Education · The Research Behind the Measurements

The Science We
Measure Against

A FieldWise assessment measures four kinds of fields in your home, plus your lighting. This page explains the research behind each measurement. It separates what is well established from what is still proposed and debated, and it is careful about one thing throughout: measuring your environment is not a diagnosis, and nothing here says that EMF causes anyone’s symptoms.

📏 Distance & Dose 📡 RF Dosimetry 🌙 Light & Melatonin 💡 LED Flicker 📋 SBM-2015 📚 Sources

How to read this page. Established means a finding is well replicated and broadly accepted. Proposed means researchers have suggested a mechanism that is still debated and not settled. FieldWise measures exposure and compares it against precautionary guidelines. We do not diagnose, we do not treat, and we do not claim that reducing exposure prevents or cures anything. The goal is not elimination, but intentional optimization.

Distance and Dose:
Why a Few Feet Changes Everything

The single most useful fact in this whole field is also the simplest. Radio-frequency exposure falls off quickly with distance. Double your distance from a source and the exposure drops by roughly 75 percent. This is the inverse-square law, and it is settled physics, not a theory under debate.

~75%
Drop in RF exposure when you double your distance from a source (inverse-square law)
4
Distinct field types an assessment measures: RF, AC magnetic, AC electric, and dirty electricity
1
Room that Building Biology treats as the highest priority: where you sleep

This is why placement is the first lever we look at, and why we measure at the actual bed, desk, or crib rather than reporting one average for the room. A signal that is unremarkable across the house can be very different a few inches from where a head rests for eight hours. Objective measurement replaces guessing, and small changes in distance often do more than anything else you could buy.

How Much a Body Absorbs,
and Why Children Are Modeled Differently

How much radio-frequency energy a body absorbs from a given signal depends on the source, the distance, and the body itself. This absorbed amount is called the specific absorption rate, or SAR, and it is a measurable, modeled quantity. Peer-reviewed modeling studies have found that a smaller head, with thinner tissue layers and different proportions, can absorb a higher share of the same signal in some tissues than a standard adult model predicts (Christ 2010; Gandhi 2012).

What this is, and what it is not. This is a statement about how energy is absorbed, a question of physics and anatomy. It is not a claim that RF exposure causes any illness, and this page does not make that claim. We include it because it explains a practical choice we make: we measure the rooms where children actually sleep, rather than assuming one number describes everyone in the house.

The same body of work makes a policy point worth knowing. Gandhi and colleagues (2012) argued that the standard model used to certify phones can underestimate real-world absorbed exposure, especially for children. Researchers still debate the size of that effect. What is not in dispute is the underlying principle: absorbed dose is not one-size-fits-all, so the honest thing to do is measure the specific place and person, not a generic average.

Light After Dark:
The Melatonin Connection

This section is about light, specifically the blue wavelengths that reach your eyes in the evening. It is one of the best-supported findings in this entire page, and it belongs to the Circadian and Light assessment rather than to EMF. Two independent studies published in 2001 mapped the action spectrum for melatonin suppression in humans and found that short-wavelength blue light is the most effective at telling the brain it is still daytime (Brainard 2001; Thapan 2001).

~460–480 nm
Blue-wavelength range most effective at suppressing evening melatonin (Brainard 2001; Thapan 2001)
Spectrum
Measured with a professional spectrometer, along with intensity and flicker

Modern LED screens and cool-white overhead lighting are rich in exactly these wavelengths. That is why we measure your lighting spectrum and evening blue-light output, and why the goal is intentional optimization rather than living in the dark. Warmer light in the hours before sleep, and brighter, bluer light during the day, tends to work with your biology rather than against it.

Keep the domains separate. This is a finding about light reaching the eye, not about magnetic fields or EMF suppressing melatonin. We keep them separate because they are separate. Conflating light science with EMF is one of the most common mistakes in this industry, and we do not make it.

Flicker You Can Measure:
The IEEE-1789 Standard

Many LED lights flicker, switching on and off far faster than the eye consciously registers. This is a measurable engineering property, expressed as a flicker percentage and a frequency. It is not a fringe topic. The Institute of Electrical and Electronics Engineers publishes a recommended practice, IEEE Std 1789-2015, that defines lower-risk and higher-risk flicker levels.

That standard exists because some viewers report effects such as eyestrain, headaches, or discomfort under higher-flicker lighting. We are careful with the wording: the standard describes what some people report and sets engineering targets to stay well clear of it. It does not let us tell you that flicker is the cause of any symptom you have, and we will not. What we can do is measure the flicker in your fixtures with a professional spectrometer and compare it against the IEEE-1789 recommended practice, so lighting choices are based on numbers rather than guesswork.

The Yardstick:
Building Biology SBM-2015

Measurements need something to be compared against, or they are just numbers. FieldWise uses the Standard of Building Biology Testing Methods, known as SBM-2015. It is a precautionary guideline set that focuses on the sleeping area and is far stricter than what the law requires. When we report your levels, we report them against this framework, in a written FieldWise Home Profile.

An honest word about limits. The measured levels in almost every home are well within legal limits, including the public-exposure limits set by the FCC. FieldWise’s value is not telling you that your home violates a rule, because it almost certainly does not. Our value is precautionary: measuring what is actually there, comparing it against a stricter voluntary standard, and giving you practical, prioritized ways to reduce what is easy to reduce.

How Voltage-Gated Calcium Channels
Respond to Electromagnetic Fields

Voltage-gated calcium channels (VGCCs) are real, well-documented structures in the membrane of nearly every cell in your body. Their job is to open in response to changes in voltage across the cell membrane, allowing calcium to flow in and trigger processes ranging from nerve signaling to hormone release.

Research has shown that VGCCs are sensitive to voltage gradients, including those introduced by external electromagnetic fields. This is not a fringe idea. It follows directly from how these channels are known to function.

What is still being worked out in the literature is the degree of that sensitivity, and which types, frequencies, and intensities of EMF meaningfully activate these channels under real-world exposure conditions. That is where the open questions live, not in whether voltage sensitivity itself is real.

The standard we hold. We measure what is present in your home with calibrated instruments and compare it against precautionary building biology guidelines. We give you the mechanism and the data. What you do with it is yours to decide.

Sources

The sources below support the specific measurement domains described on this page. Established findings and proposed mechanisms are labeled as such. FieldWise does not claim a causal link between consumer-level home EMF and any medical outcome. Page ranges and identifiers are provided so you can read the primary sources yourself.

[1]

Brainard GC, Hanifin JP, Greeson JM, et al. “Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor.” J Neurosci. 2001;21(16):6405–6412.

Established. Maps the blue-wavelength action spectrum for evening melatonin suppression. Supports the lighting section, not any EMF claim.

DOI: 10.1523/JNEUROSCI.21-16-06405.2001
[2]

Thapan K, Arendt J, Skene DJ. “An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans.” J Physiol. 2001;535(Pt 1):261–267.

Established. Independent action spectrum confirming that short-wavelength blue light drives melatonin suppression.

DOI: 10.1111/j.1469-7793.2001.t01-1-00261.x
[3]

Christ A, Gosselin MC, Christopoulou M, Kühn S, Kuster N. “Age-dependent tissue-specific exposure of cell phone users.” Phys Med Biol. 2010;55(7):1767–1783.

Established modeling. Age-dependent RF absorption (SAR) in head tissues. A dosimetry finding about absorbed energy, not a health-outcome claim.

PMID: 20208098
[4]

Gandhi OP, Morgan LL, de Salles AA, Han YY, Herberman RB, Davis DL. “Exposure Limits: The underestimation of absorbed cell phone radiation, especially in children.” Electromagn Biol Med. 2012;31(1):34–51.

Dosimetry and policy. Argues the standard certification model can underestimate absorbed RF, especially in children. The magnitude is still debated; the principle that absorbed dose varies by person is not.

DOI: 10.3109/15368378.2011.622827
[5]

IEEE Standards Association. “IEEE Std 1789-2015: Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers.” IEEE. 2015.

Established engineering standard. Defines lower-risk and higher-risk LED flicker levels. The basis for how we measure and compare lighting flicker.

IEEE 1789-2015
[6]

Institut für Baubiologie + Nachhaltigkeit (IBN). “Standard of Building Biology Testing Methods (SBM-2015).” Building Biology Institute. 2015.

Precautionary framework. The voluntary guideline set FieldWise measures against. Sleeping-area focused and stricter than legal limits. A framework, not a regulatory limit.

SBM-2015
[7]

Pall ML. “Electromagnetic fields act via activation of voltage-gated calcium channels to produce beneficial or adverse effects.” J Cell Mol Med. 2013;17(8):958–965.

Proposed and debated. The voltage-gated calcium channel hypothesis. Presented on this page as a debated proposal, not as established fact, and never as an explanation for a person’s symptoms.

PMID: 23802593

The science of non-ionizing EMF and biology is active and evolving. FieldWise presents this research to explain what we measure and why, not to make medical claims. Our assessments provide objective field measurements. Interpretation and any action are always informed decisions made by you.

See What Your Own Home Measures

The research explains the why. An assessment gives you the numbers for your actual rooms, compared against Building Biology guidelines, in a written FieldWise Home Profile.

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Serving Fort Collins, the Front Range, and the I-70 Corridor • info@fieldwiseemf.com