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Types of Light and Kelvin

What types of Light are there and how do they affect Melatonin production?

SOFT WHITE/WARM WHITE: Best for bedrooms and living rooms; providing a traditional warm, cosy feel to them

2700 K

BRIGHT WHITE/COOL WHITE: Best in kitchens, bathrooms or garages; giving rooms a whiter, more energetic feel

4100 K

DAYLIGHT: Best in bathrooms, kitchens and basements; good for reading, intricate projects, or applying makeup – provides the greatest contrast among colours

5000 - 6500 K

Kelvin Intensity Chart

Exposure to light at 6500K induced greater melatonin suppression.

LCD TV SCREEN = 5000K / 6500K or 9300K. IPHONE6 = 7300K Samsung Galaxy S3 = 7800K

The problem with Blue LED:

Blue LED illuminates with the intensity of 6500 K. 6500K is the equivalent of noon daylight. This represses the melatonin production and gives the pineal gland the idea that it has

https://www.batteriesplus.com/blog/lighting/seeing-things-in-a-different-light

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Melatonin Cycle

What is Melatonin?

Melatonin is a hormone secreted by the enigmatic pineal gland in response to darkness, hence the name hormone of darkness. Your melatonin cycle influences how rested you feel and builds up important resistance against diseases.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4334454/

How is Melatonin produced?

The production and release of melatonin from the pineal gland occur with a clear daily (circadian) rhythm, with peak levels occurring at night. Melatonin provides a circadian and seasonal signal to the organisms invertebrates. Melatonin is produced from serotonin (made from tryptophan), through a cascade of enzymatic reactions.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4334454/

Risks of decreased Melatonin

Increased chance of Diabetes 2

Increased chance of developing Cancer.

Drowsiness

Weight gain

https://theconversation.com/new-atlas-shows-extent-of-light-pollution-what-does-it-mean-for-our-health-60836

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Sleep Cycle

Sleep consists out of two parts: REM sleep (Rapid Eye Movement) and non-REM sleep. Together these stadia form the sleeping cycle, that takes around 90 minutes and happens every night around 4 or 5 times. When the body can't enter these cycles during the night, melatonin cannot be produced properly and we will feel tired, agitated and drowsy.

Sleepstadia: 

Awake:

Eyes are opened and have a lot of movement. Rapid use of facial muscles. Heartbeat and breathing are inconsistent based on activities. Melatonin production is repressed.

Stage 1: Drowsiness.

Brain activity is slower. Eyes shut often and inconsistent eye movement. The neck muscles relax what causes head bobbing. This stage lasts 5 to 10 minutes and consists of 5% of the total sleep cycle.

Stage 2: Sleep

Reduced slow eye movements and muscle tension. Disorientation with surroundings, but still easily wakeable. 

Stage 3: Deep Sleep

No eye moments and almost no muscle activity. Heartbeat and breathing become regulated and slower. Melatonin is released and influences your digestion, immune system and muscle tissue.REM SleepREM sleep is the phase where the brains are very active, but there is no connection with the surroundings. This is the phase where dreams happen. The muscles are inactive but only the eyes move.https://www.slaapinfo.nl/wat-is-slaap/

Sleep p hours

Netherlands: 8.45 hours

Sweden: 8.72 hours

United Kingdom: 8.06

South-Africa: 9.24

https://www.statista.com/statistics/521957/time-spent-sleeping-countries/

Sleep Satisfaction Holland

Data not found, but I think this could be very valuable to give more context to the overall hours of sleep.

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EFFECTS ON ANIMALS

BIRDS

Birds use the light from the Moon and stars and the setting Sun for navigation during their bi-annual migrations. City lights especially interfere with this instinctive behavior. It draws night-migrating birds toward brightly-lit buildings in urban areas. Once birds fly through a lit environment, they’ll return to that lit source and then hesitate to leave it, and in doing so, become trapped in cities and until they drop from exhaustion, becoming vulnerable to predation.

funny fact:

In 2003 three cocks kept the inhabitants of a street awake for weeks during the nights. The animals had swapped the Amstelpark for the lawn in front of the flats where they crouched loudly every half hour. The street lighting made them think that the day was by the bright lights.

Dutch bird GRUTTO:

lay their eggs away from the light, but their breeding environment is getting smaller due to the lighting of houses, cars and street lighting.

INSECTS

Some insects are attracted to artificial lights and will fly towards, and actually stop, some distance before a light, stuck there all night as if dazzled by the light, causing them to be unable to find food or to reproduce.

Other fly directly into the light and get killed by the hot glass surface. An average street lamp of about 150 insects per night, that makes 54.750 per year.

ANPHIBIANS

Anphibians have biological rhythms regulated by light. A lighter environment change their reproductive behaviour (male frogs calling for female partners) and movement activity. They are attracted to artificial lights because they can find more insects to eat but they are more likely to be bitten by cars.

REPTILES

Sea turtles are the most affected by light pollution. They nest in dark areas more and more difficult to find.

The hatchlings turtles are naturally driven by the brightest part of the beach (that should be the sea) but are distracted by artificial lights on the coast, driving them far from the sea, causing them to suffer dehydration, exhaustion, predation and possible death from cars on a nearby roadway.

MAMMALS

Herbivors reduce their activities (such as looking for food and mating)  during moonlit nights to avoid predators. Artificial lights may seem positive for predators but it causes a concentration of all of them in the same are, leading to fastest food reduction and faster disease transmission.

Similar to humans:

Artificial night lighting can disrupt circadian patterns, influencing the production of melatonin, influencing their health.

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This document focuses on potential changes to sky glow that can be expected from LED street lighting conversions, and does not address health concerns.

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As a reference, I really like this science infographic blog, they have a really interesting way to make science more accessible! http://tabletopwhale.com/

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Loved this dandelion piece at Stedelijk today, almost looks like a constellation, don't you think? 

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Many species of birds, especially the small insect-eaters, migrate at night. Migrating and nocturnal birds will use the light from the Moon and stars and the setting Sun for navigation during their bi-annual migrations. Light pollution hides their navigational aids. Artificial, city lights especially interfere with this instinctive behavior. It draws night-migrating birds toward brightly-lit buildings in urban areas. The Fatal Light Awareness Program reports that researchers have used radar imagery to determine how birds respond to lit environments. They observed that once birds fly through a lit environment, they'll return to that lit source and then hesitate to leave it, and in doing so, become trapped in cities that offer little food for them. The birds then often crash into brilliantly-lit broadcast towers or buildings, or circle them until they drop from exhaustion. Finally, once on the ground, stunned or injured birds become vulnerable to predation.

In January 2003, three cocks kept the occupants of a seniors' flat in Amsterdam for weeks sleeping through the night. The animals had swapped the Amstelpark for the lawn in front of the flats where they crouched loudly every half hour. The street lighting was the culprit: the cocks thought the day was by the bright lights.