Toddler puts everything in his mouth and chewing on corner of wall

so

Help! what the actual fuck. We have caught him chewing on the corner of this wall a few times now. I’m going nuts. We’re in Mexico but the house is brand new. I’m not sure if there’s a likelihood there’s lead in the paint so I’m concerned. Why does he have to do this!! I’m so angry and frustrated and worried for him. I keep trying to be patient and calm but I’m LOSING IT