Originally Posted by Hondo6

FWIW: various sources recommend that auto tires be replaces at either 6 or 10 years after date of manufacture. So yes, deterioration due to ozone/UV/etc . . . exposure is a real "thing" for tires of all types.

Up to you whether or not you replace the tires in question. But if they're approaching 10 years old, you might want to consider the cost of new tires vs. the inconvenience of a roadside tire failure you can't patch or boot. Or worse.