北京市环境空气放射性水平的测量与分析

目的 探讨环境空气放射性水平及与空气质量的关系。方法 选取2017年9月-12月期间,以SNOW WHITE大流量采样器进行空气样品收集,连续24 h采样,以TBM-3S测量仪对收集的样品滤膜表面进行表面放射性测量,将测得结果分别与空气质量等级、大气中PM_2.5、PM₁₀颗粒物浓度进行统计学比较分析。结果 37个大气气溶胶滤膜样品的表面放射性水平为（1.051~2.831）Bq/cm²,平均值为1.802 Bq/cm²;不同空气质量等级间比较大气中放射性水平无显著性差异（P ≥ 0.05）,不同颗粒物浓度间比较大气中放射性水平无显著性差异（P ≥ 0.05）。结论 监测期间,空气质量及大气中颗粒物含量的变化,未引起大气中放射性水平的变化,空气质量与大气放射性水平不相关。     

大气放射性核素连续监测系统的构建

目的 建立一套放射性核素最低可探测浓度较低,具有较高自动化水平、状态稳定的大气放射性核素连续监测系统,提高监测过程的溯源能力及质量控制水平。方法 以以太网为基础,集成各类传感器,对监测系统中的各个监控点实时监控并采集数据,通过专用的监测系统控制软件实现数据自动记录与传输。结果 建立的监测系统可对监测过程中的环境、气象、样品状态、检测结果等数据进行自动采集、记录并传输;该系统工作稳定,2009-2014年可开展监测工作天数比例为96.8%,对于重要人工放射性核素¹³⁷Cs和¹³¹I的最低可探测浓度达到μBq/m³水平。结论 该监测系统具有较高的自动化水平,提高了监测过程的数据溯源能力,具有较低的核素最低可探测浓度、稳定的系统工作能力。     

屏蔽室内氡对全身和肺部计数器测量性能的影响

目的 测定铅屏蔽室内氡对全身和肺部计数器测量¹³⁷Cs和²⁴¹Am的最小可探测活度的影响程度。方法 通过对屏蔽室进行通室外空气降氡。用测氡仪对屏蔽室内的氡浓度进行连续测量,同时测量全身和肺部计数器的本底谱。结果 通过实验数据分析表明,通风降氡可以降低全身和肺部计数器测量¹³⁷Cs和²⁴¹Am的最小可探测活度14%至23%。结论 对屏蔽室通风降氡,能有效地提高全身和肺部计数器的探测性能。     

低温环境空气中氚化水蒸气的采样方法探讨

目的 建立一种适合低温（-15℃~5℃）环境下空气中氚化水蒸气的采样方法，为北方核电厂外围环境空气中氚化水蒸气的监测提供技术支持。方法 以3A分子筛为吸附材料，采用主动抽气法采集室外环境空气中的水蒸气，用于环境空气中氚化水蒸气样品的采集，并对采样速率、效率、记忆性等进行了优化和测试，验证方法的适用性。结果 采样速率在1.0~3.0 L/min时采样效率大于99%，采样方法记忆效应约3%。结论 该采样方法可以实现冬季低温环境空气中氚化水蒸气样品的采集。     

HPGe探测效率和符合相加修正系数的蒙特卡罗计算

目的 介绍用蒙特卡罗(MC)方法编写的计算HPGe探测器探测效率和符合相加修正系数的程序(Cool 2000-HpGe),及实验值与计算值的比较研究。方法 用MC计算得到的探测效率和符合相加修正系数与实验得到的值进行比较。结果 对空气、水和土壤三种模拟基质体标准源由实验(ORTEC ADCOM100+GEM50195 HPGe γ谱仪系统)得到的符合相加修正系数值与模拟计算值之间的相对偏差绝对值分别为5.14%、12.1%和10.4%,在点源距探测器端窗5、10和25 cm处的由实验得到的探测效率值与模拟计算值之间的相对偏差绝对值分别为10.6%、5.6%和3.0%。结论 笔者报道的MC计算软件Cool 2000可以在环境放射性监测中用于计算HPGe探测器探测效率和符合相加修正系数。     

活性炭盒法测定矿井氡采样方法的初步研究

目的 本文研究了活性炭盒法测氡采样过程在炭盒吸附面增设滤膜、改变吸附面朝向等因素对测量结果的影响,为该方法应用于矿井高湿、高粉尘环境氡浓度检测提供技术支持。方法 按照实验方案布置活性炭盒,到吸附时间后盖上密封盖称重,放置5 h后用HD-2001型低本底γ能谱仪测试氡浓度。用RAD7氡浓度检测仪同步检测测试间氡浓度,以便于对测量结果进行比较。结果 活性炭盒吸附面朝上或朝下测得空气中氡浓度分别为（227.2 ±3.0） Bq/m³、（229.8 ±3.7） Bq/m³,两种放置方式测量结果相对偏差仅为1.1%。在活性炭盒吸附面增加定量滤纸或HI-Q型积尘滤膜后测得空气中氡浓度分别为（224.3 ±3.0） Bq/m³、（231.8 ±3.0） Bq/m³,与无滤膜时的测量结果相对偏差分别为-1.3%和2.0%。在相对湿度89.5%的环境下,活性炭盒法测得空气中氡浓度在221.5～238.1 Bq/m³之间,相同条件下RAD-7测氡仪测量结果为243 Bq/m³,两种检测方法测量结果相对偏差仅为-6.1%。结论 本次测试条件下,采样时在活性炭盒吸附面增加定量滤纸或HI-Q型积尘滤膜并将活性炭盒吸附面朝下放置,对测量结果无显著影响。该采样方法可避免由于采矿作业场所粉尘、矿渣等杂质落入活性炭盒影响检测结果。     

校园内空气微生物污染状况和净化方式的研究

目的 检测高中校园室内空气微生物污染状况,探索简便有效的空气净化方式。方法 采用自然沉降法对校园内不同地点室内空气中的细菌总数进行监测与分析,并比较3种常用的室内空气净化方式对空气的净化效果。结果 校园内5个采样点空气质量均处于微污染水平,其中以学生宿舍和餐厅质量状况最差。通风可以快速改善空气质量,紫外线对空气中细菌的净化效率达85%,但对部分芽孢杆菌和葡萄球菌作用较弱,过氧化氢消毒法净化效率达100%。结论 过氧化氢消毒法消毒作用强、杀菌谱广,结合其他方法联合使用,能够有效改善校园内空气污染状况。     

高湿度环境下活性炭盒法测氡研究

目的 简单高效地测量高湿度环境下的氡浓度。方法 活性炭盒测量法。结果 研究了活性炭盒的响应\峰面积计算、布放时间以及校准参数等,并探讨了提高活性炭盒探测效率的途径。结论 可通过实验校准降低高湿度环境对活性炭盒测氡的影响,并减小测量误差,提高测量精度。     

气溶胶总α放射性测量不确定度评定

目的 评定气溶胶中总α放射性测量实验中的不确定度。方法 通过分析计算公式中的有关参数分析测量实验中的不确定度。结果 了解到该分析实验中由测量仪器带来的不确定度为8.11%,仪器探测效率带来的不确定度为6.5%。结论 气溶胶中总α放射性主要受到测量仪器的不确定度及仪器探测效率等2个方面的不确定度因素影响。     

苏州市区居民住宅内氡水平及其影响因素分析

目的 了解苏州市居民住宅内氡水平。方法 采用双滤膜法,选用标准Pu-239源校正后的FT-648型测氡仪,效率为0.8,以40L/min的空气流速采样15min,间隔1min后记数15min,读取结果,经公式换算,得出氡浓度的数据。结果 本次调查的135户住房中氡浓度为41.4 Bq/m³。楼层、房屋结构、居住时间及装修材料对居民室内氡水平的有影响。结论 苏州市居住宅室内氡水平与世界范围的40.0 Bq/m³相当,保持良好通风是室内降低氡浓度的有效措施。     

Trends in meningococcal disease in Italy in 1988

Meningococcal disease in Italy decreased 15% in 1988 from the previous year (290 vs. 342 cases). The decline was particularly evident in military cases (1.7/100,000 in 1988 vs. 5/100,000 in 1987) reflecting the full coverage of bivalent serogroup (A + C) meningococcal polysaccaride vaccine in army recruits, achieved since January 1988. The highest proportion of cases was seen in people older than 25 years of age (25%). Serogroup C constituted 60% of the isolates, while 19% belonged to serogroup B. The proportion of strains resistant to sulphonamides was 45%, while 15% were resistant to Minocycline and none to Rifampin. Out of the five military cases, only one (due to serogroup C) was attributable to the vaccine failure. A single coprimary case, but no secondary cases occurred among civilians. These findings are consistent with the trends reported in Italy in the previous years.     

Benzene in blood and phenol in urine in monitoring benzene exposure in industry

Determinations of benzene concentration in blood and of phenol in urine were made by head-space gas chromatography techniques on samples taken near the end of the work day from two groups of workers potentially exposed to low levels of benzene in the work-place atmosphere. Preliminary results suggest that benzene in blood is more reliable than phenol tests for assessing both exposure and uptake of benzene. Normal values of phenol in urine (10 mg/liter or less) were found in nearly all those cases in which benzene was detected in the blood.     

2015年郑州市饮用水放射性水平状况调查

目的了解郑州市不同地区、不同季节、不同水源类型的放射性水平。方法分别于丰水期和枯水期采集郑州市区黄河水源水、井水源水、丹江口水源水、出厂水和末梢水各一份;以县为单位,每单位采集出厂水、末梢水、水库水、河水、井水各1份,按《生活饮用水生活标准检验方法》(GB/T 5750.13-2006)检测饮用水中总α和总β放射性水平,依据《生活饮用水卫生标准》(GB 5749-2006)进行判定。结果丰水期、枯水期水体总α、总β放射性水平均低于国家标准限值。结论郑州市不同水源类型均处于正常的天然放射性本底水平。     

2019年中国肿瘤流行病学研究进展

恶性肿瘤已成为中国居民的主要死因之一。近些年来,中国政府积极推进肿瘤预防和控制领域的研究工作,取得了很大的进步。本文简要汇总中国在肿瘤流行病学领域的研究进展,具体包括2019年的肿瘤负担、癌症危险因素及其干预、筛查和早期发现、癌症防治专项行动(2019-2022年)方案等方面,以期为我国肿瘤防治工作的有效开展提供技术支撑和理论依据。     

2012年绵阳市蔬菜中农药残留状况

目的 了解绵阳市2012年市售蔬菜中农药残留情况,为食用蔬菜监管提供依据.方法 全部样品均按照GB/T 5009-2003的方法进行农药的残留检测.依据GB 2763-2005《食品中农药最大残留限量》进行判定.结果 2012年共检测蔬菜165份,农药检出率和超标率分别为72.12％和23.64％.豆类、根茎类、叶菜类、瓜果菜类和食用菌类蔬菜检测农药残留超标率分别为8.00％、23.53％、36.00％、5.26％和27.03％,差异有统计学意义(x2=11.41,P＜0.01).不同种类农药超标率差异有统计学意义(x2 =62.42,P＜0.01).夏季和冬季蔬菜农药超标率差异无统计学意义(x2=3.44,P＞0.05).结论 绵阳市叶菜类蔬菜中农药残留情况较为严重,应采取有效措施,加强蔬菜的监督管理,从源头禁止高毒农药的使用,加大蔬菜种植、销售环节的监测,确保市民食用蔬菜的安全.     

Occupational stress in nurses in psychiatric institutions in Taiwan

Nurses are known to be exposed to occupational stress. However, occupational stress is not well documented for nurses in psychiatric institutions in Taiwan. A cross-sectional study was conducted to explore the work-related stress and risk factors of nurses in psychiatric institutions in Taiwan. A structured questionnaire was distributed to nurses at five state-owned psychiatric hospitals in Taiwan in 2001. Demographic information, working environment, and personal health status were inquired. Occupational stress was assessed based on the Chinese version of Job Content Questionnaire (JCQ). General health status and mental health were evaluated by the International Quality of Life Assessment Short Form-36 (IQOLA SF-36). A total of 573 questionnaires were disseminated to nurses and 518 (90.4%) were satisfactorily completed by nurses, including 408 female full-time nurses who had been in their current work for more than 6 months. In the past one month, 17.2% of nurses reported being under significant stress often or always. Assault episodes were reported by 45.1% of nurses in the past 6 months. Among the nurses, 16.9%, 25.2%, 50.0%, and 7.8% belong to the "High strain", "Low strain", "Active", and "Passive" groups, respectively. Perceived occupational stress was associated with young age, widowed/divorced/separated marital status, high psychological demand, low workplace support, and threat of assault at work. Lower general health score was associated with low job control, high psychological demand, and perceived occupational stress. A lower mental health score was associated with low job control, high psychological demand, low workplace support, and perceived occupational stress. We concluded that nurses in psychiatric institutions are under significant stress related to work factors.     

Changes in nursing administration in supporting transplantation in Brazil

This historical and bibliographic study aimed to understand how Nursing was organized to support care in transplantation. The HISA, LILACS, BDENF, PERIENF and DEDALUS databases were consulted, and thirteen references were found, ten of which were scientific articles, two were master's dissertations and one was a doctoral thesis. The span of time chosen for study ranges from the date of the first kidney transplant in Brazil (1965), to the date of publication of the last scientific article found in the databases mentioned above (2003). After reading these articles, the ones that were similar in topic were grouped together, thus creating the thematic axis for the presentation of the results. The results showed that the Nursing profession has played an important and active role in transplants ever since the first procedure in 1965.