Journal of Environmental Protection, 2011, 2, 1118-1126
doi:10.4236/jep.2011.28130 Published Online October 2011 (http://www.scirp.org/journal/jep)
Copyright © 2011 SciRes. JEP
Environmental Distribution of the Radon in a
Heavily Populated Area: Preliminary Hazard
Evaluation and Inference on Risk Factors in
Pescara, Central Italy
Francesco Stoppa
Dipartimento di Scienze, Università G. D’Annunzio, Chieti, Pescara, Italy.
Email: fstoppa@unich.it
Received June 29th, 2011; revised August 11th, 2011; accepted September 25th, 2011.
ABSTRACT
The presence of ionizing sources is a high-risk condition if related to a poor management of the hygiene and health of
the anthropic environment. Increased hazard derives from the addition of artificial sources to natural sources and the
consequent possible late occurrence of epidemic cancer. Therefore, the expenses for medical treatments and potential
losses of human lives are thought to be relevant. Although the role of natural exposure is still poorly assessed, it is rea-
sonable that it accounts for a chronic hazard, while the artificial one may constitute an acute hazard. In theory, the
medium and large-scale monitoring of the Radon is simple and can be applied in detail to sensible targets. However,
mitigation of Radon risk is particularly complex due to the intrinsic structural vulnerability of the urban environment
and the general lack of epidemiological data that constrain the extent of specific biological damage. In Italy was sug-
gested a limit to the exposure in working place, instead limits for other private and public facilities are not well estab-
lished. Despite legal advice, the sensitivity of the social system is low due to the elusive nature of the Radon hazard, and
the case considered in this paper account for unpreparedness of the Sanitary and Environmental Authorities when fac-
ing to a possible crisis. A monitoring field survey revealed Radon concentrations of at least three times higher than that
expected geologically in a fairly localized area of Pescara, Central Italy. The values are about 25 - 30 times the maxi-
mum allowed in the buildings. However, these measures are underground and average indoor values in the area were
still acceptable. The measures repeated after a year confirms an upward tendency of the previous values. However, it
was not possible to go deeper in the investigation about the nature of this underground anomaly because of the strong
opposition of some members of the Environmental and Sanitary Authorities. Some rumours filtered by one of this Insti-
tution, suggesting a possible correlation of the anomaly with the uncontrolled disposal of radio-iridium needles used in
the nearby hospital. A further legal action instructed against the Author discouraged the publication of the data so far.
This account for a situation of increased risk. Even if hazardous natural Radon emissions can be investigated, it is dif-
ficult to evaluate vulnerability factors related to non-natural diffusion of radio-nuclides progenitors of the Radon (i.e.
uranium and radium). Confidence on notional calculation of the hazard by means of algorithms, decreases the alert
threshold and promotes the potentially involved authorities to discourage further studies. This increases the vulnerabil-
ity of the system. Due to negligence and violation of safety norms in Italy, accidents involving ionization agent disper-
sion in the environment are likely and are an instructive study case. The result of this study may promote mitigation
actions and, hopefully, a decrease of the radioactivity risk in a populated area. This paper is intended as a case history
depicting unexpected Radon distribution in a city. In these conditions, the density of population and the system un-
awareness contribute greatly to raise the risk especially if a natural explanation could not find. The suspect of an artifi-
cial source, far more hazardous than natural Radon itself, is still up for the investigated area.
Keywords: Radioactive Pollution, Radon Measurements, Radon Distribution, Radon Risk Analysis, Pescara-Italy
1. Introduction
This Radon is an important contributor to the natural
environmental radioactivity. Among the 26 known iso-
topes of the Radon the most important is the 222Rn, which
has a mean lifetime of 5.517 days. The short half-life of
222Rn is 3.82 days, a fact which precludes slow transport
over great distances, and this make important its near-
Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference 1119
on Risk Factors in Pescara, Central Italy
surface sources [1] or concentration/transport along per-
meable discontinuities [2]. Radon becomes very mobile
exploiting the permeability of the rocks and the presence
of water and can be quickly carried to the surface and
enters building [3-11]. It accumulates in basements being
much heavier of the atmospheric air but can be distri-
buted by plumbing system, heat system and indoor as-
cending air column (i.e. stairs and elevator).
Once inhaled and dissolved in the body fluids, Radon
is conveyed in the body tissues. 222Rn decays into short-
live radioactive isotopes 218polonium and 214lead by emit-
ting high-energy alpha particles causing damage to ce-
llular DNA. This can originate cancer cells if DNA is
then reconstructed imperfectly. The health effects of Ra-
don exposure are only observed over long periods and
can result in lung cancer [12,13]. However, the human
species has evolved in contact with natural ionizing sour-
ces and in the vast majority of cases Radon does not con-
stitute a major hazard. Perturbation of this equilibrium
comes from the unsustainable use of the land, a mixture
of industrial and civil uses and improper handling and
disposal of radioactive substances or sources and medical
over exposure, as well. All these factors represent a sig-
nificant contribute to the risk and can lead to serious
health problems affecting social health-care expense and
facilities.
In Italy there is still no legislation concerning the ma-
ximum concentration of Radon in private homes and
schools, hospitals and prisons. Legislation does exist for
the industrial workplaces and is regulated upon the Le-
gislative Decree No. 241, 26/05/2000. A reference level
of 500 Bq/m³ is recommended. A similar value for public
facilities and private houses may be considered too high
compared to those of many other countries which have
adopted much lower reference values: United States re-
commends 150 Bq/m³, United Kingdom 200 Bq/m³,
Germany 250 Bq/m³. However, countries with more ra-
dioactive back-ground geological emission, such as Swit-
zerland, have shifted these limits to higher value. In all
countries the maximum value suggested for private and
public building are 50% of tho se established for working
places. It is argued that average maximum values for pri-
vate houses and schools should be around 250 Bq/m³ in
average (old and new buildings). Italian areas with vol-
canic or igneous substrata, i.e. western coast of Central
Italy, NE Sardinia, part of the Sicily and some Alpine
areas, have high geological contribute of Radon [14,15].
In these areas indoor Radon is expected to exceed the
above precaution limits. In 1990 the European Union has
issued a recommendation to take the faster and the higher
level of precaution, to identify areas with high risk of
Radon in houses, also using indirect parameters such as
Radon activity in soil and building materials. This is in
fact based on the prejudice that the hazard only comes
from natural sources (geologic) or artefacts derived from
them. There was a big effort in the literature to associate
elevated Rn soil-gas values with high indoor Rn concen-
trations [e.g. 16,17] and many authors believe that the
method can be used to evaluate the potential indoor ha-
zard of areas having elevated soil-gas value [18]. They
suggest that it is possible to define a geochemical thresh-
old, based on the 222Rn activity at equilibrium with parent
radio-nuclides in the surveyed soil [19].
It is generally assumed that:

CindCoutUsoil v

where Cind is the concentration of indoor Radon, Cout is
the concentration of outdoor Radon; Usoil is the indoor
rate of entry of Radon from the ground;
v is the rate of
ventilation. The contribution of input from the subsoil is
imagined as determined by a factor related to the geology
of the area type (
1), by a factor represented by the dis-
tance from the ground of the dwelling (
2) and a third
factor dependent by climate and type of housing, which
characterizes the routes of entry and the pressure under-
ground gas (
3). The equation above thus becomes as
follows:

   
123 ln
lnln 1ln2ln3
CindCoutCind Cout
 
 
 
 
where
is a normalization of the value of indoor Radon
concentration due to soil source. Radon samples exceed-
ing the computed valu e may be lin k ed to both natural an d
artificial accidents which can disturb this equation. Prac-
tical experience indicates that the transfer factor ground
to home (basements) Radon can varies from 1:2 to 1:100,
even if in most cases is low. Therefore, it is more prudent,
in populated zone, to build maps of hazard by determin-
ing Radon alpha-decay experimentally. The method that
seemed most readable, relatively rapid and affordable, to
this type of study is to perform standardised measures
into underground wells. This reproduces the equilibrium
condition for permeable basements, which is the less fa-
vorable case. A further comparison of the measured data
with those expected basing on the radioactivity of the
country rocks and their geology is then needed to evalu-
ate nature of the sources and distribution of the hazard.
2. Spectrometry
The contribution of the radio-nuclides present in the
Pescara country-rock types was measured at Centre of
Environmental Radioactivity ( CRA) of Perugia through a
spectrometer
HPGe. Data processing was done using
specific software leading to identify and calculate the
Copyright © 2011 SciRes. JEP
Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference
on Risk Factors in Pescara, Central Italy
Copyright © 2011 SciRes. JEP
1120
corresponding activities of radio-nuclides in the sample
(Table 1). In terms of relative error (
):
 
(activitypeakareaefficiency21 2


Uncertainty of measurements derive from interpolation
of the efficiency curve which depends on the uncertainty
of the activity of the calibration sour ces and the fitting of
the peaks.
the magnitude of which is approximately equal to:
p
eakarea2.3%1%2% efficiency
 .
Four rock-types have been selected as representative
Table 1. Radioactive nuclides content and activity for rock-types representative of the substrate of the city of Pescara and
building materials. Measurements indicate d both as Bq/kg and ppm.
Sample 238U 232Th
40K
Bq/kg % Bq/kg % Bq/kg %
Beach sand 214Pb 14.68 2.30
228Ac 10.20 5.20 342 1.10
214Bi 13.30 2.60
212Pb 12.95 2.10
212Bi 13.47 10.50
208Tl 17.63 3.40
Average 13.99 13.56
ppm 1.13 3.36 1.32
Pleistoc. sand 214Pb 42.65 1.10
228Ac 20.66 2.70 436 1.00
214Bi 39.83 1.10
212Pb 24.63 1.50
212Bi 24.74 9.50
208Tl 28.15 2.80
Average 41.24 24.55
ppm 3.34 6.08 1.69
Silt 214Pb 32.92 1.60
228Ac 30.06 2.60 587 1.00
214Bi 29.46 1.30
212Pb 34.01 1.20
212Bi 33.25 5.60
208Tl 38.38 2.40
ppm 2.53 8.40 2.27
Clay 214Pb 47.43 1.10
228Ac 27.77 2.50 496 1.00
214Bi 42.40 1.00
212Pb 32.06 1.10
212Bi 33.46 6.60
208Tl 34.19 2.30
Average 44.92 31.87
ppm 3.64 7.89 1.92
Limestone 214Pb 9.17 1.51
228Ac 1.66 7.25 6.57 8.52
214Bi 8.40 1.22
212Pb 2.89 2.90
212Bi 2.68 17.28
208Tl 6.80 2.94
Average 8.79 3.51
ppm 0.71 0.87 0.03
Gypsum 214Pb 58.91 0.80
228Ac 1.13 36.0 4.86
214Bi 52.01 0.76
212Pb 4.97 5.14
212Bi 3.98 27.57
208Tl 8.82 4.64
Average 55.46 4.73
ppm 4.50 1.17 0.14
Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference 1121
on Risk Factors in Pescara, Central Italy
of the main stratigraphic units forming the substrate of
the city of Pescara. Beach sand (sand 1) that commonly
forms the coastal plain, Pleistocene sand (sand 2) and
marine clay that form the hills and silts that form the
Pescara river alluvial plain. Limestone and gypsum sam-
ples from the Pescara province area have been measured
only for reference to building materials. The Table 1 sets
out the measures obtained with the spectrometer. Mea-
surements are indicated both in Bq/kg and in ppm. The
natural content of 238U, 232Th and 40K was determined to
understand how much they take part in the radioactivity
of the samples. The values obtained by spectrometry
were plotted constructing curves of correlation between
the rock types and their natural content of 238U, 232Th,
and 40K (Figure 1).
Limestone is always low in radionuclides. Gypsum is
high in 238U but low in 232Th and 40K. 238U is the biggest
and ubiquitous contributor to total radioactivity in the
Pescara rocks. 232Th and 40K are important only in clay
and silt. There is a constant increase in the radionuclide
contents passing through beach-sand, Pleistocene sand,
clay and silt.
Figure 1. Radionuclide content of Pescara rock types ex-
pressed in ppm. The values obtained by spectrometry were
plotted putting the rock in order of increasing content of
238U, 232Th, and 40K.
3. Measures of Environmental Radon
The measure stations were distributed in all districts of
the city, making measures of all the geological units with
a sufficient number of stations and in different locations
spaced not more than 1 km in a straight line. Most of the
stratigraphic units of Pescara are heterogeneous and con-
sist of several rock types. It was analyzed the most
abundant and representative rock type for each unit. Me-
dium and long term environmental measures on site con-
sist of a PVC pipe with inside diameter of 64 mm and 1.5
m long. The pipe has an open end that is buried to a
depth of one meter while the other end is fitted with a
screw back with gasket. The measurements were carried
out in dry and sealed pipe condition. The dosimeters
consist of cellulose-nitrate film sensitive to
-radiation
energies lower than 4 MeV. The dosimeters were put in
the pipe suspended halfway after a convenient time ne-
cessary to equilibrate the air in the pipe with that in the
ground. The dosimeters we re recov ered af ter an exposu r e
time of 168 hours and protected by further exposure to
Radon and quickly processed for counting. Even if for
outdoor measurements time is considerably greater we
consider this method is suitable in approximating indoor
measurement conditions.
radiation emitted by 222Rn
and its decay products 218Po and 210Po, with energies of
5:49, 6 and 7.69 MeV respectively, cause damage tracks
along the route taken in the film of cellulose nitrate. An
alkaline bath is used to improve the tracks before their
counting. To estimate the co ncentration of 222Rn from the
detector, the density of the traces must be divided by the
calibration factor E and h exposure time:

3
6.5
CiREhBq m.
The method [20] has an uncertainty which gets less
than 20% for values > 50 Bq/m3. The unit of measure-
ment of radiation is the Curie, wh ich is equivalent to 3.7
× 1010 disintegrations per second, but for the Radon has
been widely used the Becquerel (Bq) which is equivalent
to one disintegration per second.
The area of the municipality of Pescara can be divid ed
into four main lithostratigraphic zones having different
average concentration of Radon. Table 2 shows the num-
ber of disintegration tracks and the calculated concentra-
tion of the undergroun d measures made in the above rock
types.
Four outdoor measures performed for reference in the
Pescara area gave constant values of 4 Bq/m3 which are
below the detection method.
Underground values are always well up the detection
limit and range from near 100 to >7400 Bq/m3. Intervals
of 500 Bq/m3 are here considered significantly different
Copyright © 2011 SciRes. JEP
Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference
1122 on Risk Factors in Pescara, Central Italy
Table 2. Underground radon me asur ement.
Measure station Average tracks Bq/m3
39 240 721
40 290 702
43 375 1061
42 110 333
41 2145 7391
4 143 504
2 1355 4525
11 643 2203
37 940 2609
48 546 1784
31 34 103
35 56 164
30 496 1661
24 343 1104
36 850 2881
26 17 55
18 484 1608
21 133 437
14 31 114
23 1345 4419
45 164 526
34 144 456
38 585 1779
47 20 46
33 906 2760
49 34 107
32 39 116
3 589 2049
1 1049 3539
25 239 715
46 740 2528
29 921 2952
27 676 2142
44 11 24
22 1040 3447
19 394 1365
13 325 1144
20 1138 3946
5 125 403
18 553 1750
6 669 2386
12 306 1038
15 125 431
among measure groups and are shown in term of fre-
quency in Figure 2. Most of the measures with values
below 500 Bq/m3 (30% of the total) are from the coastal
plain. This reflects a low content of Radon parent iso-
topes, efficient exchange between porous soil and at-
mosphere due to tide oscillations.
The values of concentration between 500 and 3000
Bq/m3 account for 60% of the total of the measures and
is a range representative of the Pescara country rocks α-
emission (2318 Bq/m3). Values from 3000 to 5000
Bq/m3 show a sharp decrease and account for about 10%
of the measures. This general distribution is considered
readable because there is a good correlation between the
content of radioactive isotopes and the underground α-
emission by means of a reasonable statistical distribu-
tion.
Average values of Bq/m3 for the 4 main stratigraphyc
units of Pescara city area are: A Holocene seashore-
sands and fossil dunes with an average concentration of
718 Bq/m3, B Holocene silts, average 2376 Bq/m3, C
Pleistocene sands, average 3008 Bq/m3, D Pleistocene
clay average 1570 Bq/m3. These averages do not corre-
spond neatly to their natural radio nuclides contents.
Clay has the highest radionuclide content (Figure 1) but
an average Radon activity which is lower then Peisto-
cene sends that are lower in radionuclides. However,
beach sand radon activity is in good agreement. Average
Radon values of silt also fit in well with average radionu-
clide contents. Variation in the same geological unit
could be related to a variable quantity of water which is
the second most important factor in Radon distribution
after the abundance of parent radioactive isotopes. There
is a significant gap of measures between 5000 and 7000
Figure 2. 500 Bq/m3 intervals of underground Radon values
are shown in term of their frequency (numbers of meas-
ure/station). Unit A Holocene sands (blue), Unit B Holocene
silts (yellow), Unit C Pleistocene sands (brown), Unit D
Pleistocene cla y (green ).
C
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Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference 1123
on Risk Factors in Pescara, Central Italy
Bq/m3 explainable with the general absence of high ra-
dioactive soils in Pescara area.
The values above 7000 Bq/m3 which are well outside
of the range for Pescara Radon value, refer to measures
located in a relatively small area of the city. In this area,
measures have been repeated twice in two different holes.
It was checked if there was artefacts on the surface or
underground which may influence the measure. We did
not find any visible source of radioactivity or able to
concentrate locally Radon. The measures proved to be
real.
4. Distribution of Radioactivity
The map of the concentration curves, constructed by the
method of linear interpolation of triangles, is the fastest
way to visualise the broad distribution of gas Radon near
the interface rock-atmosphere (Figure 3(a)). It may be
expected that isochemical curves envelop and soften the
cumulate effects due to local rock-type distribution, posi-
tion of the underground water table, presence of geo-
logical discontinuities and other possible sources. This
preliminary map is only for a general Radon h azard eva-
luation. However, is easy to read and understandable to
non-geochemists and of practical use to orientate further
investigation. It can enter in the management of the ur-
ban land-use planning. It can be used as a first order
layer in the risk assessment wh en overlapped by a popu-
lation density/age and/or quality and vulnerability of the
building, public or private use and other sensible risk
factor.
Starting from the coastline and moving up hill is seen
that the concentration values increase towards inland.
There is a regular incr ease from 500 to 3500 Bq/m3 pass-
ing through unit A, D and C in the north part that goes
from the border with the town of Montesilvano up the
hill of Madonna (Figure 3(a)). Isochemical curves are
somewhat parallel to the geological formation bounda-
ries. A similar situation is seen to the south of the city
next to the border with Francavilla al Mare municipality
where values passes from 500 to 4000 Bq/m3 within a
few thousand meters going from the beach of San
Silvestro to San Silvestro hill near the Vallelunga ditch
(Figure 3(a)).
In the alluvial valley, in the unit B area, th e grad ien t of
the curves is very different north and south of the Pe-
scara River due to a large pick of Radon in the north sec-
tion. A rather complex pattern Radon distribution with a
maximum located between the Pescara Hospital, the
Pescara River and Fosso Grande creek, which extends
towards Villa Raspa. The Pescara river seem to limit the
anomaly resulting in an accumulation of isochemical
curves which become parallel passing from 500 on the
(a)
(b)
Figure 3. (a): The map of the concentration curves, constru-
cted by the method of linear interpolation of triangles, is the
fastest way to visualize the broad distribution of gas Radon
near the interface soil-atmosphere; (b): Detail of Figure 3(a)
showing the Radon isochemical curves in Bq/m3 in the hot
spot” located SW of the Pescara hospital.
right bank to over 7000 Bq/m3 on the left bank of the
river. The isochemical curves change abruptly from N-S
direction to a E-W direction. The situation change s in the
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Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference
1124 on Risk Factors in Pescara, Central Italy
south bank of the river which in co ntrast show s the low er
concentrations throughout the B unit, with a maximum
represented by the curve 2000, which has a very limited
extent. In addition, the area show relative minimum
bounded by the isochemical curve 500, near Fontanelle
area (Figure 3(a)).
Four main features rise from the isochemical map
analyses, a general overlap of Radon measures in the 4
stratigraphic units, the low value related to the co ast line
and recent alluvial plain, the influence of the river and
the presence of a Radon peak which is not related to a
particular geological feature. The data collected and pre-
sented are too limited to allow the sure statement of the
origin of the distribu tion but allow so me general assump-
tions.
5. Discussion about the Origin of the Pescara
Positive Anomaly
There are some hypothetical natural causes that can ex-
plain such an anomaly. These include the concentration
of natural radio-nuclides by reduction in organic com-
plexes or accumulation of radioactive heavy minerals.
The substrate in which the measurements were made is
of silico-clastic nature thus the possible presence of de-
tritus of radioactive minerals is compatible with the allu-
vial depositional environment of river Pescara. However,
in the Pescara river basin there are not rocks that may
contain sensible radio-nuclides or that can be related to
high values of un derground R a do n.
Among more obvious anthropic sources of radioactive
pollution, two are more likely in the investigated area:
radio-nuclides used in lightning rods to improve field of
ionization and radioactive sticks used in the treatment of
the cancer.
A radioactive lightning rod has a radioactive substance
inside the metal tip, mainly 226Radio that is capable to
emit harmful radiation for centuries. Radioactive tip has
the task to ionize the air and then makes it conductiv e to
capture lightning in a larger radius from the lightning rod
itself. The installation of radioactive lightning rods in
Italy began in 1945, when at least a dozen construction
companies were born. They were installed until the
1981when legislation completely prohibited the use in
Italy. Unfortunately, their disposal is still ongoing, it is
estimated that some thousand are still in use but perhaps
even more. It is quite difficult to distinguish radioactive
lighting rods from the others. The more critical point is
that we don’t know how many and where the dismissed
radioactive r o d s were dispose d.
Interstitial radiation therapy involves the injection of
radioactive preparations (radio, iridium) in the form of
needles, wires or seeds in the cancer tissue: it has the
advantage of concentrating high doses of radiation in a
limited area and in a short time. It was largely used for
local application in cancers of the mouth, tongue, skin,
anus. The variant intra-cavity radiation therapy involves
the insertion of interstitial radiation transmitters in the
vagina or uterus, for example. It happened in the past
that anti-cancer radio devices were misused. In some
Abruzzi Hospitals, including that of Pescara, was re-
ported lost of radio-iridio needles. When dispersed in the
environment they suffer from rapid degradation and dis-
integration. Highly radioactive particles can be carried
by sewage disposals especially in uncontrolled waste.
Can enter the river system and be transported down-
stream by emitting large amounts of Radon and radioac-
tivity.
6. Mitigation
Regarding radioprotection considerations, the values mea -
sured in boreholes or are not comparable with the in-
doors one. The ground values (>7000 Bq/m3) are rela-
tively low if compared with those of volcanic areas (such
as Rome area) and would be significant in case of under-
ground workplace (caves, mines, cellars, etc.). However,
the combination of an unevaluated radioactive hazard,
potentially unrelated to a natural source, in a densely
populated area imply a serious risk which must be as-
sessed and mitigated. Amount of the exposed value de-
pends from extension and evolution of the radioactivity,
and its acute or chronic release in the environment.
The presence of a peak of radioactivity in the ground
which is not immediately explained by geological causes
puts a light on a potential risk that may extend beyond
the indoor Radon in an area of the city of Pescara. The
Pescara Radon hotspot, may suggest a possible emer-
gence downstream of the Hospital and/or the Fossa
Grande waste disposals located about 2.5 km WNW of
the anomaly. Presence of highly active radionuclide ar-
tefacts comport a bigger hazard than Radon itself. Part of
the underground Radon in the future may also affect pri-
vate homes and public buildings located in areas with a
higher concentration of this radioactive ga s.
The Radon anomaly lies in a densely populated resi-
dential area (Figure 3(b)). In addition, there are sport
centres, the city’s main hospital, a kindergarten and an
elementary school. As mentioned, measures of indoor
Radon in the schools seem reassuring, however, the na-
ture of the hazard is not completely understood and a
subsequent risk assessment should be made. A quantita-
tive study at small-scale (1:5000) is required in con-
structing seasonal isochemical card with the aim to cir-
cumscribe the amount and nature of the goods and hu-
man life exposure. Specific statistical data and insurance
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Environmental Distribution of the Radon in a Heavily Populated Area: Preliminary Hazard Evaluation and Inference 1125
on Risk Factors in Pescara, Central Italy
data can be used but they would add a little considering
the high population density.
The vulnerability is a measure of non-response of a
community to a possible radioactive treat. In a heavily
built area is not easy to perform radioactivity survey. A
major problem arose from the distrust of the inhabitants
which are concerned about possible consequence of find
radioactivity in their property. Th is non collaborative be-
haviour has to be taken into account and suggest possible
difficulties in mitigation preparedness. Vulnerability
merges both geological and anthropogenic factors: soil
permeability, water table oscillation and exchange with
the river, ratio of outdoor/indoor and artificial/natural
exposure. Vulnerability is increased by the lack of a his-
torical analysis of the use of nearby suspicious site such
as uncontrolled landfill and waste disposals or other in-
dustrial uses. To our knowledge specific epidemiology of
lung cancer, young-people leukaemia and other critical
and potential Radon-related disease is not yet available.
Previous experience about neglecting or misinterpreting
the Radon data indicates that Authority and citizens
awareness is very low.
Nature of the hazard is complex and may be compli-
cate. The present state of the art suggests that an uneva-
luated radioactive pollution is possible. A Radon hazard
certainly exists and has to be considered. Evaluation
measures should comprise spectrometric analysis appa-
ratus and speditive measure of Radon in the soil and wa-
ter the extent and intensity of the anomaly. Also extend-
ing the monitoring to the public and private buildings to
evaluate entering ratio of indoor Radon. It would also be
appropriate to combine measures of Radon with spec-
trometry and in situ measurements of gamma exposure
(boreholes) on soil and sweepings suspected of contami-
nation, including coring operated in buried waste dispos-
als.
7. Conclusions
The distribution of the measures in the City of Pescara is
mostly explainable with the natural contribute of radio-
activity by Uranium, Thorium and K contents in the
rocks. The general distribution reflects both surface mor-
phology and substrate composition. The measures also
show that this contribute is modified by the position of
the underground wa ter table and sea shore. Th is situation
does not account for the values located among the
Pescara Hospital, the Pescara river and the Fosso Grande
creek. This area falls within isochimichal curves between
5000 and 7000 Bq/m3. Those values are not observed or
expected in the sedimentary rocks in Pescara area. Since
the Radon anomaly corresponds to the underground sec-
tion of the Fosso Grande, it is likely that this feature has
role in the an omaly formation. Radon could be conve yed
downstream from the waste disposal located along Fosso
Grande creek. The vapor pressure in the underground
section of Fosso Grande could facilitate the exchange
with the adjacent underground water table or favour the
penetration of the Radon in the soil.
The ANPA (Agenzia Nazionale Protezione Ambiente,
Italy) and CRR (Centro di Radioattività Regionale,
Abruzzo) performed lately five measurements in well
within an area roughly between the Hospital and the
Pescara river. In 3 cases they found values above 7000
Bq/m3 with a maximum of 8974 Bq/m3, the other two
measures gave lower values between 2200 and 5300
Bq/m3. The director of ANPA-CRR, G. Damiani sug-
gested that these values were completely normal if com-
pared with those obtained elsewhere for “glacial debris
with fragments of granite, uranium-rich oil shale soils
containing aluminum (sic!)”. However, none of these
rocks exist in Pescara and Abruzzo. A series of events
with legal implications, in fact paralyzed every effort to
know more about the problem. The unpreparedness and
lack of cooperation among research institutions, weak-
ness of administrative control and negation of a potential
problem demonstrate the high vulnerability of the social
context. So the nature and distribution of the hazard re-
mains unevaluated in an area which hosts a large hospital,
several schools, a segment of a river park, tourist and
sports facilities. This study demonstrates that this can
lead to a substantial underestimation of the Radon risk in
the Pe scara area.
8. Acknowledgements
The Author is indebted with dr Alessandro Firmani, Prof.
Rita Borio and Dr. Alba Rongoni of the Sezione di Fisica
Sanitaria, Dipartimento di Scienze Radiologiche, Uni-
versità di Perugia, and the Presidio Multizonale di Fisica
Sanitaria di Pescara, for their help in the Radon survey. I
am grateful to two anonymous referees whose comments
improved very much the paper. Research was granted by
ex 60% funds of G. d’Annunzio University.
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