Difficulties in applying numerical simulations to an evaluation of occupational hazards caused by electromagnetic fields

Abstract

Due to the various physical mechanisms of interaction between a worker's body and the electromagnetic field at various frequencies, the principles of numerical simulations have been discussed for three areas of worker exposure: to low frequency magnetic field, to low and intermediate frequency electric field and to radiofrequency electromagnetic field. This paper presents the identified difficulties in applying numerical simulations to evaluate physical estimators of direct and indirect effects of exposure to electromagnetic fields at various frequencies. Exposure of workers operating a plastic sealer have been taken as an example scenario of electromagnetic field exposure at the workplace for discussion of those difficulties in applying numerical simulations. The following difficulties in reliable numerical simulations of workers’ exposure to the electromagnetic field have been considered: workers’ body models (posture, dimensions, shape and grounding conditions), working environment models (objects most influencing electromagnetic field distribution) and an analysis of parameters for which exposure limitations are specified in international guidelines and standards.

Occupational exposure to electromagnetic fields in magnetic resonance environment: an update on regulation, exposure assessment techniques, health risk evaluation, and surveillance

“…The recent and rapid development in new numerical algorithms combined with relatively low-cost powerful computational resources (e.g., graphic processing units), have favoured the spreading of these algorithms, also thanks to the availability of increasingly sophisticated numerical anatomical human models, with an accurate characterization of dielectric properties of different tissues. However, numerical simulations for the exposure assessment can be affected by worker body model characteristics including posture, dimensions, shape, and grounding conditions [88]. The working environment models including objects influencing field distribution can significantly under-or overestimate the exposure effects in the body.…”

An In Situ and In Silico Evaluation of Biophysical Effects of 27 MHz Electromagnetic Whole Body Humans Exposure Expressed by the Limb Current

“…The results of LIC measurements at the volunteers were correlated with the following parameters derived from the calculated distribution of absolute value (module) of unperturbed E -field (without human body presence), to represent interperson variability of exposure level in the heterogeneous EMR near the rod antenna:The E -field at the top of the volunteer's body (at the distance from the ground equal to the volunteer's height), along the measurement line L2 or L3, respectively, for exposure variant 1 or 2 (as shown in Figure 1, the line covering the main axis of the volunteer's torso; as shown in Table 1, at the height from the ground in the range 160–190 cm), E (BA-TV-L2/L3)The arithmetic averaged value of the E -field along the main axis of the volunteer's body, respectively, for exposure variant 1 or 2 (line L2 or L3), ranging between 30 cm from the ground and volunteer's height, E (BA-AV-L2/L3)The E -field, located in front of the volunteer's chest (Variant 1 or 2), that is, in line L1 or L2, at a distance from the ground of approximately 70% of the volunteer's height (50 cm from the body axis and, as shown in Table 1, at a distance from the ground in the range 112–133 cm), E (FB-0.7VH-L1/L2)The maximum in space value of E -field affecting the workers' body in exposure variant 1 or 2, according to Directive 2013/35/UE, E (D2013/35/EU).In all investigated exposure variants and their subvariants, the strongest, proportional (physically correct), statistically significant correlations (| r | > 0.7, p < 0.001) were found between the results of the LIC measurements and the following parameters of EMR exposure (Table 4): The maximum in space value of E -field affecting the workers' body, E (D2013/35/EU)The E -field in front of the volunteer's chest, E (FB-0.7VH-L1/L2).Both parameters (exposure measures) are more strongly correlated with the LIC values than parameters discussed in the literature [17, 23]: the E -field at the top of the volunteer's body E (BA-TV-L2/L3) and the arithmetic averaged value of the E -field along the main axis of the volunteer's body E (BA-AV-L2/L3).…”

“…In all investigated exposure variants and their subvariants, the strongest, proportional (physically correct), statistically significant correlations (| r | > 0.7, p < 0.001) were found between the results of the LIC measurements and the following parameters of EMR exposure ( Table 4 ): The maximum in space value of E -field affecting the workers' body, E (D2013/35/EU) The E -field in front of the volunteer's chest, E (FB-0.7VH-L1/L2). Both parameters (exposure measures) are more strongly correlated with the LIC values than parameters discussed in the literature [ 17 , 23 ]: the E -field at the top of the volunteer's body E (BA-TV-L2/L3) and the arithmetic averaged value of the E -field along the main axis of the volunteer's body E (BA-AV-L2/L3).…”

“…For this reason, various numerical phantoms of human body were developed, with different numerical parameters, internal organ details, and anthropometric properties, such as height and body mass [ 15 , 16 ]. Results of evaluation of effects of EMF exposure in the human body, carried out by in silico measurements, are dependent on both the exposure conditions and structure of the phantoms [ 9 , 17 ].…”