孕婦可以使用電腦嗎？不少女性在工作和生活中使用計算機，當她們準備懷孕時，往往會對計算機是否可能對胎兒造成損傷而憂心忡忡。婦產科專家進行孕期跟踪時發現，兩位婦女長期接觸電腦屏幕，結果雙雙產下畸胎，而她們既沒有不良家族史，也沒有在孕期內濫用藥物。因此專家懷疑，會不會是電腦屏幕電磁輻射造成的呢？只有一點是可以肯定的，Visual Display Terminal (VDT )時間與其所帶來的危害是成正比的。視屏 (VDT) 輻射對生殖健康的影響，在各種報刊、雜誌、以及大眾傳播媒介中關於這方面的報導比較多，但從醫學流調學專業角度報導的資料較少。我在回答諮詢此類問題時，常常說目前電腦輻射對胎兒的危害尚沒有權威性定論，並說，在孕早期盡量減少淨工作時間。更具體的無法在諮詢回答中詳細闡述，可能讓許多諮詢者失望。
專業方面的調查結果是：對1583名孕產進行了病歷對照研究，結果自然流產OR值1.2，但在接觸 VDT 時間每週超過20小時的孕婦中，自然流產OR值1.8，說明大量接觸時，自然流產的危險有增高傾向。有研究結果認為，VDT 與子代先天性缺陷有關聯，OR值1.6，且當 VDT作業時間每周大於10小時時，OR值增為2.0，每週VDT作業時間大於20小時時，OR值為2.3，有劑量反應關係，因此，認為不能排除VDT作業有子代先天缺陷的危險。 90年代後，我國對此課題的研究結果發現，有1529名VDT作業女性月經週期延長，經血增多，其頻率顯著高於對照組。
(P<0.01)。 VDT 作業女性的自然流產率高於對照組， (p<0.05)。
另有報導，對從事VDT作業的361名女性和對照組484名的生殖機能和子代健康情況調查結果表明，自然流產、妊娠合併貧血的發生率也高於對照組。但是，也有相反的調查結論。目前沒有統一的認識，缺乏權威性的定論。每一項研究，都無法排除其他因素(如生活環境、飲食，身體狀況等)，調查的人數過少，只能代表被調查的局部情況。只有一點是可以肯定的，VDT時間與其所帶來的危害是成正比的。 OR值是醫學統計學中的術語，就是對研究的數值做統計學的處理，得出可靠的數值，如從事 VDT 婦女流產發生率是10%，從事非 VDT婦女的流產發生率是8%，是否能夠說從事 VDT 婦女的流產率就高於從事非 VDT 婦女的流產率呢？
不能下這樣的結論，必須經過統計學處理，這兩個率的比較是否有統計學意義。國外做法： 日本在勞動保護中規定，在異常妊娠結局是否與 VDT 有關這一問題未弄清前，孕婦不應參加VDT作業。根據現有的研究資料，至少要限制孕婦參加 VDT作業的時間是公認的，每週限制在15-20小時比較合適。權威結論： 電腦周圍存在的輻射包括有X射線、紫外線、可見光、紅外線、特高頻、高頻、極低頻、靜電場。但是他們發射的強度都是非常微弱的。遠低於我國和國際衛生組織所要求的標準。世界衛生組織的專家認為，影響電腦操作的妊娠婦女妊娠結局的原因很多，主要是工作疲勞和過度緊張，其次才是來自電腦的極低頻電磁場。
防止電腦輻射的產品，如防輻射圍巾、圍裙、背心等，屏幕遮蔽物，射線吸收儀器等，對電腦輻射的保護作用到底有多大，專家們認為這些防護品對顯示器輻射沒有任何作用，並進一步指出，即使有些防護品的確能夠減少輻射，也沒有實際價值，因為顯示器產生的電磁場和射線遠沒有超過國家和國際標准允許的暴露範圍。
醫學專家建議：1、從事視屏作業的育齡婦女不必擔心視屏輻射對下一代健康的影響。顯示器輻射對生殖健康沒有危害。
2、每週在電腦前工作時間不要超過20小時，防止流產的發生。
3、工作環境要通風，保持空氣新鮮。
4、沒有必要穿防護裝置。
5、要避免疲勞和過度緊張，保持愉快的心情，不要擔憂。
6、加強戶外活動，注意鍛煉身體。
7、定期產檢，做好孕期保健，避免導致胎兒出生缺陷的高危因素。
根據以上情況，我們建議，在孕早期(前3個月)避免長時間(每週40小時以上)接觸使用電腦，必須使用時，可每工作1小時，起身到室外或窗口活動呼吸新鮮空氣10分鐘，穿戴防輻射的衣物也是可以選擇的辦法。
VDT use
In the late 1970s, as the use of video display terminals (VDTs) in the workplace became increasingly common, questions arose concerning the potential effects on pregnancy outcomes of working with these terminals. Clusters of miscarriages and birth defects were reported at several workplaces in the United States and Canada.
Various VDT exposures and emissions have been measured: X-rays, ultraviolet radiation, visible light, infrared radiation, radio frequency fields, power-frequency EMFs, chemicals (PCBs), air ions, and static fields. Workers' exposures to these emissions are very low. However, unlike other office equipment, VDTs emit pulsed electromagnetic fields in the very low frequency (VLF) range, specifically 15,000 to 30,000 Hz (see the Electromagnetic Spectrum). In 1982, a laboratory in Spain reported that malformations occurred in chicken embryos exposed to pulsed magnetic fields at low frequencies. Although these results could not be repeated by the Spanish researchers or others, epidemiologic studies of workers were started to find out if miscarriages or birth defects occur more among VDT users.
In the following decade, more than 10 epidemiologic studies were completed in the United States, Canada, Sweden, Finland, Norway, and Denmark. Most of the studies reported that work with VDTs did not affect the risk of miscarriage or birth defects (Ericson and Kallen, 1986; Bryant and Love, 1989; Nielsen and Brandt, 1990). However, in only three studies were VDT exposures measured.
Standards
The U.S. government has no exposure or emission standards for magnetic fields from video display terminals (VDTs). The Swedish government issued guidelines recommending that VDTs purchased by the government produce extremely low frequency (ELF) magnetic fields of no more than 2 mG at a distance of 30 centimeters (11.8 inches) from the VDT surface. The standard is based on what is technologically achievable, not on medical or epidemiological research, according to the Swedish Board for Technical Accreditation (SWEDAC) which issued the standard.
In 1991, researchers at the National Institute for Occupational Safety and Health (NIOSH) studied two groups of telephone operators. One group used VDT displays; the other did not. The levels of power-frequency magnetic fields (60 Hz) measured at the operators' locations were similar for the two groups. This study reported that miscarriages happened no more often among full-time VDT users than among those workers not using VDTs. The study also reported that there appeared to be no relationship between the amount of time a woman used a VDT and her chance of having a miscarriage.
A study from Finland (Lindbohm et al., 1992) reported that women who miscarried at one of three companies were more likely to have used models of VDTs that could produce 50-Hz magnetic fields above 3 mG. Finnish investigators did not find an overall link between miscarriage or birth defects and VDT use, nor was there a relationship between increased incidence of miscarriages with increasing VLF field strength.
Recently, a large study at Yale focused on the effects of EMF exposure on the growth rate of the unborn child (Bracken et al., 1995). These researchers obtained information about power frequency magnetic field exposure from power line and home sources. VDT use over 20 hours a week was not found to affect the weight or growth rate of the baby, nor did the mother's exposure to higher magnetic fields or to "high" field sources such as electrically heated beds.
In 1994, the National Radiological Protection Board (NRPB) of Great Britain invited an advisory group of scientists to review studies of possible health effects related to the use of VDTs. They concluded that there was "no good reason to suppose" that exposure to low frequency electromagnetic fields from the use of VDTs harms the unborn child
(P<0.01)。 VDT 作業女性的自然流產率高於對照組， (p<0.05)。
另有報導，對從事VDT作業的361名女性和對照組484名的生殖機能和子代健康情況調查結果表明，自然流產、妊娠合併貧血的發生率也高於對照組。但是，也有相反的調查結論。目前沒有統一的認識，缺乏權威性的定論。每一項研究，都無法排除其他因素(如生活環境、飲食，身體狀況等)，調查的人數過少，只能代表被調查的局部情況。只有一點是可以肯定的，VDT時間與其所帶來的危害是成正比的。 OR值是醫學統計學中的術語，就是對研究的數值做統計學的處理，得出可靠的數值，如從事 VDT 婦女流產發生率是10%，從事非 VDT婦女的流產發生率是8%，是否能夠說從事 VDT 婦女的流產率就高於從事非 VDT 婦女的流產率呢？
註: OR值 Odd RatioVDT - 眼疲勞的含義
VDT（Visual Display Terminal綜合徵）/視屏終端綜合徵
眼疲勞是由於用眼過度（包括：閱讀文案、操作電腦、上網、看電視、開車等因素）以及環境因素（氣候乾燥，空調環境等）引起的一系列眼睛不適症狀。
VDT - 眼疲勞的主要表現
眼睛乾澀、異物感、視物模糊、眼睛酸脹等症狀。
VDT 的由來
因為眼疲勞更多是由於長時間注視視屏終端（電腦、電視屏幕等）引起，又被稱為VDT（Visual Display Terminal）綜合徵或視屏終端綜合徵。
不能下這樣的結論，必須經過統計學處理，這兩個率的比較是否有統計學意義。國外做法： 日本在勞動保護中規定，在異常妊娠結局是否與 VDT 有關這一問題未弄清前，孕婦不應參加VDT作業。根據現有的研究資料，至少要限制孕婦參加 VDT作業的時間是公認的，每週限制在15-20小時比較合適。權威結論： 電腦周圍存在的輻射包括有X射線、紫外線、可見光、紅外線、特高頻、高頻、極低頻、靜電場。但是他們發射的強度都是非常微弱的。遠低於我國和國際衛生組織所要求的標準。世界衛生組織的專家認為，影響電腦操作的妊娠婦女妊娠結局的原因很多，主要是工作疲勞和過度緊張，其次才是來自電腦的極低頻電磁場。
防止電腦輻射的產品，如防輻射圍巾、圍裙、背心等，屏幕遮蔽物，射線吸收儀器等，對電腦輻射的保護作用到底有多大，專家們認為這些防護品對顯示器輻射沒有任何作用，並進一步指出，即使有些防護品的確能夠減少輻射，也沒有實際價值，因為顯示器產生的電磁場和射線遠沒有超過國家和國際標准允許的暴露範圍。
醫學專家建議：1、從事視屏作業的育齡婦女不必擔心視屏輻射對下一代健康的影響。顯示器輻射對生殖健康沒有危害。
2、每週在電腦前工作時間不要超過20小時，防止流產的發生。
3、工作環境要通風，保持空氣新鮮。
4、沒有必要穿防護裝置。
5、要避免疲勞和過度緊張，保持愉快的心情，不要擔憂。
6、加強戶外活動，注意鍛煉身體。
7、定期產檢，做好孕期保健，避免導致胎兒出生缺陷的高危因素。
根據以上情況，我們建議，在孕早期(前3個月)避免長時間(每週40小時以上)接觸使用電腦，必須使用時，可每工作1小時，起身到室外或窗口活動呼吸新鮮空氣10分鐘，穿戴防輻射的衣物也是可以選擇的辦法。
Does Your Computer Monitor Pose A Risk?
Several epidemiologic studies have looked for the affect of
electric and magnetic fields on pregnancy outcomes and general health.
Various EMF sources have been studied for possible association with
miscarriage risk, including video display terminals (VDTs).
In the late 1970s, as the use of video display terminals (VDTs) in the workplace became increasingly common, questions arose concerning the potential effects on pregnancy outcomes of working with these terminals. Clusters of miscarriages and birth defects were reported at several workplaces in the United States and Canada.
Various VDT exposures and emissions have been measured: X-rays, ultraviolet radiation, visible light, infrared radiation, radio frequency fields, power-frequency EMFs, chemicals (PCBs), air ions, and static fields. Workers' exposures to these emissions are very low. However, unlike other office equipment, VDTs emit pulsed electromagnetic fields in the very low frequency (VLF) range, specifically 15,000 to 30,000 Hz (see the Electromagnetic Spectrum). In 1982, a laboratory in Spain reported that malformations occurred in chicken embryos exposed to pulsed magnetic fields at low frequencies. Although these results could not be repeated by the Spanish researchers or others, epidemiologic studies of workers were started to find out if miscarriages or birth defects occur more among VDT users.
In the following decade, more than 10 epidemiologic studies were completed in the United States, Canada, Sweden, Finland, Norway, and Denmark. Most of the studies reported that work with VDTs did not affect the risk of miscarriage or birth defects (Ericson and Kallen, 1986; Bryant and Love, 1989; Nielsen and Brandt, 1990). However, in only three studies were VDT exposures measured.
Standards
The U.S. government has no exposure or emission standards for magnetic fields from video display terminals (VDTs). The Swedish government issued guidelines recommending that VDTs purchased by the government produce extremely low frequency (ELF) magnetic fields of no more than 2 mG at a distance of 30 centimeters (11.8 inches) from the VDT surface. The standard is based on what is technologically achievable, not on medical or epidemiological research, according to the Swedish Board for Technical Accreditation (SWEDAC) which issued the standard.
In 1991, researchers at the National Institute for Occupational Safety and Health (NIOSH) studied two groups of telephone operators. One group used VDT displays; the other did not. The levels of power-frequency magnetic fields (60 Hz) measured at the operators' locations were similar for the two groups. This study reported that miscarriages happened no more often among full-time VDT users than among those workers not using VDTs. The study also reported that there appeared to be no relationship between the amount of time a woman used a VDT and her chance of having a miscarriage.
A study from Finland (Lindbohm et al., 1992) reported that women who miscarried at one of three companies were more likely to have used models of VDTs that could produce 50-Hz magnetic fields above 3 mG. Finnish investigators did not find an overall link between miscarriage or birth defects and VDT use, nor was there a relationship between increased incidence of miscarriages with increasing VLF field strength.
Recently, a large study at Yale focused on the effects of EMF exposure on the growth rate of the unborn child (Bracken et al., 1995). These researchers obtained information about power frequency magnetic field exposure from power line and home sources. VDT use over 20 hours a week was not found to affect the weight or growth rate of the baby, nor did the mother's exposure to higher magnetic fields or to "high" field sources such as electrically heated beds.
In 1994, the National Radiological Protection Board (NRPB) of Great Britain invited an advisory group of scientists to review studies of possible health effects related to the use of VDTs. They concluded that there was "no good reason to suppose" that exposure to low frequency electromagnetic fields from the use of VDTs harms the unborn child
Pregnant Women Increasingly Fearful of VDT's
By TAMAR LEWIN
New York Times
Women around the country who work on video display terminals are increasingly expressing concern that their jobs may pose a threat to their ability to bear healthy babies.
A recent study conducted by researchers in California found that women who work extensively on VDT's in early pregnancy are likelier than others to miscarry, but the study did not establish whether the terminals themselves cause the problem. Experts on occupational health agree that it is likely to be several years before there is adequate research to answer that question.
A few of the unions that represent office workers have already negotiated contracts giving pregnant women the option of transferring to jobs that do not involve work on VDT's. But lawyers specializing in women's rights say such options for pregnant workers to change jobs could ultimately work against women by discouraging employers from hiring women of child-bearing age. Instead, they put the emphasis on improving conditions for everyone who does VDT work. Health Experts Are Divided
Meanwhile, occupational health experts are divided over how seriously to take the dangers of VDT work: While some say there is no need for pregnant women to take special precautions, others strongly advise women to avoid working on VDT's while they are pregnant or trying to conceive.
That lack of consensus and the paucity of research that underlies it is a source of enormous frustration to many women who work on VDT's.
''A healthy baby is the most important thing, and I'm very concerned,'' said Chana Messer, a New York City computer graphics artist who is expecting a child in September. ''But no one seems to have much scientific information, so it's hard to know what to do.''
Lisa Gallatin, director of Boston's Office Technology Education Project, an organization that is sponsored by union women's groups, said the group's VDT Hotline has been getting about 20 calls a day, mostly from pregnant women, ever since a local television station ran a report about the study recently.
''It's a very emotional issue,'' Ms. Gallatin said. ''People imagine a little nuclear power plant zapping their baby. We can offer some reassurance. We tell them that it is simply not known whether long-term exposure leads to reproductive problems. But we also tell them that it's not a risk of major proportion. It may increase miscarriage rates somewhat, but it's not causing an epidemic. Still, we think women should have the opportunity to transfer away from work on the terminal while they are pregnant or attempting to conceive.'' Twice as Many Miscarriages
The study of 1,583 pregnant women who attended three obstetrics and gynecology clinics in northern California operated by the Kaiser-Permanente Medical Care Program in Oakland, found that women who used video display terminals more than 20 hours a week in early pregnancy suffered almost twice as many miscarriages as other office workers.
But the authors of the study said their findings did not necessarily mean that the terminals themselves caused reproductive problems, since the study did not measure other factors that might have accounted for the higher miscarriage rate, like job-related stress, poor working conditions or even the possibility that women who had miscarriages were more apt to report having spent long hours at a VDT.
Some occcupational health and technology experts who have reviewed the California study say the results point to working conditions as the culprit, not radiation from the machines.
''If you look at the study, and not the headlines about the study, it seems clear that the problem is the factory-like environment so many VDT operators work in, not the machine itself,'' said Jeanne Stellman, executive director of the Women's Occupational Health Resource Center, a Brooklyn organization. ''The most significant part of the study, one that didn't get reported, was the table showing that administrative and clerical workers who spent more than 20 hours a week on the VDT had a much higher miscarriage rate than managerial and professional women who spent the same amount of time at a computer.''
Nonetheless, Ms. Stellman said she could not give the VDT a clean bill of health, because further research was needed. Even so, she said, ''If I got pregnant again, I would have zero hesitancy about using my VDT.''
Michael Polen, one of the researchers involved in the California study, said it was simply too soon to know whether the VDT's themselves caused reproductive problems.
''It's possible that the difference between professionals and clericals workers had to do with socioeconomic differences or age or stress, or any number of other factors,'' he said.
Because of the design of the study, Mr. Polen said, it would not have picked up differences between people who worked on VDT's 20 hours a week and those who spent 40 hours at a terminal, nor would it have made any distinction between those working in an office with one VDT and those in computer rooms with hundreds of terminals. Still Cause for Concern
Mr. Polen and others say that despite the inconclusive evidence from the new study, there is cause for concern, particularly because several earlier studies on animal embryos have shown that the very low frequency, pulsed, non-ionizing electromagnetic radiation emitted from VDT's can disrupt cellular growth.
And Mr. Polen said he could not make any recommendation in individual cases.
Louis Slesin, the editor of VDT News, did offer a suggestion, however. ''I think any woman who is pregnant, or trying to become pregnant, should play it safe and stop working on a VDT,'' he said. ''The shocking thing is that millions of women are using VDT's every day, and no one really knows what that does to a fetus.''
For most women who work on VDT's, Mr. Slesin said, the easiest way to avoid radiation may be to switch to laptop computers without a video display. ''As a practical matter,'' he said,''what makes this so difficult is that women are most at risk in the early weeks of pregnancy, when they might not know they are pregnant.'' Advise Against Lead Aprons
Occupational health experts strongly advise women against wearing lead aprons to try to protect themselves from VDT the possible effects of VDT's. Not only is the weight of the apron more dangerous than the VDT, they say, but lead acts as a shield against the ionizing radiation found in X-rays, not the less dangerous, and less studied, non-ionizing radiation that is a concern with VDT's.
''We don't know enough about the kind of radiation that comes from VDT's to develop any safety standards, so the safest thing is to try to reduce your exposure,'' said Sharon Danann, the research director of 9 to 5, a Cleveland area organization of office workers. ''We do know that radiation exposure falls off very rapidly with distance,'' she said. ''Most radiation comes from the side and back of the machine, so that women who work in rooms with rows and rows of machines get the most exposure.''
Despite the concerns that have been raised, industry groups maintain that it is safe for pregnant women to use VDT's, since the studies have not found any causal connection between VDT work and human reproductive problems. They say the animal studies are not relevant since they did not use the precise pulse-length radiation that VDT's emit.
''People are getting needlessly upset by the very alarming headlines,'' said Charlotte LeGates, a spokeswoman for the Computer and Business Equipment Manufacturers Association in Washington. ''Since the study was publicized, I've gotten calls from about 30 businesses that wanted an update on the safety situation.''
Still, a few employers said the California study was worrisome enough to prompt them to re-examine their practices.
''There's no policy right now on pregnancy and VDT's, but we're aware of the new study, and we will start looking into it,'' said Noel Seberle, manager of medical administration for the American Express Company. ''Most of the studies before this concluded there was no danger, and this one isn't conclusive, but it is the most disturbing so far.'' VDT Legislation Proliferating Legislation has been introduced in at least 24 states that would regulate working conditions for those who use VDT's, often providing for routine eye examinations, regular breaks from computer work, detachable keyboards and adjustable chairs. Some of the proposed laws also require that pregnant women be allowed to transfer from VDT work. In June, Suffolk County, L.I., passed a law regulating VDT work conditions and requiring employers to pay part of the cost of eye examinations, but the law does not address the pregnancy issue.
In the last few years, several labor unions, including the Communication Workers of America and the Service Employees International Union, have negotiated contracts giving pregnant VDT workers the option to transfer to noncomputer jobs with no loss of pay or benefits.
''We got pregnancy clauses in 13 of the 22 contracts we negotiated last year,''said Denise Mitchell, a spokeswoman for the service union. ''It's getting to be quite common. Even where employers don't want to make other VDT agreements, like providing rest breaks or eye exams, they may be worried enough about potential liability so that they will agree to give pregnant workers the option of transferring.''
Even without a contract guarantee, some women who work on VDT's have been able to arrange a pregnancy transfer.
Yvette Wright, who now works at Emory University in Atlanta, said: ''When I got pregnant four years ago, I was working in a library at the University of Colorado in Boulder, and I asked the university for a written statement that it was totally safe to sit in front of a terminal. They said they couldn't do that, becuase it was too new for reliable data. So I told my supervisor that I wouldn't sit in front of the terminal, and they arranged for me to do other work during my pregnancy.''
Women around the country who work on video display terminals are increasingly expressing concern that their jobs may pose a threat to their ability to bear healthy babies.
A recent study conducted by researchers in California found that women who work extensively on VDT's in early pregnancy are likelier than others to miscarry, but the study did not establish whether the terminals themselves cause the problem. Experts on occupational health agree that it is likely to be several years before there is adequate research to answer that question.
A few of the unions that represent office workers have already negotiated contracts giving pregnant women the option of transferring to jobs that do not involve work on VDT's. But lawyers specializing in women's rights say such options for pregnant workers to change jobs could ultimately work against women by discouraging employers from hiring women of child-bearing age. Instead, they put the emphasis on improving conditions for everyone who does VDT work. Health Experts Are Divided
Meanwhile, occupational health experts are divided over how seriously to take the dangers of VDT work: While some say there is no need for pregnant women to take special precautions, others strongly advise women to avoid working on VDT's while they are pregnant or trying to conceive.
That lack of consensus and the paucity of research that underlies it is a source of enormous frustration to many women who work on VDT's.
''A healthy baby is the most important thing, and I'm very concerned,'' said Chana Messer, a New York City computer graphics artist who is expecting a child in September. ''But no one seems to have much scientific information, so it's hard to know what to do.''
Lisa Gallatin, director of Boston's Office Technology Education Project, an organization that is sponsored by union women's groups, said the group's VDT Hotline has been getting about 20 calls a day, mostly from pregnant women, ever since a local television station ran a report about the study recently.
''It's a very emotional issue,'' Ms. Gallatin said. ''People imagine a little nuclear power plant zapping their baby. We can offer some reassurance. We tell them that it is simply not known whether long-term exposure leads to reproductive problems. But we also tell them that it's not a risk of major proportion. It may increase miscarriage rates somewhat, but it's not causing an epidemic. Still, we think women should have the opportunity to transfer away from work on the terminal while they are pregnant or attempting to conceive.'' Twice as Many Miscarriages
The study of 1,583 pregnant women who attended three obstetrics and gynecology clinics in northern California operated by the Kaiser-Permanente Medical Care Program in Oakland, found that women who used video display terminals more than 20 hours a week in early pregnancy suffered almost twice as many miscarriages as other office workers.
But the authors of the study said their findings did not necessarily mean that the terminals themselves caused reproductive problems, since the study did not measure other factors that might have accounted for the higher miscarriage rate, like job-related stress, poor working conditions or even the possibility that women who had miscarriages were more apt to report having spent long hours at a VDT.
Some occcupational health and technology experts who have reviewed the California study say the results point to working conditions as the culprit, not radiation from the machines.
''If you look at the study, and not the headlines about the study, it seems clear that the problem is the factory-like environment so many VDT operators work in, not the machine itself,'' said Jeanne Stellman, executive director of the Women's Occupational Health Resource Center, a Brooklyn organization. ''The most significant part of the study, one that didn't get reported, was the table showing that administrative and clerical workers who spent more than 20 hours a week on the VDT had a much higher miscarriage rate than managerial and professional women who spent the same amount of time at a computer.''
Nonetheless, Ms. Stellman said she could not give the VDT a clean bill of health, because further research was needed. Even so, she said, ''If I got pregnant again, I would have zero hesitancy about using my VDT.''
Michael Polen, one of the researchers involved in the California study, said it was simply too soon to know whether the VDT's themselves caused reproductive problems.
''It's possible that the difference between professionals and clericals workers had to do with socioeconomic differences or age or stress, or any number of other factors,'' he said.
Because of the design of the study, Mr. Polen said, it would not have picked up differences between people who worked on VDT's 20 hours a week and those who spent 40 hours at a terminal, nor would it have made any distinction between those working in an office with one VDT and those in computer rooms with hundreds of terminals. Still Cause for Concern
Mr. Polen and others say that despite the inconclusive evidence from the new study, there is cause for concern, particularly because several earlier studies on animal embryos have shown that the very low frequency, pulsed, non-ionizing electromagnetic radiation emitted from VDT's can disrupt cellular growth.
And Mr. Polen said he could not make any recommendation in individual cases.
Louis Slesin, the editor of VDT News, did offer a suggestion, however. ''I think any woman who is pregnant, or trying to become pregnant, should play it safe and stop working on a VDT,'' he said. ''The shocking thing is that millions of women are using VDT's every day, and no one really knows what that does to a fetus.''
For most women who work on VDT's, Mr. Slesin said, the easiest way to avoid radiation may be to switch to laptop computers without a video display. ''As a practical matter,'' he said,''what makes this so difficult is that women are most at risk in the early weeks of pregnancy, when they might not know they are pregnant.'' Advise Against Lead Aprons
Occupational health experts strongly advise women against wearing lead aprons to try to protect themselves from VDT the possible effects of VDT's. Not only is the weight of the apron more dangerous than the VDT, they say, but lead acts as a shield against the ionizing radiation found in X-rays, not the less dangerous, and less studied, non-ionizing radiation that is a concern with VDT's.
''We don't know enough about the kind of radiation that comes from VDT's to develop any safety standards, so the safest thing is to try to reduce your exposure,'' said Sharon Danann, the research director of 9 to 5, a Cleveland area organization of office workers. ''We do know that radiation exposure falls off very rapidly with distance,'' she said. ''Most radiation comes from the side and back of the machine, so that women who work in rooms with rows and rows of machines get the most exposure.''
Despite the concerns that have been raised, industry groups maintain that it is safe for pregnant women to use VDT's, since the studies have not found any causal connection between VDT work and human reproductive problems. They say the animal studies are not relevant since they did not use the precise pulse-length radiation that VDT's emit.
''People are getting needlessly upset by the very alarming headlines,'' said Charlotte LeGates, a spokeswoman for the Computer and Business Equipment Manufacturers Association in Washington. ''Since the study was publicized, I've gotten calls from about 30 businesses that wanted an update on the safety situation.''
Still, a few employers said the California study was worrisome enough to prompt them to re-examine their practices.
''There's no policy right now on pregnancy and VDT's, but we're aware of the new study, and we will start looking into it,'' said Noel Seberle, manager of medical administration for the American Express Company. ''Most of the studies before this concluded there was no danger, and this one isn't conclusive, but it is the most disturbing so far.'' VDT Legislation Proliferating Legislation has been introduced in at least 24 states that would regulate working conditions for those who use VDT's, often providing for routine eye examinations, regular breaks from computer work, detachable keyboards and adjustable chairs. Some of the proposed laws also require that pregnant women be allowed to transfer from VDT work. In June, Suffolk County, L.I., passed a law regulating VDT work conditions and requiring employers to pay part of the cost of eye examinations, but the law does not address the pregnancy issue.
In the last few years, several labor unions, including the Communication Workers of America and the Service Employees International Union, have negotiated contracts giving pregnant VDT workers the option to transfer to noncomputer jobs with no loss of pay or benefits.
''We got pregnancy clauses in 13 of the 22 contracts we negotiated last year,''said Denise Mitchell, a spokeswoman for the service union. ''It's getting to be quite common. Even where employers don't want to make other VDT agreements, like providing rest breaks or eye exams, they may be worried enough about potential liability so that they will agree to give pregnant workers the option of transferring.''
Even without a contract guarantee, some women who work on VDT's have been able to arrange a pregnancy transfer.
Yvette Wright, who now works at Emory University in Atlanta, said: ''When I got pregnant four years ago, I was working in a library at the University of Colorado in Boulder, and I asked the university for a written statement that it was totally safe to sit in front of a terminal. They said they couldn't do that, becuase it was too new for reliable data. So I told my supervisor that I wouldn't sit in front of the terminal, and they arranged for me to do other work during my pregnancy.''
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