back to: Practical advice
There are two main health dangers from Compact Fluorescent light bulbs.
1. They give off strong radiation. Some authorities warn about this and provide limits for exclusion zones around such light bulbs.
2. They cause Dirty Electricity on the household wiring circuit. This causes harmful radiation close to wiring near to the light bulb.
There are two main health dangers from Fluorescent Tube lights.
H. Peter Aleff: "Baby-blinding retinopathy of prematurity and intensive care nursery lighting" (Latrogenics, 1991)
Halogen bulbs usually put Dirty Electricity frequencies and transients onto house wiring.
Some LED (Light Emitting Diode) bulbs (GU10) emit VHF radio frequencies, typically in the 30–300 MHz range.
There can also be health damage from these the light spectrum frequencies which produce predominantly UV blue light.
(a) Excess UV blue light can damage the eye.
Because LED light is so concentrated and has high blue content, it can cause severe glare, resulting in pupillary constriction in the eyes. Blue light scatters more in the human eye than the longer wavelengths of yellow and red, and sufficient levels can damage the retina. This can cause problems seeing clearly for safe driving or walking at night.
(b) Used at night in the home or in street lighting this can reduce melatonin in the body and cause circadian disruption.
Light at night for night workers is rated a 2A probable human cancer agent, partly because of its effect in reducing melatonin.
"Some LED lights are harmful when used as street lighting.
- Discomfort and disability from intense, blue-rich LED lighting can decrease visual acuity and safety, resulting in concerns and creating a road hazard.
- Blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during night. It is estimated that white LED lamps have 5 times greater impact on circadian sleep rhythms than conventional street lamps. Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.
- Excessive outdoor lighting disrupts many species that need a dark environment. For instance, poorly designed LED lighting disorients some bird, insect, turtle and fish species, and U.S. national parks have adopted optimal lighting designs and practices that minimize the effects of light pollution on the environment.
(a) minimize blue-light content:
-The AMA encourages communities to minimize and control blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare. The AMA recommends an intensity threshold for optimal LED lighting that minimizes blue-rich light.
(b) shielding and dimming in off-peak periods:
-The AMA also recommends all LED lighting should be properly shielded to minimize glare and detrimental human health and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods."
American Medical Association: "Community Guidance to Reduce the Harmful Human and Environmental Effects of High Intensity Street Lighting" (2016)
LEDs can also over-ride DAB (Digital Audio Broadcasting) radio signals and cause other interference.
You should replace all CFLs in your house with other light bulbs.
Shiftwork with light at night is classified as a human carcinogen.
Blue light, common in LEDs, smart phones and computers, reduces melatonin.
Melatonin both helps defend against cancer and helps control circadian rhythms and the body clock.
Blue light has an effect on cryptochromes by the radical pair mechanism.
Cryptochromes are found in both animals and humans,
Cryptochromes are part of the magnetoreception system in animals.
|Amount of light|
(Lux = 1 lumen per square meter)
|Source of light, |
|3||Street lamp through bedroom curtains|
Light at night: increased depression in elderly.*
Light at night: increased subclinical carotid atherosclerosis in elderly.**
|100-300||Artificially lit room|
|<200||Light in evening: suppresses melatonin.***|
|300-500||Typical office lighting||Shiftwork involving circadian disruption: 2A (probable) carcinogen: WHO/IARC.****|
|1000-2000||Daylight, winter, cloudy|
|30 000-100 000||Daylight, summer, clear sky|