I was considering buying a 55mm 1.8 takumar but i am pretty concered about the radiation and the health affects. I know that the 50mm 1.4 version is radioactive but i am still unsure of the 55mm 1.8. Is there a way i can determine if this lens has thorium in it like the 50mm. I have read extensively about the radiation of these lenses and i can't come up with a concrete answer whether it is safe or not. I know there is other lens choices out there, but i i don't think my anxiety of radiation should put me off the takumar lenses.