Table 2 Mean faecal coliform contamination levels of irrigation water and irrigated lettuce from ten farming sites in Addis Ababa

 Range

3.23–6.73

4.51–6.96

3.65–5.54

2.83–6.23

3.04–6.73

3.59–5.67

3.51–7.20

2.96–5.64

3.58–5.41

3.51–6.15

 Mean (log₁₀ MPN 100 ml⁻¹)

5.06 (1.01)^abc

5.61 (0.70)^a

5.02 (0.64)^abc

4.67 (1.04)^bc

4.82 (1.02)^abc

4.57 (0.54)^bc

4.52 (1.18)^bc

4.29(0.70)^c

4.58 (0.66)^bc

5.24 (0.75)^ab

 Range

2-81-4.72

2.66-5.18

3.04-6.96

2.83-4.30

3.04-5.67

2.96-5.32

3.23-6.96

2.83-5.15

2.65-4.64

3.15-7.20

 Mean (log₁₀ MPN 100 g⁻¹)

3.91 (0.73)^bc

4.18 (0.74)^bc

4.10 (1.00)^bc

3.46 (0.44)^c

4.05(0.80)^bc

3.93 (0.84)^bc

5.03 (1.38)^a

3.69 (0.58)^bc

3.50 (0.59)^c

4.19 (1.01)^bc