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For Damien McNamara, what started out as protecting the sky from light pollution has evolved to protecting what is underneath it.

The Oamaru astronomer spoke at the New Zealand Starlight Conference in Tekapo last month, where he shared his story of how his son’s health was affected by a seemingly innocuous streetlight.

Mr McNamara’s passion for astronomy came from his father, Danny McNamara, who was a passionate and talented astronomer.

When he died in 2012, Mr McNamara inherited his telescopes and made a promise to keep his son Reuben (12), who had just been diagnosed with autism, safe and not let him forget his grandfather.

“That, over the past year or two, has become an extremely hard struggle,” Mr McNamara said at the dark-sky conference.

“With Reuben’s autism he’s always been tantruming; he’s always had issues with change.”

In 2017, things deteriorated to the point where Reuben’s behaviour was worsening and he started to put himself in danger.

It was not until a stargazer’s conference in 2018 that Mr McNamara was alerted to the link between blue light emissions and melatonin suppression.

He realised that at the same time Reuben’s behaviour had changed, the New Zealand Transport Agency (NZTA) had installed a 114W 4000 Kelvin LED light 12m from his son’s bedroom window.

“He is obviously quite sensitive in his melatonin balance, and how he operates within his structure,” Mr McNamara said.

“That, to me, still sounds ridiculous, that a streetlight did this to him, but what I have learnt over the last two years is some amazing things.”

Shortly after, Reuben moved house and within three weeks was back to his normal self, he said.

Blue light is a part of the light spectrum that gives off a “cool white” or “blue white” colour, which is greater than 3000K.

“The argument around NZTA subsidising this 4000K LED is how they light; in a sense, they are better visually,” Mr McNamara said.

“1750K is exactly the same as what we used to have.

“Think of the Kelvins as a piece of metal you are heating up. It starts off cold, and to get it hot you have to get it to white – so you go through the red, orange, yellow before it becomes white.”

Blue light had an effect on the body’s circadian rhythm, by telling us when it was time to wake up, Mr McNamara said.

“Blue light is good for us in the morning, because it tells us to wake up. That’s why when you stay up late at night on your cellphone or laptop you struggle to get to sleep.”

He hoped the NZTA would re-evaluate its use of lights and stop the current conversion.

“We just need the likes of people from NZTA to go back, understand the new research that is coming out and the fact that these are actually harming people.

“I would love the NZTA to put their hand up and say ‘we understand there is a risk here and we want to stop the current conversion, and we want to re-evaluate and take a second look at the evidence’ – that would be my dream.”

Mr McNamara said the night-sky movement started as astronomers campaigned for better viewing conditions, but has expanded as more research is done about the effect of blue light on the environment.

“I’m sort of back-to-front, because I’m an astronomer; I don’t fight for night skies for professional services, I fight for night skies for health and wellbeing.

“If we can protect us we are automatically protecting the night sky – there is no point protecting the night sky if we are not here to see it.”

What is blue light?

  • Blue light is part of the light we get from the sun. We receive it most in the middle of the day, and much less at sunrise and sunset. The body has evolved to use these differences to keep our body clocks in time with our surroundings.
  • Some modern lighting sources can produce relatively high levels of blue light. Computer and phone screens can also produce blue light.
  • Exposure to a lot of blue light in the evenings and at night can disrupt the body clock, leading to poor sleep and effects on other body processes that depend on the body clock, such as digestion. The possibility of other effects is also being investigated. However, levels from everyday sources, such as computers, phone displays and LED lights, are too low to damage the eye.
  • Blue light from lighting can be minimised by choosing LED or CFL bulbs with a “warm-white” colour, rather than “cool-white” or “blue-white”. Some bulbs are labelled with a “colour temperature”; choose them with a temperature of 2700K or 3000K.

Source: Ministry of Health