Story highlights
The American Medical Association urges communities to minimize health and environmental risks
White LEDs are thought to be five times more effective at suppressing melatonin than sodium lamps
The American Medical Association (AMA) has just adopted an official policy statement about street lighting: cool it and dim it.
The statement, adopted unanimously at the AMA’s annual meeting in Chicago on June 14, comes in response to the rise of new LED street lighting sweeping the country. An AMA committee issued guidelines on how communities can choose LED streetlights to “minimize potential harmful human health and environmental effects.”
Municipalities are replacing existing streetlights with efficient and long-lasting LEDs to save money on energy and maintenance. Although the streetlights are delivering these benefits, the AMA’s stance reflects how important proper design of new technologies is and the close connection between light and human health.
The AMA’s statement recommends that outdoor lighting at night, particularly street lighting, should have a color temperature of no greater than 3000 Kelvin (K). Color temperature (CT) is a measure of the spectral content of light from a source; how much blue, green, yellow and red there is in it. A higher CT rating generally means greater blue content, and the whiter the light appears.
A white LED at CT 4000K or 5000K contains a high level of short-wavelength blue light; this has been the choice for a number of cities that have recently retrofitted their street lighting such as Seattle and New York.
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But in the wake of these installations have been complaints about the harshness of these lights. An extreme example is the city of Davis, California, where the residents demanded a complete replacement of these high color temperature LED street lights.
Can communities have more efficient lighting without causing health and safety problems?
Two problems with LED street lighting
An incandescent bulb has a color temperature of 2400K, which means it contains far less blue and far more yellow and red wavelengths. Before electric light, we burned wood and candles at night; this artificial light has a CT of about 1800K, quite yellow/red and almost no blue. What we have now is very different.
The new “white” LED street lighting which is rapidly being retrofitted in cities throughout the country has two problems, according to the AMA. The first is discomfort and glare. 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.
You can sense this easily if you look directly into one of the control lights on your new washing machine or other appliance: it is very difficult to do because it hurts. Street lighting can have this same effect, especially if its blue content is high and there is not appropriate shielding.
The other issue addressed by the AMA statement is the impact on human circadian rhythmicity.
Color temperature reliably predicts spectral content of light – that is, how much of each wavelength is present. It’s designed specifically for light that comes off the tungsten filament of an incandescent bulb.
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However, the CT rating does not reliably measure color from fluorescent and LED lights.
Another system for measuring light color for these sources is called correlated color temperature (CCT). It adjusts the spectral content of the light source to the color sensitivity of human vision. Using this rating, two different 3000K light sources could have fairly large differences in blue light content.
Therefore, the AMA’s recommendation for CCT below 3000K is not quite enough to be sure that blue light is minimized. The actual spectral irradiance of the LED – the relative amounts of each of the colors produced – should be considered, as well.
The reason lighting matters
The AMA policy statement is particularly timely because the new World Atlas of Artificial Night Sky Brightness just appeared last week, and street lighting is an important component of light pollution. According to the AMA statement, one of the considerations of lighting the night is its impact on human health.
In previous articles for The Conversation, I have described how lighting affects our normal circadian physiology, how this could lead to some serious health consequences and most recently how lighting the night affects sleep.
In the case of white LED light, it is estimated to be five times more effective at suppressing melatonin at night than the high pressure sodium lamps (given the same light output) which have been the mainstay of street lighting for decades. Melatonin suppression is a marker of circadian disruption, which includes disrupted sleep.
A dark night is good for your health
Bright electric lighting can also adversely affect wildlife by, for example, disturbing migratory patterns of birds and some aquatic animals which nest on shore.
Street lighting and human health
The AMA has made three recommendations in its new policy statement:
First, the AMA supports a “proper conversion to community based Light Emitting Diode (LED) lighting, which reduces energy consumption and decreases the use of fossil fuels.”
Second, the AMA “encourage[s] minimizing and controlling blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare.”
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See the latest news and share your comments with CNN Health on Facebook and Twitter. Third, the AMA “encourage[s] the use of 3000K or lower lighting for outdoor installations such as roadways. All LED lighting should be properly shielded to minimize glare and detrimental human and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods.”
There is almost never a completely satisfactory solution to a complex problem. We must have lighting at night, not only in our homes and businesses, but also outdoors on our streets. The need for energy efficiency is serious, but so too is minimizing human risk from bad lighting, both due to glare and to circadian disruption. LED technology can optimize both when properly designed.
Richard G. “Bugs” Stevens is a professor in the School of Medicine at the University of Connecticut.
FAQs
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.
What are the problems with LED streetlights? ›
Disadvantages of LED Streetlights
Circadian rhythms, which effect a person's sleep/wake cycle, among other processes, are behind this reaction. Blue content in light can keep people awake, so when they're exposed to it and their circadian rhythms are disrupted, they run the risk of health problems.
How is LED lighting risks harming health? ›
LED lights and our devices do contain a significant amount of blue light (but with important caveats and qualifications - see below), and the concern is that excessive use during evening hours will cause our bodies to continue the production of melanopsin, making it harder to fall asleep naturally.
What is the negative impact of LED lights? ›
The increased amount of light and type of light from LEDs has negative effects on human and animal health. In humans, this leads to disrupted sleep cycles and an array of health problems associated with a lack of sleep.
Are LED streetlights worse for light pollution? ›
While energy efficiency is a clear environmental benefit of LEDs, research shows that they are worsening light pollution, a clear detriment.
Why are LED lights not road legal? ›
Fitting them ensures that your lamp will not perform as designed and will prejudice the Whole Vehicle Type Approval of your vehicle, making it unroadworthy. This is why sellers tend to state that their LED bulbs are sold for off-road use only.
What are the negatives of smart street lighting? ›
Risk of theft of the automatic street light system is relatively higher since they are non-wired & are much expensive. Rechargeable batteries of the automatic street light system are required to be replaced a few times. Snow, dust or moisture can accumulate of PV panels which can hinder energy production.
Can LED lights cause anxiety? ›
Being exposed to this flickering light creates high levels of stress to the brain as it needs to work extremely hard to process the rapidly changing light signals. This then leads to high levels of adrenaline and cortisol, which in-turn leaves people feeling irritable and anxious.
Are LEDs cancerous? ›
According to the study, only outdoor artificial light that was high in blue light showed a direct correlation with an increased risk of cancer. Other kinds of outdoor artificial light like those rich in the red and green components of the visible light spectrum showed no similar effect.
Does LED affect your brain? ›
How much the LED lights affect the human brain depends entirely on the location of the LED lights. However, LED lights have more short wavelengths than incandescent lamps and fluorescent lamps. This does not mean that it has many harmful effects on the human body.
Disadvantages of LED Bulbs
Most white LED bulbs emit a cooler, blue-tinted light — rather than the “warmer” glow that is associated with incandescent bulbs. Some people prefer “daylight” or “natural light” LED options. Some LED fixtures may create sharp shadows that may not be desirable in certain places in the home.
Are LED streetlights safe? ›
LED streetlights with a CCT of 5000K can cause discomfort and glare. The high blue light content can cause severe glare, eventually resulting in pupilary constriction in the eyes. High levels of blue light can damage the retina as well. This increases the risk of accidents when driving or walking at night.
Are the components of LED lights toxic to humans and the environment? ›
LED lights do contain hazardous materials such as arsenic, lead, iron, copper, and nickel. Heightened, direct exposure or consumption of some of these substances can lead to cancer, diabetes, and skin lesions.
What are the environmental risks with LED lighting? ›
LEDs are a significant source of light pollution as they are often used in outdoor displays. These digital displays often rely on blue LEDs, which are particularly harmful to animal behavior due to their impact on melatonin.
Do LED streetlights affect insects? ›
'Eco-friendly' LED streetlights are even more harmful for insect populations than the traditional sodium bulbs they are replacing, a NERC-funded study has shown.
Are LED lights worse for the environment? ›
Greenhouse gas emissions associated with the LED lights are considerably lower than conventional incandescent or Compact fluorescent lights. According to careful calculations, one LED bulb, providing the same luminosity as one incandescent bulb emits 80% less greenhouse gases.
Are LED lights illegal in the US? ›
Yes, LED headlights are legal. LED lighting is now standard in new cars, but LED headlights cannot be brighter than 3,000 lumens. Rachael Brennan.
What color LED lights are legal? ›
Light Coloring
In compliance with federal recommendations, all states require headlights to be white or amber. It's usually illegal if any other color of light can be seen from the front of the vehicle. This restriction applies to roof lights, under-glow, and lighting in the engine compartment.
What are the pros and cons of LED street lights? ›
What are the advantages and disadvantages of LED Street Lights
| Advantages | Disadvantages |
|---|
| Energy efficiency | Initial cost |
| Long lifespan | Light pollution |
| Improved visibility | Glare |
| Durability | Compatibility issues |
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- High up-front costs.
- Transformer compatibility.
- Potential color shift over lamp life.
- Performance standardization has not yet been streamlined.
- Overheating can cause reduced lamp life.
Replacing conventional streetlights with LED lighting can greatly reduce energy use and maintenance costs while improving light quality and output at street level. Advantages of LED streetlights include: Energy efficiency: LED fixtures use 50% to 75% less energy than traditional high-pressure sodium vapor fixtures.
Why LED street lights are better? ›
Benefits of LED
LED street lighting will: minimise light pollution into homes and gardens by directing light onto the road and pavement where it is needed. last longer and reduce likelihood of faults. be much more energy efficient and reduce energy consumption.
Why do LEDs make me feel sick? ›
Arnold Wilkins—one of the leading researchers on lighting and health—has stated that LED bulbs switch on and off hundreds of times per second. This can lead to symptoms of eye movement dysfunction, double vision, headache, dizziness and the feeling of being unwell, all within 20 minutes of exposure!
Can LED lights trigger vertigo? ›
LED lights may be more likely to cause dizziness and other chronic conditions than fluorescent lights. According to Professor Arnold Wilkins, a professor of psychology at the University of Essex, “People exposed to LED lights can start feeling dizzy and ill within 20 minutes' exposure.”
Why do LED lights bother my eyes? ›
It has been shown that our eyes react to the blue light, telling our circadian rhythm to “stay awake”. Similar to the sunlight, blue light signals our brain that it's time to get going. This means that using LED excessively, especially at nighttime can cause eye strain and influence your sleep.
Do LED lights give headaches? ›
Both LED and fluorescent lighting are proven to cause migraine headaches. They're also implicated in multiple health issues, and the research is ongoing, with additional effects likely to be discovered. Stay ahead of the health curve by protecting your home and workplace with safe light filters.
Are LED lights considered hazardous? ›
While they do contain some heavy metals, such as lead and copper, the California Department of Toxic Substances Control has not classified spent LEDs as hazardous waste.
Do LED lights affect your skin? ›
Red LED light therapy may reduce inflammation and stimulate the production of collagen, a protein responsible for younger-looking skin that diminishes with age. Blue LED light therapy may destroy acne-causing bacteria (P. acnes).
Which light may accelerate aging? ›
Exposure to blue light may accelerate aging.
What happens if LED gets into your body? ›
Exposure to even low levels of lead can cause damage over time, especially in children. The greatest risk is to brain development, where irreversible damage can occur. Higher levels can damage the kidneys and nervous system in both children and adults.
Lead exposure can cause high blood pressure and brain, kidney and reproductive health issues in adults. Symptoms of lead poisoning include headaches, stomach cramps, constipation, muscle/joint pain, trouble sleeping, fatigue, irritability, and loss of sex drive.
When should you not use LED bulbs? ›
Enclosed fixtures that don't allow for proper ventilation can drastically affect the temperature of the LED bulb, causing it to overheat and shortening the lifespan of the bulb. That's why some bulbs will tell you not to use it in an enclosed ceiling fan or fully enclosed porch light fixture.
Do LED lights have EMF? ›
Yes. Some light bulbs are designed in such a way that their mechanism creates EMF radiation or UV radiation. The worst offenders are LED bulbs (with built-in transformers), CFL lights, Fluorescent lamps, and Smart light bulbs.
Do LEDs use more electricity than lights? ›
LEDs consume far less electricity than incandescent bulbs, and decorative LED light strings such as Christmas tree lights are no different.
What is the lifespan of LED street light? ›
How long do LED's typically last? The life span of the selected LED is designed to operate for around 100,000 hours, which is significantly (around 6 times) longer than that of most incandescent, fluorescent or High Intensity Discharge (traditional street lighting) lamp sources.
How can I protect my eyes from LED lights? ›
So, how can I protect my vision from LED exposure? The ANSES report recommends buying “warm white” LED home lighting, limiting your exposure to LED sources with a high concentration of blue light, and avoiding LED screens before bedtime.
Do LED streetlights emit blue light? ›
LED streetlights that generate a large amount of blue spectral content can have consequences for humans, animals, and ecosystems, researchers wrote in the journal Science Advances.
What is the life expectancy of LED street lights? ›
Long and predictable lifetime: The projected lifetime of LED street lights is usually 10 to 15 years, two to four times the life of currently prevalent HPS.
Are LED street lights good? ›
LED street lights offer many advantages. They are sustainableandcost-efficient because they last longer and consume less energy than their conventional equivalents such as incandescent, halogen or fluorescent lights.
What causes LED street lights to flicker? ›
Check your lamps, wires, ballast/driver, and tombstones for bad connections or loose wires. A common reason for flickering T8 LEDs is a loose connection within the circuit. Addressing a power-connection issue or loose wire to the driver circuit will often easily resolve the flickering or no-power issue.
While incandescent light bulbs were built to last around 1,000 hours, the most enduring LED light fixtures have been tested to last as long as 100,000 hours. On average LED light bulbs will not have to be changed for at least 20 years.
Do LED lights fade with age? ›
Let us shed light on the most common myths to give you a clearer picture of how LEDs can work for you. Do LEDs last forever? LED bulbs do last a lot longer than the average light bulb, but no, they won't last forever. Like all light sources, they eventually fade over time.
Why do LED lights have a longer lifespan? ›
Because LEDs are as much as 90% more effective than incandescent light bulbs, they have a much longer lifespan. This is because they have no working parts that will burn out or break over time. An average LED light is a very robust piece of kit.
Can LED lights last all night? ›
Because of the lifespan of an LED and its energy-saving capabilities, you'll end up saving a lot of money in the long run. So yes, you can keep LED lights on 24/7. Whether it's Christmas lights or strip lights, LED lights are the best option for prolonged usage.
What color temperature are LED street lights? ›
The color temperature of the LED street lamp is white light emitted at around 5000K, and yellow light or warm white light at around 3000K.
Why are new LED street lights blue? ›
The department installed LED lights with a white coating "a while ago," Iowa DOT said in a Facebook post. Now, that coating is flaking off, causing the lights to appear more blue or purple. The LED lights were originally installed to replace sodium vapor lights from the 1970s.
What percentage of street lights are LED? ›
In all, at least 13 percent of outdoor lighting is now LED, and many communities that haven't yet made the switch are rushing to do so. The LEDs are up to 50 percent more energy-efficient than the yellow-orange high-pressure sodium lights they replaced. They last for 15 to 20 years, instead of two to five.
Are LED street lights better than sodium? ›
LEDs are an ideal light for purposely turning on and off because they respond rather instantaneously (there is no warm up or cool down period). They produce steady light without flicker. High pressure sodium bulbs may flicker and/or cycle on and off as the bulb reaches the end of its useful life.
Why do my LED lights flicker at night? ›
But most commonly, LED bulbs may flicker or dim in your home when there are voltage fluctuations in your home's wiring. When electrical loads turn on and off in your home, this creates a change in voltage levels, which may cause the LED lights to occasionally dim or flicker.
Why do LED lights flicker before they burn out? ›
Cause: LEDs only provide light when an electrical voltage runs through them. If this voltage is not constant, flickering will happen. This only affects LED bulbs because others like halogens and incandescent maintain enough heat to cover brief gaps in voltage.
LED lights with high flicker rate can cause various health complications. Because of the flicker, human eyes are forced to rapidly adjust to changing light output, which stresses the eye muscles.
