WORLD HEALTH ORGANISATION – RADIOLOGICAL ASPECTS
The table below summarizes the reference levels above which potable water cannot be supplied to the public as recommended by the World Health Organization WHO (Table No. 9.2 of the Guidelines for drinking-water quality - 4th ed., Chapter 9 "Radiological aspects").
In the last columns of the table are shown the detection limits achieved in ALS, including a brief identification of methods used.
Radionuclide |
Conversion factor [Sv/Bq] |
Reference level[Bq/L] |
Method used in ALS for the determination |
Minimal detectable activity concentration reached in ALS [Bq/L] |
U-238 |
4.50E-08 |
10 |
ICP/SFMS |
0.001 |
U-234 |
4.90E-08 |
1 |
ICP/SFMS |
0.004 |
Th-230 |
2.10E-07 |
1 |
ICP/SFMS |
0.004 |
Ra-226 |
2.80E-07 |
1 |
ČSN 75 7622 |
0.02 - 0.03 |
ČSN ISO 10703 |
0.02 - 0.03 |
|||
Pb-210 |
6.90E-07 |
0.1 |
Health Phys. 46 (1984), No. 5, s. 1131 |
0.02 - 0.03 |
Po-210 |
1.20E-06 |
0.1 |
ČSN 75 7626 |
0.02 - 0.03 |
Th-232 |
2.30E-07 |
1 |
ICP/SFMS |
0.001 |
Ra-228 |
6.90E-07 |
0.1 |
ČSN ISO 10703 |
0.03 - 0.05 |
Th-228 |
7.20E-08 |
1 |
ČSN ISO 10703 |
0.03 - 0.05 |
Cs-134 |
1.90E-08 |
10 |
ČSN ISO 10703 |
0.05 |
Cs-137 |
1.30E-08 |
10 |
ČSN ISO 10703 |
0.05 |
Sr-90 |
2.80E-08 |
10 |
ASTM D5811-08 |
0.05 |
I-131 |
2.20E-08 |
10 |
ČSN ISO 10703 |
0.1 |
T (H-3) |
1.80E-11 |
10000 |
ČSN ISO 9698 |
2 – 10 |
C-14 |
5.80E-10 |
100 |
ISO 13162, US |
0.5 |
EPA 520/5-84-006 |
||||
Pu-239 |
2.50E-07 |
1 |
ICP/SFMS |
0.002 |
Am-241 |
2.00E-07 |
1 |
ICP/SFMS |
0.2 |
K-40 |
2.00E-09 |
- |
ČSN ISO 10703 |
1.II |
The table shows that ALS routinely reaches more than sufficient limits compared to reference levels. For 210Pb, 210Po and 228Ra our detection limit are at 20 – 30 % level of reference level, which is still commonly acceptable.