The Failure of Public HealthA Case Study in California Schools

IntroductionIn the U.S., and particularly in California, as documented by Zaffanella et al. (2000)1, far higher levels of Extremely Low Frequency (ELF) magnetic fields are present than in Europe. These fields are almost entirely the result of the distribution of electricity. Typically the frequency in North America is 60 Hz2; in most of the world it is 50 Hz.

ELF magnetic fields were declared a Group 2B (possible) Human Carcinogen by the World Health Organization (WHO) 10 years before radio frequency radiation (RFR) was also declared a Group 2B Human Carcinogen in 2011. In effect, almost the entire non-ionizing radiation (NIR) frequency spectrum (from 3 Hz to 300 GHz3) has been declared a Group 2B Human Carcinogen.

The Group 2B declaration for ELF magnetic fields was substantially based on childhood leukemia though these fields also increase risk for adult leukemia and brain tumors. As a rule-of-thumb (based on the scientific literature), 2 mG (0.2 µT)4 is roughly the threshold where an increased risk of leukemia is reported. The risk increases sharply as magnetic fields increase above 2 mG.

As can be seen in the study “Analysis of personal and bedroom exposure to ELF-MFs in children in Italy and Switzerland” by Struchen et al (2015), “sample geometric mean ELF-MF exposure was 0.04 μT [0.4 mG] for personal and 0.05 μT [0.5 mG] for bedroom measurements.” In the U.S. we typically find up to an order of magnitude higher ELF magnetic fields (4 to 5 mG) in homes and schools with net current problems.

1 Zaffanella & Hooper. Electric and Magnetic Field Exposure Assessment of Powerline and Non-Powerline Sources for California Public School Environments. Public Health Institute, California Department of Health Services, EMF Program, 5900 Hollis Street, Suite E., Emeryville, CA 94608-2008, January 31, 2000.2 Hz is hertz (a unit of frequency, as cycles per second).3 GHz is gigahertz (a unit of frequency, as billions of cycles per second). Other abbreviations are: kHz (as thousands of cycles per second); MHz (as millions of cycles per second).4 mG is milliGauss and µT is microTesla

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Net Current ProblemsZaffanella in a 1996 study (published in 2000) of California schools found that 11.6% of school areas had ELF magnetic fields in excess of 2 mG (0.2 µT).5 See Zaffanella (2000), Table 1, pdf page 10. Mostly these fields were the result of net current problems. The cost to reduce fields that originated within the schools to <2 mG was estimated at $6,800 per school (see Zaffanella, pdf page 23).

What are net current problems, you ask?

The electric current flowing to a light bulb is the same as the current flowing from the light bulb. The net current is zero [1 + (-1) = 0]. A magnetic field exists wherever there is a flowing electric current. If the wires going to and from the light bulb are in close proximity (they usual are), the magnetic fields from the current to the bulb are canceled—that is, there is no magnetic field.

However, there is a very common wiring mistake, found throughout the U.S., that results in a net current problem and thus a non-zero magnetic field. The National Electric Code (NEC) requires that there should be no net current. Since every municipal, county and state building code requires adherence to the NEC, the majority of buildings have wiring that violates the NEC Code.

How can this happen?

Electrical wiring has three wires (hot, neutral and ground). The ground and neutral wires are connected together in one place only: where the electricity enters the building. The problem happens when the neutral and ground wires are connected together within a building: now there are two paths for the current to flow back from a light bulb: the neutral wire and the ground wire. Viola!! The net current is no longer zero.

This can happen when construction companies push electricians to work very fast; it can happen when non-certified electricians are unaware of this code violation; it can happen when electrical equipment manufacturers, internal to the equipment, connect the neutral and ground wires together; it can happen when do-it-yourself home owners and/or their hired handymen changes electrical wiring and thinks the ground wire should be connected to the neutral wire for safety.

5 ELF magnetic fields external to schools, homes and buildings are excluded. Such fields, originating from electrical transmission and distribution lines, represent a small percentage of fields > 2 mG (0.2 µT) found inside of buildings.

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However a net current problem happens, the effect is invisible. The lights still work, equipment still works.

Even if a building has no net current (i.e., the only place where the neutral and ground wires are connected is where the electricity enters the building), there can be ELF magnetic fields in the building. This is because the neighboring building(s) can have net current problems, and the result is electrical current flowing in the ground wire that is literally connected to the ground (earth).

This ground/earth current must return to the electrical substation (same idea as the light bulb analogy: the electrical current flowing from a substation must return to the substation). Once the electrical current is in the ground (earth), it will take the path of least resistance back to the substation. Typically this path is via metal water pipes and gas pipes. Thus your neighborhood’s net current problems can bring an electrical current (with its magnetic field) into your house via your metal water pipes and gas pipes.

Why Is Europe Different?In Europe the main circuit breakers for a building are ground-fault-interrupt (GFI) circuit breakers. If there is any current flowing in the ground wire, the circuit breakers will turn off all the electricity in a building until the problem is resolved.

In the United States we have GFI circuit breakers in bathrooms. So if an electrical device falls into water in the bathtub or sink, the bathroom GFI will immediately disconnect the electricity and a person in the bathtub will not be electrocuted.

The Failure of Public HealthThis anomaly speaks loudly of inconsistencies in U.S. public health priorities. Saving people’s lives by reducing the risk of electrocution is deemed high priority. Saving people’s lives by reducing the risk of cancer induced by ELF magnetic fields is deemed unimportant.

This anomaly is only the proverbial tip of the iceberg.

The Zaffanella study was performed in 1996. It was published by the California Department of Health Services, CDHS (now the California Department of Public Health, CDPH) in January, 2000. The CDPH knows this problem exists and has known about it since 1996 (if not earlier).

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The California Department of Education (CDE) website, within “Health &Safety,” under “Electromagnetic Fields” lists three topics: 1) School Site Selection, 2) CPUC Electric and Magnetic Fields, 3) Power Line Setback Exemption Guidance. None of these three topics are relevant to the health risks when ELF magnetic fields are >2 mG.

Certainly the CDE has authority to enforce building code regulations yet seems to choose to ignore the regulation regarding connecting the ground wire and the neutral wire only where the electricity enters the building.

Acknowledgements:To Dr. Antoinette (Toni) Stein, PhD Environmental Engineering, for her sage advice.

To Barbara Payne for her extraordinary proof-reading skills.

L. Lloyd Morgan,

Senior Research Fellow, Environmental Health TrustIf We Do Not Look, We Cannot Find

19 December 2015.

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