I've been having really horrific headaches recently. I've had headaches my entire life, but this has been worse than usual. I'd been thinking possible causes were stress or the absurdly dry Seoul winter air. They actually got worse when I finally turned on the floor heat and started sleeping on the floor - which I thought was kind of odd, as normally I feel *better* when I sleep on the floor (my back adores the hard floor; soft mattresses are the enemy).
Today I noticed a small black patch on the wall, coming up from behind the headboard of my bed. I scooted the bed away from the wall and was immediately disgusted by the nasty mold growing all over the wall. In a panic I moved my bookshelf and wardrobe away from their respective walls, and the grossed-out feeling continued. My apartment had apparently become a prime greenhouse for not just onions, but various varieties of mold.
The walls in this place sweat when it's cold outside and the heat's on inside. The walls are made of concrete, covered with wallpaper on the inside. Where headboards, bookcases, and wardrobes press against it, mold apparently multiplied like mad.
Left: back of wardrobe