Increasing use of one type of lightbulb may disturb sleep and health across Europe, study warns

An increase in the use of artificial blue light across large parts of Europe, including in the UK, could have negative impacts on human health and the environment, a new study has warned.

With more countries adopting energy-efficient light-emitting diodes (LED), the research suggested previous studies on light pollution have underestimated its impacts.

Satellite data in previous studies did not allow for sufficient differentiation on the effects of blue, green, and red light waves, said scientists, including those from the University of Exeter in the UK.

In the new research, published in the journal Science Advances on Wednesday, scientists used imagery obtained from astronauts on board the International Space Station (ISS) to map the differences in the spectral composition of lighting across Europe for the period between 2012-13 and 2014-20.

From the data, scientists said there was a “widespread spectral shift” in artificial lighting from one linked to high-pressure sodium lights to one associated with broad white LEDs and with greater blue emissions.

Previous research has shown that long-term exposure to blue light is linked to “detrimental effects” on a range of cells and may speed up the human body’s aging process.

The spectral shift observed in the new study across Europe was most prominent in the UK, Italy, Romania and Ireland, with Austria and Germany experiencing the least change.

Citing earlier research assessing the effects of artificial nighttime light on melatonin – the hormone associated with the sleep cycle – the trend of increasing artificial lighting could widely increase the risk of harmful effects.

“Melatonin cycles are key components of the circadian systems and determinants of biological temporal organisation for a multitude of organisms and the production of this hormone is suppressed by artificial nighttime lighting,” researchers wrote in the study.

Humans are not the only ones likely affected.

The trait of some insects to move toward natural light is also affected by the growing use of artificial light, the study warned.

“Increases in emissions at blue wavelengths may also alter the phototaxic response of moths and other insects to artificial nighttime light,” the study noted, adding that some bat species may also likely be affected.

Countries like the UK, Romania and Spain have experienced particularly large increases in these environmental risks.

While LED technology has provided several benefits for public lighting, including reductions in energy costs and carbon emissions, researchers said the spectral shifts from its increasing use are also linked to an increased likelihood of its negative biological impacts.

“We find that this trend is widely increasing the risk of harmful effects to ecosystems,” scientists said, adding that further studies are needed to quantify environmental risks associated with exposure to artificial nighttime light.