Sizing up health risks of sleep-disturbing LEDs

Article By : Carolyn Mathas

The American Medical Association is cautioning cities to recommend LEDs with colour temperature no bluer than 3000K and to minimise blue outside lighting.

We have discussed the havoc LEDs cause for our crawling and feathered friends. Apparently, the impact on animals was just the precursor to awareness of a potentially bigger problem.

Now the American Medical Association (AMA) has warned that high-intensity LED streetlights emitting blue light can disturb our sleep rhythms, specifically impacting melatonin creation, and possibly increasing such health risks as cancer and cardiovascular disease. The AMA also indicated that the lights negatively affect night-time driving vision.

__Figure 1:__ *Lighting streets with powerful LEDs could have a negative impact on your health. (Source: Nature World News)*

Naturally, there’s an argument on the other side that any potential health concerns are not certain enough to overshadow the benefits. There are solutions in lower intensity LEDs and bulbs with an amber glow rather than blue. However, the blue light emission from TVs and computers is always brought up as an argument that they’re relatively safe. More recent LEDs have lower kelvin ratings that don’t emit as much harmful blue light as those in the past. The AMA is cautioning cities to recommend LEDs no brighter than 3000K and to minimise blue outside lighting.

While others including the Lighting Research Centre indicate the AMA is going further than the risk warrants, it’s probably a good idea if you are in the process of ordering LEDs for your town to at least study the question. Gloucester, Massachusetts, did just that, changing an order for streetlights that were to be 4000K LEDs to 3000K models.

In comparison, Arlington, Virginia, installed streetlights operating at 5500K, which resulted in the blue tint and caused complaints from its citizens. In response, the county installed shields to focus the light onto the sidewalk and streets as well as dimming the LEDs down to 25% of full brightness capacity. The town is now researching the AMA’s report.

I imagine this is one situation where the long life of LEDs might be a negative?