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331.
Introduction: The majority of construction companies are small businesses and small business often lack the resources needed to ensure that their supervisors have the safety leadership skills to build and maintain a strong jobsite safety climate. The Foundations for Safety Leadership (FSL) training program was designed to provide frontline leaders in all sized companies with safety leadership skills. This paper examines the impact of the FSL training by size of business. Methods: Leaders, defined as foremen or other frontline supervisors, from small, medium, and large construction companies were recruited to participate in a study to evaluate the degree to which the FSL changed their understanding and use of the leadership skills, safety practices and crew reporting of safety-related conditions. We used linear mixed modeling methods to analyze pre-post training survey data. Results: Prior to the training, leaders from small and medium sized companies reported using safety leadership skills less frequently than those from large ones. After the training, regardless of business size, we observed that the FSL training improved leaders understanding of safety leadership skills from immediately before to immediately after the training. Additionally, leaders reported greater use of safety leadership skills, safety practices, and crew reporting of safety-related conditions from before to two-weeks after the training. However, those from small and medium sized companies reported the greatest improvement in their use of safety leadership skills. Conclusions: The FSL training improves safety leadership outcomes regardless of the size company for which the leader worked. However, the FSL may be even more effective at improving the safety leadership skills of leaders working for smaller sized construction companies or those with lower baseline levels of safety leadership skills. Practical applications: The majority of construction companies employ a small number of employees and therefore may not have the resources to provide their frontline leaders with the leadership training they need to be effective leaders who can create a strong jobsite safety climate. The Foundations for Safety Leadership (FSL) training can help fill this gap. 相似文献
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334.
邱永祥 《铁路节能环保与安全卫生》2019,(1):34-38
调查铁路轨道施工工艺及施工过程中职业病危害因素,对铁路轨道施工现场进行职业卫生学调查及工作场所职业病危害因素检测。结果表明,铁路轨道施工现场部分岗位接触的矽尘/其他粉尘、水泥粉尘、电焊烟尘、锰及其化合物、手传振动和噪声是职业病主要危害因素,建议加强铁路轨道施工作业个体防护。 相似文献
335.
Cd对我国不同类型土壤硝化活性影响的主控因子研究 总被引:1,自引:0,他引:1
硝化作用是土壤中存在的一个重要生物学过程,其对环境条件的变化表现出极高的敏感性,其中包括重金属污染.本文选取我国10种不同类型土壤,采用室内模拟方法,研究硝化活性对不同Cd污染程度的响应特征以及影响Cd毒性的主要控制因素.结果表明:除红壤和黑土外,土壤硝化活性随外源Cd的增加而降低,采用Logistic模型和完全抑制模型可很好的表征两者之间的关系;通过Logistic模型获得的不同土壤ED25和ED50值分别为2.44~363.03 mg·kg~(-1)、10.99~553.64 mg·kg~(-1),由完全抑制模型拟合结果表明Cd对硝化活性的作用机理为完全抑制作用;基于土壤性质和ED50值建立的多元回归预测模型表明,pH和阳离子交换量(CEC)共同解释了回归模型变异的95.6%.综上表明在一定范围内土壤硝化活性可表征土壤Cd污染程度,土壤CEC和p H是影响Cd毒性的主控因素,可较好地预测土壤中外源Cd对硝化活性的毒性阈值. 相似文献
336.
In water, chlorine reacts with nitrogen-containing compounds to produce disinfection by-products such as nitrogen trichloride which induces ocular and respiratory irritations in swimming pool workers. This study proposes a model to predict variations in NCl3 concentration over time in a traditional indoor swimming pool as a function of its operating parameters and attendance. The model was developed taking into consideration the reaction mechanisms, thermodynamic equilibria, physico-chemical properties, and transfer mechanisms occurring at the pool's surface. This model was validated through a robust series of experiments over two days and two nights in a real swimming pool. The model was found to satisfactorily predict variations over time in the concentrations of the chemical species investigated, including nitrogen trichloride. The work presented constitutes a first step to extend the model at different swimming pools. This approach may also be used to study the influence of the main operating parameters and to evaluate the impact of setting up water treatment systems on nitrogen trichloride concentration. 相似文献
337.
炼油污水处理装置的三泥脱水实验表明,剩余污泥的脱水性能最好。根据实验结果,将浮渣与剩余污泥按比例混合进行脱水,连续少量掺入油泥,调整转速与混凝剂用量后取得较好的脱水效果。在离心机处理量13~15m3/h,离转速3000r/min,差转速5~7r/min,混凝剂量5kg/h的工况下,离心机所产泥饼含水率<85%、滤液ρ(COD)<800mg/L。脱水处理直接成本19.6元/m3。 相似文献
338.
Joga Singh Harmanjit Singh Surinder Singh B.S. Bajwa R.G. Sonkawade 《Journal of environmental radioactivity》2009
Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. The natural radionuclide (226Ra, 232Th, and 40K) contents in soil were determined for 26 locations around the Upper Siwaliks of Kala Amb, Nahan and Morni Hills, Northern India, using high-resolution gamma-ray spectrometric analysis. It was observed that the concentration of natural radionuclides viz., 226Ra, 232Th and 40K, in the soil varies from 28.3 ± 0.5 to 81.0 ± 1.7 Bq kg−1, 61.2 ± 1.3 to 140.3 ± 2.6 Bq kg−1 and 363.4 ± 4.9 to 1002.2 ± 11.2 Bq kg−1 respectively. The total absorbed dose rate calculated from activity concentration of 226Ra, 232Th and 40K ranged from 71.1 to 162.0 nGy h−1. The radium equivalent (Req) and the external hazard index (Hex), which resulted from the natural radionuclides in soil, were also calculated and found to vary from 149.4 to 351.8 Bq kg−1and from 0.40 to 0.95 respectively. These values in Upper Siwaliks area were compared with that from the adjoining areas of Punjab. The radium equivalent activities in all the soil samples were lower than the limit (370 Bq kg−1) set in the Organization for Economic Cooperation and Development (OECD) report and the dose equivalent was within the safe limit of 1 mSv y−1. 相似文献
339.
Fowler SW 《Journal of environmental radioactivity》2011,102(5):448-461
The distribution and behaviour of the natural-series alpha-emitter polonium-210 in the marine environment has been under study for many years primarily due to its enhanced bioaccumulation, its strong affinity for binding with certain internal tissues, and its importance as a contributor to the natural radiation dose received by marine biota as well as humans consuming seafoods. Results from studies spanning nearly 5 decades show that 210Po concentrations in organisms vary widely among the different phylogenic groups as well as between the different tissues of a given species. Such variation results in 210Po concentration factors ranging from approximately 103 to over 106 depending upon the organism or tissue considered. 210Po/210Pb ratios in marine species are generally greater than unity and tend to increase up the food chain indicating that 210Po is preferentially taken up by organisms compared to its progenitor 210Pb. The effective transfer of 210Po up the food chain is primarily due to the high degree of assimilation of the radionuclide from ingested food and its subsequent strong retention in the organisms. In some cases this mechanism may lead to an apparent biomagnification of 210Po at the higher trophic level. Various pelagic species release 210Po and 210Pb packaged in organic biodetrital particles that sink and remove these radionuclides from the upper water column, a biogeochemical process which, coupled with scavenging rates of this radionuclide pair, is being examined as a possible proxy for estimating downward organic carbon fluxes in the sea. Data related to preferential bioaccumulation in various organisms, their tissues, resultant radiation doses to these species, and the processes by which 210Po is transferred and recycled through the food web are discussed. In addition, the main gaps in our present knowledge and proposed areas for future studies on the biogeochemical behaviour of 210Po and its use as a tracer of oceanographic processes are highlighted in this review. 相似文献
340.
Relationship between occupational social class and exposure to organochlorine pesticides during pregnancy 总被引:2,自引:0,他引:2
Freire C Amaya E Fernández MF González-Galarzo MC Ramos R Molina-Molina JM Arrebola JP Olea N 《Chemosphere》2011,83(6):831-838