retinopathy of prematurity.org
Baby-harming medical research
about baby-blinding retinopathy of prematurity
by H. Peter Aleff, 2005 to 2009
Chapter 3: Evidence against fluorescent nursery lighting
Besides killing thousands upon thousands of babies and inflicting irreversible brain damage on many others, the failure of the medical community to acknowledge and thus end its doctrine-enshrined hidden euthanasia program of oxygen withholding also prevents nursery doctors from addressing or even admitting the real reasons for the eye damage that the misguided oxygen rationing is supposed to prevent.
3.1. Parallel beginnings of fluorescent lamps and ROP
Already Dr. Terry, the discoverer of the eye damage from ROP, suspected that it was most likely caused by light. He first observed the new condition in two children born in July and November 1940 in Boston. Already in his initial paper about this discovery, published in 1942, he postulated that "some new factor has arisen in extreme prematurity to produce such a condition", and from 1943 on, he argued consistently that this new factor was most likely excess light:
Similarly, he wrote again a couple of years later:
And by 1946, he was ailing but had his comments read to the American Academy of Pediatrics:
The new factor which Terry had postulated was indeed a new kind of light that had been commercially introduced at the New York World Fair of 1938 and 1939, a couple of years before his first ROP patients were born.
From then on, ROP quickly became an epidemic in hospitals across America where these lamps quickly became popular because their light made the rooms look cleaner and was also believed to kill germs. During the soon following world war and its immediate aftermath, ROP remained confined to the U.S.. But over the next few years, it appeared just as suddenly in other industrialized countries, again in parallel with the introduction there of these lamps.
England was the first of these new ROP countries. Both fluorescent lamps and ROP made their debut there right after the war, according to four reports presented at the 1951 session of the Ophthalmological Society of the United Kingdom.
Two of these reports described the first cases of ROP in two babies, one born in 1946 in Birmingham and the other in 1948 in Oxford. Both noted that from then on, the incidence of the disease in those centers had increased rapidly,.
The other two papers discussed experiments with fluorescent lighting in hospitals. One of their authors expressed his appreciation to the General Electric Company for their help in making the special fittings required for these lamps "so soon after the war",.
After this jump overseas, ROP appeared soon also in other countries. In 1952, Dr. Leona Zacharias from the Harvard Medical School published a literature survey, with 219 references, of just about all that was then known about ROP. Her compilation included the times of its first reported occurrence in other countries: Israel in 1947; Australia, Canada, and Sweden in 1948; Switzerland in 1949, then Cuba, France, Holland, Italy, South Africa, and Spain all in 1950.
Because the disease had appeared so suddenly, some physicians wondered if it had been there all along but had simply not been recognized before. They organized several large-scale retrospective studies on ROP among older blind people. Some of these studies claimed to have found a few isolated and uncertain cases, beginning in 1937,, but they all concluded that if ROP had existed before 1940 in the U.S.A., or before 1946 in the U.K., it must have been exceedingly rare.
This new light was different from any other that anyone had seen before because fluorescent lamps do not emit a smoothly continuous spectrum like that of any natural or incandescent radiation source. Instead, they concentrate a major portion of their energy in a few high-energy spikes, and the most energetic of these spikes radiates precisely in that wavelength region in which the unprotected mammalian retina is the most vulnerable to damage from light.
Fluorescent tubes contain an almost vacuum-like thin mixture of mercury vapor and some noble gases in which electromagnetic fields between the ends of the tube accelerate ions to high speeds and energy levels. When such a fast ion hits a mercury atom, that atom emits a high-energy photon, mostly in two wavelengths in the ultraviolet region. To transform this invisible stream of photons into visible light, the inside of the fluorescent lamp tube is coated with a layer of phosphors (Greek for "light bringer").
These phosphors absorb most of the UV radiation and then re-emit it in longer wavelengths that usually cover the entire visible range but concentrate much of their energy output in a few narrow spikes. These occur in all fluorescent lamps with the same relative intensities at the same wavelengths: 365.0 nanometer; 404.7 nm; 435.8 nm; 546.1 nm; and 578 nm, with the one at 435.8 nm being by far the most energetic. The differences between the various types of fluorescent lamps, such as “Cool White Deluxe” or “Warm White”, are mostly in the broadband spectrum between those narrow spikes which the type-specific phosphor formulations reradiate differently.
Fluorescent lamps emit their light waves independently of each other, unlike lasers which emit them in-phase as coherent light. The dangers from laser light have received much more regulatory concern than those from fluorescent light, but both types of light are equally damaging to the unprotected retina. The light receptors in the retina absorb the energy from these waves one photon at a time, whether that photon arrives in step with others or as part of an unorganized group.
Indeed, retinal damage from coherent and non-coherent light sources is indistinguishable, and the experimentally derived threshold values for retinal damage from any specific wavelength are in fairly close agreement whether the light comes from non-coherent xenon lamps and carbon arcs or from coherent helium-neon, ruby, or argon lasers.
Actually, the lowest threshold value for light damage to animal retinae in the large sampling of studies consulted happened to have been reported for non-coherent blue light at 440 nm, very close to the radiation from the most intense of the energy spikes at 435.8 nm in the fluorescent lamp spectrum.
The lamps in intensive care nurseries are the fluorescent "Deluxe Cool White" type, as specified by the Committee on Fetus and Newborn of the American Academy of Pediatrics in its 1977 Standards and Recommendations for Hospital Care of Newborn Infants. The distribution of the energy emitted by this type of lamp over the different wavelengths of its spectrum, shown in Figure 2 below, is copied from Sylvania, a maker of these lamps. The corresponding curves for "Deluxe Cool White" lamps from other manufacturers look very similar and feature the same narrow-line photon emission spikes in the same locations.
Like these other spectrum graphs, this one does not show the full height of the emission spikes since it averages the energies over bandwidths of 10 nm. The spike at 435.8 nm, for instance, is only 0.1 nm wide. It would appear almost 100 times higher on the graph if it was not averaged with the neighboring wavelengths.
spike alone packs about 8.6% of a typical nursery lamp's total
energy output (see Table 1 at the bottom of this page).
Due to the higher photochemical energy of shorter wavelengths,
this spike in the short-wave end of the visible spectrum
accounts for an even higher percentage of the total
photochemical activity produced by the lamp: in vitro
experiments of bilirubin conversion by fluorescent lamps have
shown, at least in one experiment, that the single energy spike
at 435.8 nm is responsible for more than 50% of the conversion
reaction from the entire spectrum of the lamp.
Figure 2.: Spectrum of typical
"Deluxe Cool White" fluorescent lamp. This graph from Sylvania
shows the energy in Watts for each wavelength band of 10
nanometer; it is a smooth hill except for four spikes, with the
one centered on 435 nm much taller than the other three.
As Murphy’s Law appears to have dictated it, the wavelength region where the retina is most vulnerable to damage from light is precisely the region from 435 to 440 nm. These wavelengths in the blue-violet region have caused much concern among specialists in Occupational Safety for adult industrial workers.
Already the 1974 Symposium on Illumination, sponsored by the U.S. National Institute of Occupational Safety and Health, NIOSH, warned that high lighting levels in this region of the spectrum could cause much damage to the eye, particularly retinal and macular degeneration (the macula is the most light-sensitive part of the retina). Included in the Public Health Service's "Guide to the Recognition of Occupational Diseases" is this statement in the section on laser light:
These blue-light hazard values are for normal adult eyes that have already begun their gradual age-related yellowing and therefore block at least in part some of the worst blue and violet wavelengths.
However, preemie eyes are still entirely transparent to these, and also to many of the even more energetic ultraviolet wavelengths. Their lenses as well as the aqueous and vitreous humors that fill their eyeballs let in all radiation down to about 300 nm. Even the lenses of children aged up to ten years transmit over 75% of the 300 to 400 nm UV radiation.
Baby eyes are therefore more comparable to “aphake” eyes, that is, eyes without the protection of a lens, like those that have undergone cataract surgery. Because people with such totally unprotected eyes are even more vulnerable to short wavelength light, the American Conference of Governmental Industrial Hygienists in Cincinnati began in 1991 to include in its annually updated “Biological Exposure Indices” also the Aphakic Hazard Function for such people.
This function, as copied from the 1997 edition of these Indices, and the damage-weighted retinal irradiance computed with it for each wavelength group, appear in the last two columns of Table 1 below.
The NIOSH data for this table and graph derive mostly from experiments which destroyed the retinae of monkeys, pigs, rats, and a variety of other mammals. However, the retinal structure of all mammals is virtually the same, and clinical experience with victims of welding accidents and inadvertent exposures to excess laser light confirms that humans are just as vulnerable to the same wavelengths as any of the test animals.
Nursery doctors have therefore no basis whatsoever for assuming that the developing preemie retina during its period of greatest vulnerability could be somehow immune to intense irradiation in a wavelength which quickly burns the retinae of all other mammals. Yet, much of the standard nursery lamps' energy is concentrated in precisely the wavelength region that is known to cause the most damage to all mammalian retinae.
Figure 3: Irradiance from “Cool White Deluxe” fluorescent lamp, retinal blue-light hazard protection barrier for normal adult eyes, and blue-light damage-weighted irradiance behind the “vulnerability window” in that barrier. All use wavelength as the horizontal axis.
The graph illustrates how the most intense emission spike from the fluorescent lamp passes right through the broad breach in the retinal protection barrier -- the "retinal vulnerability window". If the “Aphakic Hazard Function” applies to the babies’ more transparent eyes, then the left part of the protection barrier is eliminated, and the damage-weighted irradiance curve behind it continues down to 300 nm deep into the ultraviolet radiation. In either case, the high blue-violet spike of the fluorescent lamps at 435.8 nm penetrates the retinal protection barrier virtually unhindered as damage-weighted retinal irradiance.
In October 1988 the Academy reduced this intensity to 60 ftc. However, as you can see in the next section, 60 ftc of intensive care nursery lighting still expose a preemie's retinae in 15 min or less to the dose of damage-weighted retinal irradiance which NIOSH has established as the occupational danger limit for healthy adult industrial workers. This danger limit is not to be exceeded cumulatively over an eight-hour shift but the preemies reach it in their first quarter hour.