Right. Grab a tea or coffee. Investigations are still ongoing and I stepped into the err ‘dark side’ of dark sky reserve criteria, so that makes it the light side of attending a meeting of Lighting contractors and designers.
Last week I went to a lecture by a leading Lighting Designer, he helped with the design of the UK Antarctica base Halley. At one point, with the help of physiologists and a medical team, he ran a few experiments on the Scientists wintering over to measure their melatonin levels and how to keep their circadian rhythm working for the benefit of their physical, mental and emotional well being. The melatonin hormone is also chillingly known as the cancer hormone. It was research required due to the help issues of wintering over and to help stop staff going into what is known as free-running where sleep patterns are completely disrupted. He was presenting his results.
I managed to get him aside before his lecture for a long talk on other research he has done, LED’s and the present stance on LED colour. He used to be part of a research team studying the effect of street lighting on turtles and agrees that 2700K is good for nature reserves. However. There is no research evidence linking the 4000K of street lighting with interruptions of the circadian sleep cycle of humans and in fact his research said the opposite. He used blue light of T5 lamps upt to 10,000 and 15000K. Real blue light and there was no discernible disruption to their sleep cycles. What he found made a difference was the intensity of light, how bright it was, so he designed 14000 lux lamps for a 20 minute routine every morning routine that set the sleep patterns cycles and they weren’t effected by the lighting that day, no matter what type.
What we do have is a link between poorly designed street lighting, poorly installed and poorly shielded street lighting all playing a part in the issues we are having now. There is also the point that the poorly designed street lighting is creating glare and in particular contrast issues; making it difficult for the human eye to discern its environment in a night environment. Couple with light pollution into bedrooms he believes is the problem. Our bedrooms need to be pitch black. He also queries the blue light issue of electronic equipment and wonders how ‘bright’ the equipment is and believes a study needs to look into that aspect further. (Though personally I believe no electronic equipment in the bedroom is a good thing.)
He also pointed out to me that the issue with 2700K lighting is the same we had with the sodiums of a similar colour. The lighting at night with those colours creates no colour definition, it required to increase in power usage to get the same cover as at 4000K street light – which costs more to run, and it can play havoc with our eyes rods and cones of our night vision. The example he gave was when you walk inside from an environment of orange light you can get a purple tone across your sight as your eyes adjust to the change and for some people this contrast in lighting can make them nauseous.
I made the acquaintance of a representative of the company that installed the Wellington lights and he is very keen about responsible street lighting installation and so a direct contact to the realities of installing street lighting. The issue of the lighting over in Avonhead etc is another matter and was put down to costs. My boss has already rang to complain about the lack of light pollution control with the fittings and he should know what he is talking about!
I was told by lighting installers that Wellington is getting 3000K LED’s and in the media it was mentioned that Dunedin is also going for 3000K. that puts them in good sted with the latest criteria of the IDA. Surprisingly I was told Kaikoura also has 3000K LED’s installed and that news I will definitely follow up as it didn’t look like it August last year. Christchurch does have some areas of 3000K. e.g the Terraces, which I will check out with a few pints, and an example of good street lighting is where you cannot see the street light fixture until you are right under it e.g. The Main Road across the estuary going to Sumner.
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