106 107 0108 109 10 10" 1012

A Guide to Worrying IntelligentlyEdited by Art Kleiner

IHIS AMALGAMATION OF INFORMATION, conjecture, experiment, and reporting is theend of a 12-month odyssey. It started last June, when we were planning the "Computers asPoison" issue (Fall '84 WER).

Ve really should have something on the health hazards of video-display terminals (VDTs),"said to Kevin and Stewart. "After all, it's a major uncertainty. You sit with your nose squeezedD against the beast for hours every day: you hear vamue renortt of catararct and hirth d-.

fects; you hear, on the other hand, industry groups saying there's nothing wrong with the machines....Whom should you believe?"

A tip from Mike Castleman of Medical Self-Care Magazine led me to the Center for Investigative Reporting in SanFrancisco. A reporter there named Diana Hembree had already been investigating VDT radiation health hazards forseveral months, with a particular interest in its effects on women workers - most VDT terminal grunt workers,such as airline reservation clerks and data-entry operators, are women. At my request, she assembled a group ofinvestigators to look into potential radiation hazards from personal computers. Their original article arrived in timefor the Computers as Poison issue, but because it reported on a situation that was simultaneously controversial,extremely technical, and inconclusive, we didn't feel comfortable printing the article without scientific review.

Thus we held it and sent it to two dozen physicists, radiologists, biophysicists, and doctors - all people with apreestablished interest in this topic. Diana's original theme wasn't particulary incendiary; it basically said, "Thereseems to be cause forconcern, but nothing conclusive; more research is needed." We got back a dozen replies,some complimentary and others criticizing us for everything from hysterical sensationalism to underplaying thedanger. Some of those replies led to further interviews that supplemented Diana's already exhaustive research.Meanwhile, discussion on the EIES computer network began turning up comment from other people who hadinvestigated the Issue.

Ultimately, I edited Diana's article, plus some of the replies and other comments, into these 14 pages. We've brokenit down by Possible Health Hazard - non-ionizing radiation, glare, X-rays, noise, posture - and added a list ofnagging questions and an analysis of potential remedies. It may not be conclusive, but I feel it will give you as com-plete a picture of your choices as is possible now. And It's more newsworthy than it was last June, because severalthings have happened since then:

First, the academic/scientific establishment, which seemed firmly opposed last year to the idea that VDTs could be

80 _ ATU EViU ..a

10 102 1I03 104 10 5

l

-·i· t - l, - -lV -bL IL .I '~FUJ

ru wWm>mornagnluc raomuon is me information channel of the universe. Electricty, broadcast waves,telecommunications, X-rays, microwaves, and visible light - all travel as waves or pulses of energy,moving at the speed of light.This chart of the electromagnetic spectrum shows the overall range of electromagnetic frequencies. Inorder to fit the spectrum Into a reasonable space, the horizontal scale Is logarithmic - each markerrepresents a frequency ten times greater than the marker to its left.

illustrations by Don Ryan

producing harmful electromagnetic radiation, is admitting more doubt this year. This is partly due to some recentexperiments on the biological effects of low-frequency radiation, reported herein.Second, thanks largely to the persistence of labor unions concerned about VDT workers, there are some beginningattempts to measure low-frequency radiation from specific computer terminals and cross-check those measurementsagainst observed biolog;-al effects. The pioneer in this is a doctor named Hari Sharma at the University of Waterlooin Ontario, who is - to our knowledge - the only doctor so far to do the obvious: to investigate a particularcomplaint of health problems among VDT workers and test the machines they work on for low-frequency radia-tlon. His results are the first to suggest that different computer brands will produce radiation with differentbiological effects.Third, two of the scientists who responded to Diana's article - a physicist named Elizabeth Rauscher and her part-ner, an electronics engineer named William Von Bise - have begun to take on the daunting task of measuringradiation from various brands of personal computers and comparing them to each other. In February, they spent aday at Whole Earth's offices, measuring five different brands of computer under a variety of conditions. Thoughtheir research is far from conclusive - Whole Earth offices, for instance, bear no resemblance to a laboratory -they came up with some intriguing preliminary interpretations.Finally, a variety of radiation, glare, and static-electricity filtering shields have proliferated in the last year, designedto filter out a variety of different types of radiation. We asked Mike Skaar, who evaluates and sells screen filtersprofessionally, to help us get a sense of what's available and how they compare to each other.Unfortunately, some of the screen-filter companies are now using scare-tactic salesmanship that seems as suspectas the protests by computer manufacturers that the terminals are completely safe. "I got a call last week from aPR woman in Chicago," Time magazine computer editor Philip Elmer-Dewitt told us this spring, "pushing a companythat sold glare-and-radiation-proof screens to stick on the front of your terminal. To buttress her pitch, she cited aChicago Trib article that 'linked' time at a terminal with 'increased risk of miscarriage: She's not only yelling fire inthe maternity ward, she's probably covering up the wrong end of the CRT tube. Pinning this down once and for allwould do an invaluable service to everyone. Why is It so hard to get to the facts?"Because, Phil, the research is disparate, inconclusive, and contradictory. Many of the researchers have vested in-terests of one sort or another. Herewith, our best shot at cutting through the murk - with hopefully not toomuch oversimplification. The authors and interviewees wrote this material independently of each other, theresponsibility for editing it all together is mine. ,

27 GATE FE ROAOD SUC CA 94965 81

The core of the controversy

LOUIS JAFFE (proprietor of Chariotcomputer network, member of theSociety for Information Display):Take any ordinary AM radio, turnup the volume, and hold the antennanear your computer. The noiseemissions it picks up from the com-puter are usually loud enough todrown out local broadcast stations.

Tune the radio to different frequen-cies and move it close to differentcomponents of the computer. Alsomake the computer do variousthings: disk accesses, typing, variousscreen displays, print-outs. You willfind that the screen, keyboard,system unit, disk drive, and printerall make an amazing chorus of chirps,roars, clicks, and whines. Admittedly,you can't use this to measure theparticular frequencies the computerproduces - but it handily provesthere is energy humming aroundoutside a computer or terminal.

DIANA HEMBREE and KERRYNELSON (Center for InvestigativeReporting): Virtually all personalcomputers use video-display ter-minals (VDTs) to display their textand graphics. These terminals, likeTV sets, include a plastic or metalcase enclosing a cathode ray tube(CRT), which uses high-voltage cur-

At the Whol Earth offices,reearchers Elizabeth Rauscherand William Von Bise monitorthe electrostatic signals from anIBM PC video display terminalwith the three-tiered stackof electronic gear on the right.

82

rents to fire an electron beam atthe video screen. The high-speedelectron beam, and the electroniccomponents that gather power forit or aim it, generate a range ofelectromagnetic fields - Includingweak X-rays, ultraviolet radiation,Infrared light, and radiation of manyother frequencies. Although mostradiation is absorbed by shieldingbuilt into the computer case or theglass screen, scattered reports ofcataracts and problem pregnancy"clusters" stirred concern aboutpossible radiation hazards from com-puter terminals beginning In 1977.

In 1977 two young New York Tknescopy editors using VDTs developedearly stages of cataracts - an eyedisease that usually affects the elder-ly. Dr. Milton Zaret, a Scarsdaleophthalmologist who since 1959 haspublished controversial findings onthe effects of microwaves on thehuman eye, said that the cataractswere caused by exposure to radia-tion.2 Government investigatorssubsequently ruled out VDT emis-sions as a possible cause; but soonafterwards, early cataract symptomsturned up among several employeesat the Bltimore Sun. Here againNational Institute of OccupationalSafety and Health (NIOSH) in-vestigators found "no significantassociation" between VDT use andpremature cataracts. However,NIOSH concluded that "the issueof VDT-associated cataracts is NOTresolved by our study."3

The controversy over VDTs andradiation grew more heated duringthe next five years, as office workersreported separate "clusters" ofmiscarriages and birth defects at ISVDT worksites in the U.S., Canada,and Europe. Government investi-gators at four of these places haveexcluded VDTs as a possible culprit.and federal health agencies in theU.S. have dismissed the clusters asstatistical flukes. However, manyVDT operators, reporting eyestrain,blurred vision, headaches, dizziness,back pain, irritability, and stress, arestill worried about possible radiationhazards. Experts often trace theseeffects to assembly-line work paceand to poor VDT or work-station

357

design.4 but a small but increasinglyactive group of medical researchershave said that the radiation hazardquestion is far from answered.

Among this group is Arthur Frank,chair of the Department of Preven-tive Medicine and EnvironmentalHealth at the University of Kentuckyat Lexington. Dr. Frank, a well-known researcher on VDTs andhuman health, finds "a great paucityof scientific information ... on thepossible health effects" of VDTs,now used by an estimated IS mil-lion Americans. Unconvinced thatstudies of VDTs have given radiationa clean bill of health, Dr. Frankdescribes the VDT emissions issueas "unsettled."

Not so, say government agenciesin the United States and Canada,agencies which often have donetheir own VDT testing. The U.S.Food and Drug Administration, theAmerican Academy of Ophthal-mology, and a blue-ribbon panel ofthe National Academy of Sciencesare among the groups that haveevaluated and dismissed the idea ofradiation hazards from terminals.Any radiation given off, they argue,falls well within federal guidelinesand is too small an amount to posea threat to health.

"There is absolutely no danger withradiation emissions from VDTs. evenfor pregnant women," saysWilliam Murray, a radiation specialistfor the National Institute of Occu-pational Safety and Health. SomeIndustry officials have taken things astep further by deriding fears aboutradiation as irrational. Protectingworkers from VDT radiation "is likeprotecting them from light bulbs,"Charlotte Le Gates of the Computerand Business Equipment Manufac-turers Association (CBEMA) toldone reporter. "It's like employeessaying, 'the office is filled with cosmicrays and you have to fight them withballoons.' "s CBEMA has recentlybegun a multimillion-dollar mediacampaign, with TV spots andquestion-and-answer columns innewspapers, to convince computerusers that VDT-emitted radiationis not hazardous.

WHOLE EARTH REVIEW FALL S9

The electromagnetic spectrum

DIANA HEMBREE and KERRYNELSON: In the past few years, agrowing number of scientists havetentatively linked low-frequencyelectromagnetic (EM) radiation toprofound biological and geneticchanges in test animals.'

Scientists have found that electro-magnetic fields - regions activelydominated by electromagneticradiation - may affect organismsat certain specific frequencies, or"power windows." while evenslightly lower or higher frequencieshave no effect at all. For this reasonand others, it is risky to assumethat effects found at one frequencywill be produced by others as well.

It is also important to note that thisresearch on the biological effects ofelectromagnetic radiation has notfocused on VDT radiation - andthat no studies anywhere have con-clusively linked radiation from VDTsto health problems. However, asthe chart below shows, computerand computer terminal users areexposed to some low-frequencyelectromagnetic fields similar tothose linked to biological effects.These similarities suggest that thequestion of VDT safety is still open.Unlike X-rays, low-frequency radi-ation is non-ionizing; it does notalter the atomic or molecular struc-ture of substances through which itpasses. Because ionizing radiationhas been linked more obviously tohealth problems, much less is knownabout non-ionizing radiation. Fordecades, many physicists have arguedthat non-ionizing radiation couldnot affect the human body unlessthe electric field it created wasintense enough to produce heat oran electric shock. But last summera leading engineering journal declaredthat "a growing mass of evidencehas virtually ended that debate:

ectromagnetic felds too weakto heat an organism could stillaffect it."

"The [recent] scientific literatureon weak-field effects is massive,"said Eric Lemer, a contributing ed-itor to the Institute of Electricaland Electronics Engineers (IEEE)Spectrum. Lemer said that "evidence

27 GATE RIVE ROAD USIUSAU CA 949S

of the effects of EM fields on thenervous system and the immunesystems of animals was already weestablished by the end of the '70swhile evidence of EM effects onthe genetic material in cell nucleihas accumulated most rapidly ovethe past few years."

Discoveries that weak EM fields caffect living organisms heralds wh;prominent medical researcher Dr.Ross Adey has called "a biologicalrevolution as fundamental as anysince Descartes."' Biologists arebecoming aware that our bodies'communication network of hor-mones and nerve impulses is "supplemented by a 'radio network' o

IBM PC. Apple II, Compaq--.

Kaypro-

Observed FrequenciesIn Personal Computers

Apple II running anmesIBM PC. Apple 11. Compaq

Kaypro -Apple II running Choplifter

IBM PC- -Apple II running games. Compaq -. ,

Apple 1 Compaq -Apple II. Compaq 2

IBM PCApple 11, Compaq / -

Compaq--

Kaypro. Compaq -- -Macintosh. Kaypro L/ -

Apple II, IBM PCrKaypro, Compaq -- "

Compaq -

IBM PC w/blue background -IBM PC w/blue background---

weak electromagnetic fields."' Thismay mean that our bodies are far

ll more sensitive to external electro-i, magnetic fields than was previously

thought. For this reason, ongoingresearch In this area could have

r important implications for healinguses of EM fields - and for peopleexposed to EM fields from high-

an voltage power lines, radar andat broadcast towers, walkie-talkies,

and other electronic devices. It willalso matter to VDT operators andcomputer buffs who are exposedto weak EM fields from their ter-minals - particularly fields affectedby extremely low-frequency radiation(ELF), hitherto ignored as a possible

if health hazard. P

frequency in her (cycles per second)

biologal Effects

Increased excitability of nerve cells; Adey- /Brain wmve changs in people; Von Bis

_ /Corrects heart arrhythmia; n Ise//lncreased lymphocyes/enlarged adrenal lands in rats; Chou/Guy

- //wHumn brain wave entrainment: Von isy/IApproximates median human alpha brain wave; Walter

_ - Disturbed chicken cel embryos; Deldo10 1Entrainln human circadin rhythms; Morino, erger, Austin/Weer

--Inhibits bone cell reaction to hormone; Luen_ ~-Grater calcium efflux In cat brains; Adey

- /Chanes in rabbit brain cells; Honsson- JBirth defects In wine; PMhps

1Deformed pig and chicken offspring; Anderson:- IReduced capacity of lymphocytes to kill foreign cells; ye. Inhibits bone cell reaction to hormone; Luben

10 Dlisturbed chicken cel embryos; Delodo

- Embryonic development stunted in mice: Pofkeo

1000"Observed Frequencies In Personal Computers" were measured byRauscher and Von Bise In our offices. This is what they found between0 and 1000 Hertz. The measurements have never been duplicated, Ina lab or in our officesEach Item In "Blolical Effects" refers to a published sclntifc articlewhere the experimenter found a particular biologial effect at a par-ticular frequency within that 0-1000 Hertz range.Thee is no demonstrabe causal relationship between observed fre-quencies and bololical effects Just because a 50-Hertz frequencyonce changed some rabbit brain cells doesn't mean you should sellyour Kaypro. There could be differences In the wve shapes or differ-ences in the environment that triggered the bloeffect; the referencecould have ben misread, or Von BIse and Rauschir could havemismeasured the Kaypro.

83

Extremely Low FrequencyRadiation (ELF)Bdow 3,000 Hertz

DIANA HEMBREE and KERRYNELSON: One particular set ofdramatic findings from Spain arecausing many researchers to take aharder look at ELF radiation - non-ionizing radiation below 3,000 cyclesper second in frequency. In 1982,associates of Dr. Jose Delgado'sresearch laboratory at the Ramon yCajal Hospital in Madrid discoveredthat extremely weak pulsed mag-netic fields - as much as 500 timesweaker than the Earth's non-pulsingmagnetic field (which is, in turn,1/10,000 of the intensity of a typicalindustrial electromagnet) - had aprofound impact on the developmentof chick embryos. The researchersfound that Extremely Low Frequency(ELF) radiation (10, 100, and 1000Hertz) at field intensities rangingfrom 1.2 to 129 milligauss disturbedthe cell organization of the em-bryos, resulting in malformed heartsand central nervous systems.!

These exceptionally unusual findings

were first reported in the profes-sionally refereed Journal of Anatomy;then in VDT News, a newsletter thatfocuses on VDT health and safetyissues. The experiments arousedskepticism and amazement amongmany researchers, who found it dif-ficult to believe that such weakradiation could have such powerfuleffects. Delgado's experiments werereplicated more recently by Dr.Kjell Hanson Mild of the SwedishNational Board of OccupationalSafety and Health, who confirmedthat he found similar effects.

"The very fact that Delgado isgetting effects at such low levels [ofpulsed magnetic fields] deserves alot of attention in the scientificcommunity," said Dr. Arthur Guy,director of the BioelectromagneticsLaboratory at the University ofWashington School of Medicine inSeattle. Guy also said that the in-tensity of the current induced byat least some VDTs is "about thesame" as that induced in Delgado'sexperiment. He cautioned, however,that "even a very slight difference[in the shape of the magnetic wave-forms] may mean that the VDTwaveform is not biologically active."

Despite these reservations, in areport to IBM that the companyhas not yet released to the public,Dr. Guy compared the results of hisexperiments with those of Delgado.He concluded that "it can be seenthat induced currents where [Del-gado] observed teratogenic effectsin chicken embryos can be producedin human tissue exposed to VDTmagnetic fields." Because of thehigh electric field strengths measuredfrom some VDTs, he recommendedto IBM that terminals be shielded.

Although Dr. Guy has published anumber of papers which say that hedoes not believe VDT emissions tobe hazardous, he stresses the needfor further study.

Intrigued by the "Delgado effect,"other experts are, for the first time,"openly speculating that non-ionizingradiation from VDTs can have biolog-ical effects," reported VDT News."Dr. Richard Tell, a physicist with theEnvironmental Protection Agency,has said that the possibility of healtheffects cannot be ruled out. TheEPA, meanwhile, is planning to tryto replicate Delgado's experiments.

ART KLEINER: Cathode-ray tubebased computers produce ELF radi-ation at a variety of frequencies,depending on the type of computerand possibly even what type ofprogram is running (see "TestingComputers for VLF and ELF" laterin this article). Some of this radia-tion is generated by the terminal'sAC power source, running at either50 or 60 Hertz. Other radiation isgenerated from the pulses whichmove the electron beam verticallyto refresh the full screen.

Rauscher and Von Base measuredthe electromagnetic frequencyradiating from five computers.They photographed each signifi-cant surge of power they found.In this Image, the game LODERUNNER is played on an Applelie, with an Apple III monitorwith green letters on a blackbackground. The oscilloscopephoto shows both the electricand magnetic components ofthe detected radiation. Therange for both halves is 0-20Hertz. The top half Is takenfrom a mostly-dark screen; thebottom half from a screenfulof moving characters.

3EN57S84

Very Low FrequencyRadiation (VLF)3,000-30,000 Hertz

DIANA HEMBREE and KERRYNELSON: Until the news about theDelgado experiments broke, thegrowing concern over VDT pulseshad focused on VLF (Very Low Fre-quency) Radiation. The furor overVLF erupted in 1982, when Dr.Karel Marha of the Canadian Centrefor Occupational Health and Safety(CCOSH) measured "relativelystrong" pulsed VLF emissions fromsome VDTs and suggested that a

WHLE EARTH REVIEW FALL 1985

link between these emissions andthe clusters of problem pregnanciesat VDT worksites cannot be excludedfrom consideration.'2

"Unfortunately, no one (still) hasconducted studies on the biologicaleffects of VLF pulsed electricalfields," Dr. Marha said .cently.According to one researcher atCCOHS, pulsed VLF is "an extremelyhot research topic right now." Incomputers, the VLF frequencyradiation comes generally from thecathode ray tube's high-voltagepower source, known as the flybacktransformer. The transformer usesan electrical pulse to move an elec-tron beam horizontally across thescreen; as it does so, it emits pulsesof radiation - almost 16,000 persecond, or 16 kilohertz.

Testing Computersfor ELF and VLF

ART KLEINER: We know of only afew scientists who have made aneffort to measure computers orcomputer terminals for VLF/ELFradiation, and check the resultsagainst radiation frequencies withobserved biological effects. One isa Canadian physician, Dr. Hari Shar-ma of the University of Waterlooin Toronto, who released a paperearlier this year based on exper-iments done at the Surrey MemorialHospital, Vancouver, B.C. Respondingto complaints at the hospital offatigue and pregnancy problemsamong workers at some types ofVDTs (those made by Perkin-Elmer)but not at others, Dr. Sharma meas-ured all the VDTs for every type ofradiation and several other types ofpossibly toxic agents. He found onedifference between the terminalbrands: "The electric and magneticfields in the very-low-frequencyregion were found to be relativelyhigh in the P-E terminals.... Thedata on adverse pregnancy outcomesfrom employees working with the P-Eterminals in eight hospitals indicatedthat there might be linkage betweenexposure to EM fields and adversepregnancy outcomes.""

Another researcher of this topic isDr. Elizabeth A. Rauscher, a physicistspecializing in radiation, formerlywith the University of California atBerkeley. With her partner, elec-tronics engineer William Von Bise,'4

Dr. Rauscher came to the WholeEarth offices in February and meas-ured the electric and magnetic

27 GATE RVE ROAD SAUSAULT CA 9496S

LIGHT (infrared, visible, andultraviolet). STATIC ELECTRICITY;byproduct of electron beam strikingphosphor and glass.----

FLYBACK TRANSFORMER; I5-20 kHz,also ultrasound (above 20kHz)

Most electrical devices emit several frequencies of electromagneticradiation of varying Intensities - the Intensities proportional to thepower running through the devkce This diagram shows several sourcesassociated with the cathode ray tube in a VDT or television set.

fields emanating from five differentbrands of personal computer.

As it pulses, electromagnetic radia-tion creates two distinct phenomenawhich alternate rapidly across theregion of the electromagnetic field.One is a dynamic electric field, witha detectable electric charge thatconstantly changes from positive tonegative; the other is a magneticfield, or flow of magnetic force,constantly changing polarity. Thetwo components, which incidentallyoscillate at right angles to eachother, may produce different biolog-ical effects, are shielded by differentmetals, and may produce ambiguousresults when measured together -so Rauscher and Von Bise measuredthem separately.

The tests were preliminary, and weonly had one day to work in - sowe didn't get to compare the fivecomputers against, say, a regular TVset or a dumb video-display terminal.But the tests do suggest some veryinteresting preliminary indications.s

34P

Microwaves andBroadcast Waves50.000 Hertz-IO' Hertz

ART KLEINER: VDTs, including per-sonal computers, produce radiationat most frequencies along the elec-tromagnetic spectrum. However,existing VDTs seem to be shieldedadequately against radiation at fre-quencies higher than ELF and VLF.They're required by FCC regulations

85ICI -- rrr rarrrrr�---

Rauscher and Von Bis used anelectrostatic voltmeter, shownhere In front of the Macintosh,to measure electrostatic fields(static electricity) from each ofthe computers. Their probe usesa ferrte rod tuned to a particularfrequency. It responds to eachchange in magnetic field intensityas a change in that frequency.

cognized for its restful qualities. Myonly problem with green is the wayeverything looks amber or purplewhen you look away after staring atthe display for a long time.

ART KLEINER: We don't know ofany credible research on the healtheffects of various colors from com-puter screens - but we have solidadvice (in the "remedies" sectionof this article) on reducing andcoping with glare.

to be shielded at radio and radarfrequencies; otherwise, computerscreens would interfere with distantbroadcast and radar transmissions.Partly as a result of the controversyover microwave ovens, they'reshielded against microwaves too.

Infrared, Visible,and Ultraviolet Light10'-10" Hertz

ART KLEINER: CRTs emit all formsof light - infrared, visible, and ultra-violet - in a variety of frequencies(depending on your monitor). Thoughintense infrared and ultraviolet lightcan cause burns and cataracts, atleast one researcher concernedabout VLF/ELF levels - Dr. HariSharma - found the terminals'infrared and ultraviolet light levelsto be reassuringly low: "The levelsof all three types of [visible-lightspectrum] radiation from VDTs atthe operating brightness are verylow, and with present scientificknowledge, it is inconceivable thatthey present any hazard with respectto occupational exposure. However,the problem of brightness and glarein the workplace is of considerableimportance with respect to 'blurredvision' and visual fatigue."

86

As Eric Lerner of the IEEE Spectrumreminded us in conversation, manyof the symptoms people attributeto radiation - eyestrain, headaches,dizziness, stress, and possibly evenpermanent eye damage - might becaused or exacerbated by prolongedexposure to glare. Much of theevidence against glare is anecdotal.Our computer network correspond-ents debated about screen color:

RICHARD DALTON (regular con-tributor to Whole Earth computercoverage): A report issued by theJournal of Applied Psychology recentlyfound that screens with reversedtype (white on black or color) reducereading speed by II percent."' Thatmay explain why I've come to likeblack on amber for text production.

ERICK WUJCIK (computer colum-nist, the Detroit News): I'm glad I'llnever have to use a black-and-whitedisplay again. Up 'til ten months agothe Detroit News had old-fashionedmonitor. Every time a column wasdue I ended up with incredible eye-strain. I haven't ever had that problemon green phosphor or color mon-itors And I find the soothing blueand white of ATARIWRITER to bea source of comfort.

LOUIS JAFFE: I don't like white-background, black-text displaysbecause I'm quite sensitive toflicker, and it's much easier to seeflicker in a large area of light video,like on the Macintosh. I don't likeamber displays either. Amber waschosen because the human eye'sspectral sensitivity peaks on amber;therefore it's supposed to make themost efficient human-machine sys-tem. But some esoteric students ofcolor therapy claim that amber canproduce all sorts of negative excita-tions in people. I can believe thisafter viewing amber displays evenfor very short periods. Green, onthe other hand, has long been 're-

3'-C

Ionizing Radiation(X-Rays and Cosmic Rays)10" Hertz and greater

ART KLEINER: They don't give offcosmic rays - at least not outsideof comic books - but VDTs dogive off X-rays as a by-product ofthe impact of high speed electronson the viewing screen. This radia-tion is called "ionizing" because italters the molecular structure ofsubstances it passes through, creat-ing ions. However, the consensusamong researchers is that X-raysfrom computer terminals are rela-tively low-intensity; they're absorbedby the glass screen and by metalshielding built into the computer.'IBM tests several out of every hun-dred terminals and computers thatit produces for X-ray leaks. TheNational Institute for OccupationalSafety and Health (NIOSH) measuresworkplace VDTs for X-rays. I had atypesetting terminal tested by themin 1979; the measurer said he hadchecked hundreds of terminals andhad never found ionizing radiationleaking through. Although you'llhear scare warnings from companiesselling lead-impregnated shields, theonly legitimate concern we've heardabout X-rays involves older ter-minals with incomplete or corrodedshielding.

WHOE EARTH REVIEW ALL 1985

Off the electromagnetic spectrum: other hazards

Static electricity

DIANA HEMBREE: When Scandi-navian office workers reported awave of mysterious facial rashes in1981, Norwegian scientist WalterOlsen began an investigation. Afternumerous experiments, he linkedthe rashes to an unexpected inter-action between strong static electriifields generated by the VDTs andthe bodies of the people at thekeyboards.

Olsen discovered that unless theVDTs were deliberately shielded toblock electric fields, "high voltagesmay extend into the air surfacessurrounding the units," with someterminal operators receiving staticcharges of as much as 2,000 voltsper square meter. By measuringlevels of airborne pollutants, Olsenalso found that dust, tobacco smokeand other contaminants floating infront of the VDT became positivelycharged and sought out the nearestgrounded or oppositely chargedsurface - usually the operator'sface. Then the particles clung tothe face, causing rashes, itchy eyes,and dry skin. Olsen taped an ad-hesive-coated "collection device"on the faces of people sitting atVDTs, and measured the depositshours later. He found microscopicparticles "rained" on subjects' face!at a rate at least ten times higherwith a VDT than without one. Inone experiment the deposit ratetopped 100,000 submicroscopicparticles per square millimeterper hour."

Since Olsen's study, researchers inthe U.S. have demonstrated that thepositively charged field around aVDT tends to neutralize negativeions around the unit, creating whatthey believe to be an unhealthybuildup of positive ions. Air ionsappear to cause changes in the bod)through their impact on blood levelsof serotonin, a powerful hormonethat affects the endocrine glandsand central nervous system. Somereseachers have linked high positiveion concentrations with nausea,

fatigue, metabolic disorders, irri-tability, headaches, and respiratoryproblems.'

ART KLEINER: Where does thestatic electricity come from, youask? According to Bob DiMatteo'sbook, Terminal Shock, it's "pro-duced as a result of electrons beingejected from the electron beam.These electrons build up on thescreen and in surrounding space." 20

Static electricity is a by-productof the same force that projectselectromagnetic radiation, and isthus linked inntensity to the electro-magnetic field around the computer.The more intense the electromag-netic field, the greater the staticelectricity. Unlike electromagneticradiation, static electricity builds'up only in the direction the elec-tron beam is focused - the frontof the computer.

Sound

ART KLEINER: The "evidence"that computers and VDTs give offultra-high-pitched sounds is largelyanecdotal. Some people can hear ifa CRT is on in the general area, andclaim to be irritated by the sound.The following exchange of letters inthe January 1984 Byte magazinehighlighted the problem, saying thatflyback transformers, as they pro-duce IS kilohertz electromagneticradiation, also produce sound wavesat the same frequency. Sound wavesthemselves are not electromagneticrays (thus, they don't travel at thespeed of light), but ripples of vibra-tion passing through substances.

WILLIAM G. UNRUH (Departmentof Physics, University of BritishColumbia): [The high-frequencynoise from computers] is a ubiqui-tous problem caused, I believe,by the fact that the monitors aredesigned by deaf engineers. Mostmen have lost their hearing at 15.7kHz by their early twenties andthus build and design the monitorswith cheap flyback transformers'that vibrate at the flyback frequency.... Measurements near the cooling

17 GCATE E ROAD SAUSAUU CA 496S5

holes of many monitors give read-ings as high as 90 decibels.

GARY KEENE [quoting a letter inthe October 1984 Softalk, p. 43]:J. Barry Smith of Massachusetts, aprofessional audiologist, was able tomeasure 15-kHz sound-pressurelevels as high as 44 decibels at theoperator's ear. I think this problemmay be widespread, especially amongthe female population of computeroperators, who typically have moreacute hearing than men.2

Posture, stress, chemicals, gas

ART KLEINER: Bad posture -from prolonged sitting at a poorlydesigned workstation - may be themost widespread computer healthhazard of all. The "remedies" sec-tion of this article contains muchinformation on posture problemprevention.

According to Eric Lerner, stressseems to exacerbate other problems- particularly glare and posture.Perhaps that's why VDT workers,whose work output is often auto-matically measured against time,show more symptoms as a groupthan personal computer users(except those of us stressed bydeadlines).

Just in case you were wonder-ing, Dr. Hari Sharma performed achemical and gas analysis of hisVDTs. He found no significant traceof PCB, environmental toxins, ozone,carbon dioxide, or carbon mon-oxide.22 We have heard no othercharge that VDTs produce toxicchemicals or gases. Whew!

., -. t, ,i ,.

Why.worry aboutconp.t:^.terminals and notibout lt^sei

DR. ARTHUR FRANK (chairman,Dept. of Preventive Medicine andEnvironmental Health, University ofKentucky at Lexington): A televi-sion set is basically the same kind of

87

equipment as a computer terminal- in fact, some of your homecomputer manuals say "hook it upto your home television set." Thereare some differences, though, froma medical point of view. With theexception of little kids like my own,who like to sit right in front of thetube and kiss Mr. Rogers in theafternoon, most of us don't watchtelevision within 18 inches of thescreen - as we do with terminals.And radiation diminishes by thesquare of the distance. So the levelof radiation of whatever type thatyou get sitting six or eight feetacross the room is orders of mag-nitude less than what you get sitting18 Inches from a screen.

Televisions have indeed been aroundfor a long time and if they havehealth effects they are obviously notmajor compared to other factors inour lives. Those health problemswould either be acute and we wouldhave seen something by now, or itmay be that a generation with 30,40, or 50 years of exposure mayhave some health problems in olderage different from any previousgeneration. But that's hard to study,because some of the other factorschange as well. If TV watching addsone percent to mortality and youreduce it three percent by modify-ing your diet, you get a net loss oftwo percent mortality at a givenage, let's say, and a researcher willmiss the cause-effect relationship.

A~~~~~~~~I.

= i~jkiii hose? -

DIANA HEMBREE and KERRYNELSON: Many government andindustry officials assure computerusers that VDT radiation falls withinfederal standards, but this claim ismisleading. The U.S. has NO stand-ards - only voluntary guidelines -that limit employee exposure tonon-ionizing radiation from VDTs."What's more, the U.S. has no stand-ards at all for pulsed VLF or ELFradiation - the VDT emissionsmost suspicious now as possiblehazards. Ironically, VDTs are notsubject to the compulsory testing,reporting, and labeling requirementthat the U.S. government has devel-oped for that other common

88

cathode ray tube product -the TV set.2

Even if government guidelines onnon-ionizing radiation did apply toVDTs, the guidelines themselves aretoo weak, according to some scien-tists. "We're already seeing profoundbiological effects at exposure toradiation levels well below our cur-rent standards," insists Dr. EldonByrd, until recently a physicist atthe Naval Surface Weapons Institutein Silver Springs, Maryland. Thispoint was recently underscored bythe findings of Dr. PrzemyslawCzerski, a leading Czech radiationresearcher and visiting scientist atthe U.S. Public Health Service:microwaves may, under some cir-cumstances, cause chromosomedamage in mice at power levelseight times below the recommendedsafety standard for humans.25 VDTsdo not emit microwaves, but sinceradars, microwave ovens, and manyother products do, this finding causeda small stir.

Industry has recently started a driveto regulate electromagnetic radia-tion, partly to deter state and localgovernments from setting theirown, possibly stricter standards.2

Meanwhile, current U.S. guidelinesfor non-ionizing radiation may pro-vide only an illusion of safety. AtNIOSH, William Murray reportsthat his agency is now studying"how to take correct measurements[of non-ionizing fields] from VDTs."This suggests that the previousguidelines may be outdated, sincethe old measurements may beinvalid.

One physician, Dr. Robert Becker,is worried about standards forextremely low frequency (ELF)radiation in particular. A formerprofessor of orthopedic surgery atthe State University of New York,Becker helped pioneer the use ofELF to heal bone fractures. He alsotook part in a federally sponsoredstudy which linked 60 Hertz ELF topsychological disturbances.27 He hassaid that there is more than enoughevidence for government regulations.

"I don't want to wave a red flag,"he said at a 1982 conference onVDTs and non-ionizing radiation heldin Ottawa, "but at the same time, Ifeel obliged, as a physician ... tospell these things out ... I trustand hope I will live long enough tofinally see a response from the fed-

343

eral government that 'yes, there arebiological effects from low-frequencyradiation, and yes, they are serious,and yes, we ought to do somethingabout it.'"

aintn3 qu-t-on 13:

radiation Is such a danger,: ; .why aren' heren't the epidemics. .f cataracts and birth defects? -:

Why do they appear in Isolated-,

An'*'*. r! ~ t, ;-a-^ .; .- . ,* ,:'

ART KLEINER: Not an easy one toanswer with certainty. I've heard sixdifferent contradictory responseswhile editing this article.

I) The clusters are isolated now,just among people who use the ter-minals most; since cataracts developslowly, their incidence will appearmore widespread later.

2) The clu: ers are not as isolatedas they appear - partly becauselow-level health problems are oftennot reported, partly because nosystematic effort has been made tocatalog all the reported cases, andpartly because it's hard to recognizeclusters in uncontrolled environmentswhere cause-and-effect relationshipsare murky.

3) Indeed the so-called "clusters"'are statistical coincidences, anddemonstrate no radiation danger.

4) Since ELF measurements differso much from one brand of VDT tothe next, and since biological ef-fects vary with changes in radiationpulse frequency, some VDT modelsproduce problem "clusters" andothers do not.

5) As with allergies, some peoplemay be affected while others are not.

6) Even one cluster is too many if itcan be proven that the damage isrelated to radiation from VDTs.

;Why Is It so difficult to provehether i:neot a- cluster:, of '

McNULTY (Center for Investigative

IW'm{he or oiurtc term.Inals

"it Such *ia'stleet@ isite: A^d

DIANA HEMBREE and JENNIFER

McNULTY (Center for Investigative

WHOLE EARTH REVIEW FALLU 1

Reporting): Government healthagencies in the U.S. assure the publicthat alleged problem pregnancyclusters are statistical flukes.2 Yet,nterestingly, government research-

ers investigating these clusters -at sites in Dallas, Georgia, SanFrancisco, and Michigan - haveconsistently refused to test the VDTsthemselves for radiation emissions.

For example: more than 240 womenwork at the reservations desk ofUnited Airlines ir San Francisco.When an informal office surveyshowed a 50 percent rate of problempregnancies between 1979 and 1983,the women became alarmed aboutpossible harmful effects from VDTs.(The average miscarriage rate in theUS. approaches 20 percent; theaverage birth defect rate is 2 per-cent.) Employees requested aninvestigation by NIOSH and weresurprised when the agency failed totest the machines for radiationemissions.

When Dr. Peter Lichty, the NIOSHmedical officer in charge of thisinvestigation, was asked why therewas no VDT radiation testing in theSan Francisco cluster, he said that itwould have been "a big deal to fly acouple of techs and hundreds ofpounds of equipment" out to theoffice to measure what he described

'74

Il

/

(36, cm

The back of terminall may bemore dangrous than the front.This diagram shows whore aresarcher at Ontario HydroCorporation meaured electro-magnetic field Intensiti of 55volt/meter In varous locationaround a cathode-ray tube. Aperson sitting 120 cm (4 feet)from the rear corner will exper-ence the sae electromagnetic

radiation Intensity as a persondtting 30 cm (I foot) from thefront of the set.

as standard equipment. In a similarcase in Alma, Michigan, Lichty re-portedly told the employees thattesting for non-ionizing radiationwould be too expensive.

Diana Roose, research directorfor 9 to 5, National Associationof Working Women, says that herorganization has repeatedly askedthat VDTs in every problem preg-nancy cluster be tested for allfrequencies of radiation, NIOSHhas consistently failed to do so.Currently, NIOSH is planning alarge-scale investigation into VDTsand reproductive risks that is slatedto survey 4000 women - but whichwill not test the VDTs for radiationemissions. In the words of LauraStock, coordinator of a group of25 unions called the VDT Coalition,to rule out radiation as a possiblesource of problem pregnancieswithout testing the machines them-selves is "not giving us a completepicture of what the situation is."

ART KLEINER: What's really neededis systematic laboratory testing ofall computer and terminal brandsfor ELF and VLF - under a varietyof conditions, running a variety oftypes of software. The kind of teststhat Rauscher and Von Bise beganto do in our offices, that Sharmahas done at the University of Water-

cm

loo. Unfortunately, no one is likelyto fund that kind of comparativetesting anytime soon - certainlynot the computer manufacturers,who have a vested interest in avoidingthe subject as much as possible.The ideal testers would be a non-profit like Consumers' Union, butit's unlikely that they could affordto do it.

DIANA HEMBREE and JENNIFERMCNULTY: VDT operators are justbeginning to seek compensation forVDT-related health problems. ThisJanuary, VDT News reported that a54-year-old secretary has won whatis thought to be the first worker'scompensation case involvihg VDT-induced cataracts, for which shewas diagnosed only seven monthsafter beginning work on a VDT."VDT operators have also recentlywon worker's compensation settle-ments for a variety of other VDT-related health problems includingeye ailments, wrist inflammation,and stress-related psychologicaldisorders.

Remedies

ART KLEINER: Many remedies areaimed at more than one hazard -hence they're described separately.Much of this section is anecdotal,but we included only material aboutwhich we had reasonable confidenceand agreement. Me? I use a groundedelectrostatic shield (which I shouldreport was a gift from Mike Skaar,one of the contributors to this ar-ticle); I keep a houseplant near thecomputer to counteract positiveions; I turn down the brightness; Ioften use my non-VDT Radio ShackModel 100 instead of my VDT-basedKaypro II; and I stop periodically torest my eyes, rub my neck, take awalk. All of these make a differencethat I perceive - whether it's anactual difference or a placeboeffect, I do not know.

27 GATE FVE OAD SAUSAU CA 496S

3"C

Controlling the light

ART KLEINER: Have symptoms likeeyestrain and headaches? Worriedabout radiation? Check these reme-dies against glare first - It producesthe same symptoms.

ERICK WUJC!K: First rule of glareand light: if it hurts, stop doing it!Nothing is right for everyone. You'vegot to experiment to get it right.If your eyes are getting sore anditchy, get up, look around at dif-ferent things, change your lightingenvironment

Don't let bare bulbs or directsunlight bounce off your computerscreen. Indirect, diffused lighting isbest. All too often I've seen work-

89

6(:r

I

0n

,ter 1 ,10 cm- #A<1--.--- »»,

places with floor-to-ceiling glass,bare fluorescent bulbs, and computertubes turned up to full contrastto compensate.

Never, never, never use fluorescentlights anywhere near video terminals.This can create a really nasty flickerthat only your subliminal unconsciousmind and neural system will beaware of.

The room light intensity shouldmatch the light from the screen.My own rule of computer luminance(not supported by any scientificstudies OR government agencies)says that if your monitor light cancast shadows then the room lightis too dim.

LOUIS JAFFE: Use the minimumcontrast setting at which you cancomfortably see the text. Try settinga monitor contrast level that feels abit dimmer than you thought com-fortable. This is because when youchange the setting it takes youreyes a few moments to adjust. Youwill probably find that you can worklonger at relatively low contrastsettings. I use very low contrast andhave only had eyestrain during in-ordinately long sieges of work.

On the Kaypro, Compaq, and manyother machines, the so-called 'bright-ness' control, which is the onlyexternal adjustment for the monitor,is actually tha contrast control. If

While they were In our office,Mike Skaar helped RauKcherand Von Bie test the *ffectiveness of radiation shields. Fromtheir meaaurements, they ten-tatively concluded that groundedscreen shields neutralize thestatic electric charge (but notthe electromagnetic radiation),and eliminate the positive ionsin the air in front of the screen.

one of these systems shows bright-ness across the whole screen innormal use, then the internal bright-ness control needs to be turneddown. In a Compaq this is a simplescrewdriver adjustment accessibleby removing the top cover. Notsure about Kaypro.

Choosing a radiation shield

ART KLEINER: Shields, fitting overthe front of the computer screen,stop glare and seem to stop someother hazards too. I asked MikeSkaar, whose company ErgonomicComputer Products in.San Franciscoevaluates and sells filter shields for.VDTs, to explain the differencesbetween different models.

MIKE SKAAR: The two most af-fordable types of VDT filters arefiber mesh, which cuts glare theway a venetian blind does; and coatedfilm or glass, which diffuses glare.But we recommend either type onlywith the enhanced protection ofelectrostatic grounding (which addsabout $25 to the cost), becauseit neutralizes the static electricityfields created by VDTs. This elim-inates positive ions in the air, andgreatly reduces the amount of dustthat an electrostatic field will eitherattract to the VDT (which meansyou have to clean the shield con-stantly) or propel into your eyes.

You should consider how manyhours a day you use your computer.Five minutes a day at the terminaldoesn't justify buying a filter. What'sthe cutoff point before a shield isworth buying? The state of Californiahas vacillated between one hour andfour hours in determining theirlegislation. For now they've settledat two hours nonstop or four hoursoverall during a single day. That'sjust one legislature's opinion, but itseems reasonable to me.

ART KLEINER: Subjectively, elec-trostatically grounded shields FEELmuch better than the other kind. Ialways felt a subtle stress from myKaypro II. I feel it much less withthe shield in place, and it returneda bit when I disconnected theground wire.

Specific models? Right now (May1985), there are two surface-mounted fiber-mesh shields withelectrostatic grounding. They both

work comparably well. The lessexpensive is made by Screen DataCorporation ($50 and up); the moreexpensive by Sunflex ($70 and up).

Optical Coating Laboratories makesthe least expensive optical glassshield with an electrostatic ground- it runs $99 and up. These shieldsare all available without electrostaticgrounding - but that makes themmuch less effective. Avoid lead-coated shields - they safeguardonly against X-rays, which arealready shielded against in yourcomputer. On the other hand wehave this report...

PAUL SMITH (correspondent onCompuServe): I purchased a lead-screened shield for my Macintoshlast summer just after I got thecomputer. I had no idea just exactlywhat I was protecting myself from.. but I also didn't trust the safelevels of radiation that VDTs putout. My sales rep had a real laughwhen he saw it. Then in October afriend of mine, who is trying to getthe Canadian Broadcasting Companyto remove the communicationstower from just across the road athis summer home, brought in ameter that read ELF radiation levels.'He brought it over and tested itout on my Mac. With the screenoff, the meter read very high fromthe center of the display. With theshield in place there was little move-ment of the needle in front of thedisplay, but behind the computerthere was a high reading. The meterwas borrowed from the Universityof Waterloo and was especiallyaccurate in readings under high-voltage transmission lines.

Shielding the outside

MIKE SKAAR: At my ergonomicconsulting firm, we still have doubtsabout whether EM radiation willultimately turn out to be harmful. Ifit does, placing a filter on the frontof the VDT may offer little protec-tion. Many of the radiation sourcesare at the back of the machine, sothe entire cabinet of the VDT mustbe shielded.

DIANA HEMBREE: First, makesure that your computer or terminalhas metal shielding that covers theflyback transformer. If your terminalis a post-1980 model, it will containat least some shielding, because the

WHOLE EARTH REVIW FALL 198S90

Federal Communications Commis-sion ruled in 1979 that manufacturer:had to shield the source of elec-tromagnetic signals that had beeninterfering with radio and militarycommunications. In some models,the shielding may not cover theentire flyback transformer; you canoften check with the manufacturerfor specifics. The cost of installingcopper or aluminum foil for shieldingcan be as little as $5 per machine;but it should be done by a technician(it's too easy to shock yourselfwith current stored in themonitor's capacitors, even afterIt's turned off) and may void somewarranties.

Another shielding option, recom-mended by the Canadian Centrefor Occupational Health and Safety(CCOHS), is a do-it-yourself metalshielding hood. CCOHS researchershave found that a copper mesh foilglued to cardboard, attached to aground wire, and covering the fivesides of the VDT, cuts VLF emissionsto almost zero. The tops of terminalunits with built-in printers do notrequire shielding since the printeritself blocks VLF emissions.

JAMES STOCKFORD: It is veryimportant that the foil interior begrounded. All foil surfaces must beconnected to each other in such away that they will conduc. elec;tricity, and they must be surelyconnected to a wire that runs toa real ground. That connection isextremely important. The safetyground (round hole) in some walloutlets is not always grounded elec-trostatically. Use a cold-water pipeor be sure that the receptacle istruly grounded, not just shockgrounded.

ART KLEINER: Unfortunately,ordinary metal shielding does notblock a VDT's ELF magnetic fields.To do so, one must use a specialalloy called Mu metal, which s dif-ficult to obtain commercially andmay require special trainingto install.

DIANA HEMBREE: Even withshielding, do not sit directly behindor to the side of another terminal.Since the computer's high-voltagepower source, the flyback trans-former, is located in the back orside of a VDT, the radiation levelsare highest at the back of a terminal.On pre-1975 models, Dr. ArthurGuy has measured electric fields

one centimeter from the set withintensities up to 40,000 volts permeter - readings which he calls"astronomical, what you'd getunder high voltage wires."

ERICK WUJCIK: I couldn't agreemore about the problems of ex-posure to the sides and backs ofcomputer terminals. Don't forgetthat the machines in office erviron-merits are often MUCH more highpowered (in voltage) than most PCsat home. And workers in officeenvironments are often placeddirectly next to, or in back of, theterminals. I can think of at leastfour places in the newsroom of theDetroit News where workers rou-tinely use the backs of terminals tolean on ...

Combating static electricity

DIANA HEMBREE: Besides usingfilters and grounds, there are otherways to cut static electricity near aCRT. Keep windows open to com-bat the "tight-room" syndrome;wash your face frequently to pre-vent particle adhesion; keep indoorrelative humidity above 40 percent;grow leafy houseplants near theterminal; and/or install a negativeion generator.

Posture

LOUIS JAFFE: There are detailedergonomic standards developed inboth the USA and Europe whichaddress the questions of just howa computer operator should beseated and oriented to his/her equip-ment. The advent of the detached,low-profile keyboard is one industryresponse to this research. Generallyspeaking, some things to watch are:Make sure you have a comfortablechair, adjustable for seat height,backrest height, and backrest angle;and experiment with the heightsettings till it feels just right foryou. Don't use any furniture whichforces you into an unnatural posture.

Monitor viewing distance is partlya matter of taste and partly dic-tated by the screen size. Generally,portable computers with a built-innine-inch screen need to be elevatedor angled up quite a bit for a com-fortable viewing angle.

7 GATE HVE ROAD SAUSAM CA 9496S

One iugeted meau to reduceVLF emmlslons a copper fellshield that fits completelyaround the computer. This one,developed by the Canadian Cen.tre for Occupational Safety,boats a copper creen on topto allow the compute's hutto dlsIpate.

To see if the monitor is the rightheight, close your eyes and inclineyour head to what feels like themost comfortable sitting position;then open your eyes and see if you'rein fact looking at the monitor orabove or below it. Adjust the mon-itor height to your sitting position,not the other way around.

ERICK WUJCIK: People weren'tmade for staring up. Not as a steadything anyway. Make sure that you'relooking at a screen that's slightly(from 5 to 35 degrees) BELOWeye level.

Keep your arms straight! Youshouldn't be reaching either UPor DOWN to type on a keyboard.In a normal sitting position yourupper and lower arms should forma right angle and your hands shouldreach DOWN just a tad bit towardsthe keyboard. Nobody has perfectposture. At the keyboard you shouldslump BACKWARDS instead ofFORWARDS. Straight is best, butit's sort of an idealized goal.

VDTs and pregnancy

DIANA HEMBREE: Experts disagreewhether pregnant women shouldavoid VDT work entirely. A growingnumber of employers, includingBoston University and the City ofSan Francisco, have agreed to pro-vide alternative non-VDT workduring pregnancy. -

91

Warning: although there has beena recent surge of interest in leadaprons for pregnant operators,would-be users should know thatthey do not block low-frequencyradiation - only ionizing radiationwhich is already shielded out. Also,the CCOHS has warned that wearinga lead apron could be hazardous bycausing postural problems and puttingextra weight (and possibly extrastress) on the fetus. Concludingthat lead aprons provide "nobenefit whatsoever," CCOHSadvises women NOT to use suchequipment.

DR. ARTHUR FRANK: I get callednot infrequently by women who say"I am pregnant or want to be preg-nant, should I work with the screen?"And I say that within whatever yourcompany policy is, try to reduceyour exposure and get shifted toanother job for a while if you can,BUT the evidence isn't there yetthat you know you ought to go tothe wall and lose your job over this.These are complex issues from apublic-health perspective and anacceptable-risk perspective.

Buying a computer

ART KLEINER: It would be lovelyto say, "such-and-such a monitor issafe; so-and-so is not." Unfortu-nately, nobody has systematically

tested personal computer monitorsyet. We can't even definitively rec-ommend color monitors overblack-and-white or vice versa.

DIANA HEMBREE: Radiationspecialists I interviewed disagreedwhether color monitors on VDTswere likely to emit more radiation.They said unanimously that colormonitors generate more radiationdue to higher voltages, but somecontend that the terminals' shieldingblocks such radiation, making thedifference negligible.

LOUIS JAFFE: Video reigns now forcomputer displays only because it isinexpensive and versatile. But besidesthe safety questions, it is power-hungry, heavy, and bulky. In thenext year. for the first time, I thinkwe'll see new technologies givevideo a run for its money.

The principal contenders are LiquidCrystal (LCD), Electroluminescent(EL), and Plasma displays. Verysimply: All are flat sandwiches withouter, sealing layers, and inner,active layers. In an LCD (like thaton the Radio Shack Model 100),crystals suspended in a liquid rotateto either pass or block light (reflectedor backlight). In EL, a solid chemicallayer glows. In plasma, a layer ofsealed gas glows.

LCDs have been plagued by poorcontrast, jerky scrolling, and re-stricted viewing angles, but solutions

to these problems are at hand. Trulylegible, full-screen LCDs are out ofthe labs, will reach the retail marketin the next generation of portablecomputers, and will be cost-com-petitive with video.

Full-screen EL displays are standardequipment on the Grid Compass,and on HP's new Integral. If you'veseen either of these machines youknow their displays are sharper thanany video screen. EL displays stillcost $800 at the factory level,which is why they've appeared onlyin premium hardware. With massproduction, the price could falldrastically.

Plasma has been used for years inmilitary graphics displays. The onlycivilian product I know of is a 17-inch screen from IBM that costsabout $6000. It must be seen to bebelieved. It does something like 800x 1200 pixel graphics with perfectlinearity, or it can have four windowson screen at once, each showing25 x 80 characters.

RICHARD DALTON: At present,LCD Is certainly the most practicalalternative to CRTs, yet there is thenagging problem of poor contrastunder many ambient lighting con-ditions. Morrow claims to haveachieved a modest breakthrough inthis area with their Pivot portable.Apparently, they are using electro-luminescence as a background tomarkedly increase LCD contrast.

VDT NewsART KLEINER: Recommended sourceof current information on VDT health'hazard informalion.VDT NewsMark A. Pinsky, Editorg42/year (6 issues) from:

VDT News, P. 0. Box 3000 (Dept. JJ),Denville, NJ 07834

92

A call to arms

DIANA HEMBREE: Keep track ofthe health problems, if any, thatyou and others in your home or of-fice think might be VDT-related: 9to 5 and other labor groups whomonitor this information wouldappreciate hearing from you. Also;keep a record of the model anddate of manufacture of your ter-minal, as well as the time periodthat you used it. If you should everseek compensation for a healthproblem that you associate withyour VDT work, you'll needdocumentation.

While electronics companiescampaign to convince users thatcomputers are safe, unions andwomens' groups are pressuring the

3 7

government to set safety guidelinesfor VDT use on the job and to fur-ther investigate potential hazards.including those of radiation. NIOSHis planning a mass survey of 4000American women to determinewhether there appear to be morereproductive problems among VDTusers than non-users, but moreneeds to be done. VDT radiationmay prove co be harmless, but onlyfurther investigation will determineits safety and reassure worried users.

ART KLEINER: The Computer andBusiness Equipment Manufacturer'sAssociation argues fervently in theirliterature against government regu-lation of VDTs. The question ofgovernment regulation Is important

WHOLE EARTH REVIEW FALL 15S

for clerical workers trapped in theirjobs, but for personal computerowners it's not nearly as importantas clear information. If manufac-turers released the data on howmuch they shield their machines, itwould be a tremendous help to usconcerned purchasers. A downrighthumanitarian deed.

Not knowing the final word isfrustrating. There's enough evidenceof danger to be concerned; notenough to be convinced. It's nottime to scream "fire" in the mater-nity ward yet, but I feel personallyencouraged that people are in heresniffing for smoke. *

AddressesCanadian Centre for OccupationalHealth and Safety: 250 Main StreetEast., Hamilton, Ontario L8NIH6, Canada.

9 to 5. National Association ofWorking Women: 1224 Huron Road,Cleveland, OH 44115.

A wide selecton of VDT filter shieldsi available from: Ergonomic Com-puter Products, 1850 Union Street,Suite 125, San Francisco, CA 94123.William Von Bise suggests one sourcefor Mu metal: A-Vance Magnetics,625 Monroe Street, Rochester, IN46975; 219/223-3158.

A manufacturer of VDT shields: Sun-Flex, 20 Pimentel Court, Novato,CA 94947.

Notes

- AcknowledgementsLedger Heavilon helped articulatesome of the scientific descriptions.Annette Floystrup of Sunflex, Inc.,provided essential background ma-terial. Diana Hembree and MikeSkaar contributed research and helpfar beyond what shows here. PaulHawken and Richard Dalton prod-ded this article into existence. LeviThomas, Dr. Arthur Frank, and VDTNews editor Mark Pinsky advisedand helped.

I) Dr. Karel Marha, "The State of Knowledge Concerning RadiationEmissions from Video Display Terminals" (paper presented at "ScienceFocus," Ottawa, Canada. 1982).2) US. Congress, House Committee on Science and Technology,Potental HeaM Effects of Video Diplay Terminals and Radio FruencyHetersand Sen, May 12-13, 1981.3) Lewis Slessin and Martha Zybko, Video Disply erminals: Safetyand Health: Eerpts from Mkrowae News (New York: MicrowaveNews 1983).

4) Dr. Edward Rinalduccd et l., Video Dipltys, Work, and Vson(Wshington, DC.: National Academy Press, 1983).5) Joann S. Lublin, "Fearing Radiation, Pregint Women Win Trans-fers from Work on Video Display Terminals," Wll Stret ournal.April 6, 1984.

6) Eric J. Lemer. "The Drive to Regulat Electomagnetic Fields,"EEE Spectrm, March 1984.7) Ibid.

8) Ibid.

9) bd.10) Jose M.R. Delgado et al., "Embryological Changes Induced by

Weak, Extremely Low Frequency Electromagnetic Fielcs," Journal ofAnatomy 134 (May 1982): 533-SI.11) "Special Report: Focus on VDT Radiation Emission," VDT News,September-October, 1984.12) K. Marha, B Spinner, and J. Purdham, The Case for Concern Aboutavy Low Frequency Fields from Vsual Disply Terminls. Hamlton,

Ontario: Canadian Centre for Occupational Health and Safety,April 22, 1983.

13) Dr. Hai D Sharma, The Inestigaton of Custer of AdrsePregnncy Outcomes and Other Heah-olted Probms among EmployesWHring with Video Displky Temn s in the Accounting Office at teSuy Memorial Hospitol, Vancouer, BC., 1985. ($20 postpaid fromRadiation and Environment Management Systems, F. Box I.Waterloo, Ontario N2) 3Z6, Canada.)14) Physicist Elizabeth Rauschr and electronics engineer William VonBIe co-founded Tecnla Research Laboratories, O. Bo 667, SanLeandro, CA 94577, In 1983.15) Rauscher and Von BIse measured ELF electromanetic radiation(0-10,000 Hz) from fiv computers - IBM PC with Princeton Graphicscolor monitor, Apple Macintosh, Apple II with monochrome monitor,Kaypro II, and Compaq portable. Their observatons:Cdor Imags emted gnifpcont lectromagnetc radiatn at many mrfrequencies thn blck-and-wht mage.On te coor IJM PC, moving tert emitted gnficant rdition ot morefrequences than sttonary text. On he block-and-whlt Mac andCompaq, it did not.On the Apple I (block-and-whIte), graphc gmes (LODE RUNNER andCHOPUFTER) emitted more silificant radlaton at different frequencies

27 GCTE FIVE ROAD SMJSAUL CA 9496s

than te (sttionary or movin) on the sne computer.16) Sandra Ernst Morarty and Edward S Scheiner, "A Study of Close-st Text Type." Journd of Applied Aycholoy, November 1984.17) This "consensus" partly detailed in Dr. Sharma' paper (see note13 above). Also me Harmrd Medicl School Heh ltler, April 1983.18) Walter Cato Obln, "Electrc Field Enhanced Arosol ExposureIn Visual Display Unit Environments," in Chronces of the CHR (Beren.Norway: Michelsn Institute, 1981)19) Charles Walach, Psible Heath Hazards of VDTs, 1982. (ReportPrepared by Designs and Decisions, Inc., 8400 West Park Dr., Suite600, McLean, VA 22101.)20) Robert DiMatteo, Termina Shock: The Heat Hazards of VDTs(Toronto: NC Press 1985) (See review, pae 79.)21) Byte maazine letters column January 1984.22) Dr. Har Sharmaop. cit (se note 13 above).23) Eric . Lemer, op. cit. (se now 6 above).24) Sheryl Gordon McCioud. "Pink Collar Blues: Ptential Hazardsof Video Display Terminals," Southern California Law Reew: 57(November 1983).25) Eric J. L er. op. cit. (see note 6 above).26) Eric . Lrner, op. cit. (ee note 6 abov).27) Dr. Robert Bcker and Andrew A. Marino, Elctromqnetsmnond Ufe (Albany: Sate University of New York Press, 1982).28) Center for Disease Control. Abortion Surveillance Branch. AnUnexpected-Expctd Cluster of AdM Prennancy Outcome in VideoDisplay Teminos (EP-80-113.2), Dallas: May 11, 1981. Alo: US. ArmyEnvironmental Hyiene Agency, Istiation of Adr Prgnancy Orutcomes (Occupational Health Special Study No 66-32-1359-81),Defense Contract Administrtion, Services Region AtlantaFebruary 26, 1981.29) "NY Workers' Compensation Board Rules Cataracts Caused byVDTs," VDTNews,Janury 1985. Also ee "Pink-Colar Blues" in note 24.The biological frequencies in our "audacious" chart (p. 83) came fromfour sources Lerner (noe 6) and Sharma (note 13) pus two unpub-lished pape: Wllam Von Bee, "Extremely Low Freuency Radio andMagnetic Sgnals - New Biologic Cues in the Pacific Northwest En-vironment?" (1980. valiable throus h Tecnkcs Reearch Laboratories -ee note 14) and Hana Paikova "A Study of the Embrynic Effect of

an Electrosati Pulsed Field." 1980; tranlted by Dr. P. Petrk ofAlberta Canada amilable through Canadian Centre for OccupationalHealth and Safety (see "Addreses" above).Another unpublished paper, lthough k does not specificaly cover ELFin depth, sugests the waveforms that produce biological effectsare very different from the waveforms produced by VDTs. The paperArthur W. Guy, "Health Hazards Assessment of Radio FrequencyElectromanetic Fields Emitted by Video Display Terminals," 1984.We received our copy from the American Electronics Association.2670 Hanover Street Palo Alto, CA 94303.

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