Streetlights are important for drivers, for the most obvious reason that it helps them see when driving at night or in dark, gloomy weather.
However, the American Medical Association (AMA) has said the design of the lights could have a big impact on people’s health.
Following increasingly widespread use of LED streetlights in the USA, the AMA has adopted an official policy statement about street lighting, whereby an AMA committee issued guidelines on how communities can choose LED streetlights to “minimize potential harmful human health and environmental effects.”
According to a report by CNN, AMA recommends outdoor lighting at night, particularly street lighting, should have a color temperature of no greater than 3000 Kelvin (K).
“We encourage 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,” it said.
Colour 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.
Its other recommendations include a “proper conversion to community based Light Emitting Diode (LED) lighting, which reduces energy consumption and decreases the use of fossil fuels”, and encouraging “minimising and controlling blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare.”
Municipalities in the US are replacing existing streetlights with efficient and long-lasting LEDs to save money on energy and maintenance.
Although the move has helped achieve the savings goal, proper design of new technology is important, and though people may not consider it, there is a close connection between light and human health.
AMA said there are two major problems with the new LED lighting, namely discomfort and glare, as well as interference to the human body’s circadian rhythm.
“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.
Bright electric lighting can also adversely affect wildlife by, for example, disturbing migratory patterns of birds and some aquatic animals which nest on shore.
Lighting at night is of course very important, and streetlights using LED technology can be a good move to save on costs as well, but it must be designed properly so as not to have any detrimental effects on the public, and such moves must be well thought out.