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VDTs can be hazardous
MANY of the youth who work on computers for a long time ignore the warnings that sitting in front of computers for too long is hazardous.
There are two sets of opinions on this point. The “believers” say the radiation emitted by the VDTs are very harmful for the human body and can cause serious damage to various organs, the “non-believers” refute this claim.
A study at University of Vermont says the primary concern in computer use is radiation emitted by the visual display terminal, or VDT. Most VDTs do emit radiation, particularly low frequency fields.
High-energy ionizing radiation (X-ray) emission is not a VDT health risk. Although radiation within the X-ray band is produced in VDTs, it is absorbed by the thick glass of the screen before it can be emitted.
Unlike X-rays, these frequencies of non-ionizing radiation could cause damage by raising cell temperature, as a microwave oven heats food or overexposure to a sunlamp causes sunburn, but not in the small amounts generated by a VDT.
In short, the amount of X-ray, microwave, and ultraviolet radiation generated by a VDT are all far below the established safety thresholds.
Recently, however, attention has focused on Very Low Frequency (VLF) and Extremely Low Frequency (ELF) non-ionizing radiation frequencies, which were previously believed to have no biological effect. Almost all video display terminals (VDT) emit both VLF and ELF fields.
This radiation has become cause for concern because some studies indicate that even weak VLF or ELF fields can cause miscarriage, birth defects, or cancer. However, these studies are extremely controversial.
The general study of radiation effects on human cells does prove that ionizing radiation can have various effects on the human cells. The varying effects depend on the cell sensitivity to radiation and the amount of the dose of radiation. According to Jefferson Lab research reports, “If a damaged cell needs to perform a function before it has had time to repair itself, it will either be unable to perform the repair function or perform the function incorrectly or incompletely. The result may be cells that cannot perform their normal functions or that now are damaging to other cells. These altered cells may be unable to reproduce themselves or may reproduce at an uncontrolled rate. Such cells can be the underlying causes of cancers.”
However it is not yet confirmed that VLF and ELF fields also have such effects on cells.
Apart from these radiations and their effects, research studies was conducted by several research labs and universities relating to EMF radiations emitted by computers and several other electrical devices. Some of the particular health problems studied are:
• The link between cell phones and cancer
• Reproductive disturbances
• Foetal abnormalities and developmental defects
• Stunted growth, growth retardation and weight variations in animal studies
• Human genetic defects with malformed children from parents who worked in electric switchyards and exposed to high voltage fields. 1983 study at the University of Umea in Sweden.
• Birth defect and miscarriage clusters among pregnant women who work at Video Display terminals
• Higher miscarriage rates among pregnant women working at computers for more than 20 hours per week
• Chronic stress, skin rashes, disturbances in menstrual cycles, headaches, nausea, sleeplessness and fatigue
• Increases in childhood cancers-leukemia and brain tumors in particular
• Significant increases in learning disabilities
• Immune system disorders
• Cancer links to EMFs (specially cancers of the brain, blood, skin and glandular tissue).
Relevant to this, a study by the Northern California Kaiser Permanente Medical Care Programme found that pregnant women who reported using VDTs more than 20 hours per week during the first trimester were significantly more likely to have miscarriages than women who performed similar work without using VDTs. Although the study has been criticized for relying on recall (the women reported their VDT use from memory), it is considered by many as the strongest study to date.
The frequent complain of eye irritation and diseases, blamed on pro-longed computer-use, however, are denied by some researches. According to documents from the organization Prevent Blindness America: “Many people assume increased computer use is the source of these complaints. But extensive testing in government and private laboratories has not produced scientific evidence that VDTs will harm your eyes. Research has established that VDTs emit little or no hazardous radiation, such as x-ray, or non-ionizing radiation, such as ultraviolet rays.
“Although people who use VDTs on a daily basis often complain of eye irritation, fatigue and difficulty focusing, most of these symptoms are caused by conditions surrounding the computer screen, such as poor lighting or improper placement of equipment and supplies. In some instances, a pre-existing eye problem may be the cause.”
The question is, however, if there are such harmful effects of computers, in the present hi-tech era how can one avoid working with computers. Presently most of the office work is done on computers, the modern studies are all computer based. There is a constant 24-hour use of the machine in almost every department of life. So what should one do to steer clear of this harmful contact? The answer is precautions.
Relating to the eyesight problems, experts recommend a distance of 20-26 inches between your eyes and the monitor. Also lighting should be modified to suit the lightning of the work area and reduce harsh glare to avoid eyestrain.
Considering the radiation effects, although more research is being carried out on the effects of ELF and VLF radiation, in the mean time there are some simple precautionary steps you can take to avoid the danger.
• Try to sit about 24 to 28 inches away from the front of your own monitor (about arm’s length), and at least 40 inches away from the sides or back of any other monitors, including those behind walls or partitions. The electromagnetic fields generated by many VDTs are strongest at the back and sides of the unit, and all the fields decrease rapidly with distance.
• Even if you use a computer several times each day, you may be able to turn it off or move away from it when you’re not actually using it. Short-term exposure to VDTs is generally not considered a problem.
• It is recommended that you take a short break after working for two hours with a computer.
• Some computers, laptop models in particular, do not use cathode ray tubes. These models emit little if any VLF and ELF radiation. Also, some manufacturers of traditional VDTs have introduced low-emission monitors.
Special care should be taken by pregnant women working with VDTs, especially in the first 20 weeks of pregnancy. She shouldn’t be exposed to VLF, ELF radiations and EMF emitted by VDUs more than 20 hrs per week.
Several individual devices have been introduced including radiation shields, electronic anti-radiation devices which can be installed in a PC and even pendants for daily wear which absorb the EMF’s that are emitted by several daily use electrical products.
And now, as I have been sitting in front of my monitor, working on this article for a good few hours. I must take my precautionary break.
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