Current Outdoor Lighting Policies in China: Measures to Control Light Pollution

Abstract
Light pollution is a serious environmental issue with many adverse effects on human health and the ecosystem as a whole. Accordingly, many countries have issued laws and regulations to limit the effects of artificial lighting at night (ALAN). China is among the few countries that have drafted laws to curb light pollution. In the present study, we gathered data related to light pollution regulations and ordinances in China.

Introduction
Light pollution is one of the most rapidly increasing forms of environmental degradation. There is increasing evidence that draws potential linkages between artificial light at night (ALAN) and certain human health conditions. For example, a study by Rybnikova et al., based on World Bank databases, reported a statistically significant association between ALAN and prostate cancer incidence. A potential correlation between outdoor LAN and breast cancer incidence was also reported by Peter et al. In addition, ALAN has been linked to diabetes, fatigue, and depression. In addition to the effects of ALAN on the well-being of humans, sky glow resulting from ALAN is a major interference to astronomical activities. Furthermore, excessive and unnecessary ALAN is a key contributing factor to energy waste.
As such, these rapidly increasing adverse effects of ALAN on humans and the general interactions between ecosystems have led to subsequent legal actions against improper usage of light, especially at night. The involvement of governmental institutions, in the form of ordinances or laws against ALAN, has increased over the years. Light pollution laws, ordinances, and prescriptive measures are becoming common in many parts of Europe, Asia, and America.

The laws of China
Attention to light pollution is a recent activity in China, and theoretical research results are relatively limited. Light pollution prevention legislation is also scarce. So far, China has not issued special light pollution preventions or control legislation. The current law has failed to effectively solve China’s current light pollution problems. Therefore, it is necessary to evaluate the status quo of China’s light pollution prevention legislation.
1. Relevant Provisions of the Constitution of the People’s Republic of China
According to Article 26, “The state protects and improves the environment in which people live and the ecological environment. It prevents and controls pollution and other public hazards”. This provision can be regarded as the basis and premise for all laws and regulations on environmental pollution prevention, but it is only a principled provision of the general outline. It does not specify which types of pollution should be controlled. The expression of “other public hazards” is also vague. It cannot be used as a direct legal basis for relief.
2. Relevant Provisions of the General Principles of the Civil Law of the People’s Republic of China
According to Article 83, “In the spirit of helping production, making things convenient for people’s lives, enhancing unity and mutual assistance, and being fair and reasonable, neighboring users of real estate shall maintain proper neighborly relations over such matters as water supply, drainage, passageway, ventilation, and lighting. Anyone who causes obstruction or damage to his neighbor, shall stop the infringement, eliminate the obstruction, and compensate for the damage”. Article 83 is a provision on the principles of neighbor relations. The law states that it is necessary to correctly deal with the problem of “lighting” in neighbor relations. The so-called “lighting” means that the light is sufficient without interference from external adverse factors and harmful light. In the current case of light pollution, the court’s judgment is mostly based on neighbor relations. Therefore, it is not difficult to see that the limitations of the law in application of the case must first satisfy the condition of occurrence between adjacent real estate. This makes the neighboring right seem to be a little powerless in the relief of light pollution.
3. Relevant Provisions of the Property Law of the People’s Republic of China
According to Article 90, “An oblige of immovable shall not, in violation of State regulations, discard solid waste or discharge hazardous substances, such as air and water pollutants, noises, and optical and electromagnetic radiation”. In the legislation, the Property Law is the first to incorporate light pollution into the scope of legal regulation. It strictly prohibits destruction of the light environment and sets mandatory restrictions for emitted light. However, the provisions on light pollution in this article are too simple and have obvious limitations. This article stipulates that “obligations” are mainly restricted to real estate owners, and light pollution regulations in China require further improvement.
4. Relevant Provisions of the Environmental Protection Law of the People’s Republic of China
According to Article 24, “Units that cause environmental pollution and other public hazards shall incorporate the work of environmental protection into their plans and establish a responsibility system for environmental protection, and must adopt effective measures to prevent and control the pollution and harm caused to the environment by waste gas, wastewater, waste residues, dust, malodorous gases, radioactive substances, noise, vibration, and electromagnetic radiation generated in the course of production, construction, or other activities.”
5. China’s Local Laws and Regulations
Although China lacks national laws and regulations on light pollution prevention, the government has introduced many measures to prevent and control light pollution. Table 5 summarizes the lighting specifications issued by four different cities and the regulations and targets related to light pollution. Table 6 summarizes relevant preventive measures and related standards from relevant specifications. These standards illustrate which cities provide more comprehensive and effective measures.

（1）Urban Environmental Brightness Area Division
According to CIE (Commission Internationale de L’Eclairage), there are four types of environmental regions; namely, a naturally dark environmental region, a low-brightness environmental region, a medium-brightness environmental region, and a high-brightness environmental region, as detailed in the “Guide on the Limitation of the Effects of Obtrusive Light from Outdoor Lighting Installations”. Shanghai, Guangzhou, and Beijing also use the division of environmental areas to understand night lighting design and light radiation environmental management. Only Tianjin does not categorize brightness areas. Table 7; Table 8 show the division of urban environmental brightness.

（2）Prevention and Control of Light Pollution in Urban Environmental Lighting
In the prevention and control of light pollution in urban environmental lighting, the laws of Shanghai are clearly against direct light falling into residential buildings. All lighting facilities opposite residential buildings must take corresponding measures to prevent stray light from entering a home. To achieve this goal, building decoration materials should not use floodlighting materials. According to paragraph 2 of article 14 of the Tianjin City Lighting Management Regulations, the establishment of urban lighting facilities shall conform to the control standards of light pollution and shall be coordinated with the surrounding environment. Guangzhou Municipality stipulates that outdoor advertising, sign lighting, etc., should strictly abide by national and local lighting design standards, technical specifications, and light environment control zoning, and a rational selection of lighting sources, lamps, and lighting methods is necessary to reduce the effects of artificial lighting on the environment. Beijing has also imposed restrictions on artificial lighting at night. The specification proposes that light trespass and light interference be considered in the design of lighting systems.
（3）The Maximum Value of the Upward Light Output Ratio (ULOR) on a Luminaire
To better view the night sky, the brightness of the earth atmosphere must be reduced, so the upward light output ratio (ULOR) of outdoor lamps is important. Shanghai has a standard for the ULOR of different areas. Only Shanghai has this standard among many cities. Table 9 shows the maximum ULOR of luminaires in Shanghai (the upward light output ratio, sometimes called “upward efficiency of the luminaire”, is the fraction of the luminous flux emitted by the lamp going outside the luminaire in the upward direction. It is expressed in per cent).

（4）Residential Lighting
Regarding residential lighting, Shanghai, Guangzhou, and Beijing have corresponding regulations, but Tianjin does not. A residential area is a low-light area with low illumination. Shanghai limits the maximum vertical illumination on the surface of a residential building’s windows and the maximum light intensity for luminaires that point to the windows of the residential building. This effectively controls the impact of public road lighting. Guangzhou has drafted light radiation environmental management specifications (draft for comment). Lighting-related restrictions in residential areas have not been separately proposed. However, prohibition of housing, hospital outpatient emergency buildings and ward buildings, teaching buildings, and kindergartens is mentioned in the prohibition range of the glass curtain wall. In the interference light limitation, Beijing has proposed strict control of interference light from night lighting facilities on houses, apartments, hospital wards, etc. The maximum vertical illumination on the windows of residences and hospital wards is given, and the maximum light intensity of the illuminant is directly seen from the inside. Table 10 shows the maximum vertical illumination on windows in Shanghai. Table 11 shows the maximum light intensity limit on windows in Shanghai. Table 12 shows the vertical illumination limit on windows and light intensity of the illuminator on windows in Beijing (light intensity is the amount of visible power per unit solid angle, measured in candelas (cd, or lm/sr).

（5）Public Area Lighting
In the lighting restrictions of public activity areas, Shanghai provides lighting requirements for public activity areas and sets illumination standards for grasslands, gardens, platforms, and children’s playgrounds, where minimum illumination levels, illumination uniformity, and minimum vertical illumination are proposed. Guangzhou has imposed time limits on nighttime lighting in public areas. It is prohibited to have lighting in public areas from 22:00 to 6:00 in the evening and when it affects the normal rest of the surrounding residents. The luminaires and upward light output ratio (ULOR) of the night illumination of the square should conform to the urban nighttime lighting design specifications and must not cause glare or light environmental effects on pedestrians or motor vehicle drivers. Tianjin and Beijing have not imposed lighting restrictions on public areas. Table 13 shows the minimum illumination limit, illuminance uniformity, and minimum vertical illumination for public areas in shanghai.

（6）Commercial Center Lighting
Commercial areas are high-brightness areas. The average illuminance level of an entire shopping center (including pedestrian streets) and a square floor in Shanghai is no less than 20lx, and the uniformity (Emin/Eav) is 0.1–0.3. The vertical illumination at 1.5 m above the ground facing the viewing direction should be greater than 16 lx of uniformity (Emin/Eav) ≥ 0.2. Article 34 of the draft for comments in Guangzhou refers to the timing of signage lighting in stylistic and commercial places. The residential community and surrounding cultural and commercial establishments shall be provided with advertisements and signs that do not have outdoor lighting functions. If the surrounding interference light exceeds the technical requirements and causes complaints from residents, the city management comprehensive law enforcement department shall enforce the relevant regulations. Businesses should deactivate ads, logos, and signboard lighting at night before 23:30. This article only regulates the lighting time of style and commercial venues, which fully reduces residents’ complaints and the problem of urban light pollution. No such relevant regulations and restrictions exist in Beijing and Tianjin.
（7） Administrative Office Lighting
Administrative office areas belong to medium-brightness areas. The ambient lighting in the prescribed area of Shanghai should maintain the outdoor lighting level until the turn on/off light period and then reduce the minimum requirements to ensure pedestrians’ safety and security. After public illumination is reduced, the average vertical illumination on a floor of an office building or industrial plant floor should be less than 4lx, and the average illumination on the surrounding road should be no more than 2lx. However, this regulation only addresses safety-related issues and does not address lighting restrictions or light pollution restrictions. Other Chinese cities have no laws addressing lighting related to administrative offices.
（8） Building Exterior Lighting
In the architectural exterior lighting restrictions, Shanghai aims to determine the scale and intensity of floodlighting, the scale relationship between objects of floodlighting and the surrounding environment, and the viewing range. The direction of light projection of the building’s exterior lighting and the luminaires used should prevent glare and minimize light trespass. If the building facade is illuminated by floodlights, the direct luminous flux outside the illuminated surface should not exceed 25% of the total luminous flux of the fixture. Hospitals and residential buildings should not use floodlighting in outdoor spaces. Shanghai laws also provide maximum limit values for building surface brightness. In addition, Guangzhou City has proposed nighttime lighting requirements for buildings, glass curtain wall buildings, and night illumination of the main part of buildings, hospitals, residential buildings, etc., with a surface material reflectance less than 0.2; floodlighting shall not be used. Floodlight luminaires shall not project the beam into the interior of the illuminated building. The spilled light beyond the illuminated area shall not exceed the design specifications of the urban nightscape lighting. The main part of buildings including hotels should be encouraged to adopt the illuminating night illumination method of façade floodlighting and to use internal light-transmissive lighting. The use of internal light-transmitting illumination should limit internal light transmission and ambient light brightness and color to prevent the light from being affected by the internal light. Beijing offers a brightness limit for building facades. No regulations have been enacted in Tianjin. Table 14 and Table 15 show the maximum surface brightness of buildings in Shanghai and Beijing.

and so on.

Analysis of the Chinese Light Pollution Ordinances

In the lighting division, Shanghai has mentioned the maximum value of the upward light output ratio. In road lighting design, people often underestimate the increase in light pollution caused by the direct upward discharge of lamps. The upward light output ratio is often used to compare these emissions. Cinzano and Diaz Castro suggested that the direction of light emission is important for determining the amount of light scattered in the atmosphere and the size of the contaminated area. The spread of light pollution is also related to the direction of the launch. Therefore, decreasing the light output ratio is necessary to curb light pollution.

Furthermore, in residential lighting, Shanghai not only gives the maximum vertical illumination of windows, but also gives the standard of lighting intensity for residential areas. Falchi et al. reported that human exposure to light at night (LAN) reduces the production and secretion of pineal melatonin (MLT). Restraining the production of MLT requires two optical variables: Light intensity and wavelength. Therefore, an increase in light intensity may inhibit the production of MLT and have serious negative impacts on health. Light intensity has a negative impact not only on humans, but also on animals. Anika et al. experimented with perch, using aquariums to simulate four different light intensities for 14 days of observation. Through analysis, it was found that nighttime melatonin was inhibited as light intensity increased.

Meanwhile, Shanghai has only proposed minimum horizontal illuminance and vertical illuminance, but has not given a maximum limit for public area lighting. It has been documented that the main factor of the human sensation of glare is high light source brightness, and the overall brightness in human vision is closely related to the feeling of glare. Therefore, Shanghai has not paid much attention to the possibility of glare in public areas. The specification only mentions that the lighting in public activity areas should create a bright, clear, and friendly atmosphere. Therefore, its regulations do not constitute a standard for light pollution. In contrast, Guangzhou has clearly defined a design standard for public areas and proposed night lighting that effectively control the glare and light environment affecting pedestrians and motor vehicles.

However, although the specification mentions that lighting facilities need to meet design standards, the standards are subtly explained. In practical applications, there is a tendency for formalism and lack of maneuverability, and prevention and control of light pollution are not achieved. In addition, since commercial center lighting areas and administrative office lighting areas are in high-brightness areas, neither Shanghai nor Tianjin have given relevant restrictions on light pollution, and no specific solutions have been given. However, Guangzhou has pointed out that specific departments should solve the relevant complaints. As mentioned above in how to resolve related disputes, if there are no clear relevant standards, it is difficult for government departments to convince other departments, which brings difficulties to management. In addition, in green space and plaza landscape lighting, to avoid unnatural plant growth and generation of glare, Shanghai limits the distance, location, and time of illumination. Intense light pollution at night may disturb the growth of plants. More and more artificial lighting is used to grow plants in greenhouses, causing light pollution. Most creatures tend to be active at night, but, unfortunately, night lighting is also the most important for humans. Excessive artificial lighting not only interferes with the growth of plants, but also causes serious damage to the health of birds, fish, insects, and even humans. Therefore, a consideration of the effects on the human ecological environment is crucial. Although Shanghai has relatively curbed the production of light pollution, it has not proposed relevant standards. Similarly, Guangzhou has only limited the use of glass curtain walls, and Tianjin has only mentioned the prevention of glare.

In contrast, the emergence of floodlights has increased artistic beauty due to the emergence of modern buildings. Most floodlighting starts at the bottom of the object. This means that most of the luminous flux is directed to the sky, causing it to miss objects, especially in projects where inappropriate design or poor-quality fixtures are often used. This will lead to a huge loss of energy and light pollution. Krzysztof said that the ratio of luminous flux of floodlighting needs to be determined on the surface of the object and named this measure the floodlighting utilization factor, which is part of the luminous flux of an object. Therefore, the portion of light not directed at the object is the loss of luminous flux. He used formulas and computer simulations to calculate the floodlighting utilization factor and loss of luminous flux at different angles of illumination. Thus, the angle, the loss of luminous flux, and the floodlighting utilization factor can be used to determine the production of light pollution and the loss of energy. In Shanghai, clear regulations and standards are given for the floodlighting utilization factor and loss of luminous flux, which states that the luminous flux outside the building surface must not exceed 25% of the total luminous flux, and it gives the maximum limit of the brightness of a building surface. All in all, this measure can relatively reduce the occurrence of light pollution.

In advertising lighting, both the Illuminating Engineering Society of North America (IESNA) and the International Commission on Illumination (CIE) recommend limiting outdoor lighting. Although both give attention to this issue, the limits given by the two are different. IESNA gives the limitation of surface brightness, while the CIE150 report gives the limits of the brightness and vertical illumination of the sign. We all know that the surface brightness limit term adjusts the brightness of a single sign, while vertical illuminations are used to prevent outdoor light from entering a room. Although the latter is more suitable for evaluating the light intrusion status of advertising signs, Shanghai has not ignored the limitation of surface brightness and provides two limits.

In advertising lighting, Shanghai not only gives the limit values for surface brightness and vertical illumination, but also limits the LED display. In recent years, with the widespread use of LED displays in China, the LED advertising screens arranged in the city have seriously affected the normal life of residents. However, current international standards cannot be fully applied to the pollution status of Chinese cities. Therefore, research on LED display pollution in various cities in China is urgent. LED displays consume 12 times more energy per day than common signage lighting and severely increase the vertical illumination of the building façades in commercial areas, greatly increasing light intrusion. In addition, high-brightness dynamic picture LED displays create visual interference for drivers.

In summary, Shanghai has the most comprehensive limits on light pollution, followed by Guangzhou. However, the specifications of Guangzhou City are only drafts and do not have legal benefits. On the official website of the Guangzhou Municipal Government, to communicate with the people in a timely manner and solve problems, the government has a leadership mailbox. Some citizens have asked whether the regulations on environmental radiation management in Guangzhou have been officially promulgated and implemented. What is the basis? The government replied that it does not specifically regulate light pollution. It gives the Guangzhou building glass curtain wall management measures and the Guangzhou outdoor advertising and signboard management methods as measures related to light pollution. However, in these two regulations, only the relevant restrictions of LED display screens and glass curtain walls on second floors are specified in the relevant buildings. Finally, it can easily be seen from Table 6 that Beijing and Tianjin have not paid special attention to the relevant regulations on light pollution. Therefore, the relevant specifications given by Shanghai for the light pollution problem are the most comprehensive.

 Recommendations

The authors believe that improving China’s light pollution laws and regulations requires improvements to the legislative model, such as special legislation on light pollution. Depending on the actual situation of each city, light pollution impact assessment should be performed according to clear criteria. On the other hand, in future research of laws and regulations, the brightness of the night sky should be compared before and after the data in a range of years, so that the practicability of the current rules can be confirmed—for example, Wei Jiang et al. used the Defense Meteorological Satellite Program Operational Linescan System (DMSP/OLS) for data collection from 1992 to 2012 in assessing light pollution in China based on nighttime light imagery and analyzed the degree of light pollution in various regions of China. It was concluded that China’s light pollution has significantly expanded in provincial capital cities in the past 21 years. Therefore, by analyzing this, we can see that the degree of light pollution is on the rise when no relevant light pollution regulations are proposed. In the future, it is necessary to continue collecting proper data to compare and analyze the practicability of current rules on light pollution.

At the same time, in future research, the ecosystem needs to be paid attention to in light pollution. We can also conduct data comparison analysis. For example, Jonathan et al. [54] used DMSP/OLS in combination with GLC2000 to collect nighttime lights from 1992 to 2012 and evaluated the latest changes in nighttime artificial illumination for 43 global ecosystem types. The results indicated that the Mediterranean climate–ecosystem has experienced an enormous increase in exposure and that all terrestrial ecosystem types have experienced a certain degree of artificial light exposure and that this exposure is increasing. Through the analysis of the ecosystem, the relevant laws and regulations can be strengthened in the future.

In the era of big data, we not only need to use data collection but also need to listen to the opinions of the public—for example, the public’s views on light pollution and its impact on the environment. Lyytimaki et al. investigated the public’s views on light pollution as an environmental problem using a questionnaire survey. Of the 2053 responses to the study, 84.6% said light pollution had spread to all areas. A total of 82.9 per cent of the respondents said it was essential to be dark. Various light pollution sources were found in the problem of light pollution sources. The most commonly mentioned sources were street lamps, courtyard lamps, commercial lights, and outdoor decorative lights. Therefore, the author believes that only by combining a questionnaire survey, interviews, and DMSP/OLS data collection, etc. can the occurrence of light pollution be effectively controlled, and the effectiveness of laws and regulations be improved in the future.