Where can I recycle spark plugs? As a materials engineer I know how toxic Yttrium and Platinum can...

As a materials engineer I know how toxic Yttrium and Platinum can be if disposed of indelicately. I just required to know if there is somewhere I can without risk recycle my old spark plugs. If it help, I live in Pittsburgh, PA.
What cause the circuit breaker on an AC...
Answers:    You might want to check the EPA website for drop-off locations. Most communities own a annualy hazardous waste drop-off morning where general public can bring old paint, grease, etc. for recycling or proper disposal.
Where do you initiate to find a pool...
Your a materals obtain and don't know where or how to dispose of this stuff??????? Honestly.....I didn't know they be unsafe to throw in the trash