An assessment of the relative influence of a vapor recovery system in reducing occupational exposure to volatile organic compounds in high performance liquid chromatography

Occupational exposures to organic solvents, specifically acetonitrile and methanol, have the potential to cause serious long-term health effects. In the laboratory, these solvents are used extensively in protocols involving the use of high performance liquid chromatography (HPLC). Operators of HPLC equipment may be potentially exposed to these organic solvents when local exhaust ventilation is not employed properly or is not available, which can be the case in many settings. The objective of this research was to characterize the various sites of vapor release in the HPLC process and then to determine the relative influence of a novel vapor recovery system on the overall exposure to laboratory personnel. The effectiveness of steps to reduce environmental solvent vapor concentrations was assessed by measuring exposure levels of acetonitrile and methanol before and after installation of the vapor recovery system. With respect to acetonitrile, the concentration was not statistically significant with p=0.938; moreover, exposure after the intervention was actually higher than prior to intervention. With respect to methanol, the concentration was not statistically significant with p=0.278. This indicates that the exposure to methanol after the intervention was not statistically significantly higher or lower than prior to intervention. Thus, installation of the vapor recovery device did not result in statistically significant reduction in exposures in the settings encountered, and acetonitrile actually increased significantly.^

Dynamic occupational therapy cognitive assessment for children: Perceived utility in Australian occupational therapy practice

Background and Aim: The Dynamic Occupational Therapy Cognitive Assessment for Children (DOTCA-Ch), recently developed in Israel, assesses the cognitive areas: orientation, spatial perception, praxis, visuomotor construction and thinking operations of 6- to 12-year-old children. The dynamic aspect, which incorporates mediation and prompting, has been presented as a valuable clinical feature of this new assessment. This study investigated the cultural suitability, dynamic nature and comprehensiveness of the DOTCA-Ch as a single cognitive assessment for occupational therapy practice in Australia. Methods: Twenty-three paediatric occupational therapists participated in three tutorial and video demonstrations, which were then followed by a group interview. Results and Conclusion: Thematic analysis of transcripts identified four main themes: appropriateness of assessment tasks, language, mediation and clinical utility. Within each theme, the participants raised both positive and negative features. This paper highlights occupational therapists' mixed views on the clinical utility of this assessment in Australia. Limitations of this study and areas for further research are suggested

Ability assessment and job structure measures in occupational mobility

Recent and potential changes in technology have resulted in the anticipation of increases in the frequency of job changes. This has led manpower policy makers to investigate the feasibility of incorporating the employment skills of job groups in the general prediction of future job learning and performance with a view to the establishment of "job families" within which transfer might be considered reciprocally high. A structured job analysis instrument (the Position Analysis Questionnaire) is evaluated in terms of two distinct sets of scores; job dimensions and synthetically established attribute/trait profiles. Studies demonstrate that estimates of a job's structure/dimensions and requisite human attributes can be reliably established. Three alternative techniques of statistically assembling profiles of the requisite human attributes for jobs are found to have differential levels of reliability and differential degrees of validity in their estimation of the "actual" ability requirements of jobs. The utility of these two sets of job descriptors to serve as representations of the cognitive structure similarity of job groups is investigated in a study which simulates a job transfer situation. The central role of the index of similarity used to assess the relationship between "target" and "present" job is demonstrated. The relative extents to which job structure similarity and job attribute similariity are associated with positive transfer are investigated. The studies demonstrate that the dimensions of jobs, and more fruitfully their requisite human attributes can serve as bases to predict job transfer learning and performance. The nature of the index of similarity used to optimally formulate predictions of transfer is such that networks of jobs might be establishable to which current job incumbents could be expected to transfer positively. The derivation of "job families" with anticipated reciprocal transfer consequences is considered to be less appropriate.

Older Adult Injury Risk Assessment in the Driving and Occupational Environments

Thesis (Ph.D.)--University of Washington, 2016-08

BPA occupational exposure assessment in Europe: a scientific gap

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane one is of the greatest volume industrial chemicals utilized in the world with increased production every year. Environmental exposure to this xenoestrogen is considered a generalized phenomenon with a Tolerable Daily Intake (TDI) of4 µg/kg body weight/day established by the European Food Safety Authority. Several studies have focused in estimate human daily intake and potential associated health effects of environmental exposures, however despite of the massive BPA production and consumption in European countries, with policarbonate and epoxy resins as the major applications, occupational exposure to BPA have been overlooked and considered safe by the European authorities.

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013 : a systematic analysis for the Global Burden of Disease Study 2013

Global, regional, and national comparative risk assessment of 79 behavioral, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015 : a systematic analysis for the Global Burden of Disease Study 2015

Occupational exposure assessment to particles with task-based approach

Occupational exposure assessment can be a challenge due to several factors being the most important the costs associate and the result's dependence from the conditions at the time of sampling. Conducting a task-based exposure assessment allow defining better control measures to eliminate or reduce exposure since more easily identifies the task with higher exposure. A research study was developed to show the importance of task-based exposure assessment in four different settings (bakery, horsemanship, waste sorting and cork industry). Measurements were performed using a portable direct-reading hand-held equipment and were conducted near the workers nose during tasks performance. For each task were done measurements of approximately 5 minutes. It was possible to detect the task in each setting that was responsible for higher particles exposure allowing the priority definition regarding investments in preventive and protection measures.

Exposure and risk assessment in occupational exposure to fungi: aspects to consider in highly contaminated settings

Although a clear correlation between levels of fungi in the air and health impacts has not been shown in epidemiological studies, fungi must be regarded as potential occupational health hazards. Fungi can have an impact on human health in four different ways: (1) they can infect humans, (2) they may act as allergens, (3) they can be toxigenic, or (4) they may cause inflammatory reactions. Fungi of concern in occupational hygiene are mostly non-pathogenic or facultative pathogenic (opportunistic) species, but are relevant as allergens and mycotoxins producers. It is known that the exclusive use of conventional methods for fungal quantification (fungal culture) may underestimate the results due to different reasons. The incubation temperature chosen will not be the most suitable for every fungal species, resulting in the inhibition of some species and the favouring of others. Differences in fungi growth rates may also result in data underestimation, since the fungal species with higher growth rates may inhibit others species’ growth. Finally, underestimated data can result from non-viable fungal particles that may have been collected or fungal species that do not grow in the culture media used, although these species may have clinical relevance in the context. Due to these constraints occupational exposure assessment, in setings with high fungal contamination levels, should follow these steps: Apply conventional methods to obtain fungal load information (air and surfaces) regarding the most critical scenario previously selected; Guideline comparation aplying or legal requirements or suggested limits by scientific and/or technical organizations. We should also compare our results with others from the same setting (if there is any); Select the most suitable indicators for each setting and apply conventional-culture methods and also molecular tools. These methodology will ensure a more real characterization of fungal burden in each setting and, consequently, permits to identify further measures regarding assessment of fungal metabolites, and also a more adequate workers health surveillance. The methodology applied to characterize fungal burden in several occupational environments, focused in Aspergillus spp. prevalence, will be present and discussed.

Occupational exposure to mycotoxins: aspects to consider for the aggregate and cumulative risk assessment

Mycotoxins are an important group of naturally occurring substances known to contaminate a huge variety of agricultural products, feed and food commodities. The main concern is their widespread presence and toxic effects on humans and animals as they have been described as cytotoxic, nephrotoxic, hepatotoxic, teratogenic, immunosuppressive, mutagenic and/or carcinogenic. However, until now, risk assessments and regulations have usually been performed on individual mycotoxins despite humans and animals are being frequently exposed to a multitude of mycotoxins simultaneously. Moreover, even though some exposures through inhalation and dermal contact may potentially occur, only oral ingestion has been considered as the sole route of exposure in all the evaluations. However, more recent studies have also demonstrated airborne exposure to mycotoxins in different occupational settings with emphasis on agricultural professions. In these cases, skin contact with mold-infested substrates and inhalation of spore-borne toxins are the most important sources of exposure. Still, mycotoxins are not normally recongnize as na occupational hazard and exposure is different from the one ocurring by food intake. In this case, exposure is charaterized to be acute and simultaneous to other mycotoxins and also to fungi and dust. All these features increase the challenge implicated in the risk assessment process. Some topics will be presented and discussed in detailed such as: What occupational settings should be consider in this case; possible exposure routes; exposure characterization; how to assess exposure; co-exposure; aggregate exposure and cumulative risk assessment.

Mercury in Gas Operations - Occupational Health Risk Assessment

The project goal was to determine plant operations and maintenance worker’s level of exposure to mercury during routine and non-routine (i.e. turnarounds and inspections) maintenance events in eight gas processing plants. The project team prepared sampling and analysis plans designed to each plant’s process design and scheduled maintenance events. Occupational exposure sampling and monitoring efforts were focused on the measurement of mercury vapor concentration in worker breathing zone air during specific maintenance events including: pipe scrapping, process filter replacement, and process vessel inspection. Similar exposure groups were identified and worker breathing zone and ambient air samples were collected and analyzed for total mercury. Occupational exposure measurement techniques included portable field monitoring instruments, standard passive and active monitoring methods and an emerging passive absorption technology. Process sampling campaigns were focused on inlet gas streams, mercury removal unit outlets, treated gas, acid gas and sales gas. The results were used to identify process areas with increased potential for mercury exposure during maintenance events. Sampling methods used for the determination of total mercury in gas phase streams were based on the USEPA Methods 30B and EPA 1631 and EPA 1669. The results of four six-week long sampling campaigns have been evaluated and some conclusions and recommendations have been made. The author’s role in this project included the direction of all field phases of the project and the development and implementation of the sampling strategy. Additionally, the author participated in the development and implementation of the Quality Assurance Project Plan, Data Quality Objectives, and Similar Exposure Groups identification. All field generated data was reviewed by the author along with laboratory reports in order to generate conclusions and recommendations.

Genotoxic potential generated by biomass burning in the Brazilian Legal Amazon by Tradescantia micronucleus bioassay: a toxicity assessment study

Background: The Brazilian Amazon has suffered impacts from non-sustainable economic development, especially owing to the expansion of agricultural commodities into forest areas. The Tangara da Serra region, located in the southern of the Legal Amazon, is characterized by non-mechanized sugar cane production. In addition, it lies on the dispersion path of the pollution plume generated by biomass burning. The aim of this study was to assess the genotoxic potential of the atmosphere in the Tangara da Serra region, using Tradescantia pallida as in situ bioindicator. Methods: The study was conducted during the dry and rainy seasons, where the plants were exposed to two types of exposure, active and passive. Results: The results showed that in all the sampling seasons, irrespective of exposure type, there was an increase in micronucleus frequency, compared to control and that it was statistically significant in the dry season. A strong and significant relationship was also observed between the increase in micronucleus incidence and the rise in fine particulate matter, and hospital morbidity from respiratory diseases in children. Conclusions: Based on the results, we demonstrated that pollutants generated by biomass burning in the Brazilian Amazon can induce genetic damage in test plants that was more prominent during dry season, and correlated with the level of particulates and elevated respiratory morbidity.