Paragraph 7 Calculation of the ID

Northern Ireland

The ID must be calculated from the measured radionuclide concentrations and the dose coefficients F1referred to as “standard values and relationships” in Article 13, and recommended for the estimation of doses from internal exposure in the definition of “standard values and relationships” in Article 4(96), of the Council Directive 2013/59/Euratom laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation or more recent information recognised by the Department, on the basis of the annual intake of water (730l for adults).

Where the following formula is satisfied, it can be assumed that the ID is less than the parametric value of 0.1mSv and no further investigation is required.

\sum_{i = 1}^{n} \frac{C {}_{i}{(o b s)}}{C {}_{i}{(d e r)}} \leq 1

where

C_i(obs) = observed concentration of radionuclide i

C_i(der) = derived concentration of radionuclide i (see Table D)

n = number of radionuclides detected.

TABLE D

Derived concentrations for radioactivity in water intended for human consumption

Origin	Radionuclide¹	Derived concentration (Bq/1)
¹ This table includes values for the most common natural and artificial radionuclides; these are precise values, calculated for a dose of 0.1mSV, an annual intake of 730 litres and using the dose coefficients F2referred to as “standard values and relationships” in Article 13, and recommended for the estimation of doses from internal exposure in the definition of “standard values and relationships” in Article 4(96), of the Council Directive 2013/59/Euratom laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation ; derived concentration for other radionuclides can be calculated on the same basis, and values can be updated on the basis of more recent information recognised by the Department.
² This allows only for the radiological properties of uranium, not for its chemical toxicity.
Natural	U-238²	3.0
	U-234²	2.8
	Ra-226	0.5
	Ra-228	0.2
	Pb-210	0.2
	Po-210	0.1
Artificial	C-14	240
	Sr-90	4.9
	Pu-239 / Pu-240	0.6
	Am-241	0.7
	Co-60	40
	Cs-134	7.2
	Cs-137	11
	I-131	6.2

Annotations

Textual amendments

F1: Words in Sch. 4 para. 7 substituted (24.12.2018) by The Environment (Miscellaneous Amendments) Regulations (Northern Ireland) 2018 (S.R. 2018/200), reg. 1(1), Sch. 2 para. 15
F2: Words in Sch. 4 Table D substituted (24.12.2018) by The Environment (Miscellaneous Amendments) Regulations (Northern Ireland) 2018 (S.R. 2018/200), reg. 1(1), Sch. 2 para. 15