Light Pollution: The Many Reasons for Battling Light Pollution
There are numerous reasons for battling light pollution. Here, we will look at some of the various reasons for battling light pollution in modern-day cities in Singapore.
Effects on Animals
- Sea turtles at Risk
Sea turtles nesting along the coast of Florida in the U.S. are misguided by the bright artificial lights that illuminate the coastline. They were originally evolved to move in the direction of the sea by following bioluminescence of phytoplankton. However, these animals are guided by bright lights in hundreds towards populated areas along the coast, where urban lighting is much brighter than natural lighting and they are run over by vehicles and die in huge numbers.
- Birds at Risk
According to the Fatal Light Awareness Programme (FLAP), a Toronto-based organization, migrating birds become confused in bright urban areas when they are unable to see the guide stars that they follow and crash into buildings.
Furthermore, in cloudy or foggy conditions, light pollution reflecting off low clouds may also contribute to the disorientation. In 1954, as many as 50 000 birds died at Warner Robins Air Force Base in Georgia, U.S., when they followed lights straight into the ground over two foggy nights.
The city of Chicago in the U.S. has initiated a plan to ensure that migratory birds flying over the city at night during migratory periods are not affected by the city lights through the installation of light fixtures that do not contribute to light pollution.
Orion as seen from Singapore and Malaysia respectively. The picture on the right, taken in the Malaysian countryside, shows more stars than the one on the left, taken in light-polluted suburban Singapore.
Effects on the Environment
- Global Warming
Indirectly, light pollution also contributes to global warming. Excessive energy and resources are wasted every night as a result of light pollution. David Crawford, founder of the International Dark-Sky Association estimates that the U.S. spends about USD $2 billion each year on excessive lighting that leads to light pollution (http://www.darksky.org). This translates into high levels of greenhouse emissions when fuels (about 8 million barrels per year in the U.S.) are burnt to generate electricity to power such lighting fixtures.
Effects on the Populace
- Health problems related to prolonged light exposure
Health studies show that prolonged exposure of light over a long period of time could have negative impact on humans. Prolonged exposure to light affects hormonal levels and sleep patterns as well as the body’s natural renewal cycle. In the long-term, it could add to stress and psychological problems.
From the Environmental Building News (EBN) website BuildingGreen.com, nighttime illumination could affect estrogen levels in women, which in turn can increase susceptibility to breast cancer, according to studies still being carried out by medical researchers. The current hypothesis is that the high incidence of breast cancer in highly-industrialised countries could result from the higher dosage of estrogen.
Glare and light pollution affecting the elderly
Poor streetlight designs that are overly bright and direct light upwards ineffectively can also account for light pollution and its associated problems . According to the Illuminating Engineering Society of North America (IES), driver discomfort due to glare may cause fatigue and result in driver error.
Glare from poorly designed streetlights makes it difficult for elderly drivers to adjust their vision from dark areas to bright areas . This was shown in studies conducted by the U.S. National Highway Traffic Safety Administration (NHTSA) on the effects of different types of lighting on motorists.
From the Cut Waste Panel Replies and Suggestions page, the ‘zebra effect’ of bright and dark areas merging together causes motorists to feel tired at the wheel as eye muscles had to continually adjust to the lighting conditions. Also, elderly drivers require about thrice the amount of time compared to young people to adjust from brightly lit areas to dimmer areas, hence the potential for accidents is increased.
The increasing ageing population in many developed nations around the world means that city councils would also need to consider the lighting needs of the elderly in the near future. This is to cater to the decreased response time and sensitivity of the ageing eye when adjusting to different lighting levels (IDA Information Sheet 156, http://www.darksky.org). The ageing eye, coupled with poor lighting fixtures that cause glare, pose more risks for elderly drivers.