Assessment of the Exposure to Gradient Magnetic Fields Generated by MRI Tomographs: Measurement Method, Verification of Limits and Clearance Areas through a Web-Based Platform.

This work is the result of a campaign of measures of exposure levels to magnetic field gradients (GMF) generated by magnetic resonance imaging (MRI) tomographs, to which both healthcare staff and any persons accompanying patients who remain inside the magnet room are exposed while performing a diagnostic Investigation. The study was conducted on three MRI tomographs with a static magnetic induction field up to 1.5 T installed in two hospitals of Lombardy.

Occupational exposure in MR facilities due to movements in the static magnetic field.

Purpose: The exposure of operators moving in the static field of magnetic resonance (MR) facilities was assessed through measurements of the magnetic flux density, which is experienced as variable in time because of the movement. Collected data were processed to allow the comparison with most recent and authoritative safety standards.

Methods: Measurements of the experienced magnetic flux density B were performed using a probe worn by volunteers moving in MR environments.

Evaluation of human exposure to complex waveform magnetic fields generated by arc-welding equipment according to European safety standards.

In this paper, a procedure is described for the assessment of human exposure to magnetic fields with complex waveforms generated by arc-welding equipment. The work moves from the analysis of relevant guidelines and technical standards, underlining their strengths and their limits. Then, the procedure is described with particular attention to the techniques used to treat complex waveform fields.

Evaluation and characterization of fetal exposures to low frequency magnetic fields generated by laptop computers.

Portable - or "laptop" - computers (LCs) are widely and increasingly used all over the world. Since LCs are often used in tight contact with the body even by pregnant women, fetal exposures to low frequency magnetic fields generated by these units can occur. LC emissions are usually characterized by complex waveforms and are often generated by the main AC power supply (when connected) and by the display power supply sub-system.

Review of open problems in assessing compliance with 2004/40/EC directive exposure limit values for low-frequency current density by means of numerical techniques.

The endorsement process of the 2004/40/EC Directive (still in progress) has led to a critical analysis of the ICNIRP Guidelines, on which the directive is based. In particular, some known problems affect the applicability of the numerical techniques needed for checking compliance with limits at low frequency. A review of these open problems is presented in the paper, highlighting how such problems deal more with pre-processing and post-processing steps than with the core numerical calculation of the current density.

Quasi-static electromagnetic dosimetry: from basic principles to examples of applications.

An overview of quasi-static electromagnetic dosimetry is presented. After an introductive description of quantities and standards and a quick look at experimental and analytical approaches, attention is focused on numerical dosimetry. The process that leads to the calculation of results is analyzed in its basic steps, including the representation of the human body by means of a realistic voxel phantom.

Extremely low-frequency electromagnetic fields do not affect DNA damage and gene expression profiles of yeast and human lymphocytes.

We studied the effects of extremely low-frequency (50 Hz) electromagnetic fields (EMFs) on peripheral human blood lymphocytes and DBY747 Saccharomyces cerevisiae. Graded exposure to 50 Hz magnetic flux density was obtained with a Helmholtz coil system set at 1, 10 or 100 microT for 18 h. The effects of EMFs on DNA damage were studied with the single-cell gel electrophoresis assay (comet assay) in lymphocytes.

ELF magnetic field exposure in a neonatal intensive care unit.

In this paper, the magnetic flux density (MFD) distribution in a neonatal intensive care unit is described and MFD values inside a few open infant warming systems and incubators are reported. Typical measured values of the magnetic flux density at power frequency (50 Hz) in the "general environment" (the rooms of the unit) were lower than 0.2 microT, while higher MFD values were detected close to medical equipment and inside the open infant warming systems.