Building and Environment 81 (2014) 183e191 Contents lists available at ScienceDirect Building and Environment journal homepage: www.elsevier.com/locate/buildenv Indooreoutdoor behavior and sources of size-resolved airborne particles in French classrooms Dinh Trinh Tran a, *, Laurent Y Alleman b, c, Patrice Coddeville b, c, Jean-Claude Galloo b, c a Viet Nam National University, Ha Noi, Faculty of Chemistry, 19 Le Thanh Tong Street, Ha Noi, Viet Nam Univ Lille Nord de France, F-59000 Lille, France c Mines Douai, CE, F-59508 Douai, France b a r t i c l e i n f o a b s t r a c t Article history: Received 31 March 2014 Received in revised form 11 June 2014 Accepted 27 June 2014 Available online July 2014 Indoor and outdoor airborne particles were monitored with a 5-s time resolution in three elementary schools presenting different site typologies (rural, urban, and industrial) in the North of France We studied the influence of the children's activities, outdoor sources, temperature and relative humidity on particle mass concentrations and particle massesize distribution, and estimated cancer risk regarding particle composition The indoor weekly mean PM10 mass concentrations during teaching hours varied from 70 to 99 mg mÀ3, exceeding the French daily recommended value of 50 mg mÀ3, implying a potential impact on the respiratory system However, fine particles (