Baseline survey of psychosocial factors levels and their health effects in a cohort study of natural gas field workers / 中华劳动卫生职业病杂志

Objective: To investigate the level of psychosocial factors in workplace and their health effects among workers in a natural gas field. Methods: A prospective and open cohort of natural gas field workers was established to study the level of workplace psychosocial factors and their health effects, with a follow-up every 5 years. In October 2018, a cluster sampling method was used to conduct a baseline survey of 1737 workers in a natural gas field, including a questionnaire survey on demographic characteristics, workplace psychosocial factors and mental health outcomes, physiological indicators such as height and weight, and biochemical indicators such as blood routine, urine routine, liver function and kidney function. The baseline data of the workers were statistically described and analyzed. The psychosocial factors and mental health outcomes were divided into high and low groups according to the mean score, and the physiological and biochemical indicators were divided into normal and abnormal groups according to the reference range of normal values. Results: The age of 1737 natural gas field workers was (41.8±8.0) years old, and the length of service was (21.0±9.7) years. There were 1470 male workers (84.6%). There were 773 (44.5%) high school (technical secondary school) and 827 (47.6%) college (junior college) graduates, 1490 (85.8%) married (including remarriage after divorce), 641 (36.9%) smokers and 835 (48.1%) drinkers. Among the psychosocial factors, the detection rates of high levels of resilience, self-efficacy, colleague support and positive emotion were all higher than 50%. Among the mental health outcomes evaluation indexes, the detection rates of high levels of sleep disorder, job satisfaction and daily stress were 41.82% (716/1712), 57.25% (960/1677) and 45.87% (794/1731), respectively. The detection rate of depressive symptoms was 22.77% (383/1682). The abnormal rates of body mass index (BMI), triglyceride and low density lipoprotein were 46.74% (810/1733), 36.50% (634/1737) and 27.98% (486/1737), respectively. The abnormal rates of systolic blood pressure, diastolic blood pressure, uric acid, total cholesterol and blood glucose were 21.64% (375/1733), 21.41% (371/1733), 20.67% (359/1737), 20.55% (357/1737) and 19.17% (333/1737), respectively. The prevalence rates of hypertension and diabetes were 11.23% (195/1737) and 3.45% (60/1737), respectively. Conclusion: The detection rates of high level psychosocial factors in natural gas field workers are high, and their effects on physical and mental health remain to be verified. The establishment of a cohort study of the levels and health effects of psychosocial factors provides an important resource for confirming the causal relationship between workplace psychosocial factors and health.

Laboratory evaluation and field trial of activation indigenous microbial displacements in the reservoirs after polymer flooding / 生物工程学报

Most main oilfields in China have already entered a "double high" development stage (high water cut, high recovery degree). To further enhance oil recovery in reservoirs after polymer flooding (RAPFs), an efficient activator formulation for promoting metabolism of endogenous microorganism was studied by aerogenic experiments, physical simulation experiments, electron microscopy scanning and pyrophosphate sequencing. Results show that the activator could activate the endogenous microorganisms in the injected water and make the pressurized gas reach 2 MPa after 60 d static culture of the activator in a high pressure vessel. The oil recovery efficiency of natural core physical simulation flooding can be improved by more than 3.0% (OOIP) in RAPFs when injected 0.35 PV activator with 1.8% mass concentration, and a lot of growth and reproduction of activated endogenous microorganism in the core was observed by electron microscopy scanning. Field trial with 1 injector and 4 producers was carried out in the east of south II block of Sa Nan in December 2011. By monitoring four effective production wells, changes of carbon isotope δ13C (PDB) content of methane and carbon dioxide were -45 per thousand to -54 per thousand and 7 per thousand to 12 per thousand. Compared with east II of Sa Nan block, the oil amount increased by 35.9%, water cut stabled at 94%. The incremental oil was 5 957 t during the three and a half years, which provides an alternative approach for further improving oil recovery in similar reservoirs.

A Proportionate Mortality Ratio (PMR) and Proportionate Cancer Mortality Ratio (PCMR) Analysis among Surinamese Residents Living in Proximity to Crude Oil Fields

Since crude oil exploration and extraction activities officially started in 1982 in Suriname, no environmental and health impact study have been conducted to determine whether residents living near petroleum production oil fields had adverse health effects. Internationally there have been some studies investigating the relationship between health effects and living in proximity of an oil field, but findings are still controversial whether crude oil exploration and extraction activities have negative health impacts on residents living in proximity of these oil fields. Therefore, we conducted a proportionate mortality ratio (PMR) analysis to determine if there were excess deaths due to a particular cause of death, particularly cancer, in residents with and without long-term exposure to crude oil exploration and extraction activities. Death certificates of the department of Epidemiology were used to gather mortality data (2002-2009) of the residents living near the Tambaredjo oil field (study population) while the mortality data of the general population of Suriname (reference population) was obtained using the reports of death causes in Suriname (2002-2009) provided by the department of Epidemiology. Proportionate mortality ratios (PMRs) and sex-adjusted proportionate cancer-specific mortality ratios (PCMRs) were calculated to evaluate excess death due to a particular disease or cancer type. PMRs for malignant neoplasm (1.19), external causes (1.26), and diabetes mellitus (1.27) were elevated while the PMRs for other major causes such as cardiovascular diseases (0.74), perinatal period (0.59) and HIV/AIDS (0.59) were decreased. Furthermore, elevated PCMRs for males were found for cancers of the stomach (1.46), liver (1.59), lung/bronchus (1.62), bladder (2.32), rectum (2.43), unspecified urinary tract (6.25), and testis (9.09). Elevated PCMRs for females were found for cancers of the cervix (1.27), lung/bronchus (1.76), brain/eye (4.39), and ill-defined gastrointestinal tract (11.76). We found several studies supporting our observed findings of cancer excess, but due to some study limitations such as the limitations of PMR analysis, the use of death certificates, and a small number of deaths in decedents of the study population; we could not conclude that our study findings were conclusive for a causal relationship. Therefore, we recommend more robust designs of studies to be undertaken, such as longitudinal and exposure assessment study designs, to associate exposure to crude oil exploring and extracting activities with adverse health effects, especially cancer, on the residents living near an oil field.

A comparison of arterial blood gas values depending on the use of endotracheal tube cuff in postanesthetic patients / 대한마취과학회지

An endotracheal tube (ETT) may be thought of as a mechanical burden to a spontaneously breathing patient because increases in airway resistance might result in increases in the work of breathing,when diameter of airway is decreased in the intubated patient compared with his own tracheal diameter. We hypothesized that air removal from ETT cuff would permit the airflow between ETT and tracheal wall and could make the airway resistance decrease. Postanesthetic patients after abdominal surgery were divided into two groups. ETT cuff was inflated in group 1 (n=25) and deflated in group 2 (n=25), while 5 l/min of oxygen was delivered through the ETT via a simple oxygen supplement device without a gas reservoir. The effects of balloon on gas exchange and respiratory pattern were evaluated at 5 and 30 minutes after admission to the recovery room. Postanesthetic PaO2 was increased compared to preanesthetic value with oxygen supply. PaCO2 values revealed no significant changes in preanesthetic and postanesthetic periods. Postanesthetic respiratory rate was increased significantly but there was no difference between two groups. However, there were three hypoxemic patients whose PaO2 were below 70mmHg in group 1. It was concluded that the use of balloon of ETT in postanesthetic recovery period might contribute to airway resistance and the work of breathing. Although almost of patients could make compensations to overcome the effects of balloon, there is a risk of postoperative hypoxemia if compensated inadequately.