Focus on "blind area" under classroom lighting

Recently, the news that "the lighting conditions of classrooms in Beijing's 1496 schools is unqualified" has attracted widespread attention from all walks of life. In response, the Beijing Municipal Education Commission, the Health Bureau and other departments jointly issued the “Circular on the Standardization of the Lighting of Classrooms and Blackboards in Primary and Secondary Schools in the City”, and decided to start the new semester at the beginning of September 1 this year, the classrooms and blackboards of the primary and secondary schools in the city. The average luminance pass rate reaches 100%.

As we all know, the lighting environment has an important impact on people's eyesight. The poor lighting environment in primary and secondary schools will inevitably affect students' vision. According to statistics, the incidence of nearsightedness among Chinese students is as high as 60%, ranking first in the world. The reason for this is that in addition to the heavy burden of schoolwork leading to eye fatigue, the lighting conditions in the classroom may not be the same.

Upon inquiry, the national standards for classroom lighting in China, the Hygienic Standards for Lighting in Classrooms and Lighting in Primary and Secondary Schools (GB 7793-2010) and the Architectural Lighting Design Standard (GB 50034-2004) have been issued. Since there are already relevant mandatory national standards, why are lighting conditions still unacceptable? The reporter conducted an interview on this issue.

According to the researcher of Zhao Jianping, deputy director of the Institute of Building Physics at the Chinese Academy of Building Research, at present, the terms of the school classroom lighting in the national standard “Architectural Lighting Design Standards” are generally adopted as a reasonable illumination for classroom lighting. Judgment basis. The standard stipulates that the illumination standard of an ordinary classroom is 300Lx, the illumination standard of a blackboard is 500Lx, and specifications such as light source, glare value, and lighting power density are specified.

It is understood that the classroom lighting does not meet the requirements of the relevant standards, mainly due to the setting of the lamps. In the case of blackboard lighting, in order to achieve the corresponding illumination standards, blackboard lights need to be installed on the blackboard, and this requirement is difficult to achieve in many schools.

A teacher at Caoqudi Middle School in Chaoyang District, Beijing, said that there are no blackboard lights in the school classroom. Schools often use multimedia equipment such as projectors and electronic whiteboards. If blackboard lights are installed, the screen of the device will be blocked from moving up and down. Chalkboard lights are rarely seen on campuses visited by reporters.

Liu Shiping, secretary-general of the China Illuminating Society, said that relative to the whole country, the lighting situation of Beijing primary and secondary school classrooms is still relatively optimistic. Schools in the city have been out of school around 4:00 pm, and there is plenty of sunshine during class hours. Therefore, the lighting and blackboard lights in the classroom only play an auxiliary role, and they play a role when the classroom is not well lit under cloudy days. .

Although there are many reasons, the "Beijing 2010 National Physical Fitness Monitoring Results Bulletin" shows that the detection rate of poor vision in primary and middle school students in Beijing is: 43.5% for primary school students, 71.89% for junior high school students, and 81.89% for high school students. The rate of detection of poor eyesight continues to rise, and there is a trend towards younger people.

According to an eye specialist from Beijing Tongren Hospital, the incidence of myopia depends mainly on genetic and environmental factors. When students conduct learning activities in poorly lit classrooms, the visual organs are often adjusted too frequently to adapt to the classroom environment, causing students to use eye fatigue, which leads to myopia. Therefore, it is imperative to improve the lighting environment in the classroom and use science to make room for the classroom.

The lack of uniform standards for the installation of lamps and lanterns According to the results of studies on vision health and light environment of primary and middle school students published by Tongji University in 2007, there are many health risks in the classroom lighting environment of primary and secondary schools: First, the illumination of the blackboard is not enough, there are no blackboard lamps, and the reflection glare is serious; It is a poor level of uniformity in the level of the classroom class desk.

From this point of view, even if the light fixtures are fully equipped, because of the lack of scientific guidance in lighting design, the real “achievement standard” is also not easy. Health supervisors said that the illumination of classrooms and blackboards was unacceptable, and the lighting fixtures, mainly lighting fixtures, were installed incorrectly.

Due to the lack of a uniform installation standard, the installation of lamps in various schools varies. Some schools use bracket lamps as lighting fixtures. The actual use efficiency of the lamps is extremely low, and they can cause great glare. Some schools do not assign shades to the blackboard lamps, resulting in low average illuminance and poor uniformity of the blackboard.

Zheng Ling, vice president and secretary-general of the Heilongjiang Vision Technology Association, believes that the correct way to achieve a good visual environment in the classroom is that classroom lighting should be equipped with 40W fluorescent lamps of 9 inches or more, and the lamps should be perpendicular to the blackboard; classroom lighting should be used Lamps with lampshades should not use bare lights. The height of the lamps from the tabletop should be 1.7 to 1.9 meters. The blackboard lighting should be provided with two 40-watt horizontal fluorescent lamps and equipped with lamp shades. When the natural lighting is insufficient, artificial lighting should be supplemented. .

From this point of view, the installation of lamps and lanterns is also an important condition for lighting "attainment standards." China's classroom lighting conditions are not qualified, not only the lack of hardware equipment, but also that it is not the correct implementation of the installation. Therefore, for the classroom lighting rectification work, not only the protection of the hardware, but also need to staff lighting installation, evaluation and acceptance training.

Looking forward to a new level of standards, reporters found out that the Health Standard for Lighting in Classrooms and Lighting in Primary and Secondary Schools (GB 7793-2010), which was revised and issued by the Ministry of Health and the National Standards Committee, has been implemented since May 2011. Compared with the old standard in 1987, the new standard revised the lighting standards for teachers' desks and blackboards, and increased the regulations for uniform light glare, classroom uniform glare, lighting power density, and maintenance factor. It requires that the average illuminance on the classroom classroom table should not be less than 300Lx; the classroom blackboard should have local lights, and its average illuminance should not be lower than 500Lx. The "Standard for Design of Primary and Secondary Schools" (GB50099-2011), which was implemented on January 1 this year, also uses the average illumination of 300Lx as the lighting standard for ordinary classrooms.

Zhao Jianping stated that the vast majority of existing classrooms in China are built before 2004 and are facing rectification, especially in remote areas where there are many average illumination requirements that cannot reach 300 Lx.

Not only that, the standards implemented in China still lag far behind the standards of the United States, Japan, and other countries. In Taiwan alone, for example, since 1991, Taiwan has clearly stipulated that classroom illumination should be greater than 500Lx, and blackboard illumination should be greater than 750Lx. Liu Shiping said that at present China is moving closer to this standard.

According to the research results of the Institute of Electric Light Sources of Fudan University, 300Lx is just the bottom line of classroom illumination in primary and secondary schools. Faced with the myopic rate of Chinese students climbing year by year, and the long hours of classes that exist in most parts of the country except Beijing, we hope that the national standard can “break the bottom line” and create a bright and comfortable learning environment for students.