Have you heard about low-background steel? https://en.m.wikipedia.org/wiki/Low-background_steel https://en.m.wikipedia.org/wiki/Low-background_steel It became

Have you heard about low-background steel? https://en.m.wikipedia.org/wiki/Low-background_steel https://en.m.wikipedia.org/wiki/Low-background_steel It became scarce because of some very widespread effect.