Loading...
488 HIGHLAND AVENUE - ZBA (3) 488 HIGHLAND AVENUE (R-2) CAMP LION OF LYNN, MASS i AV n �f �ttlem, r�Httssttdtusetts Jul 6 3 31 F� board of ,c�u CITY Oi SAL( !i. MASS peal DECISION ON THE PETITION OF CAMP LION OF LYNN FOR A SPECIAL PERMIT FOR THE PROPERTY LOCATED AT 488 HIGHLAND AVENUE (R-2 ) A hearing on this petition was held June 28, 1995 with the following Board Members present: Stephen Touchette, Chairman, Gary Barrett, Nina Cohen, Albert Hill, Associate Member Joseph Ywuc. Notice of the hearing was sent to abutters and others and notices of the hearing were properly published in the Salem Evening News in accordance with Massachusetts General Laws Chapter LOA. Petitioner is requesting a Special Permit to allow transmission of signals by the airways from the tower at the property located at 488 Highland Avenue. This property is located in a R-2 District. The provision of the Salem Zoning Ordinance which is applicable to this request for a Special Permit is Section 5-3(j ) , which provides as follows: Notwithstanding anything to the contrary appearing in this Ordinance, the Board of Appeal may, in accordance with the procedure and conditions set forth in Sections 8-6 and 9-4, grant Special Permits for alterations and reconstruction of nonconforming structures, and for changes, enlargement, extension or expansion of nonconforming lots, land, structures, ,Wid uses, provided, however, that such change, extension, enlargement or expansion shall not be substantially more detrimental than the existing nonconforming use to the neighborhood. In more general terms, this Board is, when reviewing Special Permit requests, guided by the rule that a Special Permit request may be granted upon a finding by the Board that the grant of the Special Permit will promote the public health, safety, convenience and welfare of the City's inhabitants. The Board of Appeal, after careful consideration of the evidence presented at the hearing and after viewing the plans, makes the following findings of fact: 1. The petitioner will purchase the tower from Warner Cable Communications. 2. The petitioner will lease space for paging and two-way radio systems to generate revenue to further it charitable work. 3. The use would change from reception only to transmission of signals. DECISION OF THE PETITION OF CAMP LION OF LYNN FOR A SPECIAL PERMIT FOR THE PROPERTY LOCATED AT 488 HIGHLAlD AVENUE (R-2) page two 4. The petitioner will hire a professional sit manager. 5. There was opposition to the request for a Special Permit due to health concerns and questions concerning T.V. interference. On the basis of the above findings of fact, and on the evidence presented, the Board of Appeal concludes as follows: 1 . The relief requested cannot be granted without substantial detriment to the public good or without nullifying and substantially derogating from the intent of the district or the purpose of the ordinance. 2. The granting of the Special Permit requested will not be in harmony with the neighborhood and will not promote the public health, safety, convenience and welfare of the City' s inhabitants. Therefore, the Zoning Board of Appeal voted 1 in favor,4 in opposition to the motion to grant the relief requested. Having failed to garner the four affirmative votes required to pass, the motion to grant fails and the petition for a Special Permit is denied. Special Permit Denied June 28, 1995 Stephen C.Touchette, Chairman -•" Board of Appeal A COPY OF THIS DECISION HAS BEEN FILED WITH THE PLANNING BOARD AND THE CITY CLERK Appeal from this decision, if any, shall be made pursuant to Section 17 of MGL Chapter 40A and shall be filed within 20 days after the date of filing of this decision in the office of the City Clerk. Pursuant to MGL Chapter 40A, Section 11, the Variance or Special Permit granted herein shall not take effect until a copy of the decision, bearing the certification of the City Clerk that 20 days have elapsed and no appeal has been filed, or that, if such appeal has been filed, that it has been dismissed or denied is recorded in the South Essex Registry or Deeds and indexed under the name of the owner of record or is recorded and noted on the owner's Certificate of Title. n Board of Appeal -� m "_c� r a- w _ _ �n Cil to 5.`. �it i Ctf FI�PIii� asz*L SQts 9 paurb of ( 1"Ztti MTY CLl Pn.s.i 744-6900 MAY 9, 1978 DECISION ON THE PETITION OF. WARNiER_.CABLE�QRP. CONCERNING PROPERTY LOCATED AT 488 HIGHEAND AVE. OWNER, CAMP LION INC.) A hearing on this petition was held on Tuesday, May 9, 1978, at 7:00 P.M. at One Salem Green. Notices were mailed to abutters and others in accordance with Mass. General Laws, Chapter 808. Notice of the hearing was duly published in the Salem Evening News advising the public of said hearing. The following Board Members were present: Donald Eames, Arthur Labrecque, William Abbott, Jane Lundregan, James Boulger and Associate Member Douglas Hopper. Atty. Donald Koleman, 328 Essex St. , Salem, represented the Petitioners before the Board. The Petitioner is requesting a Special Permit in order to place a.100 ft. tower, in violation of the Zoning Ordinance due to height, on property located at 488 Highland Avenue. Warner Cable Corp. has obtained all the necessary licenses to date in order to operate a cable television system in the City of Salem. Warner has a contract with the City of Salem, passed by the City Council, signed by the Mayor, for said operation. The Warner Cable Corp. is requesting permission to erect a 100 ft. tower about eighty feet behind the abutting department store and SO/60 feet from Highland Ave. Research has been made to find the best transmitting station and one that would be in an area unobtrusive to the City. The Board voted to grant the Special Permit requested with the following conditions: 1. No transmitting of signals by the air way; 2. They will erect a 100 foot tower only; 3. This permit is granted to Warner Cable Corp. only; 4. The Special Permit will terminate if they go out of business or sell the system to another firm; S. The tower will be painted and kept clean at all times. The Board found that it could grant the Special Permit requested without substantial detriment to the surrounding neighborhood or without derogating from the intent of the Salem Zoning By-law. SPECIAL PERNQT GRANTED WITH CONDITIONS NOTED ABOVE ************ APPEAL FROM THIS DECISION, IF ANY, SHALL BE MADE PURSUANT TO SECTION 17 OF THE MASS. GEN. LAWS, CHAPTER 808, AND SHALL BE FILED WITHIN 20 DAYS AFFER THE DATE OF FILING OF THIS DECISION IN THE OFFICE OF THE CITY CLERK. Warner Cable Corp. May 9, 1978 488 Highland Ave. -2- PURSUANT TO MOSS. GIN. LAWS, CHAPTER 808, SECTION 11, THE VARIANCE OR SPECIAL PERMIT GRANTED HEREIN, SHALL NOT TAKE EFFECT UNTIL A COPY OF THE DECISION, BEARING THE CERTIFICATION OF THE CITY CLERK THAT 20 DAYS HAVE ELAPSED AND NO APPEAL HAS BEEN FILED OR THAT, IF SUCH AN APPEAL HAS BEEN FILED THAT IT HAS BEEN DISMISSED OR DENIED IS RECORDED IN THE SOUTH ESSEX REGISTRY OF DEEDS AND INDEXED UNDER THE NAME OF THE OWNER OF RECORD OR IS RECORDED AND NOTED ON THE OWNER'S CERTIFICATE OF TITLE. A COPY OF THIS DECISION HAS BEEN FILED WITH THE PLANNING BOARD AND THE CITY CLERK. BOARD OF APPEAL ane T. Li ndregan / Secretary Petition To City of Salem - Board of Appeal We, the residents of The Highland Condominium at Salem, MA strongly object to the petition submitted by Camp Lion of Lynn, Mass. Inc. for a special permit to allow transmission of signals by the airway from said Tower for the property located at 488 Highland Avenue (R-1) for the following reasons: Interference with Television and Telephone reception for area homeowners, -Potential radiation exposure, k__ Availability of alternative locations for said tower which would not inflict area homeowners with above listed risks. Name sin Address 2 iS -- 3 J r,(,r e 11 11QW le 4 L 5 S aS 40LeCL)ObD �. 6 7 /YYt�r„ 01 9 1441.0 10 lkJ —�7 odaq �rA i 11 / tk UYo 12 1 !� 14 / 15 16 02 17 TAAkwood Sq 18 Q. - e L / er,0 ad Vl 19 -S 20 Petition To City of Salem - Board of Appeal We, the residents of The Highland Condominium at Salem, MA strongly object to the petition submitted by Camp Lion of Lynn, Mass. Inc. for a special permit to allow transmission of signals by the airway from said Tower for the property located at 488 Highland Avenue (R-1) for the following reasons: -Interference with Television and Telephone reception for area homeowners, -Potential radiation exposure, -Availability of alternative locations for said tower which would not inflict area homeowners with above listed risks. Name sin Address 1 � ` i 2 3 7 ` 4 . s 5 6 J 7 8 J�%,�MIIA d 9 10 11 10114e40,3 /-Z i A-0 0 V 7 LL– LAV& 12 13 14 �-3 i KVV 15 16 17 18 19 20 r/ June 23 , 1995 Dear Mr . Touchette , I Stacy Wish, along with my husband Steven have been residents of the Highland Condominums , since 1987 . We re- side on 19 Indian Hill Lane . Our home is closest to a radio tower, that we understand is trying to be activated . We have been told that the tower will give off 900 mega- hurtz of radiation within a 10 mile radius . We feel that there is no scientfic proof that undoubtly insures us that no negative health risks will come to residents like us who live in such close proximity to the tower. This is of great concern to me . Especially since I was diagnosed with chronic Leukemia in 1982 . Since then I have received 3 life saving bone marrow transplants , in 1982, 1984, and 1991 . Finally after all these years I am disease free . I have gone through much pain in order to survive . I would hate for something like this to do me in. Especially after all my efforts to stay well . Secondly, we are concerned with the effects this tower will have on our TV, telephone, and radio reception. Though we have been told, if bad reception occurs someone will fix it . At the same time, it 's unfair that the chances of this happening propose another hardship for us . We would like to ask for your special consideration, and hope that you will deny the motion to activate this tower . We only forsee possible negative life threatening health risks , and inconvenient disturbances . Thank-you for your time . We look forward to seeing you at the meeting on June 28, 1995, at 1 Salem Green. Yours truly, Stacy Wish 19 Indian Hill Lane Salem, MA . 01970 (508) 744-0977 --- -- - --- --- --- --- ---------------------------------------------- ------------------------------------- - From : BROADCAST-CABLE ASSOCIATES PHONE No. : 617 595 8110 Bec.05 1994 4:15PM P0_ psw YIo crow R Gaga Ch•dwlnY 1?JtIW2U:U0:6622 ]tadio Communication Services ltndio Transmission Site Managemenl 736 Cross Country till, Pembroke N11 03275-3910 Telephone: (603) 228-3810/Wim Mail, Pngcr; (603) 666-3427 John Malty 1 Pierce Rd. Peabody, Ma, 01860 November 27, 1994 i Dear Mr. McCarthy; I have received your recent inquiry about any possible Interference to TV reception that might occur as a result of radio o erations at the Camp mp Llon tower site. Interference to TV reception can sometimes occur when nearby radio d o c ommunication sites use radio channels which are close in frequency to TV ch q y annals. I amlea p sed to report to you that the customer base that we intend to ',I I build at the Camp Lion site does not include any operations on the above mentioned troublesome frequencies. Our intended customer base would include Paging system operators on 150 MHz, 450 MHz, and 900 MHz, and two-way system operators on 450-470 MHz, 800 MHz, and 900 MHz. There Is also the potential for some two-way remote base and repeater operations In the 150-170 MHz band. One additional note a6 regards the TV interference,question. Any TV set connected to a Cable TV system is virtually impervious to any interference. Cable systems are only effected by over the air interference if the source of interference occurs at the cable company's receive antenna location. I note that you also inquire about the safety of the radiated energy from the site. The condition to which your refer is call Non-Ionizing Radiation. Non-Ionizing Radiation exists around all radio transmitting antennas, It is only a safety concern when the antennas of very powerful broadcast TV and Radio Stations are located very close to where people are present for prolonged periods of time. j The very low power levels used by the potential customers of this site are Inconsequential. if I hope that this report has been helpful to you. Please call on me if I can be of further assistance. I , Sincerely, R, Gregg Chadwick NONIONIZING RADIATION QUESTIONS AND ANSWERS Michael G. Yost, Ph.D. Department of Environmental Health School of Public Health, University of Washington, Seattle f E • f. rAe. Box 426800,San Francisco,CA 94142-6800,USA ^ AA Single copies: $2 each; quantity orers: $18 a dozen, $75 a hundred Copyright© 1988, 1993 by San Francisco Press,Box 426800, CA 94142-6800 {{1 i! I v i i I i i i I i { M What is electromagnetic radiation? Electromagnetic radiation is a form of energy that arises when electric charges are accelerated. Moving electric charges generate waves of electric and magnetic energy in space, somewhat like the waves created when pebbles are tossed into a pond of water. For exam- ple, the electric charges moving back and forth as an alternating cur- rent in a length of wire such as a radio antenna generate electromagnetic radiation. Once generated, this radiation spreads out from the source as electromagnetic waves, which propagate with the speed of light. These waves have a characteristic frequency and wave- length, and can be reflected, refracted, and absorbed when they interact with matter. What is nonionizing radiation? Nonionizing radiation is a form of electromagnetic radiation. It includes ordinary light, which we can see, and infrared radiation, which we sense as heat. Another type of nonionizing radiation, which our bodies ordinarily cannot detect, is radiofrequency (RF) radiation, including radio and TV signals and microwaves. Who is exposed to nonionizing radiation? Every member of our modern technological society is exposed to some nonionizing radiation, from natural sources like the sun and earth and man-made sources like telecommunications and navigational equipment, from medical and other commercial instruments, from pow- erlines, and from other vital services that benefit mankind. What do frequency and wavelength mean? In the radio example, suppose a vertical wire (an antenna) is con- nected to the transmitter of an FM radio station. The transmitter causes electric charges in the wire to move alternately up and down at a rate of (say) 100 million times a second. The charges moving in the wire generate electromagnetic waves. The frequency of the electromag- netic radiation corresponds to the number of waves per second that cross a fixed point in space. The frequency of the wave radiated from the wire is then f = 100,000,000 cycles per second. We designate "cycles per second" by Hz (for Hertz, the physicist who first detected radio waves), "thousand" by k (for kilo),"million" by M (for Mega), and "billion" by G (for Giga); thus, here f = 100 MHz (pronounced megahertz). 1 An observer at some distance equipped with an instrument that de- tects electromagnetic fields (such as a radio receiver) observes a rise and fall of these fields at the same frequency. The electric field lies in a vertical plane parallel to the antenna, and the magnetic field in a horizontal plane perpendicular to the electric field. Figure 1 shows these fields (which vary with time) in a sort of instant "snapshot" view. The time that elapses between successive peaks of the wave is t 1 = 1/f; we call t the period of the wave. Electromagnetic waves propa- gate through space with the speed of light v (300 million meters per se- cond); the distance traveled in one period t is called the wavelength A (lambda), so that A = vt = v/f. For the above FM frequency f= 100 j MHz, A = 300 000 000/100 000 000 = 3 meters. a� Direction in which wave is moving P Wavelength w FIG. 1.—Field and wavelength relationships in an electromagnetic wave. !I What is the frequency spectrum? 3 Although all electromagnetic waves travel through space at the 11 same speed, they can propagate at various frequencies. An orderly ar- rangement of electromagnetic waves from the lowest to the highest fre- quency is called a frequency spectrum (Fig. 2). Arranging electromagnetic waves in this manner groups similar types of radiation together in various parts of the spectrum. For example, visible light 2 i colors from red to violet is found at frequencies between 400 and 800 million MHz; infrared radiation occurs at frequencies just below visible light, at 1 to 300 million MHz. Radio waves occupy a large portion of the frequency spectrum: the AM broadcast band from about 0.5 to 1.6 ` MHz, the FM radio band at 88 to 108 MHz, the very-high-frequency t! (VHF) TV band from 54 to 216 MHz, and the ultrahigh-frequency (UHF) TV band from 470 to 806 MHz. Radio waves with frequencies just below infrared radiation, from 0.3 to 300 GHz (wavelengths A = 0.3 to 0.001 meter), are called microwaves and are used for a variety of tasks, including communications and radar. FREQUENCY IN HERTZ ELF VLF LF MF VHF UHF SHF EHF IR Light I Visible Light I UV Light Powerlines Video Displays Radio Navigation Marine Radio & Loran AM Radio Amateur & Shortwave "'_..._...._.._..._..._.._..._..._.._ .._..._..._.._...._..._ .. FM Radio :::_:::_:::_::__:::_:::_::_:::=:::7::=_::_:::_:::_::__:::_:::_ :: VHF Television UHF Television 1 Microwave Band 1 lxie 1x10 txlo' 1XIO" 1xto5 FIG. 2.—Electromagnetic frequency spectrum from"extremely"low and "very" low frequencies (ELF, VLF) "super" and "extremely" high fre- quencies (SHF, EHF) and beyond. Lower graph displays principal applications. 3 How does electromagnetic radiation convey information? The amplitude or frequency of an electromagnetic wave can be al- tered so that information can be carried by a process known as modu- lation. A primary continuous wave (called a carrier) is altered so that its amplitude or frequency changes in proportion to an imposed signal. The signal represents information, such as a radio or TV broadcast or the pulses of a radar transmission. The signal is generally at a much lower frequency than the "carrier" wave it modulates. The signal can be used to alter the carrier in several ways (Fig. 3). If the carrier's am- plitude is varied in proportion to the signal we have amplitude modu- lation (AM). Changing the carrier's frequency produces frequency modulation (FM), or the carrier may be switched on and off to produce short repetitive bursts of energy in pulse modulation (PM). warh:ow (a) r.N....m. _ �.w ti 0 (b) (c) { FIG. 3.—Methods of modulating carrier electromagnetic waves: (a) am- plitude modulation (AM); (b) frequency modulation (FM); (c) pulse modulation (PM). 4 What happens when electromagnetic waves encounter an obstacle? When electromagnetic waves encounter an obstacle they can be partially reflected, refracted, transmitted through the object, or ab- sorbed by it. A reflected wave bounces off an object like a light beam reflected from a mirror. A refracted wave is bent like light passing through a lens or prism. Part of a wave can be transmitted (pass through) an object and part can be absorbed and dissipated within the same object. Several of these effects may take place at the same time. The relative magnitude of each part of the wave depends on the fre- quency of the wave, on the angle of incidence, and on how well the ob- ject conducts electricity. A wave that strikes a highly conductive metal wall "head on" (at a right angle) is mostly reflected right back. If the wall is a poor conductor (an insulator, such as wood) most of the wave is transmitted through and only a small part of it is absorbed in the wall. Objects with an intermediate conductivity, such as most body tis- sues, may partially reflect, transmit, and absorb an incident wave. How are radio waves received beyond the horizon? High above the earth's surface there are several partially conduc- tive layers of the atmosphere called the ionosphere, which serve to re- flect waves with frequencies below about 30 MHz. When these radio waves strike the ionosphere at various angles, they bounce back and re- turn to earth at some distance from their source. In this way some ra- dio waves are transmitted over great distances. However, waves at higher frequencies (shorter wavelengths), such as those from FM radio, TV, and radar transmitters, pass through the ionosphere and are not re- flected: only the direct wave from the transmitter is received, and re- ception at a distance beyond the horizon is possible only by the use of relay transmitters such as microwave links or satellite repeaters. How can.one characterize the intensity of nonionizing radiation? A large broadcast transmitter is obviously more powerful than a hand-held set used in person-to-person communications. The intensity of the radiation depends on the strength of the source, on the distance from the source, and on whether it is spread out or focused into a nar- row beam—that is, on the "radiation pattern" (Fig. 4). If we know the distance and the pattern, we can calculate the intensity of the radiation fairly accurately. We can also measure it. A convenient unit for mea- suring intensity is the amount of radiated power, usually in fractions of a watt such as milliwatts (mW) or microwatts (µW) that pass through a 5 unit area such as a square centimeter; we speak of a power density p of, say, 0.1 mW/cm' = 100 µW/cm'. Another unit, used especially at the lower frequencies, is the electric field E in volts per meter (V/m) and magnetic field H in amperes per meter (A/m). These units are related as follows: E = 3.77p V/m, H = p/3.77 10_2 A/m where p is in microwatts (millionths of 1 watt) per square centimeter; for example, for p = 100 µW/cm', E = 19.4 V/m and H = 0.05 A/m. 330• 340" 3500 0• 10• 20° 300 320• 40• 310° 50° 300• 60^ 290• TO- 290• 60, 270° 90° I . FIG. 4.—Radiation intensity pattern from an antenna. What do the terms `far field" and "near field" mean? The term "far field" refers to the zone located beyond a certain dis- tance from a source, usually equal to at least several wavelengths. The "near field" is the zone immediately surrounding the source. In the near-field zone the electric and magnetic fields are more complex than in Fig. 1, the simple relation between E, H, and p in the above equations does not always hold, and measurements are more difficult. 6 How can one reliably measure radio-wave intensity? Two general types of measurements are used that relate to biologi- cal effects: densitometry or measurements of power density; and do- simetry or ,measurements of the absorbed energy. Power-density measurements become especially difficult in the near-field zone, where the magnetic and electric fields are not perpendicular. To get power density, the magnetic and electric fields are measured separately, and then converted to the equivalent reading for perpendicular fields, from which power densities may be calculated. Some instruments can accu- rately measure power density under a wide variety of conditions. Do- simetry generally measures the amount of energy absorbed and converted to heat by a body (or a suitable model) in calories per unit time, and these readings are converted to watts per kilogram. Dosime- try becomes even more complicated when the absorption of specific re- gions of the body is needed. That requires small temperature probes to be implanted at the measuring sites. To simulate humans, a full-size model filled with a material that has absorption properties similar to tissue is used to approximate actual conditions. Is the power density a measure of the energy absorbed by the body? Only indirectly: p is a measure of the conditions at a point in space before anything is placed there, and only part of the energy is absorbed (not necessarily uniformly) by the body. An average value of energy absorbed by the whole body can be stated in terms of the specific ab- sorption rate (SAR), expressed as power per unit body weight or watts per kilogram (W/kg). Does the energy in electromagnetic waves vary with frequency? All electromagnetic radiation can be described in terms of quantum packets of energy called photons; the amount of energy in each photon is related to the frequency (or wavelength) of the wave. The high- frequency waves have more quantum energy than low-frequency waves. One way to measure this photon energy is by how much work it can do. A measure of work commonly used is the electron-volt (eV). The pho- ton energy J in a wave measured in electron volts is given by J = hf, where h = 4.144 X 10'" and f is the frequency. For example, the pho- ton energy of a wave of visible red light at a frequency of 482 million MHz is about 2 eV. 7 i Are x rays a form of electromagnetic radiation? Yes: X rays, gamma rays, and some other forms are also electro- magnetic radiation, called ionizing radiation, whose mode of action and biological effects are substantially different from those of nonion- izing radiation. How does ionizing radiation differ from nonionizing radiation? Molecules are ionized when they lose or gain an electron; to ionize tissue requires a photon energy J of at least 10 to 12 eV. Ionizing elec- tromagnetic radiation differs from nonionizing because it has enough photon energy to create ions inside living cells (/ is high enough so that J > 10 eV); nonionizing radiation lacks sufficient photon energy to ionize cell contents. This "high-energy" (x-ray and gamma-ray) ioniz- ing radiation has frequencies above about 2420 million MHz, corre- sponding to the region of the spectrum above ultraviolet light (that is, J = hf > 10 eV). Ionizing radiation (such as x rays) has very different biological ef- fects from nonionizing radiation. When a cell's contents are ionized, very reactive compounds called free radicals are formed that can dam- age vital parts of the cell. Cells are equipped to cope with some free radicals, which can be generated by normal metabolism, but excessive ionizing radiation can overwhelm a cell's ability to control and repair the free-radical damage and disrupt normal functions. Also, if the DNA (genetic material in the cell) reacts with the free radicals, it may be permanently damaged. The damage from ionizing radiation that cannot be repaired accumulates over time in the cell. In contrast, non- ionizing radiation (such as radio waves) occurs at lower frequencies and thus lacks the energy to ionize cell contents. Nonionizing radi- ation is not known to damage DNA in the same way as ionizing radi- ation and (unless strong enough to produce actual burns) generally has not been shown to cause irreversible changes that accumulate over time. Is exposure to nonionizing radiation harmful? Exposure to high enough levels of nonionizing radiation can have adverse effects on living organisms. Whether effects occur and wheth- er they are harmful depends on exposure conditions (frequency, power density, waveform, duration) and on environmental and biological fac- tors. At SAR's above 4 W/kg (equal to or less than 10 mW/cm,' 8 depending on the body orientation and frequency), harmful effects are due primarily to excessive heating of tissues, which can lead to a rise in body temperature when the body absorbs more energy than it can compensate for or dissipate. The biological changes directly related to body heating are often called thermal effects, although temperature ef- fects would be a more accurate term. Effects below SARs of 1 W/kg (approximately 2.5 mW/cm=), par- ticularly when exposure is chronic, are less well understood. Effects on laboratory animals have been reported that appear at specific fre- quencies, power levels, and types of modulation yet without any mea- surable increase in body temperature. These biological changes are sometimes referred to as nonthermal effects. No clear cause-and-effect connection between these nonthermal phenomena and adverse effects on human health has been established. Generally the experiments that have produced biological effects used power levels well above those normally encountered in rural or urban environments. However, some studies involving Extremely Low Frequency (ELF) signals have shown results at power levels similar to those found in some homes. In the intermediate range between 1 and 4 W/kg, various re- searchers have reported observations that may or may not be due to body heating. The uncertainty surrounding the effects in this range is reflected by the general lowering of permissible exposure limits that has occurred over the past two decades. Microwaves are used to heat food; do they also heat people? As noted, microwaves and other forms of nonionizing radiation can cause heating in body tissues. This "thermal effect" depends on the amount of energy absorbed by the tissue, which is best stated in terms of the SAR for wholebody exposure conditions. The SAR (the amount of energy absorbed) depends on the intensity, duration, pattern, and frequency of the radiation, and our body's size, shape, and composition (percentage of bone, fat, muscle, etc.). The body responds to this heat, as it does to any other temperature change, by increases in blood flow near the skin, in body metabolism, and in evaporation. How well the heating is tolerated depends on factors such as age, physical condition, outside temperature and humidity, physical activity, and clothing. If the exposure is not excessive, the body's average temperature changes slightly but remains within normal limits. The heating lasts only as long as the body is exposed to the radiation, and temperatures return to resting levels within a few minutes after exposure stops. However, if 9 the heating is greater than the body can cope with, overheating and in- jury can result. Since nonionizing radiation causes heating, does it feel warm on the skin? Although nonionizing radiation usually produces detectable heat- ing of tissues, sometimes we cannot feel this effect. Most heat recep- tors lie near the skin surface, but under special circumstances the radiation can penetrate more deeply, creating a local hot spot in tissue well below the skin. For a given energy and irradiation conditions, the depth of penetration depends on the surface conditions and on the fre- quency (or wavelength) of the radiation. Energy at lower frequencies penetrates more deeply into tissues than at higher frequencies. For ex- ample, 2450-MHz radiation is mostly absorbed within about 3 cm into tissue, but most of 50 GHz radiation is absorbed within about 0.2 cm of the surface. What is diathermy? Diathermy refers to a medical use for the heating caused by radio waves. Deep heating of specific regions of the body is accomplished by radio waves aimed into the tissue. This technique is useful for warm- ing deep-lying muscles and joints and is used to remediate arthritic and similar conditions. Such heating is also used to enhance the effect of ionizing radiation in cancer therapy. What specific effects of radio waves besides overall heating have been observed? Although overall heating is the best-documented biological effect III' of nonionizing radiation, some heating effects that occur at specific i frequencies have been reported. Body resonance occurs when the wave- length.of the radiation is about the same as the size of an exposed body part. The impinging energy can be concentrated in some areas and cause local hot spots (Fig. 5). It is even possible to experience local- ized burns and electric shocks if one comes into contact with metal ob- jects. These specific heating effects are important because some body organs, particularly the testes and eyes, are especially sensitive to heating. 10 n.. .w.•f..a6.uoo V1-0.417 i� 0.691 - 0.165 5.067 0.6690.266 0.556 4 7.926 0.529 1.125 1.620 t.222 2.221 2.292 6.220 9.6W 6.471 6.996 6.766 6.096 1-1i FIG. 5.—Localized hot spots for RF energy. Numbers represent local SAR values (W/kg) when incident power density is 10 mW/cm2 and the average whole body SAR is 1.88 W/kg. (From Proc. IEEE 68: 27, 1980.) Some effects have also been reported at power levels that are too low to produce overall heating, and may depend on the radiation being modulated (AM, FM, or pulsed) at specific frequencies that arc differ- ent from those of the basic carrier radiation. Pulsed microwaves, re- peated at a few pulses per second, can cause people to hear a clicking sound inside their heads. (Most pulsed sources such as radars are re- peated at much higher rates.) There is also some evidence that the ef- fects of pulsed radio energy cannot be entirely accounted for on the basis of average power; that is, high-power pulses may have specific effects over and above those of AM or FM transmissions of equal aver- age power. Animal tests indicate that microwaves modulated at Ex- tremely Low Frequencies (ELF) near those of brain waves (0 to 30 Hz) may alter reaction times and daily activity patterns. Some experiments seem to indicate that the release of calcium ions ("calcium efflux") from brain tissue is enhanced after low intensity irradiation at specific frequency, intensity, and modulation conditions. No one knows how 11 important these "nonthermal" effects may be to human health; further research is needed to determine the consequences of exposure to these signals. How can we judge the risks from exposure to nonionizing radiation? Three key factors should be considered in the evaluation of the risk of exposure to any agent: the amount and type of exposure needed to produce an effect, the nature of the effect (harmful or benign), and the probability of exposure to radiation that produces an effect. Severe in- jury and death are possible at high exposure levels, but currently there is no established evidence of harmful human health effects at levels be- low about 0.1 mW/cm'. In the case of radiofrequency radiation, most exposures in the USA are well below this level. A survey of RF expo- sures in 15 cities by the U.S. Environmental Protection Agency (EPA) concluded that 99.5% of the general population is not exposed to levels exceeding 0.001 mW/cm' and 95% of all exposures fall below levels of 0.0001 mW/cm'. However, these are generalizations, and in some sit- uations where people live or work near RF sources (such as radio or ra- dar transmitters), average exposures may be higher than those measured in the EPA survey. (The general-population exposure mea- surements are like air-quality measurements; site-specific situations are like exposures near a chemical plant.) What about powerline frequencies (50/60 Hz)? Powerlines that carry AC electricity produce electromagnetic fields at frequencies of 50 to 60 Hz, which are thus part of the ELF band. Near high-voltage power lines, this energy is quite intense; sparking and a danger of electric shock may exist, especially near metal struc- tures such as fences, buildings, and equipment. The fields between powerlines and the ground resemble the fields produced by ELF,signals used to modulate radio waves, and some of the biological effects ob- served with ELF-modulated radio waves at specific frequencies and in- tensities may also apply to direct exposure to ELF signals. Is low-level exposure to nonionizing radiation a hazard? This is perhaps the most controversial and difficult question facing people concerned about nonionizing radiation. There is no simple an- swer. Some researchers have demonstrated biological responses to radio waves at intensities around 0.1 mW/cm'. There is no complete consensus among scientists as to the biological significance and health 12 consequences of these effects. Several points contribute to this dispute. There is disagreement about the extrapolation of cellular and animal studies to human exposures; it is difficult to explain the apparent im- portance of variables like the earth's magnetic field; it is difficult to control precisely variables such as the amount of energy absorbed by test organisms; effects that seem to appear at specific power levels, fre- quencies, and modulation patterns are not easily generalized to other situations. Some effects amount to only slight changes in body function that are within the normal subject to subject variations. Epidemiologic- al studies have produced equivocal results and many suffer from meth- odological weakness. The most clearly demonstrated adverse health effects of RF radi- ation are primarily caused by excessive body heating. Many scientists believe that because these low-level exposures produce virtually no heating they have no adverse health effects. However, some re- searchers suggest that there may be as yet unknown health effects that are caused by a nonthermal mechanism, and there is no unanimity about possible health effects of chronic low-level exposures or exposures that may occur in combination with other chemical or physical agents. We can never gather enough evidence to rule out all adverse health effects, and so must at some point make judgments based on what is known. As a cautious assessment, it seems unlikely that harmful or disabling ef- fects occur as a result of exposure at low levels. Does exposure to low-level ELF signals pose a health risk? The ELF band (0 to 300 Hz) includes some military communications frequencies, but also emissions from power transmission lines and even household wiring and appliances (such as electric blankets). Scientists are particularly interested in signals in the low ELF band (0 to 30 Hz) because brain waves and nerve impulses occur at these frequencies in man and animals. For example, some animal experiments have sug- gested that. preparations of individual brain cells alter their calcium levels when exposed to ELF signals or microwaves modulated by ELF. Other experiments have claimed changes in behavior, biochemical lev- els, and DNA transcription in response to ELF irradiation. These ef- fects seem to appear only in specific narrow "windows" of intensity and frequency and also depend on the intensity of background energy such as the earth's magnetic field. Such effects may or may not have any biological importance: studies have shown that low-level ELF sig- nals may cause physiological or behavioral changes in animals and tis- sues under particular conditions but no cause-and-effect relationship 13 between low-level exposures and any adverse impact on human health has been demonstrated. In 1985 the World Health Organization re- leased the opinion of an international panel of experts on ELF health effects. Among their conclusions: 1. Adverse human health effects from exposures to ELF electric field levels normally en- countered in the environment or the workplace have not been established. 2. Some human beings feel spark discharges in electric fields of about 3 kV/m and per- ceive fields between 2 and 10 kV/m. At present there are no scientific data that suggest that perceiving a field produces an adverse pathological effect. 3. Exposure to ELF electric fields can alter cellular,physiological, and behavioral events. Although it is not possible to extrapolate these findings to human beings, at present these stu- dies serve as a warning that unnecessary exposure to electric fields should be avoided. Finally, several studies of disease patterns in the general population (epidemiological studies) have suggested that cancer rates may be slightly higher in adults and children exposed to ELF fields. These studies have been criticized as having design and methodology flaws. Nevertheless, the World Health Organization panel considered the stu- dies and concluded: 4. The preliminary nature of the epidemiological findings on the increased incidence of cancer among children and adults exposed to ELF fields from electric wiring and the relatively small increment on reported incidence suggests that, although the epidemiological data cannot be dismissed, there must be considerable study before they can serve as useful inputs for risk assessment. Recently, scientists at the Karolinska Institute in Sweden conducted a study of nearly 500 000 persons who had resided at 530 000 addresses between 1960 and 1985 in areas served by powerlines from 220 to 400 kV. The results showed that children living within 50 m of such lines were 2.9 times more likely to develop leukemia (a very rare disease) than other children; and that these children tended to come from homes with historically higher magnetic fields. This and other epidemiological studies suggest that living near pow- erlines carrying high current contributes an increase in the risk of leu- kemia. Since such currents are characterized largely by the associated magnetic (rather than electric) fields, attention has shifted to magnetic fields in characterizing the associated exposures. What are common sources of ELF exposures? ELF exposures mainly come from our electric power distribution system, household wiring, and appliances. Table 1 shows typical 60 Hz magnetic fields measured near various appliances. In general for local- ized (point) sources like appliances the magnetic fields decrease rapid- ly with distance from the source, while fields from line sources like 14 wires tends to decrease more slowly. At distances of 1 meter or so the magnetic fields from appliances usually have decreased to background levels, which typically fall in the range of 0.5 to 10 mG in urban areas. TABLE 1.-60-Hz magnetic fields near appliances. Range of magnetic flux density near typical 115V, 60 Hz home ap- pliances at various distances from the source. Appliance Magnetic flux density,mC Dhtance 3 cm 30 cm 100 cm Can opener 10 000 to 20 000 35 to 300 0.7 to 10 Hair dryer 6 0 to 20 000 0.1 to 70 <0.1 to 3 Electric shaver 150 to 15 000 0.8 to 90 <0.1 to 3 Electric drill 4 000 to 8 000 20 to 350 0.8 to 2 Mixer 600 to 7 000 6 to 100 0.2 to 2.5 Portable heater 100 to 1 800 1.5 to 50 0.1 to 2.5 Blender 250 to 1 300 6 to 20 0.3 to 1.5 Television 25 to 500 0.4 to 20 0.1 to 1.5 Iron 80 to 300 1.2 to 3 0.1 to 0.3 Coffee maker 18 to 250 0.8 to 1.5 <O.1 Electric blanket 15 to 250 _ _ How is nonionizing radiation regulated in the USA? Both private organizations and government agencies have proposed guidelines that limit exposure to nonionizing radiation. These stan- dards can be divided into two broad categories: emission standards, which set limits on the incidental (nonpurposeful) radiation emanating from a device; and exposure standards, which set limits on the radiation power density to which a person may be exposed. Emission standards l limit unwanted leakage from devices such as microwave ovens that should contain the radiation inside the device or that have shielding to protect operators and others from exposure during normal operation. Exposure standards limit exposure of persons to radiation present in the environment, for example from a radio transmitter. How do other countries regulate nonionizing radiation? Most countries of the world have adopted maximum permissible ex- posures and policies similar to those of either the USA or the former USSR. For example, a document published by the World Health 15 USSR. For example, a document published by the World Health Orga- nization shows that standards in countries such as Great Britain, Swed- en, Canada, and Australia generally follow the U.S. exposure guidelines, whereas exposure limits in Eastern Europe more closely re- semble those in Russia. Exposure limits for nonionizing radiation in Russia are considerably lower (as much as 500 times smaller) than those used in the USA, although in practice the differences are not so great owing to various qualifications and exceptions. Similar differ- ences between exposure limits in the two countries exists for many chemical agents as well, and may be largely due to different viewpoints ) used in setting standards. (In Russia, exposure limits tend to be set be- low the level at which any observable biological effect is found; in the USA, exposure limits typically are set below the level of any harmful biological effects and incorporate a margin for safety.) What is an example of an emission standard? One device regulated by an emission standard, issued by the U.S. Food and Drug Administration (FDA), is the microwave oven. This emission standard is designed to limit human exposure to radiation that might leak out of the cooking area due to faulty door seals, or radiation due to incomplete shielding of the microwave generator. The standard limits leakage to 1 mW/cm' when the oven is new and allows a maxi- mum of 5 mW/cm' thereafter, as measured at a distance of 5 cm (2 in.) from the oven. What exposure standards exist for nonionizing radiation? In the USA, there are no legally enforceable and generally appli- cable standards limiting public or occupational exposure to nonionizing radiation. However, military and other government agencies, as well as some industrial organizations, have adopted exposure limits for their own use. The most commonly used exposure limits are those recom- mended by the Institute of Electrical and Electronics Engineers (IEEE) J and adopted by the American National Standards Institute (ANSI). All IEEE/ANSI standards are "consensus standards," agreed upon by com- mittees made up of people from universities, industry and government agencies. The most recent IEEE standard (C95.1.1991 "IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz"), recommends exposure limits that change with the frequency of the radiation, to account for energy absorption due to whole-body resonance and depth of 16 penetration,which varywith wavelength.An erlier ANSI standard C95.1-1974, recommended a maximum exposure level of 10 mW/cm' for all frequencies, and is still the basis of guidance (not a legally enforce- able standard) recommended by the Occupational Health and Safety Ad- ministration (OSHA) of the U.S. Department of Labor, which is responsible for workplace safety; OSHA continues to use the 1974 ANSI standard as a guideline, though not a legally enforceable stan- dard. There are no U.S. government standardsregulating exposure of the general population to nonionizing radiation, but EPA is considering issuance of recommended guidance. The National Council on Radiation Protection and Measurements (NCRP), a nonprofit, Congressionally chartered organization concerned mainly with ionizing radiation, has also released proposed exposure cri- teria for nonionizing radiation. The NCRP criteria are 1 mW/cm' for short-term exposures up to 6 min, and down to 0.2 mW/cm' for longer exposures (NCRP Report No. 96, 1989). Another standard, specifically for powerline fields, is contained in the National Electrical Safety Code, which requires clearances above ground large enough to limit the current between equipment under the lines and ground to 5 mA. Although the various exposure criteria have many differences, gen- erally the most restrictive exposure limits occur at frequencies between 30 and 300 MHz. At these frequencies (wavelengths between 10 and 1 in, comparable to human body size), body resonance and local hot spots arc more likely to occur. Table 2 summarizes the IEEE maximum per- missible exposure between 3 kHz and 300 GHz. Are there any Federal standards set by law? The only standards enforced by law are emission standards for mi- crowave ovens and ultraviolet lamps. There are no U.S. government standards regulating exposure to the general public to nonionizing radi- ation. EPA has been considering three levels of recommended Federal Radiation Protection Guidance, in SAR units: (1) 0.04 W/kg (i.e., 0.1 mW/cm'), (2) 0.08 W/kg, (3) 0.4 W/kg. (A fourth option is that no guidance be established, and that only information and technical assis- tance be provided.) The National Institute of Occupational Safety and Health (NIOSH) which acts as OSHA's research arm, is considering a recommendation for occupational exposure. In the absence of Federal exposure standards, State and local gov- ernments may adopt still stricter standards for exposures, and some 17 have already done so. In addition, the Federal Communications Com- mission has usually adopted existing standards in evaluating the envi- ronmental significance of facilities it licenses, especially commercial broadcast transmitters. TABLE 2.-IEEE Standard C95.1.1991 for continuous exposure in un- controlled environments (general public) between 3 kHz and 300 GHz. E = electric field in volts per meter (V/m), H = magnetic field in am- peres per meter (A/m), P = power density in watts per meter squared (W/m'), f= frequency in MHz (averaging time > 6 min ). Frequency(MHz) E(V/m) H(A/m) P(W/m') 0.003-0.1 614 163 0.1-1.5 614 16.3/f - 1.5-30 823.8/f 16.3/f 30-100 27.5 158.3/£" 100-300 27.5 0.073 2 300-10000 - f/150 10 000-300 000 100 1000 E P 100 0 1 0.1 j 0.01 o c c c 'o 7o - �y ' 11 FREQUENCY (MHz) FIG. 6.—Graph of exposure limits listed in Table 2, expressed in terms of field strengths (below 300 MHz) or power density (above 100 MHz). Who regulates the use of radio frequencies? The use of radio waves, for communications and other purposes, is regulated by agencies of the Federal government, subject to the terms of international agreements. Portions of the frequency spectrum are 18 allocated to specific uses (such as the TV broadcast band), and specific frequencies within that part of the spectrum are assigned to licensed operators. These procedures are intended to prevent interference or conflicts arising among various operators or services at a given loca- tion attempting to use the same portion of the frequency spectrum. (Imagine two local radio stations trying to broadcast at the same fre- quency.) All Federal government use of radio frequencies is regulated by the National Telecommunications and Information Administration (NTIA) in the U.S. Department of Commerce. All use of radio frequencies outside the Federal government, such as TV and radio sta- tions, is regulated by the Federal Communications Commission (FCC). These agencies regulate the use of the radiofrequency spectrum (for ex- ample by assigning frequencies and setting transmitter power limits), but they are not responsible for establishing exposure limits, even though the environmental significance of exposure must be considered in the exercise of their authorities. What U.S. government agencies are in charge of establishing envi- ronmental and safety exposure limits? Three Federal agencies have responsibilities for setting standards to limit for exposures to nonionizing radiation. The FDA's Center for De- vices and Radiological Health is responsible for setting emission stan- dards for electronic products, including consumer and medical devices such as microwave ovens and diathermy equipment. OSHA is responsi- ble for setting exposure standards for any work-related situations, such as repair of transmitters or use of radiofrequency heat-sealing ma- chines. EPA has taken the responsibility for proposing guidance on ex- posure standards for the use of government agencies. Other agencies, such as the military services, NASA, and the Federal Aviation Admin- istration, apply their own standards within their jurisdictions. What about the social and economic consequences of these regulations? Nonionizing radiation is related to many public, private, military, and commercial applications that are of great importance and benefit to our modern society. Although it seems prudent to limit unnecessary low-level exposures, overstrict regulations could have broad conse- quences. Strict limits on man-made sources of nonionizing radiation could require costly changes in AC power lines; radio and TV transmit- ters, telecommunications equipment, and radar navigation systems. 19 Overstrict exposure regulations can have an economic impact that must be weighed against the social benefits provided by modern technologies that emit nonionizing radiation. Another consequence may be unneces- sary fear and worry about unreal hazards. Abbreviations A Ampere AM Amplitude Modulation ANSI American National Standards Institute elm centimeter DNA Deoxyribonucleic Acid(genetic material in cells) ELF Extremely Low Frequency EPA Environmental Protection Agency eV electron volt FCC Federal Communications Commission FDA Food and Drug Administration FM Frequency Modulation G Giga(prefix for billion);or Gauss H magnetic field(A/m) Hz Hertz(frequency in cycles per second) J Joule k kilo(prefix for thousand) kg kilogram(1000 grams) M Mega(prefix for million) in milli(prefix for 1/1000);or meter mG milligauss(0.001 Gauss) now milltwatt(0.001 watt) NCRP National Council on Radiation Protection and Measurements NTIA National Telecommunications and Information Administration OSHA Occupational Safety and Health Administration PM Pulse Modulation RF Radio Frequency SAR Specific Absorption Rate TV Television UHF Ultrahigh Frequency V Volts VHF Very High Frequency W Watt WHO World Health Organization µW microwatt(0.000001 watt) 20 References Institute of Electronics and Electrical engineers (IEEE) Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz, IEEE C95.1-199 1991. (IEEE Inc., 445 Hoes Lane, Box 1331, Piscataway NJ 08855-1331.) Institute of Environmental Medicine, Magnetic Fields and Cancer in People Residing Near Swedish High Voltage Power Lines, Report 6/19, 1992. (IMM, P.O. Box 60208, 5-104 01 Stockholm 6, Sweden.) National Council on Radiation Protection and Measurement, Bio- logical Effects and Exposure Criteria for Radiofrequency Electromag- netic Fields. Report No. 86, 1986. (NCRP, 7910 Woodmont Ave., Bethesda, MD 20814.) U.S. Environmental Protection Agency, Biological Effects of Radio- frequency Radiation, J. A. Elder and D. F. Cahill Eds., EPA report 600/8-83-026F, Washington, DC 1984. (National Technical Information Service No. PB 85-120-848.) U.S. Environmental Protection Agency, Federal Radiation Protection Guidance: Proposed Alternatives for Controlling Public Exposure to Radiofrequency Radiation. (Federal Register 51: 27318-27339, 30 July 1986.) World Health Organization, Environmental Health Criteria 16, Ra- diowaves in the Frequency Range from 100 kHz to 300 GHz (Radiofrequency and Microwaves). Geneva, Switzerland, 1981. (WHO publications center USA, 49 Sheridan Ave., Albany, NY 12210.) World Health Organization, Environmental Health Criteria 35, Ex- tremely Low Frequency (ELF) Fields. Geneva, Switzerland, 1984. (WHO Publications Center USA, 49 Sheridan Ave., Albany, NY 12210.) World Health Organization, Nonionizing Radiation Protection, J. M. Suess and D A. Bendwell-Morison, Eds. WHO regional publications, European Series No. 25, Copenhagen 2nd ed., 1989. (WHO Publica- tions Center USA, 49 Sheridan Ave., Albany, NY 12210.) Acknowledgment The suggestions made by Dr. J. M. Osepchuk on an earlier version of this booklet are gratefully acknowledged. 21 Books on electromagnetic bioeffects from San Francisco Press: Electromagnetics In Medicine and Biology,Eds. C.T.Brighton and S.R. Pollack. 41 research and 13 review papers contributed on the 10th anniversary of the founding of the Bioelectrical Repair and Growth Society (BRAGS). Covers a broad range of topics,from the effects of EMFs on ion channels to transcriptional changes and selective enhancement of gene expression,stimula- tion of in vitro neuronal outgrowth, and treatment of osteonecrosis of the femoral head in adult patients.vii+365 pages,hardcover,$3750. Electricity and Magnetism In Biology and Medicine, Ed. Martin Blank. Contains some 200 papers presented at the Fust World Congress on the subject,held in the USA jointly by the Bioelec- tromagnefics Society(BEMS),the Bicelectrical Repair and Growth Society(BRAGS),the Bioelec- trochemical Society, the European Bioelectromagnetics Association, and participants from Japan, with support from several U.S. government agencies and industrial firms and associations, as well as official participation by URSI and IEEE.Contains significant contributions in basic research and technology, complemented by societal concerns (and skepticism) about this emerging field of study. Most complete examination of this sometimes controversial field to date. Approx. 500 pages,hardcover,$90. The Electric Wilderness,by Andrew Marino and Joel Ray. A detailed inside account of the con- troversy over the health effects of powerlines that pitted two outspoken scientists,Andrew Marino and Robert Becker, against the American power industry, State and Federal regulatory agencies, and the military. Traces the struggle from the New York hearing on the health risks of the pro- posed 765 000-volt powerlines to its conclusion (the lines were acknowledged a potential human hazard) and its bitter aftermath. Provides important insights into the politics of science and tech- nology in America. viii+120 pages,softcover,$1250. Nonionizing Radiation: A Case for Federal Standards? by Jane Clemmensen. Separates the social problem of public concern from the operational problem of delay and litigation costs. Are Federal exposure standards really necessary? A. W. Guy writes in a Preface: "This provocative examination of the continuing technical and policy issues is relevant not only to the nonionizing- radiation controversy, it also touches on many allied environmental issues of our time." vi + 90 pages,softcover,$10. Risk/Benefit Analysis:The Microwave Case,Ed.N.H.Steneck. The much-quoted compendium of opinions of some of the key contributors to the study of the bioeffects of radio-and microwaves, including O. P. Gandhi, J. M. Osepchuk, Samuel Koslov, D. R. Justesen, Przemyslav Czerski, Rochelle Medici,and A.H.Frey. xiv+231 pages,hardcover,$15. Electromagnetic Fields and the Life Environment,by Karel Marha,Jan Musil,and Hana Tuba. j (Translated from the Czech.) Still the best summary of the East European research that led to j assertions that radio- and microwaves can interact with the human nervous system in ways not observed in Western laboratories. The authors discuss these observations in detail, describe the measurement methods,justify the strict Russian standards,and propose a novel maximum-exposure limit that depends on length of irradation and has since become the basis for the present Czech standard.v+138 pages,hardcover,$15. * * Other books of interestfrom San Francisco Press: Ji Electricity and Medicine: History of Their Interaction, by Margaret Rowbottom and Charles Susskind. Traces the interplay of the two fields from the 17th century to the present. Includes chapters on "D'Arsonval and High-frequency Currents" and on "Electromagnetic Radiation and Medicine."vii+303 pages,hardcover,$30. From Compass to Computer: A History of Electrical and Electronics Engineering,by W. A. Atherton. Traces the subject's development from its earliest, primitive days to today's vast engineering applications, including the generation and distribution electrical energy. Relates important engineering developments to societal influences. Preface by Bern Dibner. xiv + 337 pages,hardcover,$30;softcover,$15. Attraction of Moths to Light and to Infrared Radiation,by H. S.Hsiao. Pioneering investiga- tion of the mechanism of phototaxis in insects, with a new hypothesis based on Mach bands. v+ 89 pages,hardcover,$10. Order direct from: San Francisco Press, Inc., Box 426800,San Francisco CA 94142-6800 No credit cards