RADIATION ASSOCIATES

A subsidiary of INNOVATIVE DYNAMICS co.

 

 

DO YOU WORRY ABOUT ELECTRONIC RADIATION IN YOUR HOUSE OR BUSINESS?

 

LET US USE OUR STATE-OF-THE-ART DETECTION TOOLS TO SURVEY YOUR HOUSE OR BUSINESS TO SEE IF THERE ARE ANY “HOT SPOTS” WHERE RADIATION IS NEAR THE GOVERNMENT SET STANDARDS FOR HARM TO YOU, YOUR FAMILY, AND PETS.

 

WE CAN GIVE YOU THE PEACE-OF-MIND YOU DESERVE !

 

Call us for a survey of your house or business facility.  562.866.6997

LAKEWOOD, CA. & GREATER LOS ANGELES AREA

 

 

Electromagnetic radiation (EMR) comes in two (2) forms, ionizing & non-ionizing.  The ionizing type will ionize atoms & break chemical bonds from photons.  This is caused by radiation in the ultraviolet or higher frequencies including X-RAY & gamma rays normally found in radioactive materials.  You need a Geiger counter, scintillation counter, or other nuclear particle detector to measure this radiation. The non-ionizing type will not ionize atoms and is associated with electrical & biological hazards.  These can lead to sparking, magnetic fields, electric fields, induced voltage in conductive materials (like you, your family, and animals).  These fields can dielectrically heat the surface of your skin or your internals (depending on the frequency & amount of radiation applied).  We perform studies for non-ionizing radiation only, using EMF meters.

Electromagnetic (electric & magnetic) fields (EMF) can be problematic from two perspectives: the concern over potential health effects from human exposure, and the disruption to sensitive equipment under high field conditions. Our EMF testing and remediation services can address both issues.

Power LineEMF exposure has become a topic of concern for many people and is an active area of biophysical research. Scientific studies in recent years have shown an apparent correlation between exposure to elevated magnetic field levels and the risk of adverse health effects. The same is true for radio frequency radiation from broadcast and cell phone towers. Significant controversy now exists over the degree of risk posed by this exposure, and the exact mechanisms of interaction by which electromagnetic fields may influence biological processes & alter DNA. Confronted with this uncertain risk, many individuals have chosen to take a cautious approach and limit their exposure where possible. Our services address this environmental health concern by providing site assessment surveys and field reduction services, We take an objective, information based approach to this issue in which clearly defined guidelines have not been established.

Equipment interference and performance degradation is a commonly encountered effect. In this case EMI, or electromagnetic interference, is the terminology usually employed. Sensitive analytical and research instrumentation are most commonly affected. An array of EMI remediation modalities, including active cancellation and shielding, are available to counter this problem.

Since 2000, we have provided cost-effective, technology-based solutions to problems regarding electric and magnetic fields. Our service offerings include commercial and residential EMF testing and mitigation, exposure assessment surveys, EMI (electromagnetic interference) investigations, land use planning analysis, and EMF consulting services.

RF Exposure Measurements
Radio Frequency (RF) EMF testing and measurement is for assessment of human exposure to broadcast and cell tower emissions outside your house or business & servers/routers inside your house or business. We can effectively address the issue of low-level, long-term, non-thermal exposures.

EMF Testing & Measurement Surveys
Normal EMF testing is done in the power frequency range (60 hz).  We can test your facility to determine where high EMF exists.  The ultimate goal of our surveys is to place you in a position to make a responsible and informed decision about the area under evaluation, and to understand the options available for field reduction.

EMF Shielding & Mitigation
Techniques for reduction of the different types and frequencies of electromagnetic field: DC, AC ELF and VLF, RF, and Microwave.

Electrical Wiring Problems
Diagnosis and abatement of net current problems that result in elevated magnetic field levels. Because most electrical wiring errors that create high fields are also code violations, there is a solid rationale for correcting them.

 

 

RF Exposure Measurements & Testing
Cell Tower - FM - TV

The popularity of cell phones and wireless communication devices has resulted in a proliferation of cell towers across the American landscape. Opposition to the placement of these towers has sometimes developed among segments of the population, usually based upon aesthetics, concern over the electromagnetic Cell Tower Radiation Testingradiation, or both.

We can conduct testing and site assessments for individuals, schools, building managers, or municipalities who wish to become aware of the RF levels at a location near cell phone or broadcast towers. The report that we provide will permit comparison of measured levels with FCC Maximum Permissible Exposures (MPEs), precautionary guidelines, and routine background levels for comparable environments. If new antennas or towers are planned for your location, our site survey can be used to establish a baseline RF level for later comparison (before and after testing). Follow-up readings are provided at substantially reduced cost compared to the initial survey.

The purpose of this testing is to empower you to make responsible, fact-based decisions about the RF environment surrounding your community, facility, home, or school. We use advanced state-of-the-art equipment to perform the most accurate and comprehensive RF exposure assessments in the industry. All services are delivered by personnel with several years of experience. If exposure reduction measures are desired, recommendations will be included in the report. The greatest advantage of our surveys over that of other providers is the ability to address the issue of low-level, long-term, non-thermal exposures, and to articulate the scientific rationale for a precautionary exposure guideline.

TV and FM Broadcast TowersWe provide enhanced testing services that involve more detailed data collection, and a more extensive and broader coverage report, than a conventional compliance survey. Our surveys incorporate procedures and equipment to separately measure cellular power density, in addition to the composite power density (the combination of all RF signals present). We use top quality professional equipment, and extensive procedural safeguards, to ensure the highest degree of RF measurement accuracy.

The purpose of our testing services is not to provide a basis for contesting the siting of cell phone towers or to seek their removal once sited.  The RF levels near a cell tower will not approach Maximum Permissible Exposures at ground level where people are present. Further, a court of law is not the best venue for a challenge to the science on which existing standards are based.  The best reason for testing and measurement services is to understand the field levels that exist, and what can be done to reduce them.

 

 

 

 

 

 

 

EMF Measurement Surveys

EMF measurement surveys are usually conducted for one of the following applications:

Evaluation of a residence from an exposure assessment perspective.

Evaluation of a commercial space where equipment is being adversely affected by building electrical systems or other interference (EMI) sources, or where concern about human exposure exists.

For power frequency magnetic fields, different types of survey are offered, depending upon the client's needs. Mapped surveys are suitable for most commercial applications and assessment of outdoor areas near power lines. Data is recorded by a gauss meter for field strength. We use top quality professional equipment, calibrated by the manufacturer, to ensure the highest degree of accuracy.

The fully documented report that we furnish our clients is an important part of each survey, and provides a point of reference for understanding the significance of measurement data. Each report references applicable exposure standards and equipment interference thresholds. The ultimate goal of our survey is to place you in a position to make a responsible and informed decision about the area under evaluation, and to understand the options available for field remediation.

Each professional EMF survey can include a full identification of the source or sources of elevated magnetic fields, radio frequency fields, and/or electromagnetic interference (EMI). This often requires evaluation of feeder imbalance, neutral current diversion, and other net current sources. An analysis of electrical wiring and grounding systems from the standpoint of field production is an essential part of a comprehensive measurement survey. The power control and distribution equipment in commercial buildings can also produce extremely high field intensities even when circuits are balanced and operating properly.

 

Office EMF Survey

 

Measurement Survey near Power Line

 

Land Use Survey Plot

 

 

 

 

Standards vs. Guidelines - The Rationale for Testing

Regulations adopted by the Federal Communications Commission (FCC) in 1996, and fully implemented in 2000, limit human exposure to electromagnetic radiation from cell phone, broadcast, and other radio communication systems. Both U.S. and international standards governing exposure to radio frequency (RF) fields have long existed, and the FCC regulations were adapted from a pre-existing standard. They establish Maximum Permissible Exposures (MPEs) for the full range of frequencies encountered near transmitting equipment, towers, and antennas. These are the formal exposure standards in the U.S., and have full regulatory force.  The allowable limit (MPE), for the general public population agreed to by the US FCC (Bulletin 65), is 0.2 mW/cm2 @ 30-300MHZ & 1 mW/cm2 @ 1500-100000MHZ over a 30 minute time period.  Allowable limits are much less in Europe & Russia (on the order of 1/100th).

For cellular antennas on towers, the level of RF energy that one would realistically be exposed to is usually less than 1% of the MPE. For broadcast towers and building mounted cellular antennas, much higher exposures are possible, although the MPEs are still unlikely to be exceeded in areas accessible to the public. So why are people concerned about cell towers, or RF exposure in general? Is some caution warranted? Three reasons for this concern are recognized:

  1. Some people don't trust the cell phone companies or the government to act with the public's best interest in mind.
  2. Many people equate the potential adverse health effects of cell phone use, which has received a lot of media coverage, with the presence of cell towers. (In reality, the energy that one is exposed to while holding a cell phone to the head is far greater than one is exposed to in the vicinity of a cell tower.)
  3. The existing exposure limitations are based primarily on the avoidance of energy deposition in the body sufficient to cause heating of tissue. More recent research data indicates that some types of radio frequency fields influence cellular function through mechanisms that do not involve heating. Therefore, the existing limitations may be based upon incomplete and outdated science, and thus not fully protective.

To address the issues raised by recent health effects research (outlined in #3 above), it is necessary to look beyond the current exposure limits. Through a review of research on exposure to radio frequency radiation, it is possible to identify a range of numbers below which no adverse effects have been noted (or which have been reported only in limited or questionable studies), and above which potentially adverse effects have been seen. This range of numbers can form the basis for a "precautionary guideline”. The science from which it is derived is not, at this time, sufficient in strength or consistency to permit the revision of existing standards. However, reference to such a precautionary guideline will permit those individuals who seek a level of protection beyond that conferred by existing standards to do so in a rational manner while research proceeds on this important public health issue.

Technical Challenges for RF Site Surveys

Measurement of the emissions from cell towers presents particular technical challenges beyond those encountered for broadcast antenna sites. To understand these challenges, a few comments about radio frequency measurement are required.

Protocols for the measurement of RF energy for the purpose of human exposure assessment often recommend the use of an "isotropic broadband probe" because this type of sensor responds equally to energy arriving from any direction, and over a broad frequency range, as does the human body. These instruments are commonly used because they permit a quick and simple measurement.

Isotropic Broadband Probe and Meter 
Isotropic Broadband RF Meter

A related problem involves the concurrent presence of other signals besides those from the cell phone system. The "broadband" characteristic of the isotropic broadband probe means that it will measure any signals across a wide range of frequencies. The reading produced by the instrument will be the combination of all signals present. In a large number of cases, the other signals present near a cell tower will be as strong as the cellular signals that one is trying to measure. Realistically, this composite measurement of all signals may be the most relevant exposure metric, but an interpretation of the significance of a reading sometimes requires that one know the frequency of the signal that produced it. For instance, is it FM, TV, cellular, or something else?

One of the most significant RF measurement problems, and one responsible for some of the greatest inaccuracy, involves an instrument erroneous response that can occur when there are two or more strong signals present at the same time. A very large proportion of antenna sites (cell and broadcast) now have multiple strong signals. Instrument design can minimize this problem, but many of the commonly used isotropic broadband meters perform very poorly in this multi-signal environment. The result is a reading that is much higher than actual, sometimes double (100% error).

An additional challenge results from the fact that power density levels at a cell tower site are not always constant, as they usually are at a broadcast antenna site. People use their cell phones more at some times of the day, and on some days of the week, than at others. The cellular service providers maintain additional capacity in the form of multiple channels which will become active as needed to meet demand. Each active channel adds to the measured power density at the cell site. The variable nature of power density levels at some sites must be taken into account.

           

Calibrated Broadband Antenna               

EMF Shielding & Mitigation Alternatives

EMF shielding is a broad term with diverse meanings, primarily because there are many different types of EMF (electric and magnetic fields, RF electromagnetic fields, different frequencies, different sources). It is important to realize, however, that shielding is not applicable to all problems, nor is it always the most cost-effective solution. A large proportion of those who are looking for EMF shielding would be better served by an alternative approach, such as field cancellation (active EMF shielding), or correction of net current problems in electrical wiring systems.

This page will describe some different types of field, and the EMF mitigation techniques used to control it. It will also explain circumstances where shielding is ineffective, and discuss alternative approaches. The concepts are the same whether the purpose is limiting human exposure (protection for people), or preventing electromagnetic interference (protection for sensitive equipment).

Type of Field
(Frequency)

Typical Sources

Shield or
Other Solution

ELF Magnetic
(50/60 Hz)

Electrical Panels
Electrical Switchgear
High Current Feeders
Transformers
Utility Electric Meters

Passive Magnetic Shielding with Bulk Materials - often a combination of high conductivity and high permeability metal plates.

Power Lines
Unbalanced Feeders and
  Branch Circuit Wiring
Current on Water Pipes
Unbalanced Underground
  Distribution Lines

Magnetic Field Cancellation
  (Active EMF Shielding)

Restore Circuit Balance

ELF Electric
(50/60 Hz)

Power Lines
Type NM Wiring
Fluorescent Lighting

Easily shielded with any grounded conductive barrier, from metal screen to a row of trees. Electric fields are most commonly a problem for electrosensitive people.

RF (radio frequency)
electric, magnetic,
plane wave
(100 KHz - 100 GHz)

Broadcast Transmitters
Mobile Two-Way Radio
Cellular and PCS Systems
Radar
Microwave Systems
RF Heat Sealers
Medical MRIs
Electrosurgery Equipment
Diathermy Equipment
Navigational Systems

Mitigation method varies widely depending upon frequency and required field attenuation. Generally involves the complete enclosure of a space by metallic or conductive materials, with special attention to shield penetrations such as doors, vents, and cables.

VLF Magnetic
(3 KHz - 100 KHz)

Induction Heating Systems
Computer Monitors
Retail Anti-Theft Systems
Electrical Transients

Passive Shielding with Bulk Materials - less material thickness required than for equivalent ELF field.

VLF Electric
(3 KHz - 100 KHz)

Corona Treating Systems (modified)

Easily shielded with any conductive barrier, such as metal foil. Industrial sources can exceed established exposure guidelines.

DC Magnetic
(0 Hz, non-time-varying)

MRIs
Aluminum Refining

Passive Shielding with Bulk Materials - often steel plate or high permeability layered metal sheet.

Radio frequency shielding was the first fully developed EMF shielding application, and is widely used in many different forms. Two broad categories of utilization are recognized: (1) protection of sensitive equipment (or people) from high intensity electromagnetic fields, and (2) prevention of signal escape from secure facilities where secret or classified information is processed. The primary design considerations are the frequencies to be shielded and the required attenuation, or degree of shielding effectiveness. Types of material utilized range from conductive coatings and fabrics to a fully welded steel enclosure (or Faraday Cage). Modular EMF shielding systems with proven performance characteristics are also available.

Power frequency magnetic shielding is what many people have in mind when they are looking for an EMF shield. It has become common in areas of commercial buildings near the power control and distribution equipment. Conventional CRT type computer monitors exhibit noticeable and often very distracting jitter or flickering under high field conditions. Once the problem is identified, human exposure concerns can become an issue as well. This type of shielding is moderately expensive for large areas, but if space is at a premium, the cost can often be justified. It is essential to ensure that the problem is not the result of a net current condition or wiring error, since shielding is not effective for these conditions, and because this form of EMF mitigation is far less expensive. In many cases, however, magnetic shielding is the only viable solution.  Equipment sometimes requires isolation from external magnetic fields. For static or slowly varying magnetic fields (below about 100kHz) Faraday shielding is ineffective. In these cases shields made of high magnetic permeability metal alloys can be used, such as sheets of Mu-metal or with ferromagnetic metal coatings. These materials don't block the magnetic field, as with electric shielding, but rather draw the field into themselves, providing a path for the magnetic field lines around the shielded volume. The best shape for magnetic shields is thus a closed container surrounding the shielded volume.

It is important to realize that a shield can be completely effective against one type of field and not at all effective against another. For instance, a well performing RF shield of copper foil or screen would be minimally effective against power frequency magnetic fields. Likewise, a power frequency magnetic shield could provide excellent reduction of 60 Hz fields, but offer little reduction of radio frequency fields. The same is true for different RF frequencies. A simple large-mesh screen shield would work well for lower frequencies, but would be ineffective for microwaves.

We can evaluate your problem and propose an appropriate and cost-effective solution, which may or may not involve shielding. We handle most mitigation projects directly, but if your application would be best served by a particular type of shielding specialty contractor, we can provide a referral to reputable companies with a track record of successful jobs. The starting point in most cases is a site survey.

 

 

 

 

 

Electrical Wiring Problems and High Magnetic Fields

Subpanel Electrical Problem - 
Click for More Photos

High magnetic field environments are created more frequently by electrical and grounding system problems than by any other source. This is true in both residential and commercial buildings. The problem usually results from unbalanced and improperly wired feeders and branch circuits. The elevated magnetic fields that result from this imbalance can be a source of electromagnetic interference (EMI) or concern over human health effects.

Since these wiring problems usually manifest no overt functional deficits in the electrical system, they often escape notice, but they are immediately apparent when an AC magnetic field meter is used. In areas (or entire buildings) where such problems exist, magnetic field levels are dramatically higher. Readings of 5 -20 mG (milligauss) are not uncommon, and occur whenever the circuits involved are in use (and with some problems, even when they are not). Fortunately, these conditions are fully correctable. The problem must be traced out, located, and rewired in a proper and code compliant manner. Conventional magnetic shielding with metal plates is ineffective for current imbalance problems.

Here is a basic explanation of how an elevated magnetic field is produced by a circuit imbalance. Most of the wiring in homes and commercial buildings consists of cables containing two or more current-carrying conductors (or conduits containing multiple conductors). At any point in time, an equal current is flowing in one direction on one wire, and in the opposite direction on another wire. Since these wires are very close together inside the cable jacket or conduit, the magnetic field around one wire is cancelled by the opposite magnetic field around the other wire. The field drops to a negligible level a few inches from the wires. In this case there is no net current on the circuit, and a clamp-on ammeter placed around the cable or conduit will indicate zero current.

Problems occur when this balance is negated by improperly wired circuits. Common examples are:

·         neutrals from separate branch circuits that are connected anywhere beyond the point of origin

·         neutral-ground shorts (intentional or inadvertent) anywhere in the system

·         improperly wired subpanels (a form of N (neutral) - G (ground) short)

·         incorrect three-way switch wiring where the hot and neutral are fed to different points in the circuit

Electrical Wiring Error - 
Click for More Photos

In each case, a portion of the normal utilization current is caused to flow over an alternate path, creating an imbalance, or net current, on two or more circuits. A clamp-on ammeter placed around the cable or conduit of such a circuit will indicate a substantial current (often 1 to 10 Amps). It is not unusual to find multiple wiring errors in new construction, and inspections conducted by local code enforcement authorities will not detect the great majority of these problems.

Although most types of electrical code violation do not create elevated magnetic fields, virtually all wiring errors that create high fields are code violations, usually of NEC Articles 250.24(A)(5), 250.142(B), and 300.3(B)(1). Thus, there is a solid rationale for correcting and avoiding these common problems which extends beyond magnetic field reduction. Any site survey should be conducted in a manner that will detect and document them. Our personnel have extensive experience in the correction of electrical wiring errors. All problem resolution services are delivered by licensed general contractor, with over 20 years of EMF remediation experience.