The Fabric of our Society

June 2023

How Can We Design for Darkness? 

Oktay Akanpinar
Senior Designer, HLB Lighting

Since we know the impact that LED lighting can have on energy savings and CO2 emissions, many believe that we are making outstanding improvements to benefit the environment. However, humanity’s rush to drive away the darkness is still having significant environmental impacts, and light pollution is perhaps the most insidious.

Living under dark sky conditions is vital to the health and wellbeing of people and local wildlife. We likely can’t achieve a pristine dark sky, but we can reduce light pollution to get closer to dark sky conditions. Creative outdoor lighting with tunable, low-level sources can achieve interesting, navigable spaces. Kerem Asfuroglu of Dark Source, who took home the Best of the Best Award at the [d]arc awards in March, has shown us a great example of this. His Plas Y Brenin project rejected uniformity in favor of pools of light from bollards, enhancing the experience of the night.

Image courtesy of [d]arc media group

When we light public spaces like this, we are likely impacting hundreds of visitors with small or large health effects. More and more research shows that light impacts our circadian rhythms and sleep processes. We used to think that circadian systems were impacted by bright lighting, but we now know that even low light levels at night may disrupt health and wellness in sensitive individuals. Studies also show lighting moderating mood disorders like dissociative identity disorder in adolescents, neurological disorders such as Alzheimer’s, and Parkinson’s, and other conditions like obesity and cancer in shift workers. 

Several large studies have been released with long-term follow-up. Researchers continue to establish new connections between lighting and additional health issues and professions. Knowing this information, we are led to believe that intense use of light at night likely has unknown health impacts.

There’s no getting away

This is not just a problem for residents of cities and suburbs. Almost 100% of the population in Europe and the US is affected by light pollution and lack of dark skies; the global number is approximately 80%. Most of the Western world must travel hundreds of miles to see the Milky Way.

From lightpollutionmap.info

Outdoor lighting produces the most light pollution, but uncontrolled indoor lighting also contributes. Cameras on the International Space Station (ISS) have provided valuable, long-term data on light pollution, and the advance of LEDs has shown improvements. However, light pollution mapping instruments by VIIRS DNB are calibrated toward the warm end of the spectrum and detect light from 412 nm to 12 µm, toward legacy light sources including HPS.

Above: Background shows typical LED and HPS lamp spectra. From Cao, Changyong & Bai, Yan. (2014). Quantitative Analysis of VIIRS DNB Nightlight Point Source for Light Power Estimation and Stability Monitoring, Remote Sens. 2014, 6(12), 11915-11935; doi:10.3390/rs61211915. Remote Sensing. 6(12)]

LEDs show huge peaks in the blue light spectrum, which means that those devices in orbit can’t truly capture light pollution from LEDs. In fact, VIRRS DNB maps that show a slight drop in light pollution after 2016 may be wildly incorrect. We just don’t know. 

What we do know is that circadian disruption affects our well-being. If we could drop light pollution levels toward dark skies, it could possibly improve circadian rhythms for vast swaths of people. The research is ongoing, but some studies prove that exposure to darkness may correct circadian entrainment and aid in creating a natural circadian rhythm. Sleep flushes waste from the brain and gives the body’s cells the chance to regenerate. One study from South Korea showed that after being exposed to restricted levels of indoor lighting at night, an increased exposure to light pollution at night correlates with increased risk of breast cancer.

Newer studies are showing that light disrupts the entire web of life. Beyond the more well-known affected bats and insects, light at night encourages different types of flora and even disturbs the health of fish near coastal cities. We are not alone on this planet. We can take special care with lighting around waterways and consider turning lights off during bird and fish migrations.

How can our livelihoods benefit from darkness?

Careful design and detailing of lighting can be beautiful and contribute to darker skies. Lighting design practitioners should consider light levels and light color (particularly color-changing LEDs) deliberately. We should be thinking outside the box and questioning default design guidelines as they come up for review. It’s about time for us to figure out how we can apply the designing-for-darkness (or dark sky) ideology to the design process.

While we are not medical professionals, the research is accumulating, and we have a responsibility to respond. So please encourage your peers to keep up with developments. Members of the IESNYC are helping to drive the industry to the next level. The International Dark-Sky Association conferences are valuable, and we should cooperate with them as much as possible. Industry professionals can ask questions of manufacturers, standards- and code-setting bodies, and industry award programs – even our colleagues.

It’s great to have questions. Start with: How can we design for darkness?