Answer to Question #1515 Submitted to "Ask the Experts"

Q

What instrumentation is used in the field to measure electromagnetic fields (EMF) at various distances from the source, for example, a main power distribution panel or electric motor? Are there any standards for safe levels of EMF, particularly for women during pregnancy? Where can I find information about the level of EMF emanating from vacuum cleaners, hair dryers, food mixers, and other common household appliances? What is the type (ionizing/nonionizing) and level of radiation emanating from conventional computer monitors? Would replacement of electron-beam monitors with flat-panel displays eliminate the monitor as a source of radiation?

A

The first place to look for most radiation detection instrument needs is the HPS Buyers Guide.

However, in the case of nonionizing radiation measurements, you may also want to see the Holaday Industries Web site for instruments.

There is a great deal of public interest in and information related to the measurement of electromagnetic fields and their potential biological effects. Unfortunately, there are few definitive human epidemiological studies in this area with low-level exposures. As with ionizing radiation, one must be concerned with the possibility of high exposures in certain occupational settings, and what might be encountered in a typical environmental scenario, within a technological society.

Below are a number of references and standards that may be reviewed online or obtained to become familiar with the physics and protection standards for EMF. The measurements and effects are very dependent on the frequency of the EMF, the physical/biological receptor, and other environmental conditions, for example, grounding. In an occupational setting there are often energy deposition limits set by federal and state labor regulations.

The federal Occupational Safety & Health Administration sets such occupational standards. In summary, there is a great deal of technical information available on the subject of EMF, with many ongoing studies and reviews. Measurements and interpretation of data should be performed by individuals who have specific training and experience in this area.

Information compiled by David J. Allard, CHP