EMI Testing in a Healthcare Facility by EMF Testing USA

A recent study was done for electromagnetic fields and radiofrequency field interference with the proper functioning of a Medtronic implantable cardiac defibrillator or pacemaker by Stuart D Bagley, MS, CIH of EMF Testing USA.  The study was conducted at a  hospital in South Carolina.

The following table shows EMI sources taken that exceed guidelines at close range and a “safe distance” where the affected heart device patient will not suffer ill effects from EMI.  These areas require precautions for heart device patients with cardiac implants.  In this building essentially similar pieces of equipment were not tested because similar pieces of equipment are known to produce nearly similar test results.

Areas Exceeding EMI Guidelines as Measured

Ortho Surgery Suite Electro Surgical UN27 Bovie “Valley Lab Force Triad” Outside of Electro Surgical Suite

(or 6 feet minimum)

Ortho Surgery Suite Arthrocare Quantum 2 Outside of Electro Surgical Suite

(or 6 feet minimum)

Heart Surgery Lab Medtronic Magnet for Pacemakers

one foot minimum

Discussion of Results

Two surgical tools in use at the hospital employ powerful radiofrequency emissions to cut and cauterize tissue. The “Electro Surgical UN27 Bovie “Valley Lab Force Triad” has a 472 kHz radiofrequency emission.  The “Arthrocare Quantum 2” has a 100 KHZ radiofrequency emission.  Both instruments are problematic for a heart implant patient at close range.

Measurements exceeding 2.65 mW per cm2 are problematic for a heart device patient.  Some of the measurements exceeded 40 mW per cm2, even at a distance of three feet.  This presents a significant risk for the heart device patient.  See the table in the appendix for more details.

Note that the highest readings are taken at or near the electromagnetic field source and that readings drop off with distance from the component.  Lead metal and lead aprons do not offer sufficient protection from radiofrequency emissions in the Electro-Surgical Suite.

Photographs at the Hospital Electro-Surgery Suite

Valley Lab Force Triad

Arthrocare Console

Arthrocare Hand Piece

Valley Lab Force Triad with Active Electrode Arthrocare console and hand piece Arthrocare Hand Piece

Return Electrode

Active Electrode

Force Triad Spec Label

Demonstration of Return Electrode Placement Close-up Active Electrode Force Triad Console Spec Label

Aquamantys Spec Label

Lead Apron

Linvatec Tower

Aquamantys Console Spec Label Lead Apron

Linvatec Tower with Arthrocare Console



Recommendations

Recommendations are made to protect the patient.  They are designed to prevent the subject heart device patient with an implanted cardiac device from coming in contact with strong electromagnetic or radio frequency fields.

About EMF Testing USA[1]

Stuart Bagley is a senior consultant from EMF Testing USA, a consulting firm in the area of electromagnetic fields testing.   Mr. Bagley has extensive knowledge of electromagnetic fields and exposure limits.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.

Mr. Bagley is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 30 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.


[1] EMF Testing USA, www.EMFTESTING.net, (800) 862-9655

Report on EMF in an Urban Setting

This is a report on the electromagnetic field (EMF) measurements at a brownstone home in New York City, NY.  The brownstone home located in New York City, NY was assessed for EMF (electromagnetic fields) exposure with regard to potential to exceed published WHO[1], US State Limits[2], ICNIRP[3], IEEE[4] guidelines and medical guidelines (for cardiac implanted devices).  The property is adjacent to an electrical utility substation on it northwest side as seen in the photo below.

Substation Building

Living Room

West 16th St. & Substation Building

Living Room of Home

Discussion of Results

The test results indicate that some locations inside or outside of the building property exceeded “WHO” Guidelines but no other guidelines.  WHO Guidelines are based on a study that pertains to leukemia in children (only).  There is no published evidence of adult leukemia at these levels.  WHO levels are hypothetical and are used only in evaluations where children may be present.

Note that the highest readings are taken at or near the source of EMF and that readings drop off rapidly with distance from them No location in the Brownstone home exceeded any individual US State Government Guidelines, the IEEE Uniform Electric and Magnetic Field Maximum Permissible Exposure Levels or the ICNIRP Guidelines for EMF Exposure.  See the acronyms below with further details.  These are published “consensus standards” or are local US state level guidelines.

Recommendations

Exposure levels are not usually elevated.  However attenuation of current exposure levels is possible through structural modifications.  Building materials provide a considerable amount of shielding.   Shielding materials that reduce the magnetic and electric fields can be incorporated into the construction of the building on the sides facing the substation to reduce the EMF if so desired.

About EMF Testing USA

Stuart Bagley is a senior consultant from EMF Testing USA, a consulting firm in the area of electromagnetic field testing, www.EMFTESTING.net.  Mr. Bagley has extensive knowledge of IEEE and ICNIRP EMF standards and policies.  He is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 30 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.

[1] WHO – World Health Organization, “Electromagnetic fields and Public health, Exposure to Extremely Low Frequency Fields”, Environmental Health Criteria, Vol. 238. Geneva, World Health Organization, 2007.

[2] National Grid EMF – EMF exposure limits in the USA, 2010

[3] ICNIRP 2010 Exposure Guidelines, International Commission on Non-Ionizing Radiation Protection (ICNIRP) 2010 Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz), Fact Sheet On ICNIRP 2010 Guidelines, Health Physics 99(6): 818-836; 2010.

[4] IEEE Standard for Safety Levels With Respect to Human Exposure to Electromagnetic Fields, 0 to 3 kHz (2002), General Population  Exposures, Institute of Electrical and Electronics Engineers (IEEE).  IEEE PC95.6-2002. Prepared by Subcommittee III of Standards Coordinating Committee 28, IEEE Standards Department. York: Institute of Electrical and Electronics Engineers, Inc.; 2002.

EMI at Fisher Tank Company

This is a report on the electromagnetic interference (EMI) measurements at the Fisher Tank Company in Jacksonville, Florida.  Fisher Tank Company requested a survey be done for electromagnetic field (EMI) and radiofrequency field (RFI) with regard to potential for interference with the proper functioning of an implantable cardiac defibrillator or pacemaker.

Results indicate that a number of pieces of equipment have the potential to exceed recommended guidelines of Boston Scientific CRM for cardiac implant devices for exposure to electromagnetic fields when the affected employee is in close proximity.  The survey and report were done by Stuart Bagley, MS, CIH, CSP of EMF Testing USA.

Photographs of the Jacksonville Site

Welder close up
New Tank Under Construction Worker Near Arc Welder Welder Up Close
Trailer with Generator & Welders Welding Leads
Trailer with Generator & Welders Welding Leads and 110V Wiring

Discussion of Results

Several pieces of equipment that exceeds Boston Scientific CRM Guidelines in the location tested.

The following are three principal types of interference with implanted cardiac devices:

  • Conducted interference …
  • Radiated fields …power lines, radio transmission towers, or two-way wireless communication equipment.
  • Static magnetic fields are those produced by a permanent or direct current (DC) electro-magnet.

Recommendations

Recommendations are made in an effort to comply with Boston Scientific CRM Guidelines (see attachment to this report).  They are designed to prevent the subject employee with an implanted cardiac device from coming in contact with strong electromagnetic or radio frequency fields.  The final course of action with regard to the employee in the workplace is at the discretion of the employer, physician and employee.

Recommendations are as follows:

  1. Maintain a suggested distance from all other sources exceeding guidelines.
  2. The affected employee must take reasonable precautions …
  3. Caution signs “Danger to Cardiac Pacemaker” can be placed on those machinery or components that exceed Boston Scientific CRM guidelines …
  4. Discuss this report with the affected persons including the employee, his physician and Boston Scientific CRM, the heart device manufacturer.
  5. Train the employee …

Potential Effects of Exposure to EMI

EMI of sufficient strength may lead to the following temporary device behaviors:

  1. Asynchronous pacing (pacing independent of underlying cardiac activity)
  2. Inhibition of pacing (pacing therapy not provided when needed)
  3. Ventricular pacing at Maximum Tracking Rate
  4. Inhibition of tachyarrhythmia therapy (shock therapy not provided when needed)
  5. Inappropriate shocks (shock therapy provided when not needed)
  6. Deactivation of tachyarrhythmia therapy.  The impact to device function is typically temporary.

About EMF Testing Services

Stuart Bagley is a senior consultant from EMF Testing Services, a consulting firm in the area of workplace health and safety, www.EMFTESTING.net.  Mr. Bagley has extensive knowledge of Boston Scientific CRM standards and policies.  He is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 30 years of experience in environmental health.

EMI and Heart Device Safety at “Acme” Dairy Company

Even a wholesome dairy has safety concerns for those with a pacemaker/defibrillator, therefore the “Acme” Dairy Company” requested a survey be done for electromagnetic field (EMI) and radiofrequency field (RFI) with regard to potential for interference with the proper functioning of a St. Jude Medical implantable cardiac defibrillator or pacemaker.  The results indicated a number of the field measurements taken exceeded St. Jude Medical Guidelines for cardiac devices.

Recommendations based on the testing results are made in an effort to comply with St. Jude Medical Guidelines and are designed to prevent the employee with an implanted cardiac device from coming in contact with strong electromagnetic or radio frequency fields.  The final course of action with regard to the employee in the workplace is at the discretion of the employer, physician and employee.

Recommendations are as follows:

  1. The affected employee must take reasonable precautions or be restricted from entering the areas exceeding guidelines shown in the facility, based on EMI survey results.
  2. Caution signs “Danger to Cardiac Pacemaker” can be placed on those machinery or components that exceed St. Jude Medical Guidelines in order to provide a warning to the affected employee.
  3. Because of the nature of electrical work, physical interaction or manipulations with live circuits or switches that have the potential for any electrical shock or inducing electrical current passing through the human body must be handled with adequate precautions such as protective gloves, etc.
  4. Train the employee on the effects of exposure of his implanted cardiac device to strong electromagnetic and radiofrequency fields.  Training should include how to minimize EMF exposures during the course of their work such as maintaining adequate distance from the source as well as de-energizing and locking out of equipment.
  5. Cellular phones are preferred over two-way radios for two-way communication since they radiate less radiofrequency energy when in use by a heart patient.

About EMF Testing USA
Stuart Bagley is a senior consultant from EMF Testing USA, a consulting firm in the area of electromagnetic fields http://www.emftesting.net.   Mr. Bagley has extensive knowledge of electromagnetic fields and exposure limits.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.

Mr. Bagley is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 25 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.


iPad2 and CRD Interference

In an article for Interference Technology, author Aliza Becker has written about a study presented at Heart Rhythm 2013 by high school freshman Gianna Chien.  This study suggests that the magnets embedded in the body and accessories of Apple’s iPad 2 tablet computers may interfere with implanted cardiac rhythm devices (CRD) and could potentially kill a user in their sleep.  The fourteen-year-old high school freshman of Stockton, Calif. made her presentation—initially organized as part of a school science fair project—to more than 8,000 doctors at the Heart Rhythm Society’s 34th Annual Scientific Sessions conference in Denver, Colorado.

iPad 2

As a safety precaution, implanted defibrillators are designed to turn off in the presence of external magnets, with most—but not all—turning back on once the magnets have been removed. While the magnets in Apple’s iPad 2 tablets, “Smart Cover” and “Smart Case” accessories are not powerful enough to cause problems when the device is held in front of the chest, it can be dangerous to rest it against the body, Chien said. If a person with an implanted defibrillator falls asleep with the tablet on their chest, it can disrupt and “accidentally turn off” the cardiac implant, resulting in the suspension of antitachycardia therapy.

For the study, a total of 19 participants with CRDs were studied at the time of the presentation, including 16 subjects with defibrillators, two subjects with pacemakers and one subject with a loop recorder. Participants were asked to hold the iPad 2 at reading distance and on top of their chests to mimic falling asleep while using the device. The effect of the iPad 2 on CRDs in their original packaging was also assessed.

iPad2 with smart cover

According to Chien, “magnet mode” was triggered 18.8 percent of patients with defibrillators who placed the iPad 2 against their chest. Two participants reportedly “exhibited magnet mode trigger, while an additional subject exhibited magnet mode trigger followed by initiation of the non-invasive program stimulation mode.” No noise or oversensing was noted in the packaged or implanted CRDs, and no effects of any kind were observed in the pacemakers or loop recorders.
Apple declined to comment on the results of the study, instead referring questions regarding the iPad 2’s safety to the online product guidewhich cautions about radio frequency interference and suggests users with pacemakers, defibrillators or other implanted medical devices keep the device at least six inches away from their chest.

Medtronic Inc. said in a statement that current testing completed by the company shows no risk of interference between iPad technology and Medtronic implanted cardiac devices when used according to the manufacturer’s instructions, but advised patients with an implanted cardiac device to follow Apple and Medtronic labeling recommendations and maintain a distance of six inches between the iPad and implanted device “as a precaution.”  A statement from St. Jude Medical was not available at press time.

Chien hopes her findings will encourage patients with implanted defibrillators to talk to their doctor about precautions to take when using an iPad 2.

Stuart Bagley, MS CIH CSP is a senior consultant and owner of EMF Testing USA, a consulting firm in the area of electromagnetic field testing.  Mr. Bagley has extensive knowledge of heart device standards and potential problems resulting from excessive EMF.  He is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 25 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.

Electromagnetic Fields Study at a Nuclear Plant, High Voltage Lines

An interesting study was done in 2013 on the electromagnetic interference (EMI) measurements at a Nuclear Power Generation Facility with adjacent high voltage power lines. In particular, employees with implanted medical devices, such as a cardiac defibrillator or pacemaker or an electronic insulin pump can be affected by the electromagnetic fields (EMF) generated.

Results showed that a number of the field measurements taken in the parking lots near high voltage power lines at the APS Palo Verde Nuclear Power Generation Facility exceeded the limits set for some implanted medical devices.

The results also showed that the magnitude of the field strength is influenced by distance from the power line and the voltage carried by those lines, as expected by the “inverse square” law of physics.

Areas with elevated levels of E and H Fields can affect medical implanted devices electronic medical devices. Since the lowest threshold for EMI for the so-called E-field (also sometimes called the “B-field”) is 1000 Volts per meter (V/m) (specifically for a Boston Scientific implanted cardiac device), any measurement exceeding that number requires precautions. Note that only the electric field exceeded heart device guidelines and not the magnetic field. Photos of the Parking Lot Measured for EMI There were numerous areas in the parking lots that exceeded heart device guidelines at the Nuclear Power Generation Facility. The highest readings are taken at or near the electromagnetic field source and that readings drop off with distance from the component. The readings taken represent current day exposures. The exposure levels may be subject to change depending on the type and operating condition of the equipment.

Recommendations
1. The affected employee(s) must take reasonable precautions.
2. Caution signs and labels such as “Danger to Pacemaker…”
3. Discuss this report with the affected persons including the employee and his physician.
4. Train the employee on the effects of exposure.

About EMF Testing USA:
Stuart D Bagley is a senior consultant from EMF Testing USA, a consulting firm in the area of electromagnetic fields. Mr. Bagley has extensive knowledge of electromagnetic fields and exposure limits. He has conducted numerous electromagnetic field investigations at client sites throughout the United States. Mr. Bagley is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 30 years of experience in environmental health. He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.<

Coal Mine EMF Case Study

Buckingham Coal Company located in Corning, OH requested a survey be done for electromagnetic field (EMI) and radiofrequency field (RFI) with regard to potential for interference with the proper functioning of a Medtronic CRDM implantable cardiac defibrillator or pacemaker.  Various pieces of machinery within the mine offered potential problems for employees with this heart device.     

 
A survey was done for electromagnetic fields and radiofrequency fields by Stuart Bagley, MS, CIH of EMF Testing USA with the assistance of personnel from Buckingham Coal Company.  Results indicate a number of the field measurements taken at The Buckingham Coal Mine exceeded Medtronic CRDM Guidelines for cardiac devices as shown in the tables below.

   

   

Outside of Mine No. 6   

 Mining Machine   

  

EMI Monitoring Results

Areas Exceeding Guidelines  
Building or Department  Work Station  Safe Distance 
Prep Plant  Flock Pumps  12 inches 
Prep Plant  Welder Floor is Ground Plane  off limits 
Shop  Welders Mug  and Stick  off limits 
Shop  Portable AC or DC Tools Drills/Grinders  off limits 
Shop  Hand Held Radio Motorola CP200  12 inches 
Shop  Mine Site Radio  12 inches 
Pit 6 NE Underground  #2 Belt Transformer 7200 VAC/480 VAC  12 inches 
Pit 6 N2 Section 1  Feeder Cable 480 VAC  12 inches 
Pit 6 N2 Section 1  Feeder Cable  12 inches 
Pit 6 N2 Section 1  Fault Wizard  12 inches 
Pit 6 N2 Section 1  Bread Crumb  12 inches 

The following are three principal types of interference with implanted cardiac devices:        

1.      Conducted interference occurs when the affected employee is in direct contact with the electrical source.  The most risk and actual accounts have occurred from poorly maintained electrical equipment.  Conducted currents should be avoided.  Physical interaction or manipulations with live circuits or switches is not recommended for anyone with a cardiac implanted device.
  
   
2.      Radiated fields are those signals which propagate through the air and may potentially induce current that can be detected by the implanted device.  Common sources of these fields include high-voltage power lines, radio transmission towers, or two-way wireless communication equipment.
     
3.      Static magnetic fields are those produced by a permanent or direct current (DC) electro-magnet.   None were encountered on this visit.   
Normally equipment is operated with protective covers and shielding in place.  Energized equipment will tend to produce higher readings (both EMI and RF) when protective covers and other shielding are removed.  For purposes of estimating potential employee exposure to EMI, similar types of equipment not tested should be assumed to produce approximately similar results to those tested. 
       

Recommendations are as follows: 
1.    The affected employee must take reasonable precautions or be restricted from entering the areas exceeding guidelines shown in the facility, based on EMI survey results.  At a distance exceeding the safety distances listed in the tables, the employee is considered to be at a safe distance from the above sources. Caution signs “Danger to Cardiac Pacemaker” can be placed on those machinery or components that exceed Medtronic CRM Guidelines in order to provide a warning to the affected employ.
   
2.      Because of the nature of electrical work, physical interaction or manipulations with live circuits or switches that have the potential for any electrical shock or inducing electrical current passing through the human body must be handled with adequate precautions such as protective gloves, etc.
     
3.      Discuss this report with the affected persons including the employee and his physician.  Train the employee on the effects of exposure of his implanted cardiac device to strong electromagnetic and radiofrequency fields.  Training should include how to minimize EMF exposures during the course of their work such as maintaining adequate distance from the source as well as de-energizing and locking out of equipment.
   
4.      If these measures are not adequate to modify their job duties so that they may avoid overexposure or it may be necessary to permanently reassign the employee to a position or job task where they will not have exposure to strong electromagnetic fields.
   
About EMF Testing USA   
Stuart Bagley is a senior consultant from EMF Testing USA, a consulting firm in the area of electromagnetic fields.   Mr. Bagley has extensive knowledge of heart device guidelines and policies.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.
   
Mr. Bagley is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 25 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.     

     

 
 

 

        

            

EMF Power Line Case Study

Chicago, IL
Chicago, IL

An electromagnetic field (EMF) and radiofrequency field (RF) survey was requested for a home located in Chicago, IL.  The area is in close proximity to high voltage overhead power lines.  The survey and report were done by Stuart Bagley, MS, CIH, CSP of EMF Testing USA .  The results indicated that there were only a few instances of exceeding of other states’ guidelines (The State of Illinois does not have guidelines.  See state guidelines below).

 State Transmission Power Line Guidelines
The following state transmission power line standards for EMF exposure are in effect.  There is no power line standard for the State of Illinois

State Transmission Power Line Standards
  Electric Field Magnetic Field
State On R.O.W.* Edge R.O.W. On R.O.W. Edge R.O.W.
Florida 8 kV/ma
10 kV/mb
2 kV/m - 150 mGa (max. load)
200 mGb (max. load)
250 mGc (max. load)
Minnesota 8 kV/m - - -
Montana 7 kV/m 1 kV/me - -
New Jersey - 3 kV/m - -
New York 11.8 kV/m
11.0 kV/mf
7.0 kV/md
1.6 kV/m - 200 mG (max. load)
Oregon 9 kV/m - - -
*R.O.W. = right-of-way (or in the Florida standard, certain additional areas adjoining the right-of-way).
kV/m = kilovolt per meter. One kilovolt = 1,000 volts.
a For lines of 69-230 kV.
b For 500 kV lines.
c For 500 kV lines on certain existing R.O.W.
d Maximum for highway crossings.
e May be waived by the landowner.
f Maximum for private road crossings.

 EMF Monitoring Results
Readings taken usually represent the peak reading at the location tested.  Using this table, the lowest acceptable exposure to low frequency power sources magnetic field is 150 mG measured at the edge of the Right of Way and 1 kV/m or 1000 volts per meter for the electric field.  This is the lowest published guideline for power line exposure in the table below. 
The United Nations World Health Organization (WHO) references a study indicating health issues at 3 to 4 MilliGauss (WHO | Electromagnetic fields and public health, Electromagnetic fields and public health, Exposure to extremely low frequency fields, Fact sheet N°322 June, 2007).  In 2002, IARC published a monograph classifying ELF magnetic fields as “possibly carcinogenic to humans”. This classification is used to denote an agent for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence for carcinogenicity in experimental animals (other examples include coffee and welding fumes). This classification was based on pooled analyses of epidemiological studies demonstrating a consistent pattern of a two-fold increase in childhood leukemia associated with average exposure to residential power-frequency magnetic field above 0.3 to 0.4 µT. (which equals 3 to 4 MilliGauss (mG)). 
Uncertainties in the hazard assessment include the role that control selection bias and exposure misclassification might have on the observed relationship between magnetic fields and childhood leukemia. In addition, virtually all of the laboratory evidence and the mechanistic evidence fail to support a relationship between low-level ELF magnetic fields and changes in biological function or disease status. Thus, on balance, the evidence is not strong enough to be considered causal, but sufficiently strong to remain a concern.”

 Front of House

Front of Home

 

 West Side of Home with Power Lines

West Side of Home with Power Lines

 

 South Side of Home

South Side of Home

 

Results
A number of measurements exceed the WHO level but not the “Seven states” Guidelines.  The WHO guidelines are in reference to an average exposure level, not the peak levels we measured.  “Average magnetic field exposures above 0.3 μT (3 MilliGauss) in homes are rare: it is estimated that only between 1% and 4% of children live in such conditions.”  It’s very unlikely that family members exceed WHO Guidelines based on their average exposure to EMF.

 About EMF Testing USA
Stuart Bagley is a senior consultant from EMF Testing USA, a consulting firm in the area of workplace health and safety.  He is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 27 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.

Boise Paper Case Study

Boise Cascade PaperMill
Boise White Paper, LLC., International Falls, MN

International Falls, Minnesota is the coldest city in the mainland USA.  But that is just the temperatures.  It’s a bit warmer inside at Boise White Paper, LLC in Int’l Falls, MN. They requested a survey be done for electromagnetic field (EMI) and radiofrequency field (RFI) with regard to potential for interference with the proper functioning of a Boston Scientific cardiac defibrillator or pacemaker.  The survey and report were done by Stuart Bagley, MS, CIH, CSP of EMF Testing USA.          

 Boston Scientific CRDM, the cardiac device manufacturer, states that electromagnetic field exposures should not exceed limits as shown in the table below.  These limits were used to establish a benchmark for exposures acceptable to Boston Scientific CRDM. 

Boston Scientific Guidelines for Electromagnetic Fields for a Pacemaker or Defibrillator
Field Description Field Type Unit of Measurement EMI Limits
E-Field Strength AC kilovolts / meter (kV/m) 1000 V/m
DC Magnetic fields DC Gauss (G) 10 Gauss
AC Magnetic Fields AC Gauss 1 Gauss
High frequency E-fields (500 kHz to 6 GHz) Radio Volts / meter (V/m) Up to 8 Watts at the source

Log Debarker
Log Debarker

Results of the survey indicated some of the field measurements taken at the Boise Paper Solutions exceeded Boston Scientific CRDM guidelines for cardiac devices.  In addition, small AC motors of less than 50 HP are rarely above acceptable limits (excepting for power tools) and are therefore routinely not measured. DC motors are more likely to exceed guidelines.    

There are a number of locations exceeding Boston Scientific CRDM Guidelines.  Note that the highest readings are taken at or near the electromagnetic field source and that readings drop off rapidly with distance from the component.  Generally a one foot distance from the source provides an adequate margin of safety for the affected employee.  The readings taken represent current day exposures.  The exposure levels may be subject to change depending on the type and operating condition of the equipment.    

Normally equipment is operated with protective covers and shielding in place.  Energized equipment will tend to produce higher readings (both EMI and RF) when protective covers and other shielding are removed.  For purposes of estimating potential employee exposure to EMI, similar types of equipment not tested should be assumed to produce approximately similar results to those tested.        

 The impact to device function is typically temporary; if the employee/patient moves away from or turns the EMI source off, the implanted device resumes its normal mode of operation. In rare instances, the impact to the device may be permanent such as memory corruption or reversion to Safety Mode operation.      

Recommendations                                                                                                                                                                                                                                                                                                                                        Recommendations are made in an effort to comply with Boston Scientific CRDM Guidelines.  They are designed to prevent the subject employee with an implanted cardiac device from coming in contact with strong electromagnetic or radio frequency fields.  The final course of action with regard to the employee in the workplace is at the discretion of the employer, physician and employee.      

 Stuart Bagley, MS CIH CSP is a senior consultant and owner of EMF Testing USA, a consulting firm in the area of electromagnetic field testing.  Mr. Bagley has extensive knowledge of heart device standards and potential problems resulting from excessive EMF.  He is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP) with 25 years of experience in environmental health.  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.  He has conducted numerous electromagnetic field investigations at client sites throughout the United States.     

      

Case Study: Electromagentic Interference for Heart Device in Work Setting

Chrome Plating Company employee at plating tanks

Chrome Plating Company employee at plating tanks

A Chrome Plating Company requested a survey be done for electromagnetic field (EMI) and radio frequency field (RFI) with regard to potential for interference with the proper functioning of a Medtronic implantable cardiac defibrillator or pacemaker.   

Summary  A survey was done for electromagnetic fields and radio frequency fields by Stuart Bagley, MS CIH CSP, of EMF Testing USA with the assistance of personnel from the Chrome Plating Company.  Results indicate a number of the field measurements exceeded Medtronic CRDM Guidelines for cardiac devices.  These areas require precautions for employees with cardiac implants.   

There were 6 types of machinery where Medtronic CRDM Guidelines were exceeded or likely to be exceeded at the Chrome Plating Company.  Note that the highest readings are taken at or near the electromagnetic field source and that readings drop off with distance from the component.  The readings taken represent current day exposures.  The exposure levels may be subject to change depending on the type and operating condition of the equipment.    

The following are three principal types of interference with implanted cardiac devices:    

  1. Conducted interference occurs when the affected employee is in direct contact with the electrical source.  The most risk and actual accounts have occurred from poorly maintained electrical equipment.  Conducted currents should be avoided.  Physical interaction or manipulations with live circuits or switches is not recommended for anyone with a cardiac implanted device.
  2.  Radiated fields are those signals which propagate through the air and may potentially induce current that can be detected by the implanted device.  Common sources of these fields include high-voltage power lines, radio transmission towers, or two-way wireless communication equipment.
  3. Static magnetic fields are those produced by a permanent or direct current (DC) electro-magnet.   None were encountered on this visit.

 Normally equipment is operated with protective covers and shielding in place.  Energized equipment will tend to produce higher readings (both EMI and RF) when protective covers and other shielding are removed.  For purposes of estimating potential employee exposure to EMI, similar types of equipment not tested should be assumed to produce approximately similar results to those tested.  EMI of sufficient strength may lead to the following temporary device behaviors:

Potential device behaviors ICDs / 

CRT-Ds   

Pacemakers / CRT-Ps 
Asynchronous pacing (pacing independent of underlying cardiac activity)
Inhibition of pacing (pacing therapy not provided when needed)
Ventricular pacing at Maximum Tracking Rate
Inhibition of tachyarrhythmia therapy (shock therapy not provided when needed)  
Inappropriate shocks (shock therapy provided when not needed)  
Deactivation of tachyarrhythmia therapy*  

Recommendations   

Recommendations are made in an effort to comply with Medtronic CRDM Guidelines.  They are designed to prevent the subject employee with an implanted cardiac device from coming in contact with strong electromagnetic or radio frequency fields.  The final course of action with regard to the employee in the workplace is at the discretion of the employer, physician and employee.    

 Recommendations are as follows:   

  1.  Because of the nature of electrical work, physical interaction or manipulations with live circuits or switches that have the potential for any electrical shock or inducing electrical current passing through the human body must be handled with adequate precautions.
  2. Maintain a safe distance from EMF sources exceeding guidelines. 
  3. The affected employee must take reasonable precautions or be restricted from entering the areas exceeding guidelines shown in the facility, based on EMI survey results. 
  4. At a distance exceeding the safety distances listed in the table, the employee is considered to be at a safe distance from the above sources. Caution signs “Danger to Cardiac Pacemaker” can be placed on those machinery or components that exceed Medtronic CRDM guidelines in order to provide a warning to the affected employee.
  5. Discuss this report with the affected persons including the employee and his physician.  Train the employee on the effects of exposure of his implanted cardiac device to strong electromagnetic and radiofrequency fields.  Training should include how to minimize EMF exposures during the course of their work such as maintaining adequate distance from the source as well as de-energizing and locking out of equipment.

If these measures are not adequate to modify their job duties so that they may avoid overexposure or it may be necessary to permanently reassign the employee to a position or job task where they will not have exposure to strong electromagnetic fields.   

Stuart Bagley, MS CIH CSP is a senior consultant at EMF Testing USA, a consulting firm in the testing of electromagnetic fields.   Mr. Bagley has extensive knowledge of heart device standards and potential problems resulting from excessive EMF.  He conducts electromagnetic field investigations at client sites throughout the United States.

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