Table 1 World Health Organization (WHO) and Sri Lanka drinking water standard 614:2013 guideline values for inorganic water chemistry parameter limits in drinking water compared against values observed in this study.

From: The water chemistry and microbiome of household wells in Medawachchiya, Sri Lanka, an area with high prevalence of chronic kidney disease of unknown origin (CKDu)

Parameter

WHO health-based limit35

This study (n = 30)

Sri Lanka standard 614 : 201336 limit

Min

Median

Average

Max

Standard deviation

As (mg L−1)

0.010

0.010

0.005

0.005

0.005

0.005

< 0.005

Ba (mg L−1)

0.700

–

0.033

0.200

0.234

0.597

0.156

Ca (mg L−1)

–

100.0

8.3

71.7

74.1

140.0a

30.3

Cl (mg L−1)

–

250.0

17.7

65.4

97.5

310.0b

80.8

Cr (mg L−1)

0.050

0.050

0.001

0.001

0.001

0.002

< 0.001

Cu (mg L−1)

2.000

1.000

0.001

0.001

0.001

0.002

< 0.001

F (mg L−1)

1.50

1.00

0.07

1.11

1.24

3.70c

0.74

K (mg L−1)

–

–

0.6

1.4

3.5

54.0

9.6

Mg (mg L−1)

–

30.0

5.6

33.9

39.7

95.2d

19.9

Na (mg L−1)

–

200.0

10.9

33.9

82.3

234.0e

19.9

Ni (mg L−1)

0.070

0.020

0.001

0.002

0.003

0.008

0.002

NO3 (mg L−1)

50.0

50.0

0.5

0.5

1.9

12.4

3.1

P (mg L−1)

–

–

0.01

0.01

0.05

0.24

0.07

U (mg L−1)

0.030

–

0.001

0.001

0.001

0.006

0.001

Zn (mg L−1)

–

3.000

0.001

0.002

0.003

0.008

0.002

  1. For the purposes of this assessment, samples falling below the limit of detection have been assigned a value equal to the limit of detection.
  2. a4 of 30 samples exceed the SLSI guideline value.
  3. b3 of 30 samples exceed the SLSI guideline value.
  4. c17 of 30 samples exceed the SLSI guideline value, 9 of 30 samples exceed the WHO guideline value.
  5. c21 of 30 samples exceed the SLSI guideline value.
  6. d1 of 30 samples exceed the SLSI guideline value.
Back to article page