Radiation measurements as tool for environmental and geophysics studies on volcano-tectonic areas

In the last years there has been an increasing concern about naturalradioactivity measurements both from the point of view of the environmental survey, especially for the human health protection, and of the geophysical-events investigation in volcanic areas and tectonic fault zones. We report on our activity in both these fields, in particular on the measurements of indoor radon concentration in a long-term passive monitoring in dwellings of the eastern region of Sicily. Because this region is characterized by high seismicity, besides the indoor radioactivity survey, in-soil radon measurements in the region (both volcanic and tectonic area) can provide a better insight and a valuable database for the study related to radon anomalies. A synthesis is reported of the results that we obtained, in the last years, in the volcanic and tectonic area of oriental Sicily both from indoor monitoring and from geophysical-events investigation

Volcanic ash detection by GPS signal

We investigate the ability of GPS to detect volcanic plumes at Mt. Etna, Italy. We use a robust statistical approach to highlight whether the presence of a volcanic plume in the atmosphere may really affect the GPS undifferenced post-fit phase residuals. The proposed method has been tested for the September 4–5, 2007 activity of Mt. Etna. This eruption produced powerful lava fountains forming a weak, a few kilometers high plume for several hours, representing typical activity at Etna over the last 5 years. We analyzed data from nineteen Etna permanent GPS stations located on the volcano flanks at different heights and applied a statistical test based on four main steps: (a) realization of a simplified model representing the volcanic plume in atmosphere; (b) evaluation of the GPS satellite and station couples intersecting the plume; (c) calculation of the volcanic plume region crossed by the GPS signal; (d) application of a robust statistical test in order to see whether the volcanic plume affected the GPS signals. Results show that during the September 4–5, 2007 explosive activity, the GPS residuals definitely include the contribution of the volcanic plume. Our analysis shows that values of the GPS residuals are ten times smaller than those found for the Miyakejima eruption (Japan), highlighting a likely relationship between residuals and eruption intensity. In the future, data derived from the GPS stations located on Etna’s flanks could be used to improve the alerting system of volcanic ash, already operating at the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo.Published485-4971.7. Osservazioni di alta e media atmosferaJCR Journalrestricte

Radon transport: laboratory and model study

In order to exploit radon profiles for geophysical purposes and also to estimate its entry indoors, it is necessary to study its transport through porous soils. The great number of involved parameters and processes affecting the emanation of radon from the soil grains and its transport in the source medium has led to many theoretical and/or laboratory studies. The authors report the first results of a laboratory study carried out at the Radioactivity Laboratory of the Department of Physics and Astronomy (University of Catania) by means of a facility for measuring radon concentrations in the sample pores at various depths under well-defined and controlled conditions of physical parameters. In particular, radon concentration vertical profiles extracted in low-moisture samples for different advective fluxes and temperatures were compared with expected concentrations, according to a three-phase transport model developed by Andersen (Risø National Laboratory, Denmark), showing, in general, a good agreement between measurements and model calculations.Published575-5814V. Vulcani e ambienteJCR Journalreserve

Volcanic ash detection by GPS signal

We investigate the ability of GPS to detect volcanic plumes at Mt. Etna, Italy. We use a robust statistical approach to highlight whether the presence of a volcanic plume in the atmosphere may really affect the GPS undifferenced post-fit phase residuals. The proposed method has been tested for the September 4–5, 2007 activity of Mt. Etna. This eruption produced powerful lava fountains forming a weak, a few kilometers high plume for several hours, representing typical activity at Etna over the last 5 years. We analyzed data from nineteen Etna permanent GPS stations located on the volcano flanks at different heights and applied a statistical test based on four main steps: (a) realization of a simplified model representing the volcanic plume in atmosphere; (b) evaluation of the GPS satellite and station couples intersecting the plume; (c) calculation of the volcanic plume region crossed by the GPS signal; (d) application of a robust statistical test in order to see whether the volcanic plume affected the GPS signals. Results show that during the September 4–5, 2007 explosive activity, the GPS residuals definitely include the contribution of the volcanic plume. Our analysis shows that values of the GPS residuals are ten times smaller than those found for the Miyakejima eruption (Japan), highlighting a likely relationship between residuals and eruption intensity. In the future, data derived from the GPS stations located on Etna’s flanks could be used to improve the alerting system of volcanic ash, already operating at the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo

In situ and laboratory measurements for radon transport process study

Characteristics of radon transport in porous media were studied through both in situ and lab-scale measurements. In situ measurements of radon activity concentration, together with soil thoron and carbon dioxide efflux, were carried out on Mt. Etna volcano. More detailed information on radon transport mechanisms has been obtained from laboratory measurements. In particular, we report the first results of a systematic study carried out at the University of Catania (Italy) by means of a facility consisting of a large cylindrical stainless steel vessel, homogeneously filled with different materials. Radon concentration vertical profiles were extracted in low-moisture samples for different advective fluxes, temperatures and porosities

In situ and laboratory measurements for radon transport process study

Characteristics of radon transport in porous media were studied through both in situ and lab-scale measurements. In situ measurements of radon activity concentration, together with soil thoron and carbon dioxide efflux, were carried out on Mt. Etna volcano. More detailed information on radon transport mechanisms has been obtained from laboratory measurements. In particular, we report the first results of a systematic study carried out at the University of Catania (Italy) by means of a facility consisting of a large cylindrical stainless steel vessel, homogeneously filled with different materials. Radon concentration vertical profiles were extracted in low-moisture samples for different advective fluxes, temperatures and porosities

Lung cancer screening with spiral CT Baseline results of the randomized DANTE trial

Background: Despite the high survival rates reported for screening-detected cases, the potential of screening of high-risk subjects for reducing lung cancer mortality is still unproven. We herewith present the baseline results of a randomized trial comparing screening for lung cancer with annual spiral computed tomography (CT) versus a yearly clinical review. Methods: Male subjects, 60-74 years old, and smokers of 20+ pack-years were enrolled. All participants received a baseline medical examination, chest X-rays (CXR) and sputum cytology upon accrual. Subjects randomized in the spiral CT group received a spiral CT scan at baseline, then yearly for the following 4 years. For controls, a yearly clinical examination was scheduled for the following 4 years. Results: 2472 subjects were randomized (1276 spiral CT arm, 1196 controls). Age, smoking exposure and co-morbid conditions were similar in the two groups. In the spiral CT group, 28 lung cancers were detected, 13 of which were visible in the baseline chest X-rays (overall prevalence 2.2%). Sixteen out of 28 tumours (57%) were stage I, and 19 (68%) were resectable. In the control group, eight cases were detected by the baseline chest X-rays (prevalence rate 0.67%), four (50%) were stage I, and six (75%) were resectable. Conclusions: Baseline lung cancer detection rate in the spiral CT arm was higher than in most published studies. The stage I detection rate was increased four-fold by spiral CT versus chest X-rays. However, more tumours in an advanced stage were also detected by CT. The high resection rate of screening-detected patients suggests a possible increase in cure rate. However, longer follow-up is required for definitive conclusions. This trial has been registered at www.Clinicaltrials.gov, registration No. NCT00420862

A randomized study of lung cancer screening with spiral computed tomography: three-year results from the DANTE trial

Rationale: Screening for lung cancer with modern imaging technology may decrease lung cancer mortality, but encouraging results have only been obtained in uncontrolled studies. Objectives: To explore the effect of screening with low-dose spiral computed tomography (LDCT) on lung cancer mortality. Secondary endpoints are incidence, stage at diagnosis, and resectability. Methods: Male subjects, aged 60 to 75 years, smokers of 20 or more pack-years, were randomized to screening with LDCT or control groups. All participants underwent a baseline, once-only chest X-ray and sputum cytology examination. Screening-arm subjects had LDCT upon accrual to be repeated every year for 4 years, whereas controls had a yearly medical examination only. Measurements and Main Results: A total of 2,811 subjects were randomized and 2,472 were enrolled (LDCT, 1,276; control, 1,196). After a median follow-up of 33 months, lung cancer was detected in 60 (4.7%) patients receiving LDCT and 34 (2.8%) control subjects (P = 0.016). Resectability rates were similar in both groups. More patients with stage I disease were detected by LDCT (54 vs. 34%; P = 0.06) and fewer cases were detected in the screening arm due to intercurrent symptoms. However, the number of advanced lung cancer cases was the same as in the control arm. Twenty patients in the LDCT group (1.6%) and 20 controls (1.7%) died of lung cancer, whereas 26 and 25 died of other causes, respectively. Conclusions: The mortality benefit from lung cancer screening by LDCT might be far smaller than anticipated

Age at Menopause and Extent of Coronary Artery Disease Among Postmenopausal Women with Acute Coronary Syndromes

BACKGROUND: Epidemiological studies have shown a higher risk of cardiovascular mortality associated with early menopause, but the relation between menopausal age and extent of coronary artery disease after menopause is unknown. We assessed the relation between menopausal age and extent of coronary disease in postmenopausal women with an acute coronary syndrome. METHODS: A prospective study was conducted in patients 55 years old undergoing coronary angiography for an acute coronary syndrome. Enrollment was stratified by sex (women/men ratio 2:1) and age (55-64, 65-74, 75-85, and >85 years). Women were administered menopause questionnaires during admission. An independent core lab quantified coronary artery disease extent using the Gensini Score, which classifies both significant (>50%) and nonsignificant lesions. Linear correlation was used to appraise the association between the Gensini score and menopausal age. RESULTS: We enrolled 675 patients, 249 men and 426 women (mean age 74 years). The mean Gensini score was 60 36 in men vs 50 32 in women (P <.001), being higher among men at any age. The median menopausal age of women was 50 years. Risk factors and age at first acute coronary syndrome were identical among women below and above the median menopausal age. The Gensini score in women showed a weak association with age (R \ubc 0.127; P \ubc .0129), but not with menopausal age (R \ubc 0.063; P \ubc .228). At multivariable analysis, ejection fraction, female sex, and ST elevation myocardial infarction were independent predictors of the Gensini score in the overall population. CONCLUSIONS: Menopausal age was not associated with the extent of coronary artery disease. Age at first acute coronary syndrome presentation, risk factors, and prior cardiovascular events were not affected by menopausal age