Mildewy wooden pegs!

I use wooden clothes pegs, and my clothes line is under cover, so its not like they are always out in the weather or anything (I even take them off the line when not in use), but they look mouldy/mildewy (tbh, I don't know what the difference is) where they come into contact with the clothes.

Can anyone tell me why? And I guess more importantly, is this a health issue? What can I clean them with, if anything?

I hate wooden pegs. I threw all mine out because they were leaving black marks on the clothes. Sorry can't tell you if its a health hazard, I wouldn't think so. You can clean them with dishwashing liquid and just scurb them.

Or you can boil them in vinegar/water solution for a few minutes when they're new, that helps repel the water that makes them age and mark clothes.