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1.
Airborne benzene concentrations were measured in a room with controlled air exchange during surface cleaning with two petroleum-based solvents (a paint thinner and an engine degreaser). The solvents were spiked with benzene to obtain target concentrations of 0.001, 0.01, and 0.1% by volume in the liquid. Personal samples on the worker and area samples up to 1.8 m away were collected over 12 events (n = 84 samples) designed to examine variation in exposure with solvent type, cleaning method (rag wipe or spatula scrape), surface area cleaned, air exchange rate, solvent volume applied, and distance from the cleaned surface. Average task breathing zone concentrations of benzene represented by 18–32 min time-weighted averages were 0.01 ppm, 0.05 ppm, and 0.27 ppm, when the solvents contained approximately 0.003, 0.008, and 0.07% benzene. Solvent benzene concentration, volume applied, and distance from the handling activities had the greatest effect on airborne concentrations. The studied solvent products containing 0.07% benzene (spiked) did not exceed the current OSHA permissible exposure limit of 1 ppm (averaged over 8 h) or the ACGIH Threshold Limit Value of 0.5 ppm, in any of the tested short-term exposure scenarios. These data suggest that, under these solvent use scenarios, petroleum-based solvent products produced in the United States after 1978 likely did not produce airborne benzene concentrations above those measured if the concentration was less than 0.1% benzene.  相似文献   

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In 1985 the Health and Safety Executive set a gravimetric Control Limit for airborne Man-Made Mineral Fibre and in 1987 a respirable fibre number Recommended Limit for Superfine MMMF. A limited investigation was carried out of the use of glass and ceramic fibre products used as protection against welding 'batter' and oxyacetylene welding flame. Airborne fibre levels are compared with the Occupational Exposure Limits.  相似文献   

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目的筛选与苯中毒有关的DNA复制及损伤修复基因。方法选取慢性苯中毒患者和无苯接触的健康人各7例配对,提取外周血白细胞总RNA。在反转录cDNA时,用Cy3,Cy5两种激发波长荧光分别标记两组样本cDNA探针。将各对探针混合后与含141条DNA复制及损伤修复的人类基因表达谱芯片杂交、扫描,分析杂交结果。结果共筛选出差异表达的基因25条,其中16条基因表达上调:9条基因表达下调,主要包括有DNA复制基因如PRIM2A,ORCIL等;DNA合成、重组及修复基因如POLK;DNA损伤信号基因/修复蛋白和DNA连接酶如RECQL,PRKDC,G22P1,ERCC3,ERCC1,CRY1。CHES1,BRCA2.APEX等;重组蛋白质如RECQL;其他DNA合成再重组和修复蛋白质如SKIV2L,RBMS1,SON.SET等。结论苯中毒患者外周血白细胞的DNA复制及损伤修复基因与正常人相比存在差异性表达,为进一步筛选苯中毒生物标志物提供了依据。  相似文献   

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The aim of this study was to assess the validity and reliability of a questionnaire to estimate water exposure through drinking, showering, bathing or swimming. Forty-seven pregnant women were recruited from antenatal or exercise classes and were randomly allocated into three groups. The first group completed the water exposure questionnaire one-week apart. The second group completed a three-day diary and then the questionnaire. The third group completed the questionnaire first followed by the diary. Agreement was assessed by the Intraclass correlation coefficient (ICC) and the Kappa statistic. The questionnaire demonstrated good reliability (ICC 0.93 for water consumption and 0.91 for time spent showering). With regard to validity, average daily water consumption was estimated to be 8.1 glasses/day (2 litres) from the diary compared with 12.2 (3 litres) from the questionnaire. The ICCs comparing the diary and questionnaire responses were 0.31 for water consumption and 0.72 for showering. The water exposure questionnaire overestimated levels of exposure when compared with diary-reporting of consumption. While a water exposure questionnaire may be a less intrusive research instrument than a diary, further development is required to improve the validity of this instrument.  相似文献   

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某焦化厂职业接触多环芳烃焦炉工肝脏某些酶活性的变化   总被引:4,自引:0,他引:4  
目的探讨多环芳烃(PAHs)对炼焦作业工人某些肝血清酶活性改变的可能影响。方法对乙肝表面抗原(HBsAg)阴性的炼焦作业工人和非PAHs职业接触工人进行总PAHs累积接触指数(CEL-PAHs)评估,尿中1-羟基芘(1-OHP)浓度等级划分,和血清中丙氨酸转移酶(ALT)、天门冬氨酸转移酶(AST)、γ-谷氨酰转移梅(GGT)、碱性磷酸酶(ALP)的检测。结果焦炉工职业性PAHs暴露水平明显高于对照组(P<0·05)。与对照组相比,血清ALT的明显升高可见于CEL-PAHs<50μg/(m3·a)组和尿中1-OHP浓度<2·3μmol/mol肌酐CEL-PAHs≥200μg/m3组,血清AST的明显升高可见于CEL-PAHs<50μg/(m3·a)组;当CEL-PAHs(200μg/(m3·a)或尿中1-OHP浓度≥10·0μmol/mol肌酐时,可发现四种肝生化指标实测值的明显升高(P<0·05),以及ALT、AST和GGT异常率的明显升高(P<0·05),以血清GGT水平的升高(10倍CEL-PAHs的上升导致1·24倍血清GGT水平的升高,10倍尿中1-OHP浓度的上升导致1·19倍的升高)和异常率的上升(logistic回归,调整OR值为6·2~7·2,P<0·05)最为明显。结论PAHs职业暴露可导致炼焦作业工人肝脏某些血清酶活性的升高。  相似文献   

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This paper examines the relationship between the physical strenuousness of work and the BMI in Finland, using individual microdata at 5-year intervals over the period 1972--2002. Data came from the National FINRISK Study which contains self-reported information on the physical strenuousness of a respondent's occupation. Our estimates show that the changes in the physical strenuousness of work explain around 7% at most of the increase in BMI for Finnish males observed over a period of 30 years. The main reason for this appears to be the effect of the physical strenuousness of work on BMI which is rather moderate. According to the point estimates, BMI is 2.4% lower when a male's occupation is physically very demanding and involves lifting and carrying heavy objects compared with a sedentary job (reference group of the estimations), other things being equal. Furthermore, it is very difficult to associate the changes in the occupational structure with the upward trend in BMI for females, and the contribution of the changes in the occupational structure is definitely even smaller for females than it is for males. All in all, we show that the changes in self-reported occupation show a slight association with the changes in the logarithm of the BMI scores.  相似文献   

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Previous studies performed in an experimental model of nutritional growth retardation (NGR) have observed metabolic adaptation. We hypothesized that changes in lipid-lipoprotein profile, glucose, and insulin levels occur, whereas overall body growth is reduced.The aim of this study was to assess serum lipid-lipoprotein profile, hepatogram, insulinemia and glycemia, and CVD risk markers in rats fed a suboptimal diet. Weanling male rats were assigned either to control (C) or NGR group. In this 4-week study, C rats were fed ad libitum a standard diet, and NGR rats received 80% of the amount of food consumed by C. Zoometric parameters, body fat content, serum lipid-lipoprotein profile, hepatogram, insulinemia, and glycemia were determined, and the cardiovascular disease (CVD) risk markers homeostasis model assessment–insulin resistance and homeostasis model assessment and β-cell function were calculated. Suboptimal food intake induced a significant decrease in body weight and length, which were accompanied by a reduction of 50% in body fat mass. Serum lipoproteins were significantly higher in NGR rats, with the exception of high-density lipoprotein cholesterol, which remained unchanged. Nutritional growth retardation rats had decreased triglycerides compared with C rats. No significant differences were detected in liver function parameters. The CVD risk markers homeostasis model assessment (HOMA)–insulin resistance and homeostasis model assessment and β-cell function were significantly lower in NGR rats. Mild chronic suboptimal nutrition in weanling male rats led to growth retardation and changes in the lipid-lipoprotein profile, glucose, and insulin levels while preserving the integrity of liver function. These data suggest a metabolic adaptation during suboptimal food intake, which ensures substrates flux to tissues that require constant energy—in detriment to body growth. The CVD risk markers suggested that mild chronic food restriction of approximately 20% could provide protection against this degenerative disease.  相似文献   

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目的 了解社区美沙酮维持治疗患者治疗期间偷吸海洛因的情况及其影响因素.方法 在江苏、安徽、云南3省9个城市社区美沙酮维持治疗门诊中抽取1301名符合条件的患者进行问卷调查与随机尿吗啡定性检测.收集一般人口学、艾滋病/毒品滥用相关高危行为、参加美沙酮维持治疗情况、抑郁与焦虑及偷吸海洛因等信息.结果 1301名调查对象中男性居多(76.2%),年龄(34.6±6.5)岁,受教育程度以初中及以下为主(71.7%).平均维持治疗剂量(48.1±29.4)mg/d,目前治疗剂量自我满意度平均得分为8.6,尿吗啡检测阳性率为27.7%.有抑郁和焦虑症状者比例分别为38.3%和18.4%,抑郁合并焦虑症状的比例为14.2%.婚姻状况、治疗时间的长短、目前治疗剂量自我满意度及是否曾退出治疗对偷吸海洛因影响的差异有统计学意义,而性别、教育程度及治疗剂量对偷吸海洛因的影响差异无统计学意义.不同省份间影响偷吸海洛因的因素有所不同,但对当前剂量自我满意度是共同的影响因素.结论 提高门诊服务质量及服药依从性、延长参加治疗的时间、提高患者对治疗剂量的满意度及避免脱失对减少治疗期间偷吸海洛因有重要意义.  相似文献   

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OBJECTIVES—This study was performed to estimate the strength of association between chronic bronchitis and lifetime exposure to occupational factors, current lifestyle, and the NS-phenotype in the MNS blood group among middle aged and elderly men.
METHODS—The study was carried out within the frameworks of the Copenhagen Male Study. Of 3387 men 3331 men with a mean age of 63 (range 53-75) years could be classified by prevalence of chronic bronchitis. As well as the completion of a large questionnaire on health, lifestyle, and working conditions, all participants had a thorough examination, including measurements of height and weight and blood pressure and a venous blood sample was taken for the measurement of serum cotinine and MNS typing; 16.5% of the men had the NS-phenotype. Chronic bronchitis was defined as cough and phlegm lasting 3 months or more for at least 2 years; 14.6% had chronic bronchitis.
RESULTS—Smoking and smoke inhalation were the factors most strongly associated with prevalence of chronic bronchitis. There were three major new findings: (a) long term (>5 years) occupational exposure to cold and draught was associated with a significantly increased prevalence of chronic bronchitis; compared with others, and adjusted for confounders, the odds ratio (OR) with 95% confidence interval (95% CI) was 1.4 (1.1 to 1.7), p=0.004; (b) a significant J shaped association existed between alcohol use and bronchitis, p<0.001, with the lowest prevalence found among moderate users; (c) a significant gene by environment association existed between smoking and the NS-phenotype in the MNS blood group; only among smokers was the NS-phenotype associated with a significantly decreased risk of chronic bronchitis, OR 0.67 (0.47-0.97), p=0.02. Other well known associations between dust, fumes, and even exposure to solvents and bronchitis were confirmed.
CONCLUSION—The results emphasise the multifactorial nature of chronic bronchitis, and show some hitherto unrecognised associations between cold and draught exposure, alcohol consumption, and the NS-phenotype and chronic bronchitis.


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Epidemiologic studies have reported an inverse association between dairy product consumption and cardiometabolic risk factors in adults, but this relation is relatively unexplored in adolescents. We hypothesized that a higher dairy product intake is associated with lower cardiometabolic risk factor clustering in adolescents. To test this hypothesis, a cross-sectional study was conducted with 494 adolescents aged 15 to 18 years from the Azorean Archipelago, Portugal. We measured fasting glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body fat, and cardiorespiratory fitness. We also calculated homeostatic model assessment and total cholesterol/high-density lipoprotein cholesterol ratio. For each one of these variables, a z score was computed using age and sex. A cardiometabolic risk score (CMRS) was constructed by summing up the z scores of all individual risk factors. High risk was considered to exist when an individual had at least 1 SD from this score. Diet was evaluated using a food frequency questionnaire, and the intake of total dairy (included milk, yogurt, and cheese), milk, yogurt, and cheese was categorized as low (equal to or below the median of the total sample) or “appropriate” (above the median of the total sample).The association between dairy product intake and CMRS was evaluated using separate logistic regression, and the results were adjusted for confounders. Adolescents with high milk intake had lower CMRS, compared with those with low intake (10.6% vs 18.1%, P = .018). Adolescents with appropriate milk intake were less likely to have high CMRS than those with low milk intake (odds ratio, 0.531; 95% confidence interval, 0.302-0.931). No association was found between CMRS and total dairy, yogurt, and cheese intake. Only milk intake seems to be inversely related to CMRS in adolescents.  相似文献   

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The objective of this study was to test the feasibility of a treatment programme based on the elements of constraint‐induced movement therapy (CIMT) to encourage use of the affected arm of a child with obstetric brachial plexus injury (OBP), as well as to document clinical changes observed with this intervention. A 2‐year‐old female child with Erb's palsy had 14 weeks of daily home‐based treatment with 30‐minute sessions planned according to the principles of CIMT. The child was assessed every 2 weeks with the Toddler Arm Use Test. Test scores throughout the intervention period demonstrated improvements in quality of movement, amount of use and willingness to use the affected extremity. The child's mother reported improved ability to perform bimanual activities at home. The results suggest that treatment based on CIMT principles has potential to promote functional gains for children with OBP. Experimental studies should test the effects of this kind of intervention for children with OBP. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

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