Basic quantification of magnetic particles in solid substance and human tissue by the SQUID magnetometer

Abstract The present study concerns an rf SQUID magnetometer enabling to measure magnetic fields of order 2 × 10 −14  T Hz −1/2 and its utilization for the detection and quantification of particles with magnetic properties in different materials and human tissue. In the first case, the mass concentration n p of powdered ferro- and ferrimagnetic material (PFM) in a physical model with known shape, volume and PFM content was estimated in order to evaluate the uncertainty of the method. Secondly, the lungs of an arc welder who was long-term exposed to welding fumes were examined. The mean n p of 0.0845 mg cm −3 of ferromagnetic dust with the mass ratio of Fe:Ni materials 99.12%:0.82% and the specific remanent magnetic moment m rs of (0.127 ± 0.076) A m 2  kg −1 was found.