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LED Lighting

Fast Facts

  • LED lighting may be more energy efficient than traditional lighting, but it comes with health risks. 

  • LED lighting can interfere with your body’s circadian rhythm and the production of melatonin, an important hormone.

  • Chronic exposure to the blue-white light produced by LED lighting can have an adverse impact on the retina of the eye, possibly leading to age-related macular degeneration.

orange street light.jpeg

LEDs or “Light Emitting Diodes” are semi-conductors that produce light from electricity.  LED lights have a longer life and use less electricity than traditional light sources, such as incandescent lights. This efficiency, combined with the facts that LED lights come in a variety of colors and are more directional, have made them the most common type of lighting in use today for a wide variety of applications, from street lighting and car lights to digital devices and lighting inside our homes, schools and offices. 


LED lights come in range of colors, from those that mimic full-spectrum daylight to those that closely resemble the warmer glow of an incandescent bulb. Correlated color temperature (CCT) indicates the color appearance of a light source and is measured in degrees of Kelvin (K) on a scale from 1,000 to 10,000. Commercial and residential lighting CCT usually falls somewhere between 2000K and 6500K.  At the lower end of the scale (2000K - 3000K), the light produced has a warmer glow. CCTs between 3000K-6000K mimic daylight and have a harsher, blue-white appearance.

Federal, state and local initiatives for energy efficiency and conservation strongly encourage the use of LED lighting and efforts are underway all over the country to further accelerate this conversion.  While energy-saving efforts are very important, the long-term health effects of human exposure to LED lighting have not been fully studied.

Sunlight contains a variety of red, orange, yellow, green and blue light rays, each with its own wavelength and energy level. According to the American Medical Association, LED streetlights with higher levels of blue light can suppress melatonin production during the night, negatively impacting the body’s circadian rhythm and leading to reduced and poorer quality sleep, excessive sleepiness during the day and reduced attention spans.  Chronic exposure to blue light, which reaches deep into the eye, is associated with retinal cell damage and age-related macular degeneration (AMD).

According to a 2015 Harvard University health publication, “Study after study has linked the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease and obesity.”

It goes on to state that “while any kind of light can suppress the secretion of melatonin, blue light does so more powerfully.” A 2017 study conducted by researchers at the Harvard School of Public Health found that “exposure to residential outdoor light at night may contribute to invasive breast cancer risk.”

On average, people have their eyes open for about 6,000 hours a year, and for the majority of that time, they are exposed to artificial lighting. It is estimated that 90% of all light sources are LEDs, so our exposure to blue light is everywhere and increasing. Add to that the fact that people are living longer and children are exposed to electronic devices from an early age and you have an emerging public health situation that needs to be addressed.

Things you can do:


  • If “daylight” LED streetlights with a bright white/blue color have been installed in your neighborhood, use blackout shades or heavy drapes to prevent light from entering bedrooms.​

  • Reach out to your town officials if they are considering switching to LED street lighting and make sure they install 2700K bulbs which have an orange/yellow glow. These are best used for street lighting in residential areas.​

  • Avoid using any LED bulbs in your home. Traditional incandescent bulbs are now available as “long life” bulbs, and are preferred from a health perspective, especially in bedrooms.​

  • If you have an older computer, install a program to change the screen color to an orange (warmer) color after dark. Applications like f.lux or Iris are free downloads you can use.

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