Effects of genetic testing on insurance : pedigree analysis and ascertainment adjustment

Gas condensate flow, which is very different from the conventional two-phase (oil and gas) flow, shows more complicated behaviour around the wellbore owing to condensate buildup and the different velocity effects on relative permeability (kr) of these low IFT fluid systems. This is especially true for complex wellbore completions, such as hydraulically fractured or perforated wells. This research programme has two separate parts. The first part is about gas condensate flow around hydraulically fractured wells (HFWs). In this part of the study, different inhouse simulators have been developed by the author. These simulators account for the changes in fluid properties with pressure, phase change, coupling (increase in kr as IFT decreases or velocity increases) and inertia (decrease in kr when velocity increases) when it is required to do so. The simulators have been used to investigate the effect of different important geometrical and flow parameters on the performance of a HFW. The new developed formulae for accurate estimation of effective fracture conductivity, fracture skin factors (mechanical and flow) and effective wellbore radius are the main practical outcomes of this part of the study. The author has also provided a new convenient method for the optimization of fracture dimensions for a given fracture volume, in gas condensate reservoirs. The second part of this research is about the study of gas condensate flow around perforated wells. Here the previously developed simulators by the Gas Condensate Research group have been used to develop a new method for estimation of mechanical perforation skin. The introduction of a method for calculation of effective wellbore radius of a perforated well by which the flow skin is negligible is another important result of this part. The new formulae introduced in this work can be used as a useful tool for estimation of well productivity/injectivity. They are also very useful in reservoir simulation, because having the effective wellbore radius for a complex wellbore geometry- such as a perforated well or hydraulically fractured well - provides an opportunity to define a simple open-hole system instead of the real wellbore. This eliminates the need for a costly and cumbersome fine grid exercise, which otherwise would be required to capture accurately the variation of flow parameters around these types of wellbores.Wellcome Trus

Development of a biomarker for penconazole: a human oral dosing study and a survey of UK residents’ exposure

Penconazole is a widely used fungicide in the UK; however, to date, there have been no peer-reviewed publications reporting human metabolism, excretion or biological monitoring data. The objectives of this study were to i) develop a robust analytical method, ii) determine biomarker levels in volunteers exposed to penconazole, and, finally, to iii) measure the metabolites in samples collected as part of a large investigation of rural residents’ exposure. An LC-MS/MS method was developed for penconazole and two oxidative metabolites. Three volunteers received a single oral dose of 0.03 mg/kg body weight and timed urine samples were collected and analysed. The volunteer study demonstrated that both penconazole-OH and penconazole-COOH are excreted in humans following an oral dose and are viable biomarkers. Excretion is rapid with a half-life of less than four hours. Mean recovery of the administered dose was 47% (range 33%–54%) in urine treated with glucuronidase to hydrolyse any conjugates. The results from the residents’ study showed that levels of penconazole-COOH in this population were low with >80% below the limit of detection. Future sampling strategies that include both end of exposure and next day urine samples, as well as contextual data about the route and time of exposure, are recommended

An inexpensive particle monitor for smoker behaviour modification in homes

Peer reviewedPostprin

Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study

A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected

Urinary biomarker concentrations of captan, chlormequat, chlorpyrifos and cypermethrin in UK adults and children living near agricultural land

There is limited information on the exposure to pesticides experienced by UK residents living near agricultural land. This study aimed to investigate their pesticide exposure in relation to spray events. Farmers treating crops with captan, chlormequat, chlorpyrifos or cypermethrin provided spray event information. Adults and children residing ≤100 m from sprayed fields provided first-morning void urine samples during and outwith the spray season. Selected samples (1-2 days after a spray event and at other times (background samples)) were analysed and creatinine adjusted. Generalised Linear Mixed Models were used to investigate if urinary biomarkers of these pesticides were elevated after spray events. The final data set for statistical analysis contained 1518 urine samples from 140 participants, consisting of 523 spray event and 995 background samples which were analysed for pesticide urinary biomarkers. For captan and cypermethrin, the proportion of values below the limit of detection was greater than 80%, with no difference between spray event and background samples. For chlormequat and chlorpyrifos, the geometric mean urinary biomarker concentrations following spray events were 15.4 μg/g creatinine and 2.5 μg/g creatinine, respectively, compared with 16.5 μg/g creatinine and 3.0 μg/g creatinine for background samples within the spraying season. Outwith the spraying season, concentrations for chlorpyrifos were the same as those within spraying season backgrounds, but for chlormequat, lower concentrations were observed outwith the spraying season (12.3 μg/g creatinine). Overall, we observed no evidence indicative of additional urinary pesticide biomarker excretion as a result of spray events, suggesting that sources other than local spraying are responsible for the relatively low urinary pesticide biomarkers detected in the study population.</p

The relationship between workers' self-reported changes in health and their attitudes towards a workplace intervention: lessons from smoke-free legislation across the UK hospitality industry

Background: The evaluation of smoke-free legislation (SFL) in the UK examined the impacts on exposure to second-hand smoke, workers’ attitudes and changes in respiratory health. Studies that investigate changes in the health of groups of people often use self-reported symptoms. Due to the subjective nature it is of interest to determine whether workers’ attitudes towards the change in their working conditions may be linked to the change in health they report. Methods: Bar workers were recruited before the introduction of the SFL in Scotland and England with the aim of investigating their changes to health, attitudes and exposure as a result of the SFL. They were asked about their attitudes towards SFL and the presence of respiratory and sensory symptoms both before SFL and one year later. Here we examine the possibility of a relationship between initial attitudes and changes in reported symptoms, through the use of regression analyses. Results: There was no difference in the initial attitudes towards SFL between those working in Scotland and England. Bar workers who were educated to a higher level tended to be more positive towards SFL. Attitude towards SFL was not found to be related to change in reported symptoms for bar workers in England (Respiratory, p = 0.755; Sensory, p = 0.910). In Scotland there was suggestion of a relationship with reporting of respiratory symptoms (p = 0.042), where those who were initially more negative to SFL experienced a greater improvement in self-reported health. Conclusions: There was no evidence that workers who were more positive towards SFL reported greater improvements in respiratory and sensory symptoms. This may not be the case in all interventions and we recommend examining subjects’ attitudes towards the proposed intervention when evaluating possible health benefits using self-reported methods. Keywords: ‘Self-Reported Health’, Attitudes, ‘Workplace Intervention’, ‘Public Health Intervention

Expectations and changing attitudes of bar workers before and after the implementation of smoke-free legislation in Scotland

BACKGROUND: In Scotland on March 26, 2006 a comprehensive prohibition on smoking in all enclosed public places was introduced. This study examines bar workers' attitudes towards a smoke-free working environment. METHODS: An intervention study comparing bar workers' opinions before and after the implementation of the smoke-free legislation. Bars were randomly selected in three Scottish cities (Glasgow, Edinburgh & Aberdeen) and towns (Aberdeenshire & Borders). Bar workers were recruited from 72 bars that agreed to participate from 159 approached. Pre- and post-implementation attitudes towards legislation, second-hand smoke and smoke-free working environments were compared. RESULTS: Initially the majority of bar workers agreed with the proposed legislation on smoking (69%) and the need for it to protect the health of workers (80%), although almost half (49%) thought the legislation would damage business. In 266 bar workers seen at both surveys, a significant positive attitudinal change towards the legislation was seen. Post-implementation, support for the legislation rose to 79%, bar workers continued to believe it was needed to protect health (81%) and concerns about the impact on business were expressed by fewer than 20%. Only the statement that the legislation would encourage smokers to quit showed reduced support, from 70% pre-implementation to fewer than 60% post-implementation. Initial acceptance was greater among younger bar workers; older workers, initially more sceptical, became less so with experience of the legislation's effects. CONCLUSION: This study shows that bar workers had generally positive attitudes towards the legislation prior to implementation, which became stronger after implementation. The affirmative attitudes of these key stakeholders are likely to contribute towards the creation of 'smoke-free' as the new social norm

Bar workers' exposure to second-hand smoke : The effect of Scottish smoke-free legislation on occupational exposure

Objectives: To examine changes in bar workers' exposure to second-hand smoke (SHS) over a 12-month period before and after the introduction of Scottish smoke-free legislation on the 26 March 2006. Methods: A total of 371 bar workers were recruited from 72 bars in three cities: Aberdeen, Glasgow, Edinburgh and small towns in two rural regions (Borders and Aberdeenshire). Prior to the introduction of the smoke-free legislation, we visited all participants in their place of work and collected saliva samples, for the measurement of cotinine, together with details on work patterns, self-reported exposure to SHS at work and non-work settings and smoking history. This was repeated 2 months post-legislation and again in the spring of 2007. In addition, we gathered full-shift personal exposure data from a small number of Aberdeen bar workers using a personal aerosol monitor for fine particulate matter (PM2.5) at the baseline and 2 months post-legislation visits. Results: Data were available for 371 participants at baseline, 266 (72%) at 2 months post-legislation and 191 (51%) at the 1-year follow-up. The salivary cotinine level recorded in non-smokers fell from a geometric mean of 2.94 ng ml-1 prior to introduction of the legislation to 0.41 ng ml -1 at 1-year follow-up. Paired data showed a reduction in non-smokers' cotinine levels of 89% [95% confidence interval (CI) 85-92%]. For the whole cohort, the duration of workplace exposure to SHS within the last 7 days fell from 28.5 to 0.83 h, though some bar workers continued to report substantial SHS exposures at work despite the legislation. Smokers also demonstrated reductions in their salivary cotinine levels of 12% (95% CI 3-20%). This may reflect both the reduction in SHS exposure at work and falls in active cigarette smoking in this group. In a small sub-sample of bar workers, full-shift personal exposure to PM2.5, a marker of SHS concentrations, showed average reductions of 86% between baseline and 2 months after implementation of the legislation. Conclusions: Most bar workers have experienced very large reductions in their workplace exposure to SHS as a result of smoke-free legislation in Scotland. These reductions have been sustained over a period of 1 year

Occupational cancer in Britain: Exposure assessment methodology

To estimate the current occupational cancer burden due to past exposures in Britain, estimates of the number of exposed workers at different levels are required, as well as risk estimates of cancer due to the exposures. This paper describes the methods and results for estimating the historical exposures. All occupational carcinogens or exposure circumstances classified by the International Agency for Research on Cancer as definite or probable human carcinogens and potentially to be found in British workplaces over the past 20–40 years were included in this study. Estimates of the number of people exposed by industrial sector were based predominantly on two sources of data, the CARcinogen EXposure (CAREX) database and the UK Labour Force Survey. Where possible, multiple and overlapping exposures were taken into account. Dose–response risk estimates were generally not available in the epidemiological literature for the cancer–exposure pairs in this study, and none of the sources available for obtaining the numbers exposed provided data by different levels of exposure. Industrial sectors were therefore assigned using expert judgement to ‘higher'- and ‘lower'-exposure groups based on the similarity of exposure to the population in the key epidemiological studies from which risk estimates had been selected. Estimates of historical exposure prevalence were obtained for 41 carcinogens or occupational circumstances. These include exposures to chemicals and metals, combustion products, other mixtures or groups of chemicals, mineral and biological dusts, physical agents and work patterns, as well as occupations and industries that have been associated with increased risk of cancer, but for which the causative agents are unknown. There were more than half a million workers exposed to each of six carcinogens (radon, solar radiation, crystalline silica, mineral oils, non-arsenical insecticides and 2,3,7,8-tetrachlorodibenzo-p-dioxin); other agents to which a large number of workers are exposed included benzene, diesel engine exhaust and environmental tobacco smoke. The study has highlighted several industrial sectors with large proportions of workers potentially exposed to multiple carcinogens. The relevant available data have been used to generate estimates of the prevalence of past exposure to occupational carcinogens to enable the occupational cancer burden in Britain to be estimated. These data are considered adequate for the present purpose, but new data on the prevalence and intensity of current occupational exposure to carcinogens should be collected to ensure that future policy decisions be based on reliable evidence