TECHNICAL INFORMATION STATEMENT
BIOLOGICAL AND HEALTH EFFECTS OF
ELECTRIC AND MAGNETIC FIELDS FROM VIDEO DISPLAY
Copyright: © 1997 Institute of Electrical and
Reprinted, with permission, from: IEEE Engineering in Medicine
and Biology Magazine 16(3): 87-92, 1997.
HTML version by: John Moulder, Medical College of Wisconsin
This material is posted here with permission of the IEEE. Such
permission of the IEEE does not in any way imply IEEE endorsement of
any products or services. Internal or personal use of this material
is permitted. However, permission to reprint/republish this material
for advertising or promotional purposes or for creating new
collective works for resale or redistribution must be obtained from
the IEEE by sending a blank email message to: email@example.com.
By choosing to view this document, you agree to all provisions
of the copyright laws protecting it.
Video display terminals (VDTs) are commonly used for
information display together with a computer and keyboard. Questions
have been raised about adverse health effects associated with the
electric and magnetic fields found near the cathode ray tube
(CRT) used in a VDT. Television receivers also use CRTs in a
similar fashion but concerns about health effects have centered
around the VDT, perhaps because it is usually used in closer
Neither laboratory nor epidemiological research has shown
convincing evidence that the electromagnetic fields emanating from
VDTs adversely affected the health of VDT operators. Studies of
effects on pregnant women using VDTs have failed to establish a link
between VDT fields and miscarriages or birth defects. However, not
all research issues have been settled and it will be valuable for
research to continue until it is possible to come to a still firmer
This paper addresses health issues related to the electric and
magnetic fields of VDTs. It was developed by the Committee on Man and
Radiation (COMAR ) of the Institute of Electrical and
Electronics Engineers, Inc. (IEEE ), and represents the
considered judgment of an international group with expertise in the
subject area. It updates an earlier statement on this topic that was
issued in August 1990.
Video display terminals (VDTs), which are also known as video
display units or monitors, produce low levels of electromagnetic
energy because of the techniques used to generate and move an
electron beam that illuminates the screen of a cathode ray tube
(CRT). These displays are used in television receivers, computers,
automated teller machines, video games, and other such devices.
Different technologies, such as transistor displays and liquid
crystal displays, are used in laptop computers and do not have the
same electromagnetic characteristics as CRTs. All relevant health
research on VDTs pertain to CRTs.
The basic electronics of VDTs may also produce electromagnetic
fields. For designs with power transformers, a 50/60 Hz sinusoidal
field may be generated. The electronic circuits used to process the
video signal may produce radiofrequency fields.
A CRT is an evacuated glass envelope with an electron gun located
in the narrow neck at the rear of the tube and a phosphor-coated
screen at the front face. There are several wire coils located around
the outside of the neck that are known collectively as the deflection
yoke. The yoke and the circuitry used to drive it, in particular the
flyback transformer, are the major sources of magnetic fields.
The energy generated by a VDT extends over a broad spectrum,
- x-ray and ultraviolet light (wavelengths below 400 nm),
- visible light (700-400 nm, 4.3-7.5x10^14 Hz),
- infrared radiation from heat generated by the
- very low and low frequency energy (VLF and LF, 3-300
- extremely low frequency energy (ELF, 30-300 Hz), and
- static electric fields.
CRTs are constructed so that the x-rays and ultraviolet rays are
absorbed by the glass screen and only visible light is
The electron beam paints the phosphor screen on the face of the
CRT with a series of horizontal lines. Successive lines are displaced
vertically in order to cover the screen from top to bottom. The
horizontal and vertical steering of the electron beam is done by
fast-changing magnetic fields at the neck of the tube.
For each horizontal line the beam must be swept steadily across
the screen by an increasing magnetic field while the electron beam is
turned on. Once the beam reaches the right-hand edge of the screen,
the electron beam is turned off and retraced to the left side of the
screen by a rapidly decreasing magnetic field. This combination of
slow- and fast-changing magnetic fields produces a sawtooth shaped
For a typical VGA mode computer monitor, about 31,500 horizontal
lines are painted each second. This requires a 31.5 kHz magnetic
field aligned, or polarized, in the vertical direction. Computer
horizontal deflection frequencies vary from approximately 15.75 kHz
to over 60 kHz. Although the magnetic field is configured to interact
with the electron beam inside the CRT, vertically polarized sawtooth
fringing fields at the horizontal deflection frequency occur around
the CRT. The vertical deflection of the electron beam requires a
horizontally polarized magnetic field which also produces horizontal
fringing fields at a distance from the yoke. Several hundred
horizontal lines (typically from 200 to over 800) must be painted
while the beam is swept from top to bottom, the sawtooth shaped
magnetic field used for vertical deflection is at a frequency several
hundred times lower than the horizontal deflection frequency and
involves a proportionately smaller amount of energy. Typical
frequencies lie between 30 and 75 Hz, depending on the graphics
The frequency content of the electromagnetic emissions from a CRT
contains more than the fundamental frequencies of the two sawtooth
waves. Sinusoidal components of these signals extend out to at least
200 kHz , even though the amplitudes of
the higher frequency components are much lower than the fundamental
frequencies. As much as 94% of the energy is at the fundamental
frequency of the horizontal deflection circuit [
VLF and LF magnetic energy is generated by the horizontal
deflection system that moves the electron beam from left to right.
ELF magnetic energy is generated by the vertical deflection system
that moves the electron beam from top to bottom. Concerns about
potential health effects have focused on magnetic fields over all
these frequencies. The ELF frequency fields generated by VDTs raise
issues similar to those involving power frequency electric and
magnetic fields which are also in the ELF region. IEEE COMAR has
prepared a Technical Information Statement, "Biological Effects of
Power-Frequency Electric and Magnetic Fields" 
treating many topics on ELF fields. VLF and LF magnetic fields induce
larger electric fields in the body than lower frequency magnetic
fields of the same strength and are thus an additional concern with
Characteristics and typical strengths of VDT electric and
The electric and magnetic fields near a VDT are characterized by
frequencies and polarizations that are similar for like designs, such
as monochrome, CGA, EGA, VGA, and SVGA. The field strengths emanating
from different units vary with product design. Electric field
strengths and magnetic flux densities at a distance of 30 cm from the
CRT screen were measured for many different models, including those
specifically designed to reduce field strengths (often called "low
emission monitors"). The measurement distance, which is approximately
one foot, is less than the typical distance at which a user sits from
the screen and represents a worst- case distance. These data are
summarized in Table 1.
Maximum Electrical Field Strength*
Typical Electrical Field Strength*
Maximum Magnetic Flux Density*#
Typical Magnetic Flux Density*#
VLF (3-30 kHz) and LF (30-300 kHz)
less than 50 V/m
less than 1.5 µT
[1, 5, 6,
ELF (30-300 kHz)
less than 65 V/m
less than 1.2 µT
[1, 6, 7,
Static (0 Hz)
less than 25,000 V/m
[7, 8(at 50 cm),
* Field levels are given as root-mean-square values.
# 0.1 µT = 1 mG
Comparisons with occupational and public exposure
Threshold limit values (TLVs) have been developed by the
American Conference of Governmental Industrial Hygienists
for occupational exposures. These TLVs are 614 V/m (electric field
strength over the range 30-3000 kHz) and 205 µT (magnetic flux
density over the range 30-100 kHz). Above 100 kHz this guideline
reduces the allowable magnetic field; at 300 kHz the TLV is reduced
to 68.3 µT. Other values are shown in Table 2.
These values match those found in IEEE/ANSI Standard C95.1-1991
 and are similar to those recommended
by other national and international bodies. The LF and VLF electric
and magnetic field levels produced by VDTs, as shown in Table
1, fall below the recommended limits. Therefore, exposures at
distances of 30 cm or more from VDT screens are within current
exposure standards and guidelines.
The Swedish Standards Institution (SIS) has developed an
emission standard (MPR-III) for VDTs 
that is fundamentally different from the standards developed by other
agencies, such as ACGIH [11, 12],
IEEE [50< /A>] or the Canadian Bureau of
Radiation and Medical Devices (BRMD) .
The MPR-III standard is based on emission levels which are
technically achievable and not on exposure limits based on health
research. Three categories of electric and magnetic field emissions
are defined in two frequency ranges at a fixed measurement distance
of 50 cm. The SIS frequency band II (2-400 kHz) overlaps the range
from 30-400 kHz where ACGIH and IEEE provide guidelines. For VDTs
that perform within the SIS limits, electric and magnetic fields at
50 cm are far below exposure standards; many such VDTs are sold as
"low radiation monitors."
Abbreviations: ACGIH - American Conference of Governmental
Industrial Hygienists; ANSI - American National Standards
Institute; BRMD - Bureau of Radiation and Medical Devices;
OSHA - Occupational Health and Safety Administration
(Massachusetts, U.S.A.); SIS - Swedish Standards
Standard or Guideline
Magnetic Flux Density
SIS MPR-III 
less than or equal to 10 V/m
less than or equal to 0.20 µT
"Category A" classification at 50 cm from center of
less than or equal to 1 V/m
less than or equal to 0.025 µT
ACGIH (1996) [10,
Frequency dependent occupational ceiling threshold limit
IEEE/ANSI C95.1-1991 
less than 3 kHz
MPE(magnetic) = 205/f (kHz)
Mass OSHA 453 CMR 5.00/1986 
Canadian BRMD Safety Code 6 - 1991[52<
General public limit
Biophysical Factors of Static, ELF and VLF Fields.
Several physical and biophysical mechanisms may be involved when
human beings are exposed to VDTs. Because a strong static electric
field exists at the CRT face, aerosols are attracted to the surface
as is evident from the rapid accumulation of dust. These aerosols may
increase exposure to airborne allergens .
VDT users can be electrostatically charged and thereby attract
particles to their bodies.
In addition to electric fields directly associated with high
voltage circuitry in VDTs, time varying magnetic fields also induce
electric fields in conductive media, such as the human body. The
magnitude of the induced electric field depends on the strength of
the magnetic field and its rate of change.
It is unknown whether the internal electric and magnetic field,
if either, can produce biological effects in the tissues of an
exposed human being or animal. As a result, both electric and
magnetic fields need to be considered. For a similar reason, there is
no accepted dose measure for personal exposure to VDT fields. Most
research reports root-mean-squared amplitudes of the electric field
strength and magnetic flux density in units of V/m(rms) and &
Health Studies in Human Populations.
There have been many epidemiological studies of workers exposed
to VDTs on the job. To date, all studies have been limited by
inadequate assessment of field exposures to the individual subjects.
Some recent studies have used field strength meters at selected work
sites and some obtained estimates of the number of hours of exposure
per week. Other research simply contrasted VDT users with non-users.
Some took into account the great diversity of models found in most
offices, but other did not. No study was able to fully distinguish
effects of VDT use, which include potential job related stress and
the effects on eyes, hands and the musculoskeletal system, from
effects of exposure to fields.
More than a dozen studies have focused on reproductive effects,
such as rates of spontaneous abortion and birth defects. Other
studies have dealt with effects on vision and the musculoskeletal
system. Ocular studies of workers have not shown any relationship
between VDT use and ophthalmologic disease or abnormalities,
including cataracts [14, 15 ,
A statistically significant association was reported between a
type of brain cancer, glioma, and self-reported occupational exposure
to ionizing and non- ionizing radiation in Australian women
. These results were based on 25 cases,
7 that reported "radiation" exposure. In 6 of the 7 cases, CRTs were
cited as the exposure source. For CRT exposures, the age adjusted
odds ratio was 4.99 (95% CI: 1.43-17.38), with a
slightly lower value of 4.34 (95% CI: 0.95-19.72) when only "good
quality, non-proxy interviews" were used as a basis for CRT exposure.
Male glioma cases showed no such effect. The authors cautioned that
the results were difficult to interpret in view of the small number
of cases, possibility of recall bias, lack of exposure information,
and the possibility that the elevated odds ratios for CRT users were
a chance occurrence in a study where many comparisons were made.
VDTs and Pregnancy.
The question of whether VDT use affects pregnancy arose after a
few reports of apparent clustering of spontaneous abortions
(miscarriages) at workplaces in which VDTs were used by the affected
women. These reports prompted a series of epidemiological studies to
examine whether or not miscarriages occurred more frequently in women
who used VDTs. A finding of higher miscarriage rates may have various
explanations, which could include exposure to electromagnetic fields,
ergonomic factors, sitting for long periods, and psychological stress
related to job conditions.
Interest in this issue was enhanced by reports that women who
spent more time at VDTs had more miscarriages. Goldhaber and Polen
 interviewed women receiving prenatal
health care from a large health care group in California to obtain
data relating the amount of time spent at a VDT to the occurrence of
miscarriages. The self-reported duration of daily VDT use was
correlated with miscarriage frequency with an odds ratio of 1.8 (95%
CI: 1.2-2.8). Because miscarriage rates were not consistently
affected within specific occupational categories, the validity of the
association of VDTs and miscarriage is questionable. A study by
McDonald et al. [19 ] indicated a small
risk, but the majority of the studies which followed found that use
of VDTs did not increase the risks of either miscarriage or birth
defects [20, 21, 22,
In a recent large prospective epidemiological study
, subjects were interviewed during
pregnancy rather than afterward, as in previous studies. Intrauterine
growth rate of the fetus and birthweight were not altered by VDT use.
There was no information on miscarriage rates. A meta-analysis of
nine published papers showed no association between VDT use and
miscarriage, low birth weight, or birth defects .
The power of this analysis was estimated to exclude risk increments
of 20% or more.
Two studies of workers who used VDTs are of particular interest
because they obtained information on exposure levels. In the first,
VDT users were compared with other employees whose jobs were similar
except that they used older equipment without CRTs [26,
27]. The study design allowed separation of any
effects of physical and psychological job characteristics from those
of VDT emissions. Measurements showed that VDT-related ELF exposures
to the abdomens of these workers were comparable to background
levels. VLF fields at the abdomen, although higher for the VDT users,
were low and well within exposure guidelines. The results showed no
difference in spontaneous abortion rates among 323 telephone
operators during any month of pregnancy (odds ratio for the first
trimester = 0.93, 95% CI: 0.63-1.38), nor did the rate vary by the
amount of VDT use per week.
In the second study  VDT workers
also were found not to be at increased risk for spontaneous abortion
(odds ratio = 1.1, 95% CI: 0.7- 1.6). VDT magnetic fields were
measured in the laboratory. When the subset of VDT workers exposed to
the highest ELF fields (greater than 0.9 µT peak-peak, 0.3
µT rms) was compared to those in the low exposure group (less
than 0.4 µT peak-peak, 0.15 µT rms) the odds ratio was 3.4
(95% CI: 1.4-8.6). There was no such increase when the high ELF field
group was compared to non-users of VDTs (odds ratio = 1.6, not
significant) and there appeared to be a protective effect for the
group exposed to low-level ELF fields (odds ratio = 0.4, 95% CI:
0.4-0.8). These latter findings are unexpected and inconsistent. They
serve to warn about possible statistical anomalies in this data set.
Since the majority of VDTs in use today are classified as "low
emission" monitors, it may not be possible to establish or disprove
by future studies the suggested ELF association found by this
VDTs and Electrosensitivity.
Problems such as burning or tingling sensations, and fatigue or
dizziness have been reported by individuals who work with VDTs. The
symptoms are subjective and occur in the general population. Like
other reported reactions to weak electric or magnetic fields, these
have been called "electrosensitivity" although it is not known if the
various complaints are etiologically related. Studies of VDT users
have focused on job conditions, stress, electromagnetic fields, or
humidity, which may be related to skin sensitivity. Complaints are
rare in comparison to the number of people who use VDTs
In the laboratory, a double blind study of individuals who
reported VDT related skin symptoms showed the subjects could not
reliably distinguish between similar-appearing units that had low or
high levels for static electric fields and ELF and VLF magnetic
fields . In a controlled study,
subjects reported that skin sensitivity was somewhat reduced as a
result of shielding electric fields .
Objective signs of disease have been studied and were not found to be
more prevalent in those who worked with VDTs, nor were they linked
with electromagnetic fields . A case
controlled study based on questionnaires examined factors in the
"total electrical environment" with the findings that electrostatic
fields were not associated with skin sensitivities but ambient 50 Hz
electric fields and VDT generated ELF magnetic fields were
The Swedish National Board of Health and Welfare has reviewed the
relevant data on electrosensitivity and does not ascribe it to any
specific environmental exposure or condition .
Their summary regarding general health effects of electric and
magnetic fields states:
"The range of symptoms and the reported effects of
treatment of the electrically sensitive can best be understood
within a psychological explanatory framework -- which neither
denies the existence of the symptoms nor claims they are
Information from Biological Experimentation.
Tests on developing embryonic systems can provide sensitive
warning signals for hazardous effects. Likewise, the absence of
effects in developing systems would suggest VDT associated electric
and magnetic fields are unlikely to cause adverse effects in more
mature systems. Several studies of laboratory animals looked at the
possibility of teratogenic effects from exposures to VDT-like fields.
Tribukait et al.  found no greater
incidence of mouse embryo mortality or fetal resorptions with VLF
sawtooth or pulsed magnetic field exposures during gestation but did
find a significant increase in malformations for exposures to
sawtooth magnetic fields. On the other hand, Frölén et
al.  found no effects of VLF sawtooth
magnetic fields on malformations but did observe higher rates of
fetal resorption for mouse embryos exposed early in pregnancy,
although litter size was unaffected. A number of other reproductive
studies have been conducted with rats and mice, some with wholly
negative findings [37, 38,
39, 40 ]. One study showed
effects on drug treated mice . A number
of studies with chick embryos  have
established a large and inconsistent set of results on developmental
defects in this avian species. However, mammalian species are
considered to be the appropriate model for predicting developmental
toxicity in humans. In a review, Chernoff et al. 
concluded that although inconclusive, the laboratory data leave open
the possibility that under some experimental conditions adverse
reproductive and developmental effects occur in laboratory
Laboratory research using novel experimental approaches continues
to appear. For example, Dimberg 
reported that brain development was altered in mice exposed to
sawtooth VLF magnetic fields in utero. He reported that various brain
neurochemicals and brain weight were affected, particularly when
studied at 308 days of age. Additional research is warranted to
resolve outstanding issues. The resolution may identify specific
experimental conditions needed for consistent observations of
biological effects or conclude that the reported positive results,
generally small in number, are chance events of no biological or
Other Reviews of VDT Effects.
Several scientific organizations have reviewed the relevant
literature, both epidemiological studies of VDT use and laboratory
studies of ELF and VLF exposures. A scientific advisory group to the
National Radiological Protection Board (NRPB) of Great Britain
concluded that the studies did not support the idea that exposure to
ELF and VLF energy causes abnormal effects on the growing fetus or
congenital malformations (birth defects), nor is there evidence of an
increase in miscarriages for VDT users .
A working group of five scientists convened by the International
NonIonizing Radiation Committee ( INIRC) of the International
Radiation Protections Association (IRPA ) also reviewed the
literature and summarized their findings as follows :
"Based on current biomedical knowledge it can be
concluded that there are no health hazards associated with
radiation or fields from VDUs [VDTs]. Thus there is no
scientific basis to justify shielding or radiation monitoring, nor
eye examinations to search for ocular pathology due to radiations
in VDU operators. However, since a large number of people are
involved in VDU work, it is important that further knowledge is
gained on certain areas where our knowledge must be regarded as
Other groups offered similar conclusions concerning possible
reproductive effects from ELF electric and magnetic fields. The
International Conference on Large High Voltage Electric Systems
(CIGRÉ) working group from Australia, Canada, France,
Great Britain, Italy, Sweden, and the United States concluded that,
"In general, studies of EMF exposure and reproduction do not
demonstrate evidence of harm." . A
scientific panel convened by the Oak Ridge Associated Universities
reached a similar conclusion regarding reproductive effects from
electric and magnetic fields [< A HREF="#48">48].
Recommendations for Users of CRT-based Devices.
Based on present information, there is no basis for programs to
monitor or reduce CRT emissions in occupational settings. The use of
"protective" devices, such as "radiation screens" has not been shown
to be helpful; such devices are ineffective in reducing magnetic
field strengths and affect only the electric fields. Special
monitoring of user health because of VDT use also is not warranted.
VDT users need to be aware of ergonomic problems, which can be
ameliorated by the use of antiglare screens, proper eyeglasses, good
habits for the use of eyes, and furniture that assists good posture.
Consumers should know that inexpensive "EMF meters" do not provide
useful information about electromagnetic fields from CRT-based
devices. However, consumer advice and worker training on VDTs are
appropriate and encouraged. Topics should include ergonomic hazards
to the eyes and musculoskeletal system and education about
electromagnetic exposures with a summary of the scientific knowledge
concerning human health .
Cathode ray tube devices, including VDTs and television
receivers, utilize electromagnetic energy over a broad spectrum. For
VDTs, the measured electric and magnetic fields in the ELF, VLF, and
LF frequency ranges are well within existing exposure guidelines. The
consensus drawn from several epidemiological studies is that
workplace use of VDTs is not a risk factor for either miscarriage or
birth defects, the topics raised to prominence by early observations
and research. Based on animal studies and epidemiological study, no
other disease or syndrome has been conclusively associated with VDT
use. These facts lead to recommendations for education of users on
the ergonomic and electromagnetic aspects of VDT use but mitigate
against the need for programs to reduce or monitor exposures or to
have health surveillance programs for any specific disease or adverse
The scientific literature is, however, incomplete in important
ways. The duration of exposures in many studies has been brief
compared to either human working years, life span, or latency periods
for diseases such as cancer. Exposure assessment for users of CRTs
has been weak or absent in most epidemiological studies. The
inconsistency of laboratory studies in a number of relevant areas
needs resolution; this requires additional research. Although, at
present, there is good evidence showing that miscarriages and birth
defects are not associated with VDT use, there has been little health
research on other possible adverse outcomes.
This statement was prepared by the VDT Subcommittee of the IEEE
Committee on Man and Radiation (COMAR) with significant contributions
from the following: Eleanor R. Adair, Ph.D., Robert Ashley, C. K.
Chou, Ph.D. (Chairman, COMAR), Robert Curtis, Linda S. Erdreich,
Ph.D., Gregory D. Lapin, Ph.D., Kjell Hansson Mild, Ph.D., Ronald
Petersen, Asher R. Sheppard, Ph.D. (Chairman, VDT Subcommittee),
Richard Tell, and J. Patrick Reilly, Ph.D.
GLOSSARY OF TERMS
CI: Confidence Interval. A measure of
statistical reliability. A smaller range shows greater reliability.
In epidemiology, a range for an odds ratio that excludes 1.0, for
example, 1.3 to 2.6, indicates a statistically reliable increase in
risk; a range such as 0.2 to 0.5 indicates reliably reduced risk.
Typically, the range is selected for a 95% chance of including the
true risk ("95% CI").
computer monitor: A CRT-based display used with a computer;
CRT: Cathode ray tube.
ELF: Extremely low frequency, 3 to 300 Hz.
frequency: The rate of variation of a periodic signal.
hertz: The MKS unit of frequency, abbreviated Hz. Equal to
cycles per second.
LF: Low frequency, 30 to 300 kHz.
microtesla: One millionth of a tesla, abbreviated µT.
Equal to 10 milligauss.
non-sinusoidal: A waveform where the rate of change does not
follow the trigonometric sine function. Examples include sawtooth,
square wave, pulsed, triangle wave, speech and music.
polarization: The direction along which an electric or
magnetic field is aligned. For example, the magnetic field from a
loop of wire in the horizontal plane is perpendicular to the loop and
is said to be polarized vertically.
sawtooth: A waveform in which the signal changes at two rates.
For example, after a period of slow increase, the signal rapidly
decreases to the original value. The resulting pattern resembles the
teeth of a saw blade.
sinusoidal: A waveform in which the rate of change of a signal
varies from zero to a maximum value in a smooth and regular manner
that is described by the trigonometric sine function.
spontaneous abortion: Miscarriage, the unintended loss of a
fetus.< br> tesla: The MKS unit of magnetic flux
density, abbreviated T. Equal to 10,000 gauss.
VDT: Video display terminal.
VDU: Video display unit.
VLF: Very low frequency, 3 to 30 kHz.
1. Hitchcock RT, Patterson RM: Radio-Frequency and
ELF Electromagnetic Energies: A Handbook for Health Professionals.
Van Nostrand, Reinhold, NY, 1995.
2. Guy AW: Health hazards assessment of radio
frequency electromagnetic fields emitted by video display terminals.
In: Knave B, Wideback PG (Eds): Work with Display Units 86,
International Scientific Conference on Work with Display Units.
Elsevier, Amsterdam 69-80, 1987.
3. Tofani S, D'Amore G: Extremely-low-frequency
and very-low- frequency magnetic fields emitted by video display
units. Bioelectromagnetics 12(1):35-45, 1991.
4. IEEE: Biological Effects of Power-Frequency
Electric and Magnetic Fields. IEEE USAB, Washington, DC (approved
11/16/88; issued 3/9/89), 1989.
5. Sapashe D, Ashley R: Video display terminal
fringing magnetic field measurements. IEEE Trans on Instrumentation
and Measurement 41(2):178-184, 1992.
6. Kavet R, Tell RA: VDTs: Field levels,
epidemiology, and laboratory studies. Health Phys 61(1):47-57,
7. Mild KH, Sandström M: Health aspects of
electric and magnetic fields from VDTs. In: Lin, JC (Ed.): Advances
in Electromagnetic Fields in Living Systems, Vol. 1.. Plenum Press,
NY, pp. 155-183, 1994.
8. Sandström M, Mild KH, Stenberg B, and Wall
S: A survey of electric and magnetic fields among VDT operators in
Offices. IEEE Trans. on Electromagnetic Compatibility 35(3):394-397,
9. Walsh ML, Harvey SM, Facey RA, Mallette RR:
Hazard assessment of video display units. Am Ind Hyg Assoc J
10. American Conference of Governmental Industrial
Hygienists: Documentation of the Threshold Limit Values and
Biological Exposure Indices. Sixth edition. ACGIH, Cincinnati, Ohio,
11. American Conference of Governmental Industrial
Hygienists: Threshold Limit Values for Chemical Substances and
Physical Agents and Biological Exposure Indices. ACGIH, Cincinnati,
12. Swedish Standards Institution: Computers and
office machines - Measuring methods for electric and magnetic near
fields. Svensk Standard SS 46 14 90. Stockholm, December 1995.
13. Wedberg WC: Risks to VDT operators. Nature
14. Smith AB, Tanaa S, Halperin W, Richards RD:
Report on a cross-sectional survey of VDT users at the Baltimore Sun.
HETA 80-127- 1337, the Baltimore Sun, Baltimore, Maryland. Natl.
Inst. for Occupational Safety and Health (NIOSH), Hazard Evaluation
and Technical Assistance Branch.: Natl. Inst. for Occupational Safety
and Health (NIOSH), Cincinnati, pp. 1-160, 1982.
15. Boos SR, Calissendorff BM, Knave BG, Nyman KG,
Voss M: Work with video display terminals among office employees.
III. Ophthalmologic factors. Scand J Work Environ Health
16. Bonomi L, Bellucci R: Consideration of the
ocular pathology in 30,000 personnel of the Italian telephone company
(SIP) using VDTs. Bollettion Di Oculistica 68(S7): 85-98, 1989.
17. Ryan P, Lee MW, North JB, McMichael AJ: Risk
factors for tumors of the brain and meninges: results from the
Adelaide adult brain tumor study. Int J Cancer 51:20-27, 1992.
18. Goldhaber MK, Polen MR: The risk of
miscarriage and birth defects among women who use visual display
terminals during pregnancy. Am J Ind Med 13(6):695-706, 1988.
19. McDonald AD, McDonald JC, Armstrong B, Cherry
N, Nolin AD, Robert D: Work with visual display units in pregnancy.
Br J Ind Med 45(8):509-515, 1988.
20. Ericson A, Kallen B: An epidemiological study
of work with video screens and pregnancy outcome: I. A registry
study. Am J Ind Med 9(5):447-457, 1986.
21. Ericson A, Kallen B: An epidemiological study
of work with video screens and pregnancy outcome: II. A case-control
study. Am J Ind Med 9(5):459-475, 1986.
22. Bryant HE, Love EJ: Video display terminal use
and spontaneous abortion risk. Int J Epidemiol 18(1):132-138,
24. Bracken MB, Belanger K, Hellenbrand K, Dlugosz
L, Holford TR, McSharry JE, Addesso K, Leaderer B: Exposure to
electromagnetic fields during pregnancy with emphasis on electrically
heated beds: association with birthweight and intrauterine growth
retardation. Epidemiology 6:263-270, 1995.
25. Parazzini F, Luchini L, La Vecchia C,
Crosignani PG: Video display terminal use during pregnancy and
reproductive outcome-a meta-analysis. J Epidemiol Community Health
26. Schnorr TM, Grajewski BA, Hornung RW, Thun MJ,
Egeland GM, Murray WE, Conover DL, Halperin WE: Video display
terminals and the risk of spontaneous abortion. N Engl J Med
27. Schnorr TM, Grajewski BA, Murray WE: Video
display terminals and spontaneous abortions (Letter). N Engl J Med
28. Lindbohm ML, Hietanen M, Kyyronen P, Sallmen
M, von Nandelstadh P, Taskinen H, Pekkarinen M, Yliksoski M, Hemminki
K: Magnetic fields of video display terminals and spontaneous
abortion. Am J Epidemiol 136(9):1041-1051, 1992.
29. Stenberg B, Eriksson N, Mild KH,
Höög J, Sandström M, Sundell J, Wall S: Facial skin
symptoms in visual display terminal (VDT) workers. A case-referent
study of personal, psychosocial, building- and VDT-related risk
indicators. Int J Epidemiol 24(4):796-803, 1995.
30. Swanbäck G, Bleeker T: Skin problems from
visual display units. Provocation of skin symptoms under experimental
conditions. Acta Derm Venereol (Stockh) 69(1):46-51, 1989.
31. Oftedal G, Vistnes AI, and Rygge K: Skin
symptoms after the reduction of electric fields from visual display
units. Scand J Environ Health 21:335-44, 1995.
32. Bergqvist U, Wahlberg JE: Skin symptoms and
disease during work with visual display terminals. Contact Dermatitis
33. Sandström M, Mild KH, Stenberg B, and
Wall S: Skin symptoms among VDT workers and electromagnetic fields,a
case referent study. Indoor Air 5:29-37, 1995.
34. Swedish National Board of Health and Welfare:
Evaluation of the Effects on Health of Electrical and Magnetic
Fields. Stockholm, 1995.
35. Tribukait B, Cekan E, Paulsson LE: Effects of
pulsed magnetic fields on embryonic development in mice. Proceedings
of the International Congress Work and Display Units, National Board
of Occupational Safety and Health, Stockholm, pp. 68-70, 1986.
36. Frölén H, Svedenstål,
Paulsson L- E: Effects of pulsed magnetic fields on the developing
mouse embryo. Bioelectromagnetics 14(3):197-204, 1993.
37. Huuskonen H, Juutilainen J, Komulainen H:
Effects of low-frequency magnetic fields on fetal development in
rats. Bioelectromagnetics 14(2):205-213, 1993.
38. Stuchly MA, Ruddick J, Villeneuve D, Robinson
K, Reed B, Lecuyer DW, Tan K, Wong J: Teratological assessment of
exposure to time-varying magnetic field. Teratology 38(5):461-466,
39. Wiley MJ, Corey P, Kavet R, Charry J, Harvey
S, Agnew D, Walsh M: The effects of continuous exposure to 20-kHz
sawtooth magnetic fields on the litters of CD-1 mice. Teratology
40. Svedenstål BM, Johanson KJ: Fetal loss
in mice exposed to magnetic fields during early pregnancy.
Bioelectromagnetics 16(5):284-289, 1995.
41. Chiang H, Wu RY, Shao BJ, Fu YD, Yao GD, Lu
DJ: Pulsed magnetic field from video display terminals enhances
teratogenic effects of cytosine arabinoside in mice.
Bioelectromagnetics 16(1):70- 74, 1995.
42. Berman E: The developmental effects of pulsed
magnetic fields on animal embryos. Reprod Toxicol 4(1):45-49,
43. Chernoff N, Rogers JM, Kavet R: A review of
the literature on potential reproductive and developmental toxicity
of electric and magnetic fields. Toxicology 74(2/3):91-126,
44. Dimberg Y: Neurochemical effects of a 20 kHz
magnetic field on the central nervous system in prenatally exposed
mice. Bioelectromagnetics 16(4):263-267, 1995.
45. National Radiological Protection Board (NRPB):
Review of Occupational Exposure to Optical Radiation and Electric and
Magnetic Fields With Regard to the Proposed EEC Physical Agents
Directive. National Radiological Protection Board (NRPB), Great
46. INIRC/IRPA (International Non-Ionizing
Radiation Committee of the International Radiation Protection
Association): Visual Display Units: Radiation Protection Guidance.
International Labour Office, Geneva, 1994.
47. CIGRÉ (Conference Internationale des
Grand Reseaux Electriques á Haute Tension) Working Group 36.06
on Electric and Magnetic Fields and Health: Current status of
research on power-frequency electric and magnetic fields and
reproduction. Electra April (153):33, 1994.< p>
48. Oak Ridge Associated Universities Panel: Health
Effects of LowFrequency Electric and Magnetic Fields. Available from
NTIS:ORAU 92/F-8. Oak Ridge Associated Universities, 1992.
49. Paul M: Video display terminals. In: Paul M
(Ed): Occupational and Environmental Reproductive Hazards: A Guide
for Clinicians. Williams & Wilkins, Baltimore, MD, pp. 190-200,
Notes added to the Web version:
50. IEEE Standards Coordinating Committee 28 on
Non-Ionizing Radiation Hazards: IEEE standard for safety levels with
respect to human exposure to radio frequency electromagnetic fields,
3 kHz to 300 GHz (IEEE C95.1-1991), New York:The Institute of
Electrical and Electronics Engineers, Inc., 1991.
51. The published version of this document implies
that this is a federal OSHA standard, but it appears to be a
Massachusetts State OSHA regulation.
52. Health Canada: Limits of exposure to
radiofrequency fields at frequencies from 10 kHz - 300 GHz Safety
Code 6, Ottawa, Canada:Canada Communication Group, 1993.