PBTs have a high environmental mobility relative to other contaminants mainly due to their resistance to degradation (persistence). This allows PBTs to travel far and wide in both the atmosphere and in aqueous environments.nother factor that makes PBTs especially dangerous are the degradation products which are often relatively as toxic as the parent compound. These factors have resulted in global contamination most notable in remote areas such as the arctic and high elevation areas which are far from any source of PBTs.
They have been claimed as the oldest free-standing structures on Earth, although the largely buried GÃ¶bekli Tepe complex is far older. Archaeologists believe that these megalithic complexes are the result of local innovations in a process of cultural evolution.
Interesting Facts. 1  Constructed in 1610, the Palace of the Governors in Santa Fe is the oldest seat of government in the United States.  On July 16, 1945, the worldâs first atomic bomb was tested at the Trinity Site in central New Mexico.