"There is no question that video display terminals (VDTs) make many tasks easier," reports the Harvard Medical School Health Letter, "but they do not necessarily make a job easier, more pleasant or healthier."

Health hazards associated with VDT use fall into four categories:

1. Alleged radiation hazard--"On the basis of existing evidence," the newsletter concludes, "there appears to be no radiation hazard from VDTs." Concern about possible reproductive difficulties, however, has prompted the National Institute for Occupational Safety and Health to undertake a study of pregnant women who work with VDTs. The results are expected to be released in about two years.

2. Visual difficulties--"More than half of VDT operators have eye complaints, mainly irritation, fatigue or difficulty with focus or accommodation. When VDTs create visual difficulties for operators, it is usually because they are located in improperly designed work areas."

To minimize the problem: VDTs should be in a glare-free position and have brightness and contrast controls the operator can adjust. Room lighting should be low if the operator looks mostly at the screen, and relatively bright if the operator mostly reads from a paper and enters material into the computer.

3. Job stress--"The frequency of complaints about VDT use is higher than in any other work situation . . . Over 75 percent of (users) have physical or stress-related complaints attributable to the use of the terminal." Most stem from "lack of planning."

Among the solutions: Proper training, reasonable workload, more variety and flexibility, less monitoring by supervisors.

4. Musculoskeletal difficulties--"A long period of sitting puts a strain on the back and neck, slows circulation in the legs and generally reduces muscle tone. To compensate . . . frequent breaks are advisable."

Computer Calisthenics: Users suffering from keyboard cramps and other word processor woes might check out "Tone Up at the Terminals," a new exercise guide featuring an array of do-at-your-desk stretches designed to combat techno-stress associated with VDT use.

Developed by Verbatim Corporation--the world's largest supplier of flexible computer disks--the free 12-page booklet features 20 exercises designed and demonstrated by Los Angeles exercise physiologist Denise Katnich. Among the routines:

* Hug yourself. "Cross arms in front of chest and reach fingertips toward your shoulder blades."

* Back Relaxer. Sit on chair. Drop your neck, shoulders and arms, then bend over from the waist as far as you can. Return to upright position, straighten out and relax.

For a free copy, send a self-addressed, legal-size, stamped envelope to Verbatim Corpor., Tone Up at the Terminals, 323 Soquel Way, Sunnyvale, Calif. 94086.

VDT Hotline: In the last few years, a disturbing number of problem pregnancies and reproductive disorders among VDT operators has surfaced, reports 9 to 5, the National Association of Working Women, which has launched a new VDT hotline.

"We cannot afford to wait," says executive director Karen Nussbaum. "While scientists argue over possible causes and links, millions of men and women are sitting in front of these terminals."

Operators at 1-800-521-VDTS will send information about VDTs and health and will gather information to support the need for more study of the possible link between pregnancy problems and VDT work.