Risk Assessment of Heavy Metals Pollution in Agricultural Soils of Siling Reservoir Watershed in Zhejiang Province, China

Table 4

Description of enrichment factor (EF), contamination factor (𝐶_𝑓), geoaccumulation index (𝐼_geo), and degree of contamination (𝐶_deg) (Hakanson 1980 [36]; Sutherland 2000 [62]).

Value	Soil quality
EF < 2	Deficiency to minimal enrichment
2 < EF < 5	Moderate enrichment
5 < EF < 20	Significant enrichment
20 <EF < 40	Very high enrichment
40 < EF	Extremely high enrichment
𝐶𝑓<1	Low contamination factor indicating low contamination
1≤𝐶𝑓<3	Moderate contamination factor
3≤𝐶𝑓<6	Considerable contamination factor
6≤𝐶𝑓	Very high contamination factor
𝐼geo<0	Practically uncontaminated
0<𝐼geo<1	Uncontaminated to moderately contaminated
1<𝐼geo<2	Moderately contaminated
2<𝐼geo<3	Moderately to heavily contaminated
3<𝐼geo<4	Heavily contaminated
4<𝐼geo<5	Heavily to extremely contaminated
5<𝐼geo	Extremely contaminated
𝐶deg<8	Low degree of contamination
8≤𝐶deg<16	Moderate degree of contamination
16≤𝐶deg<32	Considerable degree of contamination
32≤𝐶deg	Very high degree of contamination