Questions about living in a room someone cooked meth in?

[Sarah H]

Okay my brother and his gf used to live in the room next to me. They ended up going to jail for warrants they had. We found out my brother and his girlfriend were addicted to meth. My sister asked if they used to smoke or cook it in the house, and they said yes. I remember i was pregnant at the time and i used to smell chemicals and weed almost everynight,i was all ready to move out until they got arrested.(I read how it could have effects on an unborn child && I didnt want any drugs in my life.) Okay well once they moved out and i had my baby, i made their old room into my sons room. I did see red-orange stuff all over the walls and my mom found a hot plate and some other stuff when we were cleaning it. What harm could it do to my son? im really nervous about him being in that room now. What are some signs I should look for if it is effecting him? and what should I do about it if it is possibly harmful? Thank you so much