Civil Engineering Reference
In-Depth Information
Recent investigations carried out in Portugal show that of the 8,514 lung cancer
deaths observed, 18-28 % could be associated with indoor radon exposure (Veloso
et al.
2012
).
Children are considered a risk group in terms of radon since association between
residential radon and acute leukemia risk was reported (Brauner et al.
2010
).
Synergic effects between smoking and radon, in lung cancer, have also been
reported (Barros-Dias et al.
2012
). Other authors confirm the radon-smoking
synergism (Bochicchio et al.
2012
).
A possible correlation between radon and skin cancer was suggested by other
authors (Wheeler et al.
2012
). However, Sethi et al. (
2012
) state that the possibility
of radon having a causative effect on other cancers has been explored but not yet
proven.
Brauner et al. (
2012
) analyzed the interaction between radon decay products
and particular matter such as NOx from traffic-related air pollution, but the results
were not conclusive.
In the past, it was commonly accepted that only radon concentrations above
400 Bq/m
3
could be a source of concern; however, recent investigations show that
this threshold is far from being safe. Dinua et al. (
2009
) studied 90 households in
Spain with a maximum radon concentration of 366 Bq/m
3
, stating that an exces-
sive number of cancer-related deaths occurred in that area.
Krewski et al. (
2006
) show health-related risks even for radon concentrations
below 200 Bq/m
3
. This is the radon concentration at which action is currently
advocated for in many countries. Recent epidemiological findings from residential
studies, however, demonstrate that lung cancer risk can arise from exposure to
indoor radon at levels of the order of 100 Bq/m
3
(COM
2011
).
According to WHO (
2009
), the lung cancer risk increases linearly with long-
term radon exposure, with no evidence for a threshold. Extensive large-scale
surveys of indoor radon in Norway show that 9 % of the present housing stock
(approximately 175,000 dwellings) has an annual average radon concentration
exceeding the Norwegian action level of 200 Bq/m
3
. Also, it states that 30,000
Norwegians live in dwellings where the average radon concentration is higher than
1,000 Bq/m
3
(Jelle
2012
).
A recent survey analyzed 506 schools located in southeast Italy, concluding that
about 7 % of schools showed radon concentration values above 500 Bq/m
3
(Trevisi et al.
2012a
).
Nevertheless, some surveys show that the majority of the public seems to
consider the health risks involved from exposure to radon as being negligible.
Bradley et al. (
1997
) found that only 10 % of those with a raised level of radon
took any steps to remediate this problem. Similar figures were given by Arthur
(
2003
) and by Chow et al. (
2007
).
Ryan and Kelleher (
1999
) discovered that even when householders knew of the
existence of raised radon levels in their dwellings, they rarely remediated. There is
also the general problem that the majority of the public seems to consider the
health risks resulting from radon as being negligible (Phillips et al.
2000
).
