City of stars, there’s so much that I can’t see (literally)
Cities and bright lights are synonymous, and stunning nightscape are often an important feature of a vibrant and flourishing city. Indeed, cities are meant to be sparkling, but bright lights have robbed us of other wonders of the world. For example, we know for sure that stars exist above our heads in the sky, but why is it that we see nothing but pitch black when we tilt our head up to the skies at night in the city? In this blog post, we will be looking into the frequently overlooked phenomenon of light pollution.
What exactly is light pollution?
Throwing back to the definition of pollution I gave in the very first post; pollution is introduction of harmful materials into the environment, in this case, light is our pollutive substance. It is important to note that pollutive light mainly refers to artificial lighting, so no, we will not have to fight the sun when combatting light pollution. Light pollution is a major side effect of urbanisation, and is often an underlying contributor to various health implications and ecosystem disruptions.
Sleepless nights in a city that never sleeps
In a city, one is rarely shrouded in darkness. Take Singapore for an example, to ensure safety and visibility at night, almost every corner of neighbourhoods is illuminated by a street lamp. Although light acts as a safety mechanism in the urban setting, as it discourages criminal activity (NCPC, 2003), constant exposure to artificial light can be detrimental to the natural rhythms in living things. Humans have an internal circadian clock that regulate our sleep cycle through roughly 24 hours. Exposure to artificial light at night when the body is supposed to be sleeping causes the clock to delay the production of melatonin, the hormone that triggers drowsiness. Longterm disruption of circadian cycle will eventually result in insomnia and related illnesses such as stress and anxiety from the lack of rest (NIH, 2021). There was even a study that linked circadian disruption to being a carcinogen to humans (IARC, 2007).
Dancing in the streetlights?
City light pollution also affects the wildlife that live close to or within urban environments. Many animals have the natural instinct to follow the sun or the moon for directional guidance, such as turtle hatchlings. Just recently in Singapore at Changi Beach, there was a sea turtle hatching event that caught the attention of the general public. Turns out, instead of moving towards the sea, the hatchlings mistook the park’s street-lamps as the moon, and made its way onto the bike paths, where many were crushed by unsuspecting cyclists. Thankfully, citizens noticed the tiny hatchlings and helped to divert and guide them back to the waters (Lee, 2021).
Do we turn off our lights at night then?
Of course it is not plausible to power off an entire metropolis at night time, however, there are still room for improvement in the current lighting structure of a city. For example, making the switch to energy-efficient and lower blue light LED street-lamps can decrease blue light exposure (which prevents melatonin release). Legislations can be established to control outdoor lighting, and sensors can be used for areas with less foot-fall. We can also do our part by installing blinds to prevent light trespassing.
References
International Agency for Research on Cancer. (2011, July 21). IARC Monographs Programme finds cancer hazards associated with shiftwork, painting and firefighting. https://web.archive.org/web/20110721001355/http://www.iarc.fr/en/media-centre/pr/2007/pr180.html
Lee, J. (2021, December 18). Sea turtles hatch near changi coast cycling path, passers-by rescue most of them. Must Share News – Independent News For Singaporeans. https://mustsharenews.com/sea-turtles-hatch-changi/
National Crime Prevention Council. (2003). CPTED Guidebook. https://www.ncpc.org.sg/cpted.html
National Institute of General Medical Science. (2021). Circadian rhythms. https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx#:~:text=Circadian%20rhythms%20are%20physical%2C%20mental,the%20study%20of%20circadian%20rhythms