Toxicity Issues: Radon - Nearly Zero Energy Building Refurbishment - page 356

Despite numerous awareness campaigns, limited numbers of householders have
tested their homes and only a minority of the affected householders has remediated
the problem. Moreover, a recent survey shows a wide range of the public per-
ception on radon risk not significantly influenced by public health campaigns
(Denman et al. 2005 ).
Antignani et al. ( 2012 ) mentioned that in a very recent wide radon survey that
took place in Italy, 40 % of the contacted participants refused to participate or did
not even respond to the contact emails. Those authors compared the consent rate
with the one obtained by other authors using the same email approach noticing that
UK, Ireland, and Australia showed even lower consent rates.
The building sector is the largest energy user and CO 2 emitter in the European
Union (EU) and is responsible for about 40 % of the EU's total final energy
consumption and CO 2 emissions. The European Energy Performance of Buildings
Directive 2002/91/EC (EPBD) has been recast in the form of the 2010/31/EU of
the European Parliament. (European Union 2003 , 2010 ).
One of the new aspects of the 2010/31/EU is the introduction of the concept of
near-zero-energy building. The article nine of the European Directive establishes
that, by December 31, 2020, all new constructions have to be near-zero-energy
buildings. However, new buildings have limited impacts on overall energy
reduction as they represent just a tiny fraction of the existent building stock.
Existing buildings constitute, therefore, the greatest opportunity for energy effi-
ciency improvements (Xing et al. 2011 ). Besides, new homes use four to eight
times more resources than an equivalent refurbishment (Power 2008 ), which
constitutes an extra argument in favor of building refurbishment. The energy
efficiency building refurbishment context constitutes, consequently, a great

opportunity to emphasize and try to solve the radon problem.

2 Regulation on Indoor Radon

Reference level represents the maximum accepted average annual radon concen-
tration in a residential dwelling. When radon measurements indicate that this level
has been exceeded, it is strongly recommended that action is taken to reduce the
radon concentration (Synnott and Fenton 2005 ).
The concept of reference level differs from that of action level. The latter was
used in most countries prior to the most recent recommendations of the Interna-
tional Commission on Radiological Protection (ICRP) ( 2008 ).
In the UK, the National Radiological Protection Board identified, in 1990, an
action level of 200 Bq/m 3 . Additionally, when more than 1 % of domestic prop-
erties in an area of the UK are above the action level, the area is designated as a
''radon-affected area'' in which regulatory and promotional measures are adopted
(NRPB 2008 ).
A WHO survey of 36 countries found that almost all of them have set reference
levels for existing housing of between 200 and 400 Bq/m 3 . Some countries have