The potential for spills and leaks of contaminated liquids from shale gas developments.

Rapid growth of hydraulic fracturing for shale gas within the USA and the possibility of shale developments within Europe has created public concern about the risks of spills and leaks associated with the industry. Reports from the Texas Railroad Commission (1999 to 2015) and the Colorado Oil and Gas Commission (2009 to 2015) were used to examine spill rates from oil and gas well pads. Pollution incident records for England and road transport incident data for the UK were examined as an analogue for potential offsite spills associated with transport for a developing shale industry. The Texas and Colorado spill data shows that the spill rate on the well pads has increased over the recorded time period. The most common spill cause was equipment failure. Within Colorado 33% of the spills recorded were found during well pad remediation and random site inspections. Based on data from the Texas Railroad Commission, a UK shale industry developing well pads with 10 lateral wells would likely experience a spill for every 16 well pads developed. The same well pad development scenario is estimated to require at least 2856 tanker movements over two years per well pad. Considering this tanker movement estimate with incident and spill frequency data from UK milk tankers, a UK shale industry would likely experience an incident on the road for every 12 well pads developed and a road spill for every 19 well pads developed. Consequently, should a UK shale industry be developed it is important that appropriate mitigation strategies are in place to minimise the risk of spills associated with well pad activities and fluid transportation movements.

An assessment of the footprint and carrying capacity of oil and gas well sites: The implications for limiting hydrocarbon reserves.

We estimate the likely physical footprint of well pads if shale gas or oil developments were to go forward in Europe and used these estimates to understand their impact upon existing infrastructure (e.g. roads, buildings), the carrying capacity of the environment, and how the proportion of extractable resources maybe limited. Using visual imagery, we calculate the average conventional well site footprints to be 10,800m2 in the UK, 44,600m2 in The Netherlands and 3000m2 in Poland. The average area per well is 541m2/well in the UK, 6370m2/well in The Netherlands, and 2870m2/well in Poland. Average access road lengths are 230m in the UK, 310m in The Netherlands and 250m in Poland. To assess the carrying capacity of the land surface, well pads of the average footprint, with recommended setbacks, were placed randomly into the licensed blocks covering the Bowland Shale, UK. The extent to which they interacted or disrupted existing infrastructure was then assessed. For the UK, the direct footprint would have a 33% probability of interacting with immovable infrastructure, but this would rise to 73% if a 152m setback was used, and 91% for a 609m setback. The minimum setbacks from a currently producing well in the UK were calculated to be 21m and 46m from a non-residential and residential property respectively, with mean setbacks of 329m and 447m, respectively. When the surface and sub-surface footprints were considered, the carrying capacity within the licensed blocks was between 5 and 42%, with a mean of 26%. Using previously predicted technically recoverable reserves of 8.5×1011m3 for the Bowland Basin and a recovery factor of 26%, the likely maximum accessible gas reserves would be limited by the surface carrying capacity to 2.21×1011m3.

The flux of radionuclides in flowback fluid from shale gas exploitation.

This study considers the flux of radioactivity in flowback fluid from shale gas development in three areas: the Carboniferous, Bowland Shale, UK; the Silurian Shale, Poland; and the Carboniferous Barnett Shale, USA. The radioactive flux from these basins was estimated, given estimates of the number of wells developed or to be developed, the flowback volume per well and the concentration of K (potassium) and Ra (radium) in the flowback water. For comparative purposes, the range of concentration was itself considered within four scenarios for the concentration range of radioactive measured in each shale gas basin, the groundwater of the each shale gas basin, global groundwater and local surface water. The study found that (i) for the Barnett Shale and the Silurian Shale, Poland, the 1 % exceedance flux in flowback water was between seven and eight times that would be expected from local groundwater. However, for the Bowland Shale, UK, the 1 % exceedance flux (the flux that would only be expected to be exceeded 1 % of the time, i.e. a reasonable worst case scenario) in flowback water was 500 times that expected from local groundwater. (ii) In no scenario was the 1 % exceedance exposure greater than 1 mSv-the allowable annual exposure allowed for in the UK. (iii) The radioactive flux of per energy produced was lower for shale gas than for conventional oil and gas production, nuclear power production and electricity generated through burning coal.

Directed forgetting of trauma cues in adults reporting repressed or recovered memories of childhood sexual abuse.

An item-cuing directed forgetting task was used to investigate whether women reporting repressed (n = 13) or recovered (n = 13) memories of childhood sexual abuse (CSA) exhibit an avoidant encoding style (and resultant impaired memory) for trauma cues relative to women reporting no CSA experience (n = 15). All participants viewed intermixed trauma (e.g., molested), positive (e.g., confident), and categorized neutral (e.g., mailbox) words on a computer screen and were instructed either to remember or to forget each word. The results provided no support for the hypothesis that people reporting either repressed or recovered memories of CSA are especially adept at forgetting words related to trauma. These groups recalled words they were instructed to remember more often than words they were instructed to forget regardless of whether they were trauma related.

Cognitive processing of trauma cues in adults reporting repressed, recovered, or continuous memories of childhood sexual abuse.

Psychologically traumatized people exhibit delayed color naming of trauma words in the emotional Stroop task. Four groups of participants were asked to color name positive words, neutral words, and trauma words; these groups included 15 women who believed that they harbored repressed memories of childhood sexual abuse (CSA), 13 women who reported recovered memories of CSA, 15 women who had never forgotten their CSA, and 12 women who had never been abused. Repressed-memory participants exhibited patterns of interference indistinguishable from those of the nonabused control group participants. Irrespective of group membership, the severity of self-reported posttraumatic stress disorder symptoms was the only significant predictor of trauma-related interference, r(48) = .30, p < .05.

Personality profiles, dissociation, and absorption in women reporting repressed, recovered, or continuous memories of childhood sexual abuse.

Women reporting either repressed, recovered, or continuous memories of childhood sexual abuse or no abuse history completed questionnaires tapping personality traits, absorption (fantasy proneness), dissociation, depression, and posttraumatic stress. Planned contrasts indicated that recovered memory participants scored higher on absorption and dissociation than did those reporting either continuous memories or no abuse history; repressed memory participants scored nonsignificantly higher than did recovered memory participants. On measures of distress, continuous memory participants were indistinguishable from nonabused participants, repressed memory participants scored highest, and recovered memory participants scored midway between continuous and repressed memory participants.

False recognition in women reporting recovered memories of sexual abuse.

False recognition--the mistaken belief that one has previously encountered a novel item--was examined in four groups of subjects: women reporting recovered memories of childhood sexual abuse, women who believe that they were sexually abused as children but who cannot recall this abuse (the "repressed" group), women who were sexually abused as children and always remembered the abuse, and women with no history of childhood sexual abuse. Subjects were administered a Deese/Roediger-McDermott paradigm. The results suggest that the recovered-memory group was more prone to false recognition than the other groups. In addition, women reporting recovered and repressed memories showed greater reduction in false recognition across study trials than did other subjects, perhaps reflecting strategic changes in performance.

Effects of guided imagery on memory distortion in women reporting recovered memories of childhood sexual abuse.

We tested whether having participants imagine unusual childhood events inflates their confidence that these events happened to them, and tested whether this effect is greater in women who report recovered memories of childhood sexual abuse than in women who do not. Participants were pretested on how confident they were that certain childhood events had happened to them before being asked to imagine some of these events in the laboratory. New confidence measures were readministered. Although guided imagery did not significantly inflate confidence that early childhood events had occurred in either group, the effect size of inflated confidence was more than twice as large in the control group as in the group with recovered memory. These data suggest that individuals can counteract memory distortions potentially associated with guided imagery, at least under some conditions.

Directed forgetting of trauma cues in adult survivors of childhood sexual abuse with and without posttraumatic stress disorder.

The authors used a directed-forgetting task to investigate whether psychiatrically impaired adult survivors of childhood sexual abuse exhibit an avoidant encoding style and impaired memory for trauma cues. The authors tested women with abuse histories, either with or without posttraumatic stress disorder (PTSD), and women with neither abuse histories nor PTSD. The women saw intermixed trauma words (e.g., molested), positive words (e.g., confident), and categorized neutral words (e.g., mailbox) on a computer screen and were instructed either to remember or to forget each word. Relative to the other groups, the PTSD group did not exhibit recall deficits for trauma-related to-be-remembered words, nor did they recall fewer trauma-related to-be-forgotten words than other words. Instead, they exhibited recall deficits for positive and neutral words they were supposed to remember. These data are inconsistent with the hypothesis that impaired survivors exhibit avoidant encoding and impaired memory for traumatic information.

Cardiorespiratory symptoms in response to physiological arousal.

OBJECTIVE: To develop a laboratory paradigm for assessing the tendency to amplify somatic symptoms and report bodily distress. METHOD: Reports of four different cardiopulmonary symptoms were obtained during standardized, treadmill exercise, while the physiological parameters which induce these symptoms were simultaneously measured. Two indices were developed to compare symptom reporting across patients: symptom severity after reaching 80% of predicted, maximal exercise capacity; and the magnitude of physiological arousal necessary to induce an initial sensation of discomfort. RESULTS: Fifty-one medical outpatients with a chief complaint of palpitations were studied. Symptom distress at 80% of maximal exercise capacity was significantly associated with state anxiety and daily life stress. The complaint of "heart racing" first occurred at a significantly lower heart rate for patients who were older, more anxious, and reported more daily life stress. Measures of hypochondriasis, somatization, bodily amplification, and bodily absorption were not significantly associated with either symptom measure. CONCLUSIONS: Standardized exercise testing may provide a suitable paradigm with which to study the tendency to amplify symptoms and to somatize. The distress reported by different subjects at 80% of maximal exercise capacity may be considered an index of the discomfort engendered by a standardized stimulus, whereas the point of onset of discomfort may be a measure of the patient's threshold for becoming symptomatic. These findings are not conclusive, but do suggest that patients who are more anxious and under more stress tend to report more intense cardiopulmonary symptoms at comparable levels of physiological arousal, and to have a lower threshold for experiencing discomfort.

Differential diagnosis of palpitations. Preliminary development of a screening instrument.

OBJECTIVE: To develop a self-report screening instrument to assist in the differential diagnosis of medical outpatients complaining of palpitations. DESIGN: Patients completed self-report questionnaires assessing somatization, cardiac symptoms, and hypochondriacal concerns about health. Principal components analysis was performed to identify a subset of questions that could be used to distinguish patients with palpitations who have panic disorder from those with palpitations who do not have panic disorder. PATIENTS: Sixty-seven medical outpatients referred for Holter monitoring because of a complaint of palpitations. MAIN OUTCOME MEASURES: Patients with palpitations were classified into 2 groups, those with and those without current panic disorder (established with a structured, diagnostic interview). The sensitivity, specificity, and posttest probability of the screening instrument were determined. RESULTS: A reliable, stable, 10-item instrument was derived. It seems to tap diffuse, vague, or generalized somatic complaints and worry about physical illness. With the use of a criterion cutoff score of 21, this instrument had a sensitivity of 0.81, a specificity of 0.80, and a post-test probability of.57 in detecting current panic disorder in patients with palpitations. CONCLUSIONS: A psychometrically sound and brief self-report instrument was developed to assist in the differential diagnosis of palpitations. It can be used to identify patients whose symptoms are more likely to result from panic disorder and in whom ambulatory monitoring might be deferred.

Somatized psychiatric disorder presenting as palpitations.

BACKGROUND: Psychiatric disorder is underdiagnosed in primary care practice, often because it is somatized and the patient reports only physical symptoms. Palpitations are among the symptoms that often are somatized. METHODS: We studied prospectively 125 consecutive medical outpatients referred for ambulatory electrocardiographic monitoring to evaluate a chief complaint of palpitations. They completed an in-person research interview at the time of monitoring and a telephone follow-up interview 3 months later. The referring physicians completed questionnaires about their patients before receiving the results of the monitoring and again 3 months later. RESULTS: Forty-three patients had clinically significant cardiac arrhythmias. Twenty-four (29%) of the remaining 82 patients had a current psychiatric disorder, and 20 of these patients (83%) had major depression or panic disorder. These patients were significantly younger and more disabled, somatized more, and had more hypochondriacal concerns about their health than did patients who had no psychiatric disorder. Their palpitations were more likely to last longer than 15 minutes, were accompanied by more ancillary symptoms, and were described as more intense. At 3-month follow-up, about 90% of the patients in both groups continued to experience palpitations. Symptoms of somatization, hypochondriacal concerns, and impairment of intermediate activities had improved in both groups, but remained higher in patients with psychiatric disorder than in patients without psychiatric disorder. During the follow-up interval, patients with psychiatric disorder had more emergency department visits. The physicians of patients with psychiatric disorder were more likely to ascribe the palpitations to anxiety or depression, and ordered fewer laboratory tests on them, but few patients who had not already been in psychiatric treatment were referred or started on psychotropic medication. CONCLUSIONS: Physicians are aware of a psychiatric component to the clinical presentation of palpitation, but this observation does not result in psychiatric treatment or referral in most cases.