Problems With Nocturnal Lighting

Effect on Sleep Patterns

• The natural body clock of most people works to keep them awake during the hours of light, and make them sleep during the hours of darkness. Exposure to nocturnal lighting can impact on this, disrupting sleep patterns. This occurs because the light affects the pineal gland, which produces melatonin to help induce sleep. Light can block the stimulation of the gland, resulting in less melatonin being produced, which can make it more difficult to sleep.

Effect on Health

• While melatonin helps to induce sleep, it is also thought to have other uses in keeping the body healthy. Exposure to nocturnal lighting that results in suppressed melatonin production can, therefore, have a link with health problems. This may include an increased chance of suffering some types of cancer, such as breast cancer, as well as conditions such as impaired immune function and Alzheimer's disease.

Driving Safety

• Nocturnal lighting can interfere with night vision, as bulbs may produce a glare that makes it more difficult to see. This can have safety implications, especially with regard to driving. Off-shore glare can also have implications for vessels navigating within sight of land, with the glare affecting the sight of navigation markers.

Effect on Nocturnal Flora and Fauna

• Nocturnal animals make up about 50 percent of the species on Earth, and they rely on darkness for a range of purposes, including hunting, concealment from predators and navigation. Night lighting which impacts their natural habitat can adversely affect their life cycle. Examples of this can include the navigation of migratory birds affected by the lights of buildings in towns and cities. Many plants also can have their natural life-cycle affected by nocturnal lights, which can affect flowering and chlorophyll production.

Light Trespass

• Excessive nocturnal lighting can cause light trespass problems between neighbors. Light trespass occurs when lighting used in the outdoor area of one home also illuminates other properties around it. Generally, outdoor lighting should have a sensitive design to ensure that it does the job required without affecting others.

Obscures the Night Sky

• The beauty of the stars in the night sky has a natural wonder that most people appreciate. The sky-glow caused by nocturnal lights tends to obliterate the view of the night sky in towns and cities, denying this wonder to many people. Amateur astronomers in particular will notice this, as it limits their opportunities to view astronomical bodies in the sky.