States, tobacco is often fertilized with the mineral apatite, which partially starves the plant of nitrogen, to produce a more desired flavor. Apatite, however, contains radium, lead 210, and polonium 210—which are known radioactive carcinogens.
而维基百科关于磷灰石的介绍中提到:Apatite is occasionally found to contain significant amounts of rare earth elements and can be used as an ore for those metals. This is preferable to traditional rare earth ores, as apatite is non-radioactive and does not pose an environmental hazard in mine tailings.
Except some apatite in Florida used to produce phosphate for U.S.
tobacco crops contains uranium, radium, lead 210 and polonium 210 and
radon.