Effects of reducing light pollution

Below are excerpts from The Journal of Epidemiology & Community Health. For listings of authors, affiliations, and references, please follow the link to the posting. I found the posting through an article by Eric Betz in Astronomy Magazine, Humans cling to their primal fear of the dark.

The effect of reduced street lighting on road casualties and crime in England and Wales: controlled interrupted time series   analysis                           

• Received 6 May 2015                                 
• Revised 2 June 2015                                 
• Accepted 3 June 2015                                 
• Published Online First 28 July 2015                                 

Abstract

Background Many local authorities in England and Wales have reduced street lighting at night to save money and reduce carbon emissions. There is no evidence to date on whether these reductions impact on public health. We quantified the effect of 4 street lighting adaptation strategies (switch off, part-night lighting, dimming and white light) on casualties and crime in England and Wales.                                 

Methods Observational study based on analysis of geographically coded police data on road traffic collisions and crime in 62 local authorities. Conditional Poisson models were used to analyse longitudinal changes in the counts of night-time collisions occurring on affected roads during 2000–2013, and crime within census Middle Super Output Areas during 2010–2013. Effect estimates were adjusted for regional temporal trends in casualties and crime.                                 

Results There was no evidence that any street lighting adaptation strategy was associated with a change in collisions at night. There was significant statistical heterogeneity in the effects on crime estimated at police force level. Overall, there was no evidence for an association between the aggregate count of crime and switch off (RR 0.11; 95% CI 0.01 to 2.75) or part-night lighting (RR 0.96; 95% CI 0.86 to 1.06). There was weak evidence for a reduction in the aggregate count of crime and dimming (RR 0.84; 95% CI 0.70 to 1.02) and white light (RR 0.89; 95% CI 0.77 to 1.03).                                 

Conclusions This study found little evidence of harmful effects of switch off, part-night lighting, dimming, or changes to white light/LEDs on road collisions or crime in England and Wales.                                 

• ACCIDENTS
                              
• SPATIAL ANALYSIS
                              
• Environmental epidemiology
                           

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/

Comments

[Ole Phat Stu]

FWIW : Belgium, which lights its Autobahns at night has 77 deaths per 10 billion vehicle-kilometers.
Germany, which doesn't, has only 50.

[Ingineer66]

I have not been to England, so I do not know first hand what their typical lighting levels are, but many European nations light their highways much more than we do in the U.S. I am a fan of more lights on the highway, not less. There is no doubt that lighting helps with traffic safety and helps reduce crime in innercity areas. In California, we have replaced many street lights with LEDs. These use far less electricity, so we are meeting our Carbon reduction goals and they produce a much whiter light that helps drivers see objects and animals in the road better than sodium vapor lights.

Stu, I am curious, what percentages of those Autobahn crashes were during hours of darkness. We need to whole picture to analyze the data.

I wonder if Hattie will chime in on this subject as well. The Big Island is quite dark and street lights are fairly rare because of all the telescopes on the mountains. The lights they do have are special low glare lights.

[Ole Phat Stu]

If you hire a motorcycle (or indeed a bicycle) to get around in Shangai, make sure you know how to turn the lights OFF at night, lest the cops charge you with potentially dazzling people!
No lights allowed on traffic at night in Shangai!

[Cop Car]

I have a personal hate toward street and house lighting. The house across the street has a porch light on all night long. The house across the street from our driveway has three lights on all night long (porch, and a bank of high-illumination lights pointing up-street and down-street) - all of which light up the interiors of the rooms on the front of our house if the vertical blinds are closed with the vanes in one direction. The street light next door lights up the rooms if the blinds are closed with the vanes in the other direction. That's why I made a basement room, at the back of our house, into my bedroom a few years ago.

Another consideration that Ingineer probably doesn't consider is the glare factor. Many of us elderly people, and some younger people with eye problems, can't see for the glare of all the lighting at night. With our aging population, this is a real issue!

All other issues aside, I wish I could see the stars at night. I remember that they were there when I was a kid and I'm betting that most of them still are; but, how would I be able to tell????

[Ingineer66]

It sounds like your neighbors are way overboard on lights. I do not leave any outside lights on after I go to bed. There is a streetlight that puts some light on the front yard.
I wear glasses and I am almost 50 so I hate glare as much as anybody. If I am on the open road at night with no headlights in my eyes, then I do not need street lights. But in a town with lots of traffic then lights are very welcome. I like to see stars as well.

[Cop Car]

Ingineer--I know that cataracts, Keratoconus, and Glaucoma are some of the eye disorders that can really cause problems with glare. I hope that you have none of them! My own issue, at the moment, is posterior capsule opacification - clouding of the part of the lens covering (capsule) that remains after cataract surgery. It is in my left eye - unfortunately, my dominant eye. Surgery has been scheduled for the 31st of this month which, 5 years following my original cataract removal in each eye, will hopefully let me see out of that eye, again. I didn't notice the degradation until several months ago.

There is a great interactive map of light pollution and an excerpt centering on Wichita from the global map. The larger city NE of Wichita is the Kansas City metro area, S of Wichita is Oklahoma City, and SE of Wichita is Tulsa.

[Ingineer66]

That is a cool map. You can see that Nortthern California is pretty dark. I was surprised at how different the east half of the U.S. Is compared to the west.

[Cop Car]

Ingineer--I was surprised how dark most of California is!

[buffy]

I wish you well in your surgery. I'm developing a cataract, but it should be some years until anything needs to be done. I'm still able to thread needles!!

It was difficult to adjust to all the light on our block when we moved. The two neighbors facing us leave their outdoor lights on, either all night, or well past our bed time. We also have four windows in the bedroom with blinds, and I don't wish to cover them with blackout drapes. I finally started using a sleep mask when I realized I had become light sensitive at night.

[Cop Car]

Buffy--As long as you can see to quilt, you'll be fine - lol! Hunky Husband is just now starting to develop cataracts but he didn't know he had 'em until the doc told him, so they aren't bad.

I can't imagine using a sleep mask; but, I'm happy that it works for you.

BTW: When I talked to our own neighbor, who has the brightest banks of lights, I was told that the lights kept the armadillos from attacking his lawn.