| Chinese | English |
| 背景噪音 | background noise Noise coming from source other than the noise source being monitored (来自非监测渠道的噪音。) |
| 背景空气污染监控网 | background air pollution monitoring network |
| 背景级别 | background level Term used in a variety of situations, always as the constant or natural amount of a given substance, radiation, noise, etc. (此名词使用在多种情况，通常是指自然或者固定含量的某一给定物质、辐射、噪音等。) |
| 背景辐射 | background radiation Radiation resulting from natural sources, as opposed to man-made sources, and to which people are exposed in everyday, normal life; for example from rocks and soil (来自于自然界的辐射而非来自于人为来源的辐射，正常情况下人们每日都暴露于此辐射下，例如来自于岩石和土壤。) |
