The shot noise of the current through single-atom contacts has been measured in a scanning tunneling microscope at a temperature of 5K. Electrical measurements at frequencies up to 120kHz were performed on Au, Fe, and Co atoms on Au(111) using Au tips. The data from Fe and Co indicate spin polarized transmission through a single conductance channel. Optical measurements at sub-petahertz frequencies were carried out on Cu adatoms on Cu(111) using Cu tips. The data are consistent with previous observations from coinage metal contacts.