A comparison of ICNIRP and IEEE guidelines to evaluate low frequency magnetic field localised exposure

摘要

Numerical calculations of exposure to magnetic field of operators of suspended hand-operated resistance welding guns were performed using the own homogeneous, flexible human body models CIOP-MAN of the 95th and 5th percentile of adult men dimensions (185 and 164 cm in height), in 16 exposure situations with various postures of operator - typical for automotive factory. An assessment concerned calculated values of an induced electric field (Ein) in the brain and the heart - according to the ICNIRP (International Commission on Non-Ionizing Radiation Protection, 2010) and the IEEE (Institute of Electrical and Electronics Engineers, 2002). The results show applicability of flexible human body models in exposure evaluation based on Ein values, even homogeneous. The values of Ein in the brain and the heart are up to 34% higher when calculated following ICNIRP requirements than the values calculated following the IEEE method. The values of a welding current producing a B-field in the heart area of 100 μT/50Hz (i.e. the exposure limit for cardiac pacemakers users provided by ACGIH (American Conference of Governmental Industrial Hygienists, 2016) and CENELEC standard (European Committee for Electrotechnical Standardization)) are in the range of 0.43-1.6 kA, which is significantly lower than the typical current used in the industry (5-15 kA). Cardiac pacemaker users should not operate welding guns, as a result of the individual risk assessment required by the European directive on workers' protection (Directive 2013/35/EU).