Amalgam in Dentistry A Health Hazard for Dental Personnel?

In a cross sectional study done in 1993 among dental personnel in Norrbotten, self-reported prevalence of muscular pain, headache, tremor, insomnia, irritation, impaired memory and depression, as well as information regarding different mercury exposures were collected Mercury exposures were determined as “number of amalgam fillings in teeth,” “years in practice,” “insufficient ventilation at work,” “total number of amalgam removed, produced and polished per day,” and “working in dental clinics.” As controls, physicians and nurses from the same geographical area were selected. The correlation between symptoms and different mercury exposures was calculated using logistic regression. The results suggested a higher prevalence of muscular fatigue and tremor for female dental personnel compared to controls Controls reported a lower prevalence of symptoms with increasing number of amalgam fillings in teeth. There was no correlation between the number of amalgam fillings handled per day and symptoms for dental personnel. Male dental personnel associated muscular fatigue headache, impaired memory, and depression with increased handling of amalgam in the clinic’ whereas the female dental personnel associated the same symptoms with the number of amalgam fillings in teeth. The strongest correlation was found between symptoms and insufficient ventilation at dental clinics for dental personnel.     

Dental Workers,Musculoskeletal CumulativeTrauma,and Carpal Tunnel Syndrome: Who is at Risk? A Pilot Study

A pilot study was conducted at a dental clinic to identify (a) the prevalence of musculoskeletal cumulative trauma disorders (MCTD), (b) associated symptoms (with special attention paid to carpal tunnel syndrome [CTS]), and (c) practitioners at risk. Videotapes, two questionnaires, a medical record review, and interviews were used. Forty-five dental workers participated and were classified into three categories: (a) dentists, (b) dental assistants and special assistants (DA/SA), and (c) dental hygienists and dental assistant-expanded function (DH/DAEF). Categorical data were analyzed using the chi- square statistic and risk ratios. The Fisher exact probability test was used for categorical data with a small cell. One or more symptoms associated with CTS were noted by 75.6% of the dental workers, 11% reported diagnosed CTS, and 53% reported back and shoulder pain. Both psychosocial factors and job demands appear to be associated with MCTD. All three categories of dental workers reported MCTD symptoms, and the DH/DAEF group was found to be at greatest risk for developing upper extremity symptoms, CTS, and back pain.     

Exposure to Methyl Methacrylate and Its Subjective Symptoms Among Dental Technicians,Tehran, Iran

Exposure to methyl methacrylate (MMA), total dust and health symptoms were investigated in 20 dental laboratories located in Tehran, Iran. Time-weighted average (TWA) of MMA and peak concentrations were determined, using XAD-2 tubes followed by GC-ID analysis. Total dusts were evaluated gravimetrically. Health symptoms were asked using a questionnaire. TWA for technicians with direct and indirect exposure to MMA were 327.28 ± 79.42 and 282.9 ± 41.84 mg/m³ , respectively. Peak concentration of MMA for those technicians were 337.0 ± 36.81 and 328.88 ± 45.40 mg/m³, respectively.

There were no significant differences between TWA of MMA and peak concentration in different weekly workdays; however, within-day variations were observed (P < .05).

TWA of MMA and peak concentration correlation with the laboratory volume were 0.61-0.65. Dust exposure of technicians was 2.35 ± 2.70 mg/m³. Cough and skin dryness were the common health symptoms. Smoking and asbestos exposure history were factors influencing cough prevalence (p < .05).

It is concluded that the current Short-Term Exposure Limit (STEL) is not low enough to protect technicians against the adverse effects caused by MMA.     

Users’ Demands Regarding Dental Safety Glasses. Combining a Quantitative Approach and Grounded Theory for the Data Analysis

Eye infections are common among dentists and many are concerned, but few are using proper eye protection. To understand users’ demands behind the low use of safety glasses, all dental teams in Sweden were asked which factors they found most important when choosing dental safety glasses, and rate the importance of 31 statements regarding ergonomic aspects of dental safety glasses in a questionnaire. Data were analysed using the Grounded Theory and a quantitative approach. Results showed that dentists ranked the visual aspects as most important and chair assistants the protective aspects. The highly visual demanding work performed by dentists requires safety glasses that are not yet available on the market, which might explain the low use.     

Implementing risk management to reduce injuries in the U.S. Fire Service

IntroductionRisk management, a proactive process to identify and mitigate potential injury risks and implement control strategies, was used to reduce the risk of occupational injury in a fire department. The objective of this research was to study the implementation of the risk management process for future replication. A second objective was to document changes in fire personnel's knowledge, attitudes, and behaviors related to the selected control strategies that were implemented as part of the risk management process.MethodA number of control strategies identified through the risk management process were implemented over a 2-year period beginning in January 2011. Approximately 450 fire personnel completed each of the three cross-sectional surveys that were administered throughout the implementation periods. Fire personnel were asked about their awareness, knowledge, and use of the control strategies.ResultsFire personnel were generally aware of the control strategies that were implemented. Visual reminders (e.g., signage) were noted as effective by fire personnel who noticed them. Barriers to use of specific control strategies such as new procedures on the fireground or new lifting equipment for patient transfer included lack of knowledge of the new protocols, lack of awareness/access to/availability of the new equipment, and limited training on its use. Implementation challenges were noted, which limited self-reported adherence to the control strategies.ConclusionsFire personnel generally recognized the potential for various control strategies to manage risk and improve their health and safety; however, implementation challenges limited the effectiveness of certain control strategies. The study findings support the importance of effective implementation to achieve the desired impacts of control strategies for improving health and safety.Practical applicationsEmployees must be aware of, have knowledge about, and receive training in safety and health interventions in order to adopt desired behaviors.     

Permeability of Medical Gloves to Mono- and Dimethacrylate Monomers in Dental Restorative Materials

Dental personnel manually handle methacrylate-based restorative materials, which can cause skin irritation and allergies. The protection given by different types of medical gloves is not well known. Breakthrough time (BTT, min) was used as a measure of protection according to a European standard, using 2 test mixtures consisting of respectively 3 and 5 monomers. Fourteen gloves representing natural rubber latex, synthetic rubber, and synthetic polymeric material were tested. The BTT ranged from some minutes to more than 2 hrs for the 4 monomers with a molecular mass less than 300. The longest protection was recorded for Nitra Touch (nitrile rubber), Tactylon (synthetic rubber), and Metin (PVC).     

Experts,Bayesian Belief Networks,rare events and aviation risk estimates

Bayesian Belief Networks (BBN) are conceptually sensible models for aviation risk assessment. The aim here is to examine the ability of BBN-based techniques to make accurate aviation risk predictions. BBNs consist of a framework of causal factors linked by conditional probabilities. BBN conditional probabilities are elicited from aviation experts. The issue is that experts are not being asked about their expertise but about others’ failure rates. A simple model of expertise, which incorporates the main features proposed by researchers, implies that a best-expert’s estimates of failure rates are based on accessible quantitative data on accidents, incidents, etc. Best-expert estimates will use the best available and accessible data. Depending on the frequency of occurrence, this will be data on similar events, on similar types of event, or general mental rules about event frequencies. These considerations, plus the need to be cautious about statistical fluctuations, limit the accuracy of conditional probability estimates. The BBN framework assumes what is known as the Causal Markov Condition. In the present context, this assumes that there are no hidden common causes for sequences of failure events. Examples are given from safety regulation comparisons and serious accident investigations to indicate that common causes may be frequent occurrences in aviation. This is because some States/airlines have safety cultures that do not meet ‘best practice’. BBN accuracy might be improved by using data from controlled experiments. Aviation risk assessment is now very difficult, so further work on resilience engineering could be a better way of achieving safety improvements.     

Exposure to methyl methacrylate and its subjective symptoms among dental technicians, Tehran, Iran.

Exposure to methyl methacrylate (MMA), total dust and health symptoms were investigated in 20 dental laboratories located in Tehran, Iran. Time-weighted average (TWA) of MMA and peak concentrations were determined, using XAD-2 tubes followed by GC-FID analysis. Total dusts were evaluated gravimetrically. Health symptoms were asked using a questionnaire. TWA for technicians with direct and indirect exposure to MMA were 327.28 +/- 79.42 and 282.9 +/- 41.84 mg/m3, respectively. Peak concentration of MMA for those technicians were 337.0 +/- 36.81 and 328.88 +/- 45.40 mg/m3, respectively. There were no significant differences between TWA of MMA and peak concentration in different weekly workdays; however, within-day variations were observed (P < .05). TWA of MMA and peak concentration correlation with the laboratory volume were 0.61-0.65. Dust exposure of technicians was 2.35 +/- 2.70 mg/m3. Cough and skin dryness were the common health symptoms. Smoking and asbestos exposure history were factors influencing cough prevalence (p < .05). It is concluded that the current Short-Term Exposure Limit (STEL) is not low enough to protect technicians against the adverse effects caused by MMA.     

Perceptions of the Importance and Control of Professional Problems in the Clinical Setting

The objective of this study was to identify the relative importance of culturally relevant professional problems and the degree of control over them, as perceived by dentists and dental students in Mexico City, Mexico. The dentists and students ranked 13 problems according to importance and then according to the perceived degree of control over each one. Novice clinicians were less secure about their ability to cope with the legal, financial, and clinical performance problems, whereas experienced clinicians were more concerned about occupational hazards and the dental market and culture. Both reported similar perceptions of their control of the problems. This preliminary information should support introducing into dental schools relevant practice-management courses, targeting continuing education efforts, and instituting professional counseling measures to meet the challenges posed by these problems.     

地铁隧道施工安全风险演化的BP-SD模型研究

为深入研究地铁隧道施工风险的动态演化过程,结合系统动力学(SD)、误差反向传播(BP)神经网络与平均影响值（MIV）算法,确定模型中影响因素间的因果关系和影响函数,构建地铁隧道施工风险演化的BP-SD模型。模型仿真结果表明:安全管理风险系统与施工人员风险系统的值的变化对地铁隧道施工风险值影响最大,施工环境系统的值的变化对地铁隧道施工风险值影响次之,机械设备系统的值的变化对地铁隧道施工风险值影响最小。因此,可通过降低安全管理风险值与施工人员风险值控制地铁隧道施工风险发生的概率。     

事故树-风险矩阵评估高校实验室火灾风险

为了使高校实验室安全管理科学化、精准化,应用事故树-风险矩阵法进行风险评估。首先采用事故树法对实验室火灾事故进行分析,得出导致事故发生的基本事件,然后依照事故致因理论,得出事故隐患三级原因,采用层次分析法对事故发生的频率和后果严重度及安全措施补偿系数的等级赋值,得到四级风险矩阵模型,对基本事件调查并由专家评估得出其风险值。评估结果表明导致实验室火灾事故的主要原因为:燃烧反应失控、加热、人员消防素质、操作不当、实验室管理水平、火灾报警系统缺陷、电气火花、灭火材料不足、消防系统缺陷、木制品、反应放热、存放不当。根据基本事件风险值高低针对性采取相应预防措施可以一定程度上提升实验室安全管理水平。     

火灾中聚合物材料热解对汽油辨识的影响分析

火灾中聚合物材料的燃烧过程产生的热解产物,从而增加化学分析谱图的复杂性,对助燃剂鉴定造成干扰。针对常见的聚合物材料开展了一系列燃烧实验,对其在燃烧过程中的热解机理进行了分析,并通过汽油存在条件下的聚合物材料燃烧实验分析了热解对汽油辨识产生的干扰。     

建筑企业专职安全管理人员现状调查与分析

建筑业是我国重要的支柱产业之一，近年来，建筑施工安全事故频频发生，影响了我国建筑业的发展和行业形象。建筑施工企业专职安全管理人员素质的高低直接关系到建筑安全生产目标的实现，因此，笔者5年来通过对三省一市多家建筑施工企业专职安全管理人员基本情况的调查和分析，发现建筑施工企业专职安全管理人员队伍在专业构成、学历结构、职称结构和人员数量等诸多方面存在的问题，并剖析了问题产生的原因，其目的在于提醒建筑企业负责人加强专职安全管理人员队伍建设，避免人为因素导致建筑安全事故的发生。     

基于FDS+EVAC的某高校学生宿舍楼火灾疏散能力研究

针对高校学生宿舍火灾事故频发、人员疏散难的问题,选取某高校南区的一栋标准宿舍楼作为研究对象,根据实际情况,利用FDS+EVAC软件建立几何模型,设置火灾场景及疏散相关参数,模拟宿舍发生火灾时火灾的发生发展过程,以及人员在火灾情景下的疏散行为;对软件模拟结果进行分析研究,得出可用安全疏散时间和必需安全疏散时间,将这2个时间进行对比判断,评价该宿舍楼的安全性能不达标;对比现行的标准规范,认为该宿舍楼不符合安全标准规范的要求,必须采取合理有效措施增加可用安全疏散时间或降低必需安全疏散时间;最后,通过FDS+EVAC模拟结果对比,结合宿舍楼的实际情况,给出合理的整改建议。研究成果可为高校学生宿舍楼的火灾安全性能分析和改进,提供参考和借鉴。     

The use of assistance while lifting

Using assistance during lifting is a desirable behavior. Assistance can eliminate or reduce the amount of biomechanical stress associated with a lift, significantly reducing the risk of low back injury. This paper describes lifting activities engaged in by nursing care workers. Only 15% of all lifts performed by the hospital nursing personnel in this study were assisted lifts. The analysis suggests that the use of assistance can be associated with specific factors such as type of object lifted, work stress associated with the lift, number of preparations that must be made before the lift can be attempted, years of experience of the lifter, and the idiosyncratic behavior patterns of lifters with respect to using assistance. It is recommended that attention be given to psychological and social, as well as biomechanical, factors in the control of low back injury.     

Two discrete choice experiments on laboratory safety decisions and practices

IntroductionThe path toward enhancing laboratory safety requires a thorough understanding of the factors that influence the safety-related decision making of laboratory personnel. Method: We developed and administered a web-based survey to assess safety-related decision making of laboratory personnel of a government research organization. The survey included two brief discrete choice experiments (DCEs) that allowed for quantitative analysis of specific factors that potentially influence safety-related decisions and practices associated with two different hypothetical laboratory safety scenarios. One scenario related to reporting a laboratory spill, and the other scenario involved changing protective gloves between laboratory rooms. The survey also included several brief self-report measures of attitude, perception, and behavior related to safety practices. Results: Risk perception was the most influential factor in safety-related decision making in both scenarios. Potential negative consequences and effort associated with reporting an incident and the likelihood an incident was detected by others also affected reporting likelihood. Wearing gloves was also affected somewhat by perceived exposure risk, but not by other social or work-related factors included in the scenarios. Conclusions: The study demonstrated the promise of DCEs in quantifying the relative impact of several factors on safety-related choices of laboratory workers in two hypothetical but realistic scenarios. Participants were faced with hypothetical choice scenarios with realistic features instead of traditional scaling techniques that ask about attitudes and perceptions. The methods are suitable for addressing many occupational safety concerns in which workers face tradeoffs in their safety-related decisions and behavior. Practical Application: Safety-related decisions regarding laboratory practices such as incident reporting and use of PPE were influenced primarily by workers’ perceptions of risk of exposure and severity of risks to health and safety. This finding suggests the importance of providing laboratory workers with adequate and effective education and training on the hazards and risks associated with their work. DCEs are a promising research method for better understanding the relative influences of various personal, social, and organizational factors that shape laboratory safety decisions and practices. The information gained from DCEs may lead to more targeted training materials and interventions.     

Acute exposure to chemicals during ‘do-it-yourself’ activities: survey of enquiries to the Swedish Poisons Information Centre in 1996

In 1996 the Swedish Poisons Information Centre performed a follow-up study concerning poisonings related to ‘do-it-yourself’ activities. The study was supported by the National Institute of Public Health in Sweden. The objectives were to investigate and define monthly variations, route of exposure, type of products and, in particular, exposures to corrosives, age and sex groups, place of treatment, severity of symptoms, place of the accident, special risk products and risk situations. The Poisons Information Centre was contacted concerning 1609 cases, with a peak during the summer months. There was no or uncertain connection between exposure and symptoms in 117 cases. This means that 1492 cases were left to study. Inhalation and eye exposure were the predominant routes, followed by skin exposure and ingestion. Cleaning agents were the most common type of products involved. Of the 1492 cases included in the study 1033 were possible to follow up. Among these, 20–29 year olds and 30–39 year olds predominated, and there was a dominance for men. In total, 28% of those exposed were subject to medical attention, either in hospital or in outpatient clinics. According to the Poisoning Severity Score 78% had mild (grade 1) and 7% moderate (grade 2) symptoms. There were no severe intoxications and no deaths. Severity grade 2 occurred 3.6 times more often among those with exposures involving risk of corrosive damage than among others in the study population. Most accidents occurred in the home. Special risk products and risk situations were exposure to corrosive products, release of chlorine when mixing hypochlorite and acid, ‘fire-eating’, siphoning gasoline and diesel fuel, welding, and inhalation of carbon monoxide from exhaust gases. The Swedish Poisons Information Centre registered 1609 cases of poisoning accidents during ‘do-it-yourself’ activities, which means an average of four to five cases per day. Although this type of accidents is not uncommon, significant poisoning seems to be rare. Some special risk situations were identified.     

Developing a chaotic pattern of dynamic risk definition for solving hazardous material routing-locating problem

In the case of determining routes and locations for constructing distribution centers on hazardous materials (Hazmat) transportation, risk and cost are considered as the main attributes for developing mathematical models. Since, Hazmat transport risk may be defined as a chaotic factor, using dynamic risk changes the selected routes and optimized locations for constructing distribution centers.In the present paper, an iterative procedure has been proposed to determine the best routes and optimized locations of distribution centers for transporting hazardous materials based on the concept of chaos theory in which hazmat transport risk is defined as a dynamic variable. A mathematical model has been developed for solving Hazmat routing and locating problems, simultaneously. Daily transport risk, defined as a chaotic variable, is iteratively updated using one-dimensional logistic map equation over the time period (year). An experimental road network, consists of eighty nine nodes and one hundred and three two-way edges, has been selected for analytical process and model validation. Results revealed that although different amounts of risk and cost priorities change optimized locations of distribution centers and their associated supplies, but the most frequent set of optimized centers remains independent. Therefore, the proposed procedure is capable to determine the best routes and optimized locations for distributing hazardous materials. While risk is iteratively updated over a specific time period, results show that the main property of chaos theory known as dependency upon initial condition would not be a serious concern for decision makers who are dealing with Hazmat management.     

Associations between driving under the influence or riding with an impaired driver and future substance use among adolescents

Objective: Risky driving behaviors among adolescents, such as riding with a drinking or impaired driver (RWID) or driving while under the influence (DUI) of alcohol or drugs, are significant public health concerns. Few studies have examined associations of RWID and DUI with future substance use and problems after controlling for baseline substance use. Given that the DUI/RWDD event may be a teachable moment to prevent future consequences (e.g., when injured or arrested), it is important to understand how this risk behavior relates to subsequent use and problems. This study therefore examined characteristics of adolescents who reported DUI and RWID and assessed their risk of future alcohol and marijuana use and consequences 6 months later.

Methods: Participants were 668 adolescents aged 12 to 18 (inclusive) recruited at 1 of 4 primary care clinics in Pittsburgh and Los Angeles as part of a larger randomized controlled trial. They completed surveys about their health behaviors at baseline and 6 months after baseline. We examined baseline characteristics of adolescents who reported DUI and RWID and then assessed whether past-year DUI and RWID at baseline were associated with alcohol and marijuana use and consequences 6 months after baseline.

Results: Fifty-eight percent of participants were female, 56% were Hispanic, 23% were Black, 14% were White, 7% were multiethnic or other, and the average age was 16 years (SD?=?1.9). At baseline, participants who reported RWID or DUI were more likely to be older, report past-year use of alcohol and marijuana, and more likely to have an alcohol use disorder or cannabis use disorder versus those who did not report RWID or DUI, respectively. At 6-month follow-up and after controlling for baseline demographics and baseline alcohol use, RWID was associated with more frequent drinking episodes in the past 3 months and greater number of drinks in the past month when they drank heavily. DUI at baseline was associated with more frequent heavy drinking episodes and alcohol and marijuana consequences 6 months later.

Conclusions: RWID and DUI are significantly associated with greater alcohol and marijuana use over time. This study highlights that teens may be at higher risk for problem substance use in the future even if they ride with someone who is impaired. Prevention and intervention efforts for adolescents need to address both driving under the influence and riding with an impaired driver to prevent downstream consequences.     

川藏铁路桥隧施工安全风险评价

通过评估川藏铁路工程建设的施工风险等级,为高质量推进川藏铁路工程建设提供理论支撑。剖析了国内外学者关于风险评估研究的理论与方法,针对川藏铁路施工建设中的5座特大桥梁工程和9座超长隧道工程,分析了桥梁隧道建设工程的特征,构建了川藏铁路桥梁工程的17个安全风险评价指标体系和隧道工程的20个安全风险评价指标体系,通过建立基于模糊综合评价法的风险评估模型完成了对川藏铁路重点桥梁和隧道工程的风险评价,最后构造BP神经网络模型对风险评估结果进行验证,以川藏铁路部分重点桥梁工程评分数据和部分重点隧道工程评分数据为训练数据,以剩余评分结果为验证数据,预测桥梁和隧道工程的风险等级。结果表明:采用BP神经网络预测桥梁隧道工程安全风险等级的准确率高达98. 82%,BP神经网络对于该工程施工安全风险评价具有适用性;川藏铁路重点桥隧工程项目有50%处于较危险以上,只有20%的工程处于安全级别。