Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol oleh Mara Gallastegi, Mònica Guxens, Ana Jiménez-Zabala, Irene Calvente, Marta Fernández, Laura Birks, Benjamin Struchen, Martine Vrijheid, Marisa Estarlich, Mariana F. Fernández, Maties Torrent, Ferrán Ballester, Juan J Aurrekoetxea, Jesús Ibarluzea, David Guerra, Julián González, Martin Röösli, Loreto Santa-Marina