ELF EMF Environmental Surveys

Magnetic fields (the M in EMF) from power lines are an issue of public concern. Various scientific studies in the United States and especially Sweden have documented the carcinogenic health effects of long term magnetic field exposure on children and occupational workers. Recently, Consumer Reports (May 1984) addressed the potential health issues and subsequent impact on property values near transmission lines. The National Energy Policy Act of 1992 (Public Law 102- 486) authorized the Secretary of the Department of Energy to establish a five-year $65 million dollar ELF EMF program to ascertain the affects of ELF EMF on human health, develop magnetic field mitigation technologies, and provide information to the public. The final report will be issued in 1999.

Magnetic fields radiate from transmission and distribution lines, transformers, service wires, electrical panels, appliances (i.e., video display terminals, microwave and electric ovens, hair dryers, televisions, etc.), and even sometimes from metal water pipes (known as plumbing currents) throughout the house. Every home and commercial property buyer should have an ELF EMF survey inspection written into their contract to protect both their health and financial investment. ELF EMF surveys must be performed by a qualified ELF EMF survey engineer (not a home or building inspector). Generally, the electric utility provides free ELF EMF surveys to local customers. However, if you want an independent, unbiased, comprehensive assessment, call a professional ELF EMF survey engineer.

There are two types of residential and commercial ELF EMF surveys: spot and contour. Spot ELF EMF surveys collect data (milligauss-mG) in spots such as the center of each room and selected points around the property and building. Contour ELF EMF surveys use a mapping wheel attached to a programmable gaussmeter to collect three-axis (horizontal and vertical) data (mG) along a contour path at selected intervals. For a typical home (2,500 sq.ft.), ELF EMF spot and contour surveys cost between $150-$300 and $200-$400, respectively. Commercial contour surveys start at $2400-$4800 (2,500 sq.ft.) and range up to $10,000-$25,000 depending on building and property size.

Professional ELF EMF surveys should include triaxial (Resultant-Rrms) milligauss readings around the perimeter of the property and building; from the nearest transmission and distribution lines to the building wall; all rooms within the building; and, selected appliances (microwave/electric ovens, refrigerators, analog clocks, etc.) at 4- and 18-inch intervals. Computer monitors should be measured and comply with the Swedish MPR II & IEEE 1140-1994 standards. And finally the grounding system must not have any excessive and potentially dangerous net (electrical service), ground (rods, telephone & cable), and plumbing currents (metal water service pipe).

After the survey is complete, the ELF EMF survey engineer should issue a final report that includes a drawing of the property, building, nearest power sources, recorded milligauss (mG) readings, and any grounding problems with cited National Electrical Code (NEC) violations. Clients should also receive Risk Assessment Information -- the latest news in ELF EMF scientific research. If the magnetic field levels in the building are significant (greater than 3 mG), then the ELF EMF survey engineer should provide practical mitigation solutions such as: