Corning Mug. Year unknown.
Tested with an XRF instrument.
Positive for lead at 33 parts per million (ppm), +/- 13 ppm.
This is considered safe by all standards.
The amount of lead that is considered toxic in a modern/newly manufactured item intended for children is anything 90 ppm lead or higher. Mugs are not considered items intended for use by children and, as such, are not regulated for total lead content as detectable when tested with an XRF instrument.