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  • Dec 29, 2014
  • Updated: 10:54pm
NewsHong Kong

Light pollution in Hong Kong 'worst on the planet'

It’s 1,200 times brighter over Tsim Sha Tsui than a normal dark sky, three-year study finds, posing a danger to health and wildlife

PUBLISHED : Wednesday, 20 March, 2013, 12:00am
UPDATED : Wednesday, 20 March, 2013, 8:55am

Hong Kong is believed to be the world's worst city for light pollution, with levels in Tsim Sha Tsui 1,200 times brighter than a normal dark sky.

The findings were described as shocking by survey leader Dr Jason Pun Chun-shing, of the Department of Physics at the University of Hong Kong.

He said he could find nowhere else on earth as badly affected.

From the notorious hotspot of Tsim Sha Tsui to the remote Sai Kung countryside, the researchers found excessive brightness of varying degrees that scientists said could damage health and wildlife.

Unlike major cities elsewhere - including London, Frankfurt, Sydney and Shanghai - Hong Kong has no laws to control external lighting.

But Secretary for the Environment Wong Kam-sing said he hoped a government task force on light pollution could come up with proposals for more "regulatory elements" for public discussion in the middle of this year.

He did not say if he meant legislation.

In the world's largest light pollution study, scientists collected more than five million brightness measurements at 18 monitoring stations over the past three years. They used an instrument known as a Sky Quality Meter installed on roofs. The worst reading was at the Space Museum in Tsim Sha Tsui from 8.30pm to 11pm, which was 1,200 times the International Astronomical Union standard.

Brightness started to dip after 11pm when lights gradually went out. Tsim Sha Tsui residents once threatened to take developers to court over excessive lights.

Even at the Astropark stargazing facility near High Island Reservoir - where most would expect a natural dark sky - the brightness was still 20 times the standard. Health specialists say light pollution could disrupt the biological clock and affect brain and hormone function.

Pun said that in some European cities like Madrid and Florence, the readings were normally below 100 times the standard.

He said energy-wasting signboards or spotlights that usually point upwards could generally be blamed in Hong Kong.

He added: "Lighting is supposed to provide safety and security for people's daily life. Lights are for human use and not for the sky. But what we see is that many lights are pointing to the sky."

Lighting is supposed to provide safety and security for people's daily life. Lights are for human use and not for the sky. But what we see is that many lights are pointing to the sky

Conservationists were alarmed by the reading at the Wetland Park in Tin Shui Wai at 130 times the standard.

Hong Kong Entomological Society chairman Yiu Vor said he feared the brightness would affect the breeding of fireflies, including the endemic bent-winged firefly, which relied on light signals to mate.

"They might not be able to notice the signals in a bright environment or they simply release the signal less frequently. This would affect their continuing survival." Yiu said insects that relied on moonlight to navigate could also be affected.

Pun said Hong Kong needed tougher measures to curb light pollution, instead of relying on voluntary technical guidelines.

Sydney requires all private illuminated signs to be scrutinised by the city council.

London also makes such nuisances a statutory offence carrying a fine or even imprisonment.


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This article is now closed to comments

I have yet to be convinced of the health problems caused by HK's iconic night lights. The only problem identified by this article appears to be the disruption to breeding of fireflies! I can live with that. I have yet to see one and to know what it does or doesn't do.
PS. Don't people have window blinds to cut out unwanted light from the outside anyway?
It is about affecting your breathing and health. Wear a mask? Those lighted signs are powered by electricity which burns air polluting coal in Hong Kong. Sure you love those signs, lit or not lit only if you own that wall or space and with added bonus the power plant too. Consumers just pay for the rent and electrical bill through the added cost of what being advertised. The magnitude in these outdoor advertisements has exceeded the purpose in lowering pricing by economy of scale. It has become a vanity struggle at the expanse of the general public’s health and wealth.

It is much easier to find fireflies if you leave the city streets.
The article is poorly put together and not inspiring for an average workaholic Hongkonger. Yes, if you do not care about other animals, light pollution may be a non-issue for you. Animals that rely on the natural nighttime environment have obviously been impacted the most from our light pollution.
For people, if you bathe yourself in the city lights until late every night, it does have an impact on your circadian rhythms, but many of us have the luxury of going home after dinner and closing our curtains before bed. (How about other people though?) Light pollution also can degrade the air quality for the next day; where typically some semi-natural chemistry "cleans" the air at night, that process is reduced with heavy light pollution. The impact from light pollution on the poor daytime air quality of HK could be as high as 5-10%, which may seem small but every little bit counts when it comes to our lungs.
Although it is is probably of a low value for most people, there is a night sky where on a clear night you should be able to see stars. However, a city like HK with its' intense light pollution does not make it possible for the majority of residents to ever see stars. I encourage you to look UP some nights and you may be able find planets and if you ever make it to a remote region of the world, it will blow your mind what the night sky actually looks like.
shortage of hospitals/worse health conditions/elderly people care/jobs/living standards/law and order/shortage of daily usage items even like baby milk/a big list of other problems. citizens legal rights are on high abuse in SAR and my repescted Dr Jason is worrying for lights thats the only/important issue in SAR which we should worry that much? All tax payers money SAR departments using for useless things there is no any improvments coming into SAR citizen's life day by day going worse
"The findings were described as shocking by survey leader Dr Jason Pun Chun-shing, of the Department of Physics at the University of Hong Kong"
Respected Dr Jason Pun > is this is the only problem hk have now ?
people are killing their love ones becuase of discreminating laws of SAR departments.people life is getting hand to mounth.citizens are begging for their legal rights and you are wasting time for these light surveys



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