Health hazard evaluation report: HETA-2002-0441-2920, Yosemite National Park, El Portal, California.
Cardarelli-J II; Methner-M
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, HETA 2002-0441-2920, 2003 Dec; :1-18
On September 9, 2002, the National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation (HHE) at the Yosemite National Park, El Portal, California. The park Safety Office requested an evaluation of potential radio frequency (RF) exposures from a cell-phone antenna base station. On October 22, 2002, NIOSH investigators conducted a site visit at Ranger Camp Tuolumne Meadows and completed a source characterization of the RF fields emitting from the base station. This evaluation assessed occupational exposure to magnetic fields (60 Hz) and electric fields in the frequency range from 100 kilohertz (kHz) to 5 gigahertz (GHz) among workers during a typical daily work regimen. All of the measurements taken with the Holaday HI-4433 STE probe (electric field) and EMDEX-II ELF instrument (magnetic field) were below their respective limits-of-detection. The only measurable results were obtained with the Holiday HI-6005 probe (electric field); all of these measurements were below the exposure limits applied to the general public. Further, none of the measurements exceeded 0.1 percent of the applicable limit which indicates that the emissions from this base station pose no threat to employees or the general population who visit or pass through the area or to workers at the Tuolumne Meadows Camp Site. No RF exposure hazards exist from the base-station cellular communication system located in the Tuolumne Meadows Camp Site. This conclusion is based on the fact that: (1) all the measurements were well below any RF exposure limits for the general population, (2) the antenna height (70 feet above grade) prevents accidental exposures within a few feet of the antenna, and (3) the geographic layout provides sufficient distance between the base-station antennas and housing units.
Region-9; Radiation; Nonionizing-radiation; Magnetic-fields; Electrical-fields; Forestry; Forestry-workers; Radio-waves; Occupational-exposure; Exposure-levels; Measurement-equipment; Hazard-Unconfirmed;
Author Keywords: Forestry Services; Antenna; Non-Ionizing Radiation; Radiofrequency; RF; cellular communications; magnetic fields; electric fields
Field Studies; Hazard Evaluation and Technical Assistance
NTIS Accession No.
National Institute for Occupational Safety and Health