I don't know if it's much to worry about, but it's interesting reading anyway:
Decades-Old Lenses May Be Radioactive, Especially if They're Made by Kodak
Radioactive lenses - Camerapedia
I particularly noticed this one from Camerapedia (bolding by me):
"The Kodak Instamatic 814 was a coupled coincident rangefinder camera for 126 (Kodapak) film cartridges - one of a large range of Instamatics. It was made by Kodak in the US, between March 1968 and August 1970. A surprisingly heavy camera, it is well constructed and has a superb Ektar 38mm f/2.8 lens. A Tessar design, the lens contains thorium oxide and is, in fact, radioactive (one of many Kodak lenses from the 40's, 50's, and 60's that share this attribute). The shutter has user-selected speeds of 1/60, 1/125, and 1/250 sec. plus bulb. Film advance is via a spring motor drive that is wound by pulling on a long nylon strap that rewinds into the camera's bottom. The CDS photocell light meter is powered by two PX825 mercury cells, and controls the camera's automatic aperture."
And I always thought photography was such a healthy activity