潜在生态危害系数 ${\text{E}}_{\text{r}}^{\text{i}}$

潜在生态危害指数RI

污染程度

${\text{E}}_{\text{r}}^{\text{i}}$ < 40

RI < 150

轻微生态危害

40 ≤ ${\text{E}}_{\text{r}}^{\text{i}}$ < 80

150 ≤ RI < 300

中等生态危害

80 ≤ ${\text{E}}_{\text{r}}^{\text{i}}$ < 160

300 ≤ RI < 600

强生态危害

160 ≤ ${\text{E}}_{\text{r}}^{\text{i}}$ < 320

600 ≤ RI < 1200

很强生态危害

${\text{E}}_{\text{r}}^{\text{i}}$ ≥ 320

RI ≥ 1200

极强生态危害