Table 1.

The relationships among ${\mathrm{E}}_j^i$, RI_j, and their ecological risk levels.

${\mathsf{E}}_{\mathit{j}}^{\mathit{i}}\mathbf{and}\mathbf{Level}$		RIj and Level
${\mathrm{E}}_{\mathrm{j}}^i$ < 40	Slight	RIj < 150	Slight
40 ≤ ${\mathrm{E}}_j^i$ < 80	Moderate	150 ≤ RIj < 300	Moderate
80 ≤ ${\mathrm{E}}_j^i$ < 160	Strong	300 ≤ RIj < 600	Strong
${\mathrm{E}}_j^i$ ≥ 160	Serious or higher	RIj ≥ 600	Serious