Littérature scientifique sur le sujet « Academic Occupational Exposure »

Introduction Workers are potentially exposed to known and suspected carcinogens in the workplace, many of which have not been fully evaluated. Despite persistent need, research on occupational cancer appears to have declined in recent decades. The formation of the Occupational Cancer Research Centre (OCRC) is an effort to counter this downward trend in Ontario. The OCRC conducted a survey of the broad stakeholder community to learn about priority issues on occupational cancer research. Methods The OCRC received 177 responses to its survey from academic, health care, policy, industry, and labour-affiliated stakeholders. Responses were analyzed based on workplace exposures, at-risk occupations and cancers by organ system, stratified by respondents’ occupational role. Results Priority issues identified included workplace exposures such as chemicals, respirable dusts and fibres (e.g. asbestos), radiation (e.g. electromagnetic fields), pesticides, and shift work; and occupations such as miners, construction workers, and health care workers. Insufficient funding and a lack of exposure data were identified as the central barriers to conducting occupational cancer research. Discussion The results of this survey underscore the great need for occupational cancer research in Ontario and beyond. They will be very useful as the OCRC develops its research agenda.

Abstract Introduction Occupational exposures to contaminated biological material in dental teaching settings can place students at higher risk of bloodborne infections. Methods This cross sectional study was conducted using a self-administered questionnaire culturally adapted to Portuguese language, Brazil. In total, 173 undergraduate dental students agreed to participate in the study, answered the questionnaire, and filled in the details about their own occupational exposures. The association of these factors was analyzed by the chi-square test or Fisher's exact test using Stata® software. Results High prevalence of occupational exposures (40%) was observed among the participants, and 52% of the accidents were not reported to the clinical instructor. The most frequent type of accident was related to “puncture/cut/abrasion” (56%). Significant correlation was observed between number of exposures and academic year (p=0.002), age (p=0.012), gender (p=0.010), and between number of injuries in the last 6 months and academic year (p=0.003). No significant correlation was observed between number of exposures and dominant hand, use of protective eyewear or Hepatitis B vaccination status (p>0.05). Conclusion Additional teaching strategies need to be developed to motivate adherence to occupational post-exposure protocols regarding biological material, improving the notification of the occupational exposures that occur among dental students.

Introduction. Noise is one of the most common worldwide environmental pollutants, especially in occupational fields. As a stressor, it affects not only the ear but also the entire body. Its physiological and psychological impacts have been well established in many conditions such as cardiovascular diseases. However, there is a dearth of evidence regarding diabetes risk related to noises. Aim. To evaluate the relationship between occupational exposure to noise and the risk of developing diabetes. Methods. This is a cross-sectional analytical study enrolling two groups of 151 workers each. The first group (noise exposed group: EG) included the employees of a Tunisian power plant, who worked during the day shift and had a permanent position. The second group (unexposed to noise group: NEG) included workers assigned to two academic institutions, who were randomly selected in the Occupational Medicine Department of the Farhat Hached University Hospital in Sousse, during periodical fitness to work visits. Both populations (exposed and unexposed) were matched by age and gender. Data collection was based on a preestablished questionnaire, a physical examination, a biological assessment, and a sonometric study. Results. The mean equivalent continuous sound level was 89 dB for the EG and 44.6 dB for the NEG. Diabetes was diagnosed in 24 workers from EG (15.9%) and 14 workers from NEG (9.3%), with no statistically significant difference ( p = 0.08 ). After multiple binary logistic regression, including variables of interest, noise did not appear to be associated with diabetes. Conclusion. Our results did not reveal a higher risk of developing diabetes in workers exposed to noise. Further studies assessing both level and duration of noise exposure are needed before any definitive conclusion.

Background Occupational health hazards are ubiquitously found in the operating room, guaranteeing an inevitable risk of exposure to the surgeon. Although provisions on occupational health and safety in healthcare exist, they do not address non-traditional hazards found in the operating room. In order to determine whether surgeons or trainees receive any form of occupational health training, we examine the associations between occupational health training and exposure rate. Study design A cross-sectional survey was distributed. Respondent characteristics included academic level, race/ethnicity, and gender. The survey evaluated seven surgical disciplines and 13 occupational hazards. Multivariable logistic regression was used to examine the association between academic level, surgical specialty, and exposure rate. Results Our cohort of 183 respondents (33.1% response rate) consisted of attendings (n = 72, 39.3%) and trainees (n = 111, 60.7%). Surgical trainees were less likely to have been trained in cytotoxic drugs (OR 0.22, p<0.001), methylmethacrylate (OR 0.15, p<0.001), patient lifting (OR 0.43, p = 0.009), radiation (OR 0.40, p = 0.007), and surgical smoke (OR 0.41, p = 0.041) than attending surgeons. Additionally, trainees were more likely to experience frequent exposure to bloodborne pathogens (OR 5.26, p<0.001), methylmethacrylate (OR 2.86, p<0.001), cytotoxic drugs (OR 3.03, p<0.001), and formaldehyde (2.08, p = 0.011), to name a few. Conclusion Although surgeon safety is not a domain in residency training, standardized efforts to educate and change the culture of safety in residency programs is warranted. Our study demonstrates a disparity between trainees and attendings with a recommendation to provide formal training to trainees independent of their anticipated risk of exposure.

Global climate change is a clear and present danger to our environment, but the impacts of climate change on human health are less known. People in Asian countries are more susceptible to the negative impacts of climate change and the subsequent environmental exposures because of the high population density, rapid urbanization, and natural geography of the region. The objective of this multidisciplinary collaborative ecological study was to explore the impact of environmental exposures such as temperature (°C), noise (db), humidity (%rh), air conditioning exposure time (hours), and distance traveled to school (km) on the comfort and academic success of school children in Singapore. Analysis of a large dataset from the Singapore National Science Experiment revealed a positive correlation between the distance traveled to school and favorable environmental conditions (moderate temperatures, low noise, low humidity, and higher amount of air conditioning time) and student academic performance. The analysis revealed that the distance traveled between home and school for public school students falls within a larger range than that for independent (private) school students. On average, students traveled farther distances to attend schools of higher academic caliber thereby increasing their exposure to environmental pollution. Student exposure to pollution can be minimized if all schools adhere to higher standards of environmental comfort and standardized academic caliber. If students can attend the school closest to their homes, they can minimize their daily pollution exposure due to traffic/commute, thereby mitigating the resultant negative health consequences.

AbstractSARS disproportionately affects healthcare providers. A physician survey was administered within three hospitals providing care to SARS patients. Knowing a colleague who contracted SARS and previous occupational exposure to infectious agents were significantly predictive of greater perceived risk, whereas perceived effectiveness of precautions and provision of direct care were not.

Objective: In spite of great developments in infection control during recent years, many problems are still seen at the level of faculties, private, and public hospitals. Therefore, this research was carried out to evaluate the frequency of occupational exposure in dentistry students of Ahvaz Jundishapur University of Medical Sciences, Southwest of Iran.Methods: This study was conducted using a descriptive and cross-sectional method in 2016. The population of the study included all the 124 dentistry students graduated from Ahvaz Jundishapur University of Medical Sciences (AJUMS), southwest of Iran, who started their clinical education. The data were collected through a researcher-developed questionnaire and were analyzed using SPSS 22 software.Results: A total of 84 (67.7%) of the participants were male and 40 (23.3%) were female. Of all the participants, 54.8% of the students had no occupational exposure, 17.9% had needle stick experience, 17.9% of them had splash exposure, and 8.9% had a history of exposure to both needlestick acid and patient discharge. In the current research, no significant relationship was found between job exposure and age, gender, and marital status (p<0.05). However, a significant relationship was found between occupational exposure, year of admission to university, academic semester, and educational environment (p<0.05).Conclusion: Given the relatively high prevalence of occupational exposure in students, the development of prevention and exposure to occupational protocols and requiring students to comply with these protocols in clinical dentistry environments is recommended.

OBJECTIVE: To assess the impact of academic life on health status of university students. METHODS: Longitudinal study including 154 undergraduate students from the Universidade de Aveiro, Portugal, with at least two years of follow-up observations. Sociodemographic and behavioral characteristics were collected using questionnaires. Students' weight, height, blood pressure, serum glucose, serum lipids and serum homocysteine levels were measured. Regression analysis was performed using linear mixed-effect models, allowing for random effects at the participant level. RESULTS: A higher rate of dyslipidemia (44.0% vs. 28.6%), overweight (16.3% vs. 12.5%) and smoking (19.3% vs. 0.0%) was found among students exposed to the academic life when compared to freshmen. Physical inactivity was about 80%. Total cholesterol, high density lipoprotein-cholesterol (HDL-C), triglycerides, systolic blood pressure, and physical activity levels were significantly associated with gender (p<0.001). Academic exposure was associated with increased low density lipoprotein-cholesterol (LDL-C) levels (about 1.12 times), and marginally with total cholesterol levels (p=0.041). CONCLUSIONS: High education level does not seem to have a protective effect favoring a healthier lifestyle and being enrolled in health-related areas does not seem either to positively affect students' behaviors. Increased risk factors for non-transmissible diseases in university students raise concerns about their well-being. These results should support the implementation of health promotion and prevention programs at universities.

We describe the initial presentation, diagnostic work-up and treatment of three adult immunocompetent men who presented within a short time frame of each other to an academic medical centre with acute respiratory distress syndrome. Their presentation was found to be secondary to a large inoculum of histoplasmosis from remodelling a building with bat droppings infestation. We discuss the pathophysiology of histoplasmosis and highlight the importance of exposure history in patients with acute respiratory failure and why patients with the occupational risk of exposure to fungal inoculum should wear protective respirator gear.

Thesis (M.S.)--Medical University of Ohio, 2006.
"In partial fulfillment of the requirements for the degree of Master of Science in Occupational Health." Major advisor: Sheryl Milz. Includes abstract. Document formatted into pages: iv, 110 p. Title from title page of PDF document. Bibliography: pages 72-86.

Thesis (M.S.)--University of Toledo, 2006.
"In partial fulfillment of the requirements for the degree of Master of Science in Occupational Health." Major advisor: Sheryl Milz. Includes abstract. Document formatted into pages: iv, 66 p. Title from title page of PDF document. Title at ETD Web site: Advantages of using the ANSI/ASHRAE 110-1995 tracer gas test method versus the ANSI/AIHA Z9.5-1992 face velocity test method for chemical laboratory hood certification. Bibliography: pages 58-61.

Thesis (D. Tech. (Environmental Health)) -- Central University of technology, Free State, 2013
Some epidemiological studies suggest that exposure to high levels of electromagnetic fields (EMFs) may be linked with the development of adverse health effects. However there is still controversy on this matter. Due to rapid technological growth in the modern society, employees in the welding and electrical industries are highly exposed to electromagnetic fields and may be at a high risk for developing occupational diseases. The health effects which may result from exposure to electromagnetic fields are related to the strength and frequency of the fields. This study was conducted to (i) assess the exposure levels to EMFs in the welding industry, (ii) determine the possible health risks associated with exposure levels, and (iii) develop a health and safety model to guide the industry on how to reduce exposure to EMFs. The study was conducted in one mega welding company in the Mangaung Metropolitan Municipality. Welders, fitters and office workers (88 in total) gave consent to participate in the study and completed questionnaires (ethical clearance attached). Measurements of extremely low frequency EMFs were taken in workshop A, workshop B and working offices. Measurements for magnetic fields were taken at distances of 1, 2 and 3 meters (m) from the EMFs sources. The exposure levels of magnetic fields were very high in the workshops, with welders and fitters exposed to about 7.6 microtesla (μT). Electric fields were relatively low in all workstations. Participants in the study were experiencing symptoms of ill health such as headaches, sleep disorders, fatigue and distress. The symptoms reported by the workers were similar in the both groups (exposed and control). There is no clear relationship between recorded exposure levels and the development of the reported symptoms. The health and safety model was developed to guide the industry to reduce exposure to electromagnetic fields. The model describes the implementation of engineering and administrative control measures in an effort to reduce exposure to EMFs. The model also highlights the importance of wearing personal protective equipment to shield against EMFs amongst others. This study suggests that occupational exposure to high levels of extremely low frequency EMFs may increase the risk for development of chronic diseases such as leukaemia, brain and breast cancer and other diseases among highly exposed employees. Implementation of safety measures is necessary to reduce exposure to EMFs.

Thesis (M.P.H.)--University of Texas Health Science Center at Houston, School of Public Health, 2008.
Source: Masters Abstracts International, Volume: 46-04, page: 2059. Adviser: George L. Delclos. Includes bibliographical references.

Problematic school absenteeism is the primary focus of When Children Refuse School: A Cognitive-Behavioral Therapy Approach, Therapist Guide. Youths who complete high school are more likely to experience greater success at social, academic, occupational, and economic aspects of functioning than youths who do not. Youths with problematic school absenteeism are at risk for lower academic performance and achievement, lower reading and mathematics test scores, fewer literacy skills, internalizing and externalizing behavior problems, grade retention, involvement with the juvenile justice system, and dropout. The treatment program presented here is designed for youths with primary and acute school refusal behavior. The program is based on a functional model of school refusal behavior that classifies youths on the basis of what reinforces absenteeism. For children who refuse school to avoid school-based stimuli that provoke negative affectivity, the treatment uses child-based psychoeducation, somatic control exercises, gradual reintroduction (exposure) to the regular classroom setting, and self-reinforcement. For children who refuse school to escape aversive social and/or evaluative situations, the treatment uses child-based psychoeducation, somatic control exercises, cognitive restructuring, gradual reintroduction (exposure) to the regular classroom setting, and self-reinforcement. For youths who refuse school to pursue attention from significant others, parent-based treatment includes modifying parent commands, establishing regular daily routines, developing rewards, reducing excessive reassurance-seeking behavior, and engaging in forced school attendance. For youths who refuse school to pursue tangible rewards outside of school, family-based treatment includes contingency contracts, communication skills, escorting the child to school and from class to class, and peer refusal skills.

AbstractSex workers experience multi-factorial threats to their physical and mental health. Stigma, human rights violations and occupational exposures to violence, STIs, HIV, and unintended pregnancy create complex health inequities that may not be effectively addressed through programmes or services that focus on a single disease or issue. Meeting cisgender female, male, and transgender sex workers’ unmet needs and realities effectively requires more nuanced, multi-faceted public health approaches. Using a community-informed perspective, this chapter reviews layered multi-component and multi-level interventions that address a combination of structural, behavioural, and biomedical approaches. This chapter addresses (1) what are integrated interventions and why they are important; (2) what types of integrated interventions have been tested and what evidence is available on how integrated interventions have affected health outcomes; (3) what challenges and considerations are important when evaluating integrated interventions. Key findings include the dominance of biomedical and behavioural research among sex workers, which have produced mixed results at achieving impact. There is a need for further incorporation and evaluation of structural intervention components, particularly those identified as highest priority among sex workers, as well as the need for more opportunities for leadership from the sex work community in setting and implementing the research agenda.

A cohort study is one in which the outcome (usually disease status) is ascertained for groups of individuals defined on the basis of their exposure. At the time exposure status is determined, all must be free of the disease. All eligible participants are then followed up over time. Since exposure status is determined before the occurrence of the outcome, a cohort study can clarify the temporal sequence between exposure and outcome, with minimal information bias. The historical and the population cohort study (Box 9.1) are efficient variants of the classical cohort study described above, which nevertheless retain the essential components of the cohort study design. The exposure can be dichotomous [i.e. exposed (to obstetric complications at birth) vs. not exposed], or graded as degrees of exposure (e.g. no recent life events, one to two life events, three or more life events). The use of grades of exposure strengthens the results of a cohort study by supporting or refuting the hypothesis that the incidence of the disease increases with increasing exposure to the risk factor; a so-called dose–response relationship. The essential features of a cohort study are: ♦ participants are defined by their exposure status rather than by outcome (as in case–control design); ♦ it is a longitudinal design: exposure status must be ascertained before outcome is known. The classical cohort study In a classical cohort study participants are selected for study on the basis of a single exposure of interest. This might be exposure to a relatively rare occupational exposure, such as ionizing radiation (through working in the nuclear power industry). Care must be taken in selecting the unexposed cohort; perhaps those working in similar industries, but without any exposure to radiation. The outcome in this case might be leukaemia. All those in the exposed and unexposed cohorts would need to be free of leukaemia (hence ‘at risk’) on recruitment into the study. The two cohorts would then be followed up for (say) 10 years and rates at which they develop leukaemia compared directly. Classical cohort studies are rare in psychiatric epidemiology. This may be in part because this type of study is especially suited to occupational exposures, which have previously been relatively little studied as causes of mental illness. However, this may change as the high prevalence of mental disorders in the workplace and their negative impact upon productivity are increasingly recognized. The UK Gulf War Study could be taken as one rather unusual example of the genre (Unwin et al. 1999). Health outcomes, including mental health status, were compared between those who were deployed in the Persian Gulf War in 1990–91, those who were later deployed in Bosnia, and an ‘era control group’ who were serving at the time of the Gulf war but were not deployed. There are two main variations on this classical cohort study design: they are popular as they can, depending on circumstances, be more efficient than the classical cohort design. The population cohort study In the classical cohort study, participants are selected on the basis of exposure, and the hypothesis relates to the effect of this single exposure on a health outcome. However, a large cohort or panel of subjects are sometimes recruited and followed up, often over many years, to study multiple exposures and outcomes. No separate comparison group is required as the comparison group is generally an unexposed sub-group of the panel. Examples include the British Doctor's Study in which over 30,000 British doctors were followed up for over 20 years to study the effects of smoking and other exposures on health (Doll et al. 1994), and the Framingham Heart Study, in which residents of a town in Massachusetts, USA have been followed up for 50 years to study risk factors for coronary heart disease (Wolf et al. 1988). The Whitehall and Whitehall II studies in the UK (Fuhrer et al. 1999; Stansfeld et al. 2002) were based again on an occupationally defined cohort, and have led to important findings concerning workplace conditions and both physical and psychiatric morbidity. Birth cohort studies, in which everyone born within a certain chronological interval are recruited, are another example of this type of study. In birth cohorts, participants are commonly followed up at intervals of 5–10 years. Many recent panel studies in the UK and elsewhere have been funded on condition that investigators archive the data for public access, in order that the dataset might be more fully exploited by the wider academic community. Population cohort studies can test multiple hypotheses, and are far more common than any other type of cohort study. The scope of the study can readily be extended to include mental health outcomes. Thus, both the British Doctor's Study (Doll et al. 2000) and the Framingham Heart Study (Seshadri et al. 2002) have gone on to report on aetiological factors for dementia and Alzheimer's Disease as the cohorts passed into the age groups most at risk for these disorders. A variant of the population cohort study is one in which those who are prevalent cases of the outcome of interest at baseline are also followed up effectively as a separate cohort in order (a) to study the natural history of the disorder by estimating its maintenance (or recovery) rate, and (b) studying risk factors for maintenance (non-recovery) over the follow-up period (Prince et al. 1998). Historical cohort studies In the classical cohort study outcome is ascertained prospectively. Thus, new cases are ascertained over a follow-up period, after the exposure status has been determined. However, it is possible to ascertain both outcome and exposure retrospectively. This variant is referred to as a historical cohort study (Fig. 9.1). A good example is the work of David Barker in testing his low birth weight hypothesis (Barker et al. 1990; Hales et al. 1991). Barker hypothesized that risk for midlife vascular and endocrine disorders would be determined to some extent by the ‘programming’ of the hypothalamo-pituitary axis through foetal growth in utero. Thus ‘small for dates’ babies would have higher blood pressure levels in adult life, and greater risk for type II diabetes (through insulin resistance). A prospective cohort study would have recruited participants at birth, when exposure (birth weight) would be recorded. They would then be followed up over four or five decades to examine the effect of birth weight on the development of hypertension and type II diabetes. Barker took the more elegant (and feasible) approach of identifying hospitals in the UK where several decades previously birth records were meticulously recorded. He then traced the babies as adults (where they still lived in the same area) and measured directly their status with respect to outcome. The ‘prospective’ element of such studies is that exposure was recorded well before outcome even though both were ascertained retrospectively with respect to the timing of the study. The historical cohort study has also proved useful in psychiatric epidemiology where it has been used in particular to test the neurodevelopmental hypothesis for schizophrenia (Jones et al. 1994; Isohanni et al. 2001). Jones et al. studied associations between adult-onset schizophrenia and childhood sociodemographic, neurodevelopmental, cognitive, and behavioural factors in the UK 1946 birth cohort; 5362 people born in the week 3–9 March 1946, and followed up intermittently since then. Subsequent onsets of schizophrenia were identified in three ways: (a) routine data: cohort members were linked to the register of the Mental Health Enquiry for England in which mental health service contacts between 1974 and 1986 were recorded; (b) cohort data: hospital and GP contacts (and the reasons for these contacts) were routinely reported at the intermittent resurveys of the cohort; (c) all cohort participants identified as possible cases of schizophrenia were given a detailed clinical interview (Present State examination) at age 36. Milestones of motor development were reached later in cases than in non-cases, particularly walking. Cases also had more speech problems than had noncases. Low educational test scores at ages 8,11, and 15 years were a risk factor. A preference for solitary play at ages 4 and 6 years predicted schizophrenia. A health visitor's rating of the mother as having below average mothering skills and understanding of her child at age 4 years was a predictor of schizophrenia in that child. Jones concluded ‘differences between children destined to develop schizophrenia as adults and the general population were found across a range of developmental domains. As with some other adult illnesses, the origins of schizophrenia may be found in early life’. Jones' findings were largely confirmed in a very similar historical cohort study in Finland (Isohanni et al. 2001); a 31 year follow-up of the 1966 North Finland birth cohort (n = 12,058). Onsets of schizophrenia were ascertained from a national hospital discharge register. The ages at learning to stand, walk and become potty-trained were each related to subsequent incidence of schizophrenia and other psychoses. Earlier milestones reduced, and later milestones increased, the risk in a linear manner. These developmental effects were not seen for non-psychotic outcomes. The findings support hypotheses regarding psychosis as having a developmental dimension with precursors apparent in early life. There are many conveniences to this approach for the contemporary investigator. ♦ The exposure data has already been collected for you. ♦ The follow-up period has already elapsed. ♦ The design maintains the essential feature of the cohort study, namely that information bias with respect to the assessment of the exposure should not be a problem. ♦ As with the Barker hypothesis example, historical cohort studies are particularly useful for investigating associations across the life course, when there is a long latency between hypothesized exposure and outcome. Despite these important advantages, such retrospective studies are often limited by reliance on historical data that was collected routinely for other purposes; often these data will be inaccurate or incomplete. Also information about possible confounders, such as smoking or diet, may be inadequate.

Introduction: Over the years, the evolution of forest fires has occurred as a result of the evolution of the human species. However, forest fires are still a major challenge for society, placing firefighters with greater occupational exposure. The present study has as main objective to carry out a systematic review of the literature on the main techniques and variables for assessing the occupational exposure of firefighters, during the fight against forest fires.Methodology: The systematic review utilised The Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statementmethodology. This methodology was applied in the Scopus, Web of Science, Pubmed and Academic Search Complete databases with different keywords. The review will include articles written in English only. Results: In the present study, 34 articles were included, in which it was found that exposure to smoking is the most studied variable, and it was in 2019 that a greater evolution of studies in this area of research was observed. Regarding the variables, the studies were organised in groups. Here it is possible to check the different variables selected by the authors and the methods and equipment applied.Discussion: The fact that firefighters carry out their tasks in diverse scenarios and extreme conditions has hindered the application of innovative equipment. It is necessary to combine different variables and equipment for the assessment of occupational exposure. However, it is not always possible to develop this type of equipment in order to be inserted from the user's perspective, from the perspective of the environment, where it will be applied, and from an economic perspective, making it difficult to effectively apply it in the field. Conclusion: As future perspectives, it is recommended that new variables are introduced together, in order to improve the assessment of occupational exposure, namely, through the use of carbon monoxide (CO) and lactate assessment.

Introduction: Occupational noise is still a matter within the industrial practice with nefarious consequences on the worker’s health. Pulmonary diseases, cardiovascular problems, disturbances in sleep, fatigue, and, in the worst-case scenarios, hearing loss (this one with a permanent character) are some of the most common adverse effects reported in the literature. This issue covers itself in even more significant concern when analysing the mining industry context. Almost every operation works as a potential noise source, not only for the workers but also for the surrounding populations. Objective: To identify the exposure setting to occupational noise in the extractive industry and similar works (i.e. earthworks), particularly related to tasks and equipment. Methodology: The Preferred reporting items for systematic reviews and meta-analyses (PRISMA) was used as a guideline to help conduct the research and report of this work. The most relevant keywords were selected and later combined in the selected databases and multidisciplinary academic journals in the first phase. After, the articles were filtered with a set of exclusion criteria, to know: 1) Publication year, 2) Document type, 3) Source type, and 4) Language. The subsequent stage was to determine, within the remaining articles, the pertinence of each study and its later inclusion in the study. Each set of data was then classified according to the measurement context, and the results were analysed. Results and discussion: In the records’ identification phase, a total of 1148 papers were recovered. By applying the previously mentioned exclusion criteria, 547 were removed related to publication year, 146 due to document type, 12 related to source type and 25 because of language. Additionally, 360 records were excluded because were not in accordance with the proposed objective, 25 were duplicate articles, and 7 had no full-text available. From the last analysis, 11 more papers were excluded, which lead to a final result of 15 included studies. According to theoccupational noise measurements set, the records were divided into four categories: activity, equipment, job category, and working area. Different equipment was associated with high noise levels: crusher –between 85.6 and 104 dB, trucks and bulldozes –above 100 dB, and shovel –103 dB, whereas the only analysed activity was blasting, where studies concluded that increasing distance leads to lower noise measurement values. Conclusions: Considering this research, although it was possible to identify the tasks and equipment usually associated with occupational noise in the extractive industry, a lot of work still needs to be done, especially data analysis. However, this research serves as a starting point for future study.

It is estimated that up to 9.3 million persons may be impacted by locomotive horn noise and up to 4.6 million of those may be severely impacted.1 In 2009, there were over 1,900 incidents, over 700 injuries and over 240 fatalities at highway-rail grade crossings.2 The National Academy of Engineering Committee on Technology for a Quieter America has indicated that the public would benefit if train warning horns were more directional and has recommended that research and development be undertaken to better understand the effects on safety and benefits to the public.3 A directive train horn has the potential to focus audible warning signals to desired locations including pedestrians and motorists at highway-rail grade crossings while minimizing noise to the surrounding community and employees in the locomotive cab. As a part of an ongoing Federal Railroad Administration (FRA)-sponsored research and development effort, the authors have examined the feasibility of and recommended an acoustical specification for an optimized train horn that would improve the detectability of the warning signal for motorists at critical positions along the crossing road while reducing the area of environmental noise impact. The detectability, noise impact area and occupational noise exposure have been compared for the optimized horn and several typical standard horns. Near the beginning of most sounding events (1/4-mile from the grade crossing) the optimized horn reduces noise exposure because a narrow beam of sound can be generated and focused at the grade-crossing. As the train approaches the crossing, the beam width must become wider. It is found that detectability could be improved and noise impact area reduced by up to 57%, but the optimized horn must have a directivity pattern and amplitude that dynamically changes as a function of train position relative to the crossing. Current acoustic source technologies which generate directive sound were examined including “acoustic hailing devices” (AHDs) which are recent technological advancements typically used for naval communications. Capable of focusing high amplitudes of sound within a narrow beam and dynamically changing the directivity pattern through electronic beam steering, AHDs have been identified as a feasible means of meeting the required specifications. A critical design issue for the optimized horn is controlling the directivity pattern at low frequencies. Development and testing of a prototype is in progress and actual improvements to detectability and reductions in noise impact will be analyzed. The paper briefly discusses the feasibility of the optimized horn and general information on cost and implementation.

It is estimated that up to 9.3 million people may be impacted by locomotive horn noise and up to 4.6 million of those may be severely impacted.1 In 2009, there were over 1,900 incidents, over 700 injuries, and over 240 fatalities at highway-rail grade crossings.2 Approximately 4,000 times per year, a train and highway vehicle collide at one of over 262,000 public and private highway-rail grade crossings in the United States. Compared to a collision between two highway vehicles, a collision with a train is eleven times more likely to result in a fatality, and five and a half times more likely to result in a disabling injury. Approximately half of all collisions occur at grade crossings that are not fully equipped with warning devices. Some of the drivers involved in these collisions may have been unaware of the approaching train.3 The National Academy of Engineering Committee on Technology for a Quieter America has indicated that the public would benefit if a train horn was more directional and has recommended that research and development be undertaken to better understand the effects on safety, with benefits to the public.4 As a part of an ongoing Federal Railroad Administration (FRA)-sponsored research and development effort, the authors have developed an Acoustical Warning Device (AWD) prototype with an overall goal of maximizing safety at a grade crossing and minimizing environmental noise pollution (at the wayside and in the cabin of a locomotive in reducing railroad worker occupational hazard noise exposure). An initial prototype was created that consisted of one acoustical element. An advanced prototype is currently being developed with three acoustical elements to provide variable directivity and steering capabilities through beamforming. A digitized horn signal has been created based on characteristics from an analog air-pressure locomotive horn. The initial AWD prototype has been analyzed for detectability and noise impact area and the directivity pattern of its sound emissions have been tested. The expected performance of the advanced three-unit prototype has been evaluated based on the test results of the initial prototype and acoustic simulation modeling. During development of the initial AW D prototype, spectrograms, polar directivity plots, frequency response plots, 1/3-octave band plots, and LAeq measurements of the AWD propagation were analyzed to ensure proper functionality of the AWD, in accordance with FRA and QinetiQ North America’s (QNA) specifications. Based on acoustic simulation modeling, the advanced AWD prototype is expected to generate sound up to 110 dBA at 100 feet forward of the locomotive. The AWD prototype is expected to improve detectability and reduced environmental noise exposure to the community and locomotive cabin.