Instituto Tecnológico e Nuclear, URSN, E.N. 10, 2686-953 Sacavém, Portugal
Escola Superior de Tecnologia da Saúde de Lisboa, Avenida D. João II lote 4.69.01, 1900-096 Lisbon, Portugal
CERENA/IST, Technical University of Lisbon, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
Department of Radiation, Radionuclides & Reactors, Section RIH (Radiation and Isotopes in Health), Faculty of Applied Sciences, Technical University of Delft, Mekelweg 15, 2629 JB Delft, The Netherlands
Total particulate matter (TPM) was passively collected inside two classrooms of each of five elementary schools in Lisbon,
Portugal. TPM was collected in polycarbonate filters with a 47 mm diameter, placed inside of uncovered plastic petri dishes.
The sampling period was from 19 May to 22 June 2009 (35 days exposure) and the collected TPM masses varied between 0.2 mg
and 0.8 mg. The major elements were Ca, Fe, Na, K, and Zn at μg level, while others were at ng level. Pearson′s correlation
coefficients above 0.75 (a high degree of correlation) were found between several elements. Soil-related, traffic soil re-suspension
and anthropogenic emission sources could be identified. Blackboard chalk was also identified through Ca large presence. Some
of the determined chemical elements are potential carcinogenic. Quality control of the results showed good agreement as confirmed
by the application of u-score test.