Concentration of bioelements in hair of pre-school children in relation to their state of health Journal title: Medycyna Ogólna i Nauki o Zdrowiu Authors: Emilia Kolarzyk, Małgorzata Szady-Grad, Anna Janik Subject(s): Orthopedics, Health Care Sciences & Services, Medicine, Research & Experimental, Public, Environmental & Occupational Health, Primary Health Care