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New ICRP Recommendations on Radon Abel J. Gonz á lez Vice-President of ICRP Thiagan Pather National Nuclear Regulator. Radon. 50% World population radiation doses Proven lung carcinogen Until recently studies of miners formed main basis for estimating risks from radon
Abel J. González
Vice-President of ICRP
National Nuclear Regulator
50% World population radiation doses
Proven lung carcinogen
Until recently studies of miners formed main basis for estimating risks from radon
Recent case-control studies of residential radon now provide direct estimates of radon risk
Two recent important international consensus
UNSCEAR 2006, Annex E, estimates on radon
WHO 2009 International Radon Project
ICRP Radon Statement (Nov 2009)
(e.g. activity per unit volume or potential energy over time)
into radiation protection quantities.
(e.g. effective dose)
Usual radon (Bq/m3)
Usual radon (Bq/m3)
Statement on Radon
Approved by the Commission in Porto on November 2009
*) The Commission’s findings are consistent with other comprehensive estimates of UNSCEAR and WHO.
Coal why not?
Exposure to radon in workplaces, which is not required by, or is not directly related to, the work in the workplace(adventitious exposure)
entry level = ?
1000 Bq/m3 is a defensible entry level!
While recognising and accepting the scientific evidence that active smokers are at a much higher risk from radon than non-smokers or ex-smokers, should judge as appropriate to establish radon-related radiation protection requirements on the basis of a single
nominal risk co-efficient
for a population of all ages that includes
smokers, ex-smokers and non-smokers?
Developing/newly industrialized countries:
requirements 1.39, 3.4(c), 3.4(d), 5.1(c)(i), 5.19, 5.20, 5.21, 5.27, 5.28, 5.29 (including related footnotes 48 - 50 and 52 - 53), and
Schedule III-8 and its associated Table III-1.
Where radon concentrations remain above 1000 Bq/m3, exposure to radon, along with any other worker exposures, are to be subject to the relevant requirements for occupational exposure in planned exposure situations. The use of two different values causes confusion and is unnecessary.
For radon exposures in workplaces that fall into the category of existing exposure situations, it was considered appropriate, in line with the recent ICRP statement, that the regulatory body or other relevant authority shall set a reference level which does not exceed a maximum annual average concentration of 1000 Bq/m3.
Where it is not possible to reduce radon concentrations below the established reference level, the regulatory body should have flexibility to decide how to deal with these exposures i.e. the concept of an “entry point” to planned exposure situations should be deleted.
In other planned exposure situations, such as workplaces where sealed sources are used, exposure to radon is considered as an existing exposure situation and is subject to the requirements related to the reference level; such exposure is not assessed for compliance with dose limits.
For radon exposures in dwellings, it was considered appropriate, in line with the recent ICRP statement, that the regulatory body or other relevant authority shall set a reference level which does not exceed a maximum annual average concentration of 300 Bq/m3.
The reference level for dwellings should also be applied to other buildings with a high occupancy rate by the public i.e. schools, prisons, nursing homes etc.
Exposure of workers to radon in workplaces shall be considered to be occupational exposure (and therefore a planned exposure situation) and subject to the relevant occupational exposure requirements, if:
the exposure in the workplace, whatever its level, is required by, or is directly related to, the work in the workplace1, or
the exposure in the workplace is not required by or is not directly related to the work in the workplace, but cannot be reduced below the reference level to be established by the regulatory body for the purpose of reducing the exposure level in the workplace through optimizing radiation protection; the value chosen for the reference level shall not be higher than an average radon concentration of 1000 Bq m-3 y-1 in the workplace2.
1 For example, exposure of miners and of workers at spas
2 This is the entry-level into the occupational protection regime established for these types of exposures in current international standards as recommended by the International Commission on Radiological Protection for the purpose of intergovernmental harmonization
For dwellings and other buildings with high occupancy rates by the public, the reference level shall not normally exceed an average radon concentration of 300 Bq m-3 y-1. However, in special circumstances, where extreme local conditions require flexibility, a higher value of reference level may be used.
The scientific evidence that active smokers are at much higher risk from radon than non-smokers or ex-smokers is recognized and accepted. Nevertheless, for the purposes of the BSS it is considered appropriate to establish radon-related radiation protection requirements on the basis of a detriment-adjusted nominal risk co-efficient as defined by the International Commission on Radiological Protection.
Add a paragraph on the synergy between radon and smoking to the explanatory text in section 1
Rewrite the overarching requirement 5-6
Add footnotes of illustrative examples of workplaces to be regarded as planned exposure situations
Add a footnote that where a dwelling also serves as a workplace (e.g. a doctor’s surgery in his/her private residence), the more restrictive reference level for dwellings should apply
Add footnotes to the text specifying the values of reference levels for workplaces and dwellings to indicate the relationship between radon concentration and effective dose
Review the footnote referring to buildings with high occupancy by members of the public
Review the definition of ‘reference level’ in the glossary both for clarity and to ensure consistency with the definition in ICRP Publication 103
Consider the need to include a definition of ‘(the) public’ in the glossary