2.3.3.4. Examination and psychological technique in children: - Examination technique: internal medical examination including weight, height, chest index performed by the pediatric specialists at the health station of Ban Thi and Tan Long communes - Psychological evaluation technique: Test ASQ (Ages and Stages Questionnaires) for children ≤6 years old Test Raven for children >6 years old: calcul and classify IQ score Neurological-behavior assessment: Development Behavior checklist (DBC-P) and Vanderbilt scale, for all children involved 2.3.3.5.