I've noticed something weird in several of the F34T12s I got:

Some of them that I've started using in everyday use are getting these little gray lines and a few dots on the inside along the whole length that look like scratches/dots and when the lamps are cold (on a magnetic ballast) and are just starting sometimes there are fairly bright white sparks on those scratches right as they start.

I would post a video but it's a bit hard to catch it since usually the other lamps are too bright to catch the effect, what is causing this?
It's not like the pink sparks that happen at the ends