The Basic Environment Act is a law that aims to promote environmental conservation comprehensively and systematically by establishing fundamental principles for environmental conservation, clarifying the responsibilities of the national government, local governments, businesses, and citizens, and defining the basic matters concerning environmental conservation measures, thereby contributing to securing a healthy and cultured life for the people of the present and future, as well as contributing to the welfare of humankind (Article 1).
Article 2, Paragraph 3 of the Basic Environment Law defines "pollution" as "damage to human health or the living environment caused by widespread air pollution, water pollution, soil contamination, noise, vibration, ground subsidence, and offensive odors resulting from business activities or other human activities, among other obstacles to environmental conservation." To prevent each type of pollution, laws such as the "Air Pollution Control Law," the "Water Pollution Control Law," the "Soil Contamination Countermeasures Law," the "Noise Regulation Law," the "Vibration Regulation Law," the "Law Concerning the Regulation of Groundwater Extraction for Buildings," the "Industrial Water Law," and the "Offensive Odor Prevention Law" have been established.
Under the Noise Regulation Law and the Vibration Regulation Law, noise and vibration regulations are to be set by the prefectural governor (or the mayor of the municipality if there are natural or social circumstances in the area) within the range of standards set by the Minister of the Environment. Therefore, vibration and noise regulations for each region may be set by the prefecture or by the municipality.
The standards set by the Minister of the Environment are stipulated in the following notifications from the Environment Agency, etc.
The "Environmental Standards for Noise (Ministry of the Environment Notification No. 64, September 30, 1998; revised: Ministry of the Environment Notification No. 45, May 26, 2005)" sets environmental standards at 55 to 65 dB for areas facing roads (65 to 70 dB for roads carrying main traffic), depending on the area and time of day, and 40 to 60 dB for other areas.
The noise evaluation method, in principle, is based on the equivalent sound level (L Aeq) over the entire duration for each time segment. Furthermore, noise measurements are performed using a sound level meter that meets the requirements of the Measurement Law, and the frequency response uses A-weighting. The measurement method generally follows JIS Z8731.
The "Standards for the Regulation of Noise Generated at Designated Factories, etc. (Ministry of Health and Welfare, Ministry of Agriculture and Forestry, Ministry of International Trade and Industry, Ministry of Transport Notification No. 1 of November 27, 1968; revised: Ministry of the Environment Notification No. 132 of September 29, 2006)" sets out standards for noise regulation at designated factories, etc. (40 to 70 dB depending on the area and time of day).
Noise measurements are performed using a sound level meter that meets the requirements of the Measurement Law, with A-weighting used for frequency characteristics and FAST for dynamic characteristics. The measurement method follows the noise level measurement method specified in JIS Z8731, and the determination of noise magnitude is as follows:
- If the reading of the sound level meter does not fluctuate or fluctuates only slightly, that reading shall be used.
- If the reading of the sound level meter fluctuates periodically or intermittently, and the maximum value of the reading remains approximately constant, the average of the maximum values for each fluctuation shall be used.
- If the sound level meter reading fluctuates irregularly and significantly, the upper limit of the 90% range of the measured value (5% time factor sound level L5) should be used.
- If the sound level meter reading fluctuates periodically or intermittently, and the maximum value of the reading is not constant, the upper limit of the 90% range of the maximum value for each fluctuation shall be used.
The "Standards for the Regulation of Noise Generated by Specific Construction Work (Ministry of Health and Welfare and Ministry of Construction Notification No. 1, November 27, 1968; revised: Environment Agency Notification No. 16, March 28, 2000)" stipulates that the noise from specific construction work must not exceed 85 dB at the site boundary. Furthermore, the method of noise measurement and the determination of noise levels are the same as those in the "Standards for the Regulation of Noise Generated in Specific Factories, etc."
The "Permissible Limits for Automobile Noise Levels (Ministry of the Environment Notification No. 53, September 4, 1975; revised: Ministry of the Environment Notification No. 12, February 21, 2000)" specifies the permissible limits and measurement methods for automobile noise.
Steady-state driving noise refers to noise measured at a height of 1.2 m above the ground, 7.5 m to the left of the vehicle's centerline, perpendicular to the direction of travel. The permissible limit is set at 65 to 85 dB depending on the type of vehicle. There are also regulations regarding proximity exhaust noise and acceleration noise.
The "Standards for Regulating Vibrations Occurring in Designated Factories, etc. (Ministry of the Environment Notification No. 90, November 10, 1976; revised: Ministry of the Environment Notification No. 18, March 28, 2000)" sets forth standards for regulating vibrations in designated factories, etc. (55 to 70 dB depending on the area and time of day).
Noise measurements are performed in the vertical direction using a vibration level meter that meets the requirements of the Measurement Law. The determination of the vibration level is as follows:
- If the reading of the measuring instrument does not fluctuate or fluctuates only slightly, that reading shall be used.
- If the reading of the measuring instrument fluctuates periodically or intermittently, the average of the maximum readings for each fluctuation shall be used.
- If the instrument reading fluctuates irregularly and significantly, the upper limit of the 80% range of the measured values (10% time-factor vibration level L10) should be used, based on a 5-second interval, 100 measurements, or a similar interval.
In addition to the above, the following notifications have also been issued regarding environmental standards for noise and vibration.
- Regarding environmental standards for aircraft noise (Environmental Standards Bureau, July 2, 1974, No. 42)
- Regarding environmental standards for Shinkansen railway noise (Environmental Affairs Bureau, October 3, 1975, No. 100)
- Guidelines for noise reduction measures when constructing new railway lines or making major improvements to existing railway lines (Kandai-ichi No. 174, December 20, 1995)
(Excerpt from the email newsletter issued on December 22, 2011)
