Radio Hazard Safety Assessment for Marine Ship Transmitters: Measurements Using a New Data Collection Method and Comparison with ICNIRP and ARPANSA Limits
Malka N. Halgamuge. Radio Hazard Safety Assessment for Marine Ship Transmitters: Measurements Using a New Data Collection Method and Comparison with ICNIRP and ARPANSA Limits. Published: 19 May 2015. (This article belongs to the Special Issue Electromagnetic Fields and Health)
We investigated the levels of radio frequency electromagnetic fields (RF EMFs) emitted from marine ship transmitters. In this study, we recorded the radio frequency (RF) electric field (EF) levels emitted from transmitters from a marine vessel focusing on the areas normally occupied by crew members and passengers. Previous studies considered radiation hazard safety assessment for marine vessels with a limited number of transmitters, such as very high-frequency (VHF) transceivers, radar and communication transmitters. In our investigation, EF levels from seven radio transmitters were measured, including: VHF, medium frequency/high frequency (MF/HF), satellite communication (Sat-Com C), AISnavigation, radar X-band and radar S-band.
Measurements were carried out in a 40 m-long, three-level ship (upper deck, bridge deck and bridge roof) at 12 different locations. We developed a new data-collection protocol and performed it under 11 different scenarios to observe and measure the radiation emissions from all of the transmitters.
In total, 528 EF field measurements were collected and averaged over all three levels of the marine ship with RF transmitters: the measured electric fields were the lowest on the upper deck (0.82–0.86 V/m), the highest on the bridge roof (2.15–3.70 V/m) and in between on the bridge deck (0.47–1.15 V/m).
The measured EF levels were then assessed for compliance with the occupational and general public reference levels of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) standards. The ICNIRP and the ARPANSA limits for the general public were exceeded on the bridge roof; nevertheless, the occupational limits were respected everywhere. The measured EF levels, hence, complied with the ICNIRP guidelines and the ARPANSA standards.
In this paper, we provide a new data collection model for future surveys, which could be conducted with larger samples to verify our observations. Furthermore, this new method could be useful as a reference for researchers and industry professionals without direct access to the necessary equipment.
In this investigation, we performed measurements and analysed radio frequency radiation emitted by the transmitters aboard a marine vessel, focusing on areas normally occupied by crew members and passengers. In total, 528 electric field measurements were taken. Additionally, we developed a new data collection protocol and performed various scenarios to accurately measure the radiation from all transmitters. Under the normal operating conditions, there were a few marine ship transmitters and antennas transmitting continuously, and other radios operate intermittently. By considering this, for the first time, we report measuring the electric field from each transmitter condition, which is insignificant, and this must be carefully taken into account for future studies. Our results show that the electric field levels were highest on the bridge roof and the lowest in the upper deck, and the measured values were within a range of 0.001–39.46 V/m. The limits for the general public were exceeded on the bridge roof; nonetheless, the occupational limits were respected everywhere. Hence, this complies
with the occupational and general public reference levels of the ICNIRP guidelines and the ARPANSA standards. Some further conclusions that can be drawn from this paper are: (i) electric field levels were high with the VHF fixed (Sailor 6006) transmitter; and (ii) high frequency electric field levels that are radiated from the vessels’ transmitters on the bridge roof will not have much impact for crew members and passengers. Nevertheless, this study should be useful as a reference for many researchers and
industry professionals without direct access to the necessary equipment. Further research is desired to determine the electric field levels for a larger amount of ships using the proposed protocol in this paper. Such research would provide a basis for establishing safety distances and support the development of guidelines by suitable authorities.
Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley
Electromagnetic Radiation Safety
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