Table 1 The evaluation standard of the Nemerow pollution index.
From: Assessment of environmental impacts of heavy metal pollution in rice in Nanning, China
Level | Nemerow pollution index | Pollution level |
|---|---|---|
I | PN ≤ 0.7 | Clean (security) |
II | 0.7 < PN ≤ 1.0 | Light clean (cordon) |
III | 1.0 < PN ≤ 2.0 | Light pollution |
IV | 2.0 < PN ≤ 3.0 | Moderate pollution |
V | PN > 3.0 | Heavy pollution |
