SAS Urban Survival Handbook (69 page)

VDUs

Visual Display Units—the screens of computers—are like televisions (see
Leisure
). They emit some radiation, but are usually manufactured to higher standards than televisions. Working at a VDU does demand that the operator sits at much closer proximity than the viewer of a television would choose for comfort or safety.

Japanese studies (unconfirmed) suggest exposure to radiation from VDUs could influence miscarriages or deformity of the foetus during pregnancy. It has also been suggested that sperm may be affected.

Measurable levels of very and extra-low frequency radiation do occur, though there is no firm evidence that these have any biological effect on humans. These emissions do not come from the screen, but from the transformer windings and would be present in many kinds of domestic apparatus.

It has also been suggested that using a VDU damages the eyesight. It seems probable that eye problems among VDU users have been revealed by the use of the screen rather than caused by the VDUs themselves, but any prolonged and concentrated viewing can cause eyestrain.

REMEMBER

Anyone with uncorrected, or imperfectly-corrected eye defects is likely to suffer greater eyestrain when using VDUs than those with properly-corrected vision. A thorough eye test by an ophthalmologist is recommended before anyone begins work with VDUs, and annually thereafter. Restrict working time to about an hour, before taking a break for a few minutes to rest the eyes.

The flickering of the screen, though usually imperceptible, may be a risk to people already subject to forms of epilepsy affected by flickering light or striped patterns.

The build-up of an electrical charge on the screen may be linked to forms of dermatitis on the face and hands of some computer operators with particularly sensitive skin.

Most VDU problems are caused by bad work postures, poor lighting conditions or concentrated work for long periods without break or exercise.

RADIOGRAPHERS

Radiographers, dental nurses and others who operate x-ray equipment are continually at risk from radiation, if they do not take proper precautions. Always retreat behind the appropriate shields before operating the x-ray (and make sure that the subject is also protected, except for the area which is being investigated). There may still be some slight risk from cumulative exposure, leading to cancer, though this may not become apparent until ten or more years after you have given up the job.

WORK POSTURE

Badly-designed seats, having to stand for long periods, poor lighting that forces people to get too close to their work, uncomfortable bench or desk heights and reaching too far, are all causes of bad work posture. They place parts of the body under undue strain.

Back problems and knee strain occur from lifting heavy weights, whether office furniture, sacks of cement or hospital patients. Sitting all day in a bad posture will also cause back problems, whether driving a bus or working at a desk. Piles and varicose veins can be caused/aggravated by the same conditions, and also by standing all day.

A brisk walk, or lying with the legs raised, will help to counter a build-up of circulatory back pressure and improve the flow of blood to the heart. During a break, ‘put your feet up’!

Optimum bench/desk heights

• ◑ Work surfaces should be at a level which allows the arms to be bent at the elbow at right angles to the body.
  
• ◑ It should be possible to reach work by extending the arms while still keeping the back straight.
  
• ◑ Computer and typewriter keyboards should be at a level which allows the forearms to be at right angles to the body or slightly lower so that the wrists are not bent upwards. This is lower than a convenient writing height.
  
• ◑ When sitting, thighs should be parallel to the ground, with the legs bent at a right angle at the knee. Feet should touch the floor or a footrest used to prevent pressure on the back of the thighs.
  

Can you avoid lights or images reflected in the screen?

Screens should NOT face windows. If direct or reflected glare cannot be avoided, it must be shaded and direct sunlight into the room should be diffused. Anti-glare screen filters also help to cut down on reflections.

Is normal office lighting suitable for working at computer stations?

No. Ideal room illumination for operating a VDU is 300 lux, for general officework 500 lux or above. If you do

other work at your computer station you should have separate desk illumination.

Should you be able to read the screen without leaning forward?

You should be able to read the screen by looking down slightly, without bending your neck.

How long should you work at your computer?

You should take frequent pauses, long enough for eyes to recover from the effort of reading the screen and to interrupt the repetitive strain of keyboarding. Breaks should be at least 15 minutes per hour of intensive work or every two hours of less intensive work. Mixing VDU work with other activities is the most efficient way of providing these breaks.

On your feet all day?

There are many jobs which involve standing for long periods which can lead to circulatory problems producing varicose veins and aggravating conditions such as haemorrhoids (piles). Resting when possible, preferably with the feet raised, and taking a brisk walk whenever there is an opportunity will help minimize these effects. Other aspects of the job will cause further problems. These are just some examples:

Hairdressers
Staying at your work station while an assistant runs your errands is not a good idea. By all means let your assistant wash a client’s hair, but collect the client from reception yourself and take the need to fetch towels or equipment as an opportunity for exercise. Assistants shouldn’t be reluctant to fetch a client’s coffee—it all helps to counter the static nature of your job!

Nurses
Are subject to many of the problems which doctors have to face. They frequently have to lift heavy patients in awkward positions, placing great strain on the back. Follow all the advice given in training to make lifting easier and get help with heavy patients. Back strain is a major cause of nurses being off duty and of them leaving the profession. Undue strain not only damages you—it puts patients at risk as well!