Noise control standards in the city of Tokyo.

The authors used the data on noise pollution processed by the Tokyo Metropolitan Institute for Environmental Protection, and discussed noise control standard in Tokyo. In the 23 wards, the noise level is between 52 and 69 dB, while in suburban city districts, the level is between 46 and 65 dB. When the level of noise is below 60 dB outdoors, the level is less than 50 dB indoors. When the level of noise exceeds 55 dB, more than 50% of the inhabitants feel uncomfortable. The standard outdoor noise level in residential districts is 60 dB in the daytime, and 50 dB in the nighttime. It must be 5 dB below the above in districts where quiet is particularly important, such as near hospitals. Regulation of noise control can only be dealt with through the cooperation of industries and inhabitants under the surveillance of the Tokyo Metropolitan Government.