[Chalk dust in the lecture room (author's transl)].
D000393:Air Pollutants / Q000032:analysis; D002118:Calcium / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D010316:Particle Size; D012572:School Health Services
D000393:Air Pollutants; D004391:Dust; D002118:Calcium