流动人员职业健康监护存在的问题与对策

流动人口的职业健康监护问题是职业卫生工作的重点与难点,是预防控制职业病,是保障流动人口职业健康和公平劳动权益的重要环节。根据对北京、浙江、山东、湖北、内蒙等地的调研,对流动人口职业健康监护存在的问题及原因进行了总结分析,结合目前我国职业卫生资源提出了政策建议。     

流动人员职业健康监护模式分析与探索

流动人口的职业健康监护是职业卫生工作的重点与难点,是预防控制职业病,是保障流动人口职业健康和公平劳动权益的重要环节。根据对北京、浙江、山东、湖北、内蒙等地的调研,我们对流动人口职业健康监护现有模式进行了分析比较,并提出了新的模式框架与实施条件,以提高流动人口的职业健康监护率,保障流动人口职业健康．     

Nickel oxide nanoparticles exert cytotoxicity via oxidative stress and induce apoptotic response in human liver cells (HepG2)

Increasing use of nickel oxide nanoparticles (NiO NPs) necessitates an improved understanding of their potential impact on human health. Previously, toxic effects of NiO NPs have been investigated, mainly on airway cells. However, information on effect of NiO NPs on human liver cells is largely lacking. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and induction of apoptotic response in human liver cells (HepG2) due to NiO NPs exposure. Prepared NiO NPs were crystalline and spherical shaped with an average diameter of 44 nm. NiO NPs induced cytotoxicity (cell death) and ROS generation in HepG2 cells in dose-dependent manner. Further, ROS scavenger vitamin C reduced cell death drastically caused by NiO NPs exposure indicating that oxidative stress plays an important role in NiO NPs toxicity. Micronuclei induction, chromatin condensation and DNA damage in HepG2 cells treated with NiO NPs suggest that NiO NPs induced cell death via apoptotic pathway. Quantitative real-time PCR analysis showed that following the exposure of HepG2 cells to NiO NPs, the expression level of mRNA of apoptotic genes (bax and caspase-3) were up-regulated whereas the expression level of anti-apoptotic gene bcl-2 was down-regulated. Moreover, activity of caspase-3 enzyme was also higher in NiO NPs treated cells. To the best of our knowledge this is the first report demonstrating that NiO NPs caused cytotoxicity via ROS and induced apoptosis in HepG2 cells, which is likely to be mediated through bax/bcl-2 pathway. This work warrants careful assessment of Ni NPs before their commercial and industrial applications.     

Book Reviews

Books reviewed:
Rutherford H., Platt et al. Disasters and Democracy: The Politics of Extreme Natural Events
S., Suri Orissa Disaster: Agony of the Living     

The Accuracy of Mortality Reporting in Displaced Persons Camps During the Post-emergency Phase

For humanitarian organisations, accurate data are essential to identify emerging health problems and determine programme needs. We visited 45 post-emergency phase displaced persons camps and collected three months' mortality data which we compared with organisations' routine mortality reports. Organisations reported 612 deaths and we identified 741 deaths, for a mortality-reporting ratio, defined as the number of organisation-reported deaths divided by the number of investigator-identified deaths, of 83 per cent. For the majority of camps which under-reported deaths, mortality reporting ratios were significantly higher for women than men, and for camps with central mortality registers rather than those without. In the few camps which over-reported deaths, these occurred primarily among children younger than five years of age, probably due to the inclusion of abortions and stillbirths. Despite the overall under-reporting of deaths by humanitarian organisations, the existing health information systems appear to estimate mortality rates adequately in these post-emergency camps. However, organisations should improve the precision and completeness with which they report the characteristics of deaths in order to provide valuable data to target their programmes at the most vulnerable people.     

Evaluation of the Impact of Long-range Transport and Aerosol Concentration Temporal Variations at the Eastern Coast of the Baltic Sea

Ambient particles vary greatly in their ability to affect visibility, climate and human health. The fine fraction of aerosol is responsible for greater and wider effects on human health; thus, investigation of this fraction is very important. Continuous measurements of PM2.5 (particulate matter below 2.5 μm in size) concentrations at the Preila monitoring station started in 2003. During a period of 2 years, the episodes of high daily and semi-hourly concentrations of PM2.5 were measured. These episodes did not depend on the season or time of day. The substantial role of long-range transport of pollutants to these increases in concentration was shown using chemical and statistical analysis. It was found that most of the severe episodes occurred when air masses came from a specific site besides it was established that air masses of different origin were characterized by different mixing layer depth. Lower mixing depth was observed in air masses characterized by higher observed concentrations at the measuring site and vice versa. PM2.5 concentrations showed diurnal and seasonal variations whose pattern reflected the regional origin of the aerosol. The regional pollution level was evaluated by the statistical analysis of PM2.5 concentrations. The background annual average of PM2.5 mass concentration for the eastern coast of the Baltic Sea was 15.1 ± 0.8 μg m⁻³.     

Nitrogen Content of Letharia vulpina Tissue from Forests of the Sierra Nevada, California: Geographic Patterns and Relationships to Ammonia Estimates and Climate

Nitrogen (N) pollution is a growing concern in forests of the greater Sierra Nevada, which lie downwind of the highly populated and agricultural Central Valley. Nitrogen content of Letharia vulpina tissue was analyzed from 38 sites using total Kjeldahl analysis to provide a preliminary assessment of N deposition patterns. Collections were co-located with plots where epiphytic macrolichen communities are used for estimating ammonia (NH₃) deposition. Tissue N ranged from 0.6% to 2.11% with the highest values occurring in the southwestern Sierra Nevada (range: 1.38 to 2.11). Tissue N at 17 plots was elevated, as defined by a threshold concentration of 1.03%. Stepwise regression was used to determine the best predictors of tissue N from among a variety of environmental variables. The best model consisted only of longitude (r ² = 0.64), which was reflected in the geographic distribution of tissue values: the southwestern Sierra Nevada, the high Sierras near the Tahoe Basin, and the Modoc Plateau, are three apparent N hotspots arranged along the tilted north–south axis of the study area. Withholding longitude and latitude, the best regression model suggested that NH₃ estimates and annual number of wetdays interactively affect N accumulation (r ² = 0.61; % N ∼ NH₃ + wetdays + (NH₃ × wetdays)). We did not expect perfect correspondence between tissue values and NH₃ estimates since other N pollutants also accumulate in the lichen thallus. Additionally, other factors potentially affecting N content, such as growth rate and leaching, were not given full account.     

Measurement of selected indoor physical environmental factors in hairdresser salons in a Turkish City

Objectives The purpose of this study was to determine electromagnetic fields, electric fields, humidity, temperature, and illumination levels in hairdresser salons located in the downtown area of Aydin, Turkey. Also some health problems which could be related with the occupational factors are evaluated. Materials and methods The study was carried out in 30 hairdresser salons, all of which had been registered within the past 5 years. Electric and electromagnetic fields, illumination, temperature and humidity measurements were determined for hairdryers, hood hairdryers and depilatory heaters in the participating salons. A brief questionnaire about characteristics and the health status of hairdressers and workplace conditions was prepared and administered to the hairdressers at the salons. Results The mean electric fields of hairdryers, hood hairdryers and depilatory heaters were determined as 518 ± 74, 1,123 ± 199, and 648 ± 146 in V/m, respectively, at 5 cm from the surface of each device. These appliances generate mean electromagnetic fields in excess of 0.25 μT at 5 cm: hand-held hairdryers, 5.0 ± 0.7 μT; hood hairdryers, 1.6 ± 0.3 μT; and depilatory heaters 1.9 ± 0.6 μT. Total average of cumulative electric and electromagnetic fields, measured at a distance of 90 cm from the surface of these three devices was calculated to be 98.8 V/m and 0.5 μT, in the participating salons. Conclusions This preliminary study suggests that physical environmental factors in the salons may be contributing to the health problems of the hairdressers, and the electrical equipments in the workplaces may have cumulative electric and electromagnetic effects.     

城市大气颗粒物表面半醌自由基的测定方法

采集上海市城区和郊区2个典型站位的大气颗粒物样品,以二氯甲烷作萃取溶剂,采用索氏抽提法萃取分离吸附在颗粒物表面的稳定自由基,并利用电子自旋共振波谱技术(ESR)分析测定其种类和浓度。结果表明,测试样品的波谱特征表现为显著的三重信号峰,且g因子值均为2.002 7~2.004 7,通过与醌类物质的碱性饱和溶液ESR图谱比对,可以推断颗粒物表面至少吸附一种邻位半醌自由基。同时,通过锰标定量的方式估算了闵行和普陀2个采样点颗粒物样品表面的半醌自由基浓度,闵行采样点TSP、PM10和PM2.5表面半醌自由基的平均浓度分别为5.02×105、5.54×105、9.43×105g-1,而普陀采样点的平均浓度分别为2.02×105、3.50×105、7.16×105g-1。     

基于多级灰关联法的博斯腾湖水生态健康评价

采用生态系统健康结构和功能指标建立了由物理化学指标体系、生态指标体系2个二级指标体系组成的生态系统健康评价指标体系。将多级灰关联理论引入系统综合评价之中,采用多级灰关联评价方法和综合营养状态指数评价方法相结合,对博斯腾湖自2001年以来水生态健康变化情况进行了综合评价与分析。评价结果显示,自2001年以来博斯腾湖的生态系统健康状态总体情况为中等,自2007年以来生态系统健康综合指数呈一定的下降趋势,并找出了导致水环境恶化的主要原因。