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BLOG: March 2009

EMF safety standards - are they safe?

EMF&Health - EMF spectrum - Electricity 2 - Official view 2 - Politics 2 - Protection

Call it electrical pollution, electropollution, dirty electricity, stray voltage, microwave radiation, or any other of its many informal names and forms, the question is just the same: Do all those energy fields around us adversely affect health, possibly at the exposure levels much below current official safety standards?

Officials say: "Worry not". But the existing evidence falls seriously short from fully supporting their view, which is based on the mere assumption that these fields are biologically inactive, or nearly so.

 In all likelihood, electromagnetic pollution is stepping onto the stage of a historic battle between special and global economic interests coupled with ignorance on one side, and facts, sanity and health preservation of the broad population on the other.

 Following text examines the facts surrounding this mega-controversy.

There are many sources of electromagnetic fields (EMF) pollution these days. High-energy radiation, such as that produced by X-rays or radioactive materials, is officially recognized as health hazard. On the other hand, health effect of low-energy electromagnetic fields is, at least officially, dimmed as insignificant at common exposure levels.

These low-energy fields - specifically, non-ionizing radiation - include the most widespread EMF pollutant, the

energy field created by electricity,

such as those radiating from power lines, wiring, appliances and electronics inside your home, work, or from your cell phone.

Following chart shows ICNIRP (International Commission on Non-Ionizing Radiation Protection) safety limits for non-ionizing radiation. Added are the levels of exposure to electrical and magnetic fields linked to adverse health effects in a few out of a large number of studies that did establish such link over the last few decades.

These safety limits are nearly identical to those issued by the Institute of Electrical and Electronics Engineering (IEEE. Standard C 95.1-1999), and represent internationally adopted standards. They are also the basis for the FCC (Federal Communications Commission, U.S.) non-ionizing radiation exposure limits, with the exception being that FCC does not regulate frequencies below 300kHz.

For reading the chart, as well as EMF-related texts in general, following commonly used terms and conversions may be helpful.

 EFM-related TERMS

frequency (ν)

in hertz, 1Hz=1 oscillation per second

wavelength (λ)

λ=300,000,000/ν meters

current (flow of electrical charge, I)

in ampere (A)

current density (J)

A/m2 or Am-2 (ampere per square meter)

electric field strength (E)

V/m or Vm-1 (volt per meter)

magnetic field strength (H)

A/m or Am-1 (ampere per meter)

magnetic flux density (B)

T (tesla)

power density (S)

W/m2 or Wm-2 (watt per square meter)

specific energy absorption (SA)

J/kg or Jkg-1 (joule per kilogram)

specific energy absorption rate (SAR)

W/kg or Wkg-1 (watt per kilogram)

CONVERSIONS

magnetic (H) to electric (E) field strengtha

E(V/m)=377H(A/m)

magnetic field strength (H) to flux density (B)

B(μT)=1.256H(A/m), 
1μT=10mG (milligauss)

electric field strength (E) to power density (S)a

S(W/m2)=E(V/m)2/377=0.1S(mW/cm2)

magnetic field strength (H) to power density(S)a

S(W/m2)=377H(A/m)2

power density or internal E-field to specific absorption rate (SAR)

SAR=P/ρ=σE2/ρ,  ρ=densitybσ=conductivityc

 SAR to specific energy absorption (SA)

SA=SAR x exposure time

a valid only in far field (>10λfrom the source); in near field (<λ from the source) there is no constant relationship between the two fields - they need to be determined separately
 
b density of the conductive medium, ~1,000kg/m3 for most tissues
 c varies with the medium and frequency (for the body, from the minimum of  0.05 to 0.08 for fat tissue to near-maximum of 0.94 to 1.4 for brain from 900-1800MHz, respectively)


The red marks are the exposure levels at which significant link to adverse health effect has been found. There is many studies on this subject; these few shown are only to illustrate how much below the official safety levels various energy fields are biologically active and implicitly harmful. Here's a brief on each mark, by the number:

1 - Majority of studies since 1979 (Wertheimer and Leeper) did establish consistent link between exposures of ~4μT (well over 100 times below the ICNIRP safe limit) and higher with significantly (approximately 2 to 4 times) increased risk of childhood leukemia; for vulnerable children, such as those recovering from leukemia, even lower exposures (1-2μT) significantly - 280% - decrease survival rate vs. children exposed to less than 1μT fields (Foliart et al. 2006). Expectedly, adverse effects may not be limited to childhood: children raised within 300m from high-voltage power line also have 3-5 times higher risk of developing some form of cancer later in life (Lowenthal et al. 2007).

2 - Canadian study of occupational exposure of electricity utility workers (Miller et al. 1996) establishes significantly increased risk of leukemia and other forms of cancer at exposure levels dozens of times below the official safe level.

3 - Occupational study of communication equipment handlers exposed to 3-30MHz microwave radiation roughly at the safe limit level for general population establishes significantly higher rate of adverse pathological changes vs. unexposed group (central nervous system 3.8, cardiovascular 5.2, gastrointestinal 1.7, peripheral nervous system 1.4, respiratory 2.8), in addition to early aging syndrome. Incidence of adverse health effects was significantly related to employment duration, regardless of individual age. Long-term exposure (over 10 years) effects remained after cessation of the EMF exposure (Nikitina, 2000)

4 - Recent Israeli study (Friedman et al. 2007) demonstrates that mobile phone EMF fields change cellular functions (protein formation and protein-based regulatory mechanisms) starting at field intensities nearly 100 times below the average cell phone radiation level. For the first time, this study determines molecular mechanism through which this type of low-level microwave radiation effects cellular processes. Initially, radiation stimulates mitochondrial membranal enzyme (NADH oxidase) into production of ROS (reactive oxygen species). This in turn initiates specific chain of events resulting in altered transcription, as well as stability and expression of a number of regulatory cell proteins. For instance, the radiation activates extracellular signal-regulated kinases (ERK) and epidermal growth factor, both important factors in cellular division and growth.

Among a number of factors capable of activating the ERK cellular pathway are viral infections and carcinogens. Disruption/alteration of this pathway is

common in cancer.

The study does not prove that cell phone microwave radiation causes cancer, but it does show that very low level radiation of this type significantly alters cellular processes, including those commonly altered in cancer. At this point, we can only speculate about specific health consequences it can cause, but the possibility of it contributing to cancer development cannot be excluded.

This study is only a continuation of the long string of studies establishing that officially "safe" levels of non-ionizing radiation exposure have the capacity to affect cellular function, and inflict cellular damage in humans and other animals (enzyme reaction rates, Blank and Soo, 1996/98, Mullins et al. 1999, electron transfer rate, Blank and Soo, 2001, stress protein synthesis, Goodman et al. 1994, Lin et al. 1998, DiCarlo et al. 2000, melatonin inhibition, Liburdy et al. 1993, interacting with DNA, dePomerai et al. 2000, Kwee et al. 2001, Lin et al. 2001, Leszczynski et al. 2002, Weisbrot et al. 2003, DNA damage, Lai and Singh, 1997, Phillips et al. 1998, Mashevich et al. 2003, REFLEX 2004, and others).

5 - Another Israeli study (Dovrat et al. 2005) finds that exposing eye lens to near continuous (50min each hour) microwave radiation in the typical cell phone frequency range (~1.1GHz), at about double the average occupational safe limit, causes both significant macro-degeneration (deteriorated focusing ability) and micro-degeneration (formation of microscopic bubbles within the lens) evident after 48 hours and progressing to its saturation level after 6-8 days. Macro-degeneration was reversible within days after radiation ceased, but micro-degeneration (within 15-day period of the study) remained.

These effects were also evident at less than half the intensity (0.89 vs. 2.2 mW/cm2), only with the period needed to reach specified stages of degeneration doubled. Consequently, applying ICNIRP criteria of the average occupational safety limit as 1/10 of the radiation intensity beginning to cause degradation to biological tissue, the safety limit should be, according to this study results, more than 12 times lower than what it is currently. In addition, the study has found out that pulsed radiation with identical total energy causes 4.7 times more damage, also through athermal mechanisms, indicating that safety standards for this type of non-ionizing radiation are even more inadequate.

Adverse health effects in these selected few examples have occurred across the radio-frequency range. It implies that

no radio frequency, or exposure level can be assumed harmless.

Although these studies were selected, somewhat randomly, to illustrate this point, they are not an exception: majority of studies to this date did find that exposure to non-ionizing radiation much below the official safety level resulted either in a direct adverse health effect, or significant biological effect of uncertain implications and consequences.

Why is it, then, that the officials in international organizations and governments did not act accordingly, by drastically tightening current official safe exposure levels to man-made electromagnetic fields? Let's hear their side. Following page presents the official basis of current EMF safety standards and details how ICNIRP answers this question in their 1998 Guidelines for limiting exposures to non-ionizing radiation up to 300GHz.

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