1. To investigate the illuminance levels at different times of the day in some areas of Hong Kong
2. To examine the potential effects of light illuminance levels on people at different times of the day
3. To indicate whether government should set up legislations to solve the problem of light pollution or not
Hong Kong may proud to be called as one of the most beautiful city in the world, due to the majestic lights protruding from each of its districts. Ironically, this award had led to another one; being entitled as the worst light polluted city in the world. Light pollution had been a major phenomenon in the last few decades, particularly in urban areas. It was mainly caused by outdoor lights that scattered in the atmosphere and eventually reflected back to the ground. According to a survey conducted by physicists from University of Hong Kong, the light pollution in Hong Kong was so severe, to the extent that the urban night skies were averagely 100 times brighter than the skies at darkest rural sites. Moreover, in Mong Kok, the light pollution level recorded was even 500 times higher than the rural sites on Lantau Island (Pun & Chu, 2007).
Unlike Sydney and London that had already controlled their light pollution problems by issuing strict legislations, Hong Kong government had not set up any of them. Therefore, this study was necessary to give insights on the occurrence of light pollutions in some areas of Hong Kong and the citizens’ opinion about this matter.
Illuminance was the term used to measure the occurrence of light pollution. It was defined as the amount of light energy on a surface area per a unit, called as lux. 1 lux was equivalent to 0.0929 food candle or 1 lumen per square meter. Each location had different recommended illumination levels, due to the fact that each exhibited different environments. For instance, outdoor entrances were recommended to have 30 lux and kitchens to have 500 lux.
We hypothesized that the illuminance levels in Hong Kong will be really high, leading to a possibility of light pollution occurrence. As sunlight was natural lightning, we expected the illuminance levels at daytime would be lower than at night. We knew that more lightning were used to illuminate indoors places than outdoors places. Hence, we predicted indoor places would have higher light illuminance levels than outdoors places. In general, the members of public would feel distracted with the presence of excessive light or the occurrence of light pollution.
Methods and Materials
Before proceeding to other steps, smartphone with light meter application was installed. The ‘Light Meter’ application was chosen after checking its credibility and reading the users’ comments. Then, 4 different areas in Hong Kong were selectively picked, considering that all of them had both natural and artificial light sources. The selected areas were Mong Kok, Kowloon Tong, Tsim Sha Tsui, and Kwun...