Electrical Sensitivity

A Comprehensive Approach to Abatement

http://www.emfservices.com/sensitivity.htm

Electrosensitivity, or electrical hypersensitivity, describes a condition where individuals experience discomfort or adverse health effects near equipment or devices which produce electric and magnetic fields (EMFs). On this page, we have delineated four broad areas that often require attention by individuals who manifest electrical sensitivity. Not all people will need work in all areas. The approach presented here describes alterations to the physical environment to reduce or eliminate electrical phenomena thought to be a problem. Other sources have suggested that approaches directed toward altering the biology of the electrosensitive individual can also be helpful.

1.0 Power Frequency Electric Fields

Most people who describe themselves as electrically sensitive have a sensitivity to at least electric fields, and often to other fields as well. Electric field suppression can be time consuming and expensive, but for those who need it, this work can make a profound difference in comfort level. The fields that are most often a problem for individuals with electrical hypersensitivity arise from electrical wiring within the building, or from appliance wiring. Although power frequency electric fields can be measured directly, the preferred approach for this type of work is "body voltage testing," which is actually a very sensitive method for measuring the weak electric fields inside a room. The corrective measures described below for electric fields apply to abatement work in existing buildings. In new construction, a very large savings of time and material cost is possible if the right approach is taken from the beginning. (See Low EMF Home Design.)

Corrective measures:

1.1   Electric field shielding, using conductive paint, mat, or screen.

1.2   As an alternative to 1.1, replace all existing wiring with armored cable. (This is usually impractical and extremely expensive unless remodeling work is in progress.)

1.3   Shield all appliance sources.

1.4   Eliminate elevated neutral to ground voltage on the building electrical system through proper grounding, as described in 3.1 below.

1.5   Other techniques, as required, to achieve adequate field suppression in sensitive areas such as bedrooms.

2.0 Power Frequency Magnetic Fields

Magnetic fields are present wherever electricity is in use, and emanate from power lines, appliances, electrical wiring, etc. Many people who suffer from electro-sensitivity experience discomfort in the presence of these fields. In addition, extensive epidemiological studies have correlated long-term exposure to power frequency magnetic fields with a small increased risk of serious health conditions. Magnetic fields are measured with an AC gaussmeter.

Corrective measures:

2.1   Eliminate plumbing current (neutral current diversion) problems.

2.2   Eliminate all "net currents," or current imbalance problems, on electrical circuits in the building.

2.3   Magnetic shielding for high current point sources, such as electrical service panels.

2.4   Active magnetic cancellation for power line fields, and other off-site fields.

2.5   Under some circumstances, magnetic fields from sources outside the home cannot be adequately controlled, and relocation may be necessary.

3.0 Higher Frequency Fields - Conducted

This usually refers to multi-frequency electrical noise that is conducted into your home wiring system through the power feed and grounding system, or generated within the house by dimmer switches or motorized appliances, and then radiated from the wiring in a form (type of field) consistent with the frequency of the signal. If high power broadcast transmitters are close by, their RF signal will also ride in on the power feed. Specific measurement techniques exist to assess high frequency conducted interference, such as VLF/MF/RF spectral analysis, transient monitoring, and electrical noise measurements. Addressing these issues is an important part of electrical hypersensitivity abatement.

Corrective measures:

3.1 Improve the grounding at your house. The power company neutral in the electrical feed to your house is connected to ground for multiple reasons, but the ones that are significant for electrosensitivity reasons are to conduct high frequency noise and transients to ground, and to stabilize the neutral-to-ground voltage. Incoming neutrals can carry a lot of electrical noise, and this noise will be radiated from the electrical grounding network that extends throughout the house as part of the wiring. A good low resistance ground is essential to eliminate this problem, and the 25 ohm maximum required (allowed) by the NEC is inadequate. A maximum should be 10 ohms, and lower is better. In cases where this type of problem is severe, and grounding is difficult, an electrolytic ground will usually provide sufficiently low ground resistance.

3.2 Install a good EMI filter on the incoming power feed to suppress noise on the line conductors. The plug-in capacitors that are now being marketed by some "electrical sensitivity consultants" are a low cost, but somewhat effective, alternative to an actual EMI filter, but they need a good ground as described in 3.1 above to be fully effective. In addition, they must be connected into the electrical system at the right location. Simply plugging them in everywhere throughout the house can increase the level of some types of emission, and cause more harm than good.

4.0 Higher Frequency Fields - Radiated