According to the "People's Republic of China (PRC) Urban Regional Noise Standard", the maximum limits of environmental noise in five urban areas are clearly defined:

1, sanatorium area, senior villa area, senior hotel area, 50 decibels during the day and 40 decibels at night;

2, mainly residential, cultural and educational institutions, 55 decibels during the day and 45 decibels at night;

3, residential, commercial and industrial mixed zone, 60 decibels during the day and 50 decibels at night;

4, industrial zone, 65 decibels during the day and 55 decibels at night;

5. The primary and secondary trunk roads of roads, inland waterways and railways in the city are 70 decibels during the day and 55 decibels at night (from 22: 00 to 6: 00 the next morning at night).