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HomeMy WebLinkAboutMCUP 08-14; T-MOBILE SD06438 LA COSTA PLAZA; RADIOFREQUENCY AND POWER DENSITY SITE MEASUREMENTS; 2008-07-29Darrell W. Daugherty PLAN com Inc. 302 State Place • JERROLD T. BUSHBERG Ph.D., DABMP, DABSNM ♦HEALTH AND MEDICAL PHYSICS CONSULTING♦ 7784 Oak Bay Circle Sacramento, C~ 95831 (800) 760-8414-jbushberg@hampc.corn Escondido, California 92029-1362 Introduction July 29, 2008 At your request, I have measured the current cumulative maximum radiofrequency, (RF), power density from the T-Mo bile (TM) wireless telecommunications site, ( referenced as SD0643 8), located at the La Costa Plaza Shopping Center 7750 Rancho Santa Fe Road, Carlsbad, California as depicted in attachment 1. Site measurements were made to included all ambient sources of RF exposures including the contribution from other wireless facilities. This information was used to determine compliance with Federal Communications Commission (FCC) requirements for RF public exposure safety. This TM telecommunication site (previously owned and operated by Cingular Wireless as site SD-438-04), consists of a Personal Communications Services (PCS) wireless facility. The facility utilizes directional transmit panel antennae configured in three (3) sectors. The antennae are recessed into the facade of the existing building directed at O (sector A), 120 (sector B) and 240 (sectorC) degrees true north. The antenna centers are 22.3 feet above grade for sector A and 19.9 feet above grade for sectors B&C. The antennas specified are EMS Wireless model #RR65-18-00DPL2 for sector A, #RR65-18-02DPL2 for sector B and #RR90-17-02DPL2 for sector C. The sectorized antennas are designed to transmit with an effective radiated power (ERP) ofup to 800 watts per sector within a bandwidth between approximately 1,850 and 1,990 MHz RF Exposure Measurement Methods & Results The measurements at the subject property were made during the afternoon on July 23, 2008 utilizing a N arda Industries model 8718B broadband exposure meter (serial number 6062) with an associated frequency shaped B87 4 2D pro be ( serial number 08002). Weather conditions during the measurement period were fair and the temperatures were moderate. Outdoor measurements were made at locations of highest potential public exposure and surrounding area. All measurements were made in accordance with the manufacturer's recommendations as provided in their users guide for this instrument. This included an RF response check to assure that the meter and probe were responding appropriately to an RF energy source. This response check was performed immediately before and after the site measurements and, along with other operational parameters, were found to be operating normally as specified by the manufacturer. In addition, all environmental operating conditions, as specified by the manufacturer for this instrument, were satisfied. The probe and meter were calibrated by the manufacturer with standards traceable to the U.S. National Institute of Standards and Technology (NIST) on August 23, 2007. In accordance with the manufacturer's recommendations, the next calibration will be due prior to August 23, 2009. 1 The Narda meter/probe combination senses fields within the frequency range from 300 kHz to 3 GHz and indicates exposure as a percentage of the FCC public exposure standard. The dynamic range of the instrument is between 0.6% and 600% of the FCC public exposure standard. For PCS :frequencies, this response range equates to a power density range between 6 µWI cm2 and 6 mW I cm2• Reading obtained below 0.6% MPE are reported as the minimum range of the instrument (i.e., 0.6% MPE). The data supplied by the manufacturer sets the frequency response of the probe as± 1 dB and calibration accuracy and isotropicity as± 0.5 dB and± 1 dB respectively. The probe is isotropic, meaning that it can directly measure the strength of complicated fields independent of the orientation, polarization, or arrival angle. Measurements were made from ground level to head height ( ~6 feet) above the ground. The probe was swept over approximately± 3 feet to avoid destructive interference thus assuring the highest power density was being measured at a given location. A continuous observation of the exposure allowed the location of the maximum power densities to be determined During the survey the meter displayed RF exposure levels between 0.0442 and 1.1255% of the FCC public exposure safety standard. Thus the maximum environmental RF exposure measurement result, at all locations, was recorded as less than 1.125 5 % of the FCC public exposure safety standards for continuous exposure. In so far as it was not possible to determine if all antennae at the site were transmitting at maximum power during the measurements, a conservative multiple of five ( 5) was applied to all reading in order to assure that maximum potential exposures would Iiot exceed the values provided in this report. Even with the conservative multiple of five applied to the measured value (i.e., 1.1255 %) the exposures would still be below the public MPE (i.e., 5.63%). A chart of the electromagnetic spectrum and a comparison of RF power densities from various common sources is presented in figures two and three respectively in order to place exposures from PCS telecommunications systems in perspective. RF Exposure Standards The two most widely recognized standards for protection against RF field exposure are those published by the American National Standards Institute (ANSI) C95.1 and the National Council on Radiation Protection and measurement (NCRP) report #86. The NCRP is a private, congressionally chartered institution with the charge to provide expert analysis of a variety of issues ( especially health and safety recommendations) on radiations of all forms. The scientific analyses of the NCRP are held in high esteem in the scientific and regulatory community both nationally and internationally. In fact, the vast majority of the radiological health regulations currently in existence can trace their origin, in some way, to the recommendations of the NCRP. All RF exposure standards are frequency-specific, in recognition of the differential absorption of RF energy as a function of frequency. The most restrictive exposure levels in the standards are associated with those frequencies that are most readily absorbed in humans. Maximum absorption occurs at approximately 80 MHz in adults. The NCRP maximum allowable continuous occupational exposure at this frequency is 1,000 µW/cm2. This compares to 5,000 µW/cm2 at the most restrictive of the PCS frequencies (~1,800 MHz) that are absorbed much less efficiently than exposures in the VHF TV band. 2 The traditional NCRP philosophy of providing a higher standard of protection for members of the general population compared to occupationally exposed individuals, prompted a two-tiered safety standard by which levels of allowable exposure were substantially reduced for "uncontrolled " ( e.g., public) and continuous exposures. This measure was taken to account for the fact that workers in an industrial environment are typically exposed no more than eight hours a day while members of the general population in proximity to a source of RF radiation may be exposed continuously. This additional protection factor also provides a greater margin of safety for children, the infirmed, aged, or others who might be more sensitive to RF exposure. After several years of evaluating the national and international scientific and biomedical literature, the members of the NCRP scientific committee selected 931 publications in the peer-reviewed scientific literature on which to base their recommendations. The current NCRP recommendations limit continuous public exposure at PCS frequencies to 1,000 µ W / cm2, and to 200 µ W / cm2 for the most restrictive frequencies ( e.g., VHF TV band). The 1992 ANSI standard was developed by Scientific Coordinating Committee 28 (SCC 28) under the auspices of the Institute of Electrical and Electronic Engineers (IEEE). This standard, entitled "IEEE Standards for Safety Levels wit]). Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz" (IEEE C95.l-1991), was issued in April 1992 and subsequently adopted by ANSI. A revision of this standard (C95.1 2005) was completed in October 2005 by SCC 39 the IEEE International Committee on Electromagnetic Safety. Their recommendations are similar to the NCRP recommendation for the maximum permissible exposure (MPE) to the public at cellular and PCS frequencies (410 µW/cm2 and 950 µW/cm2 for continuous exposure at 820 MHz and 1,900 MHz respectively) and incorporates the convention of providing for a greater margin of safety for public as compared with occupational exposure. Higher whole body exposures are allowed for brief periods provided that no 30 minute time-weighted average exposure exceeds these aforementioned limits. On August 9, 1996, the Federal Communications Commission (FCC) established a RF exposure standard that is a hybrid of the current ANSI and NCRP standards. The maximum permissible exposure values used to assess environmental exposures are those of the NCRP (i.e., maximum public continuous exposure at PCS frequencies of 1,000 µ W/cm2). The FCC issued these standards in order to address its responsibilities under the National Environmental Policy Act (NEPA) to consider whether its actions will "significantly affect the quality of the human environment." In as far as there was no other standard issued by a federal agency such as the Environmental Protection Agency (EPA), the FCC utilized their rulemaking procedure to consider which standards should be adopted. The FCC received thousands of pages of comments over a three-year review period from a variety of sources including the public, academia, federal health and safety agencies ( e.g., EPA & FD_A) and the telecommunications industry. The FCC gave special consideration to the recommendations by the federal health agencies because of their special responsibility for protecting the public health and safety. In fact, the maximum permissible exposure (MPE) values in the FCC standard are those recommended by EPA and FDA. The FCC standard incorporates various elements of the 1992 ANSI and NCRP standards which were chosen because they are widely accepted and technically supportable. There are a variety of other exposure guidelines and standards set by other national and international organizations and governments, most of which are similar to the current ANSI/IEEE or NCRP standard, figure one. 3 The FCC standards "Guidelines for Evaluating the Environmental Effects of Radio frequency Radiation" (Report and Order FCC 96-326) adopted the ANSI/IEEE definitions for controlled and uncontrolled environments. In order to use the higher exposure levels associated with a controlled environment, RF exposures must be occupationally related (e.g., PCS company RF technicians) and they must be aware of and have sufficient knowledge to control their exposure. All other environmental areas are considered uncontrolled (e.g., public) for which the stricter (i.e., lower) environmental exposure limits apply. All carriers were required to be in compliance with the new FCC RF exposure standards for new telecommunications facilities by October 15, 1997. These standards applied retroactively for existing telecommunications facilities on September 1, 2000. Summary and Conclusion The T-Mobile wireless facility, as described above is in full compliance with the FCC standards for public RF exposure safety. PCS radio transmitters, by design and operation, are low-power devices. The maximum cumulative RF power density measured at and around this facility, together with a five fold increase to assure that maximum potential exposures would not be exceed during maximum transmission conditions, was 5.63% of, (i.e., approximately 17 times lower than), the FCC public exposure standard for these RF frequencies. It is important to realize that the FCC maximum allowable public exposures are not set at a threshold between safety and known hazard but rather at 50 times below a level that the majority of the scientific community believes may pose a health risk to human populations. Thus the previously mentioned maximum cumulative exposure from the site represents a "safety margin" from this threshold of potentially adverse health effects of approximately 888 times. Given the low levels of radio frequency field exposure and given the evidence on biological effects in a large data base, there is no scientific basis to conclude that harmful effects will attend the utilization of this telecommunication facility. This conclusion is supported by a large numbers of scientists that have participated in standard setting activities in the United States who are overwhelmingly agreed that RF radiation exposure below the FCC exposure limits has no demonstrably harmful effects on humans. These findings are based on my professional evaluation of the scientific issues related to the health and safety of non-ionizing electromagnetic radiation, measurements of existing RF exposures, and my analysis of the technical specification as provided by T-Mobile. The opinions expressed herein are based on my professional judgement and are not intended to necessarily represent the views of any other organization or institution. Please contact me if you require any additional information. Sincerely, Je~=~ABSNM Diplomate, American Board of Medical Physics (DABMP) Diplomate, American Board of Science in Nuclear Medicine (DABSNM) Enclosures: Figures 1-3; Attachment 1; Statement of Experience. 4 Attachment 1 · Site Specifications • STATEMENT OF EXPERIENCE Jerrold Talmadge Bushberg, Ph.D., DABMP, DABSNM (800) 760-8414 jbushberg@hampc.com Dr. Jerrold Bushberg has performed health and safety analysis for RF & ELF transmissions systems since 1978 and is an expert in both health physics and medical physics. The scientific discipline of Health Physics is devoted to radiation protection, which, among other things, involves providing analysis of radiation exposure conditions, biological effects research, regulations and standards as well as recommendations regarding the use and safety of ionizing and non-ionizing radiation. In addition, Dr. Bushberg has extensive experience and lectures on several related topics including medical physics, radiation protection, (ionizing and non-ionizing), radiation biology, the science of risk assessment and effective risk communication in the public sector. Dr. Bushberg's doctoral dissertation at Purdue University was on various aspects of the biological effects of microwave radiation. He has maintained a strong professional involvement in this subject and has served as consultant or appeared as . an expert witness on this subject to a wide variety of organizations/institutions including, local governments, school districts, city planning departments, telecommunications companies, the California Public Utilities Commission, national news organizations, and the U.S. Congress. In addition, his consultation services have included detailed computer based modeling of RF exposures as well as on-site safety inspections and RF & ELF environmental field measurements of numerous transmission facilities in order to determine their compliance with FCC and other safety regulations. The consultation services provided by Dr. Bushberg are based on his professional judgement as an independent scientist, however they are not intended to necessarily represent the views of any other organization. Dr. Bushberg is a member of the main scientific body of International Committee on Electromagnetic Safety (ICES) which reviews and evaluates the scientific literature on the biological effects of non- ionizing electromagnetic radiation and establishes exposure standards. He also serves on the ICES Risk Assessment Working Group that is responsible for evaluating and characterizing the risks of non- ionizing electromagnetic radiation. Dr. Bushberg was appointed and is serving as a member of the main scientific council of the National Council on Radiation Protection and Measurement's (NCRP). He is also a Scientific Vice-President of the NCRP, a member of the NCRP Board of Directors and chairs its committee on Radiation Protection in Medicine. In addition, Dr. Bushberg is a member of NCRP's scientific advisory committee on Non-ionizing Radiation Safety. The NCRP is the nation's preeminent scientific radiation protection organization, chartered by Congress to evaluate and provide expert consultation on a wide variety of radiological health issues. The current FCC RF exposure safety standards are based in large part on the recommendations of the NCRP. Dr. Bushberg was elected to the International Engineering in Medicine and Biology Society Committee on Man and Radiation (COMAR) which has as its primary area ofresponsibility the examination and interpreting the biological effects of non-ionizing electromagnetic energy and presenting its findings in an authoritative and professional manner. Dr. Bushberg is also a member of a six person U.S. expert delegation to the international scientific community on Scientific and Technical Issues for Mobile Communication Systems established by the Federal Communications Commission. Dr. Bushberg is a full member of the Bioelectromagnetics Society, the Health Physics Society and the Radiation Research Society. Dr. Bushberg received both a Masters of Science and Ph.D. from the Department of Bionucleonics at Purdue University. Dr. Bushberg is certified by several national professional boards with specific sub-specialty certification in radiation protection and medical physics. Prior to coming to California, Dr. Bushberg was on the faculty of Yale University School of Medicine.