I thought it was an isolated experience with my TI3 set that I hadn't touched in months. The hexes had these little splotches of green snowflakes on most of them.
So I fixed that months ago, and now I open my box of MEQ and the insert has the exact same problem. How do I avoid this? Is it because it's humid in our country? Stupid mold. :( Will this have permanent damage on the games in the long term?
Well it ain't good, but if you clean up the mold and keep the game dry you should be OK. We live in an incredibly damp apartment, and run two dehumidifiers to keep the humidity down. We have a game "shelf" and a game "closet" and each has a dehumidifier near it. I try keep the humidity below 40%, which is probably lower than necessary, but I rest easier knowing all the money spent on games isn't moist and moldy. I've never had mold originate in our apartment, but I have received or bought games that had mold. With good clean-up, several days to dry out, and low humidity I've never had mold return.
If you've had mold issues with two games, I'd check the rest of them too. Clean them ALL up, and if you've got high humidity then find a way to bring it down. Mold can and will spread if it's able, so your best option to get rid of all of it and then do preventive care from that point forward.
Put 5 pound bags of rice in plastic containers, and punch many pinholes in the lid (like, hundreds of holes). If you keep the games in a closet, simply put these in there, and change monthly. It's a cheap dehumidifier.