Reduction Of Occupational Exposure Research Articles

Rapid prototyping Lab-on-Chip devices for the future: A numerical optimisation of bulk optical parameters in microfluidic systems

Nuclear reactor process control is typically monitored for pure β-emitting radionuclides via manual sampling followed by laboratory analysis, leading to delays in data availability and response times. The development of an in situ microfluidic Lab on Chip (LoC) system with integrated detection capable of measuring pure β-emitting radionuclides presents a promising solution, enabling a reduction in occupational exposure and cost of monitoring whilst providing improved temporal resolution through near real-time data acquisition. However, testing prototypes with radioactive sources is time-consuming, requires specialist facilities/equipment, generates contaminated waste, and cannot rapidly evaluate a wide range of designs or configurations. Despite this, modelling multiple design parameters and testing their impact on detection with non-radioactive substitutes has yet to be adopted as best practice. The measurement of pure β emitters in aqueous media relies on the efficient transport of photons generated by the Cherenkov effect or liquid scintillators to the detector. Here we explore the role of numerical modelling to assess the impact of optical cell geometry and design on photon transmission and detection through the microfluidic system, facilitating improved designs to realise better efficiency of integrated detectors and overall platform design. Our results demonstrate that theoretical modelling and an experimental evaluation using non-radiogenic chemiluminescence are viable for system testing design parameters and their impact on photon transport. These approaches enable reduced material consumption and requirement for specialist facilities for handling radioactive materials during the prototyping process. This method establishes proof of concept and the first step towards numerical modelling approaches for the design optimisation of microfluidic LoC systems with integrated detectors for the measurement of pure β emitting radionuclides via scintillation-based detection.

The National Occupational Respiratory Disease Registry (NORDR): it is time to learn from failure.

The National Occupational Respiratory Disease Registry (NORDR): it is time to learn from failure.

Control measures for airborne ammonia and respirable dust exposure in swine barns

ABSTRACT Extended exposure to airborne contaminants such as ammonia (NH3) and respirable dust in swine facilities has been associated with various health problems among swine barn workers. The overall goal of this study was to assess the impact of selected control measures, namely, canola oil sprinkling, low crude protein diet, high level of cleaning, and manure pH manipulation, on NH3 and respirable dust concentrations in swine production rooms through area sampling and on worker exposure to these contaminants in accordance with National Institute of Occupational Safety and Health (NIOSH) methods for occupational exposure monitoring. Results from five trials showed that low crude protein diet can be used for reducing worker exposure to NH3 while oil sprinkling can be used for controlling respirable dust levels in swine rooms. Reduction in airborne levels did not translate to reduction in occupational exposure. Commercial NH3 monitors showed higher readings than the standard NIOSH 6015 method.

Reduction of Occupational Exposure Using a Novel Tungsten-Containing Rubber Shield in Interventional Radiology.

This study investigates whether a novel tungsten-containing rubber shield could be used as substitute shielding material in interventional radiology to reduce the occupational exposure of operators to scattered radiation from a patient. The tungsten-containing rubber is a lead-free radiation-shielding material that contains as much as 90% tungsten powder by weight. Air kerma rates of scattered radiation from solid-plate phantoms, simulating a patient, were measured with a semiconductor dosimeter at the height of the operator's eye (1,600 mm from the floor), chest (1,300 mm), waist (1,000 mm), and knee (600 mm) with and without tungsten-containing rubber shielding (1-5 mm thickness). The tungsten-containing rubber and a commercial shielding material (RADPAD) were affixed onto the phantom on the operator's side, and reductions in air kerma rates were compared. Reduction rates for tungsten-containing rubber shielding with thicknesses of 1, 2, 3, 4, and 5 mm at each height level were as follows: 70.37 ± 0.40%, 72.17 ± 0.29%, 72.95 ± 0.31%, 72.58 ± 0.35%, and 73.63 ± 0.63% at eye level; 76.36 ± 0.19%, 77.13 ± 0.10%, 77.36 ± 0.14%, 77.62 ± 0.25%, and 77.66 ± 0.14% at chest level; 67.78 ± 0.31%, 68.12 ± 0.19%, 68.88 ± 0.28%, 68.97 ± 0.14%, and 68.85 ± 0.45% at waist level; and 0.14 ± 0.94%, 0.72 ± 0.56%, 1.08 ± 0.74%, 1.77 ± 0.80%, and 1.79 ± 1.82% at knee level, respectively. Reduction rates with RADPAD were 61.80 ± 0.67%, 60.33 ± 0.61%, 64.70 ± 0.25%, and 0.14 ± 0.66% at eye, chest, waist, and knee levels, respectively. The shielding ability of the 1 mm tungsten-containing rubber was superior to that of RADPAD. The tungsten-containing rubber could be employed to minimize an operator's radiation exposure instead of the commercial shielding material in interventional radiology.

Use of personal protective equipment under occupational exposure to cytostatics

A growing number of cancer cases enhances the usage of cytostatic agents and thereby contributes to the increase in the number of health care workers occupationally exposed to cytostatics. This article presents the results of the survey aimed at obtaining data on the reduction of occupational exposure through using personal protective equipment by the medical and pharmaceutical personnel involved in handling cytostatics. The questionnaires were sent by mail or e-mail to oncology hospitals and pharmacies preparing cytostatic drugs. Responses were received from 94 people employed in these workplaces. The main questions concerned the forms of cytostatics; job activities; types of personal protective equipment used and working time under exposure to cytotoxic drugs. The majority (over 90%) of the healthcare personnel declared the use of personal protective equipment when working under conditions of exposure to cytostatic drugs. Depending on the type of protection, 15-35% of people reported that the most frequent time of their single use of the apron, the overalls, the gloves, the cap, the goggles or the respirators did not exceed few minutes. Gloves were changed most frequently. However, half of the responses indicated that the time after which the respondents removed protection equipment greatly differed. Almost the whole group of respondents applied personal protective equipment when working under exposure to cytostatics. However, personal protective equipment was not used every time in case of exposure. The medical and pharmaceutical staff worked under exposure to cytostatics for a few or even dozen hours during the working day. Med Pr 2016;67(4):499-508.

May the Reduction of Exposure to Specific Sensitizers Be an Alternative to Work Cessation in Occupational Asthma? Results from a Follow-Up Study

Background: Few data are reported on the effects of a reduction of exposure to specific sensitizers in occupational asthma (OA). The objective of this study was to evaluate the clinical outcome of subjects with OA, comparing the effect of a reduction with that of the persistence or cessation of occupational exposure to the specific sensitizer. Subjects and Methods: Forty-one subjects with OA due to different sensitizers were diagnosed via a specific inhalation challenge. After a follow-up interval of 3.5 years, subjects were reexamined by clinical assessment, bronchial hyperresponsiveness (BH) and induced sputum. Results: At follow-up, subjects who had reduced occupational exposure (n = 22) showed a significant improvement in BH and a nonsignificant improvement in sputum eosinophilia (from 5.3 to 1.1%, n.s.), while subjects still exposed (n = 10) showed a significant decrease in FEV₁. Subjects who ceased work (n = 9) showed a trend of improvement in BH and sputum eosinophilia. Logistic analysis showed that the major determinant of improvement in BH at follow-up was the severity of BH at diagnosis, with a minimal contribution from the duration of exposure and treatment with inhaled corticosteroids during follow-up; reduction of work exposure did not enter into any model. Conclusion: The reduction of occupational exposure could not be considered to be as effective as work cessation, which remained the best treatment for OA. However, it was not associated with a deterioration of FEV₁ as observed in subjects with persistent exposure.

TCT-403: Reduction of Occupational Exposure to Scatter Radiation during Endovascular Interventions: A Prospective, Placebo Controlled Trial Comparing the Effectiveness of a Disposable Radiation-Absorbing Drape

TCT-403: Reduction of Occupational Exposure to Scatter Radiation during Endovascular Interventions: A Prospective, Placebo Controlled Trial Comparing the Effectiveness of a Disposable Radiation-Absorbing Drape

Treatment vault shielding for a flattening filter-free medical linear accelerator

The requirements for shielding a treatment vault with a Varian Clinac 2100 medical linear accelerator operated both with and without the flattening filter were assessed. Basic shielding parameters, such as primary beam tenth-value layers (TVLs), patient scatter fractions, and wall scatter fractions, were calculated using Monte Carlo simulations of 6, 10 and 18 MV beams. Relative integral target current requirements were determined from treatment planning studies of several disease sites with, and without, the flattening filter. The flattened beam shielding data were compared to data published in NCRP Report No. 151, and the unflattened beam shielding data were presented relative to the NCRP data. Finally, the shielding requirements for a typical treatment vault were determined for a single-energy (6 MV) linac and a dual-energy (6 MV/18 MV) linac. With the exception of large-angle patient scatter fractions and wall scatter fractions, the vault shielding parameters were reduced when the flattening filter was removed. Much of this reduction was consistent with the reduced average energy of the FFF beams. Primary beam TVLs were reduced by 12%, on average, and small-angle scatter fractions were reduced by up to 30%. Head leakage was markedly reduced because less integral target current was required to deliver the target dose. For the treatment vault examined in the current study, removal of the flattening filter reduced the required thickness of the primary and secondary barriers by 10–20%, corresponding to 18 m3 less concrete to shield the single-energy linac and 36 m3 less concrete to shield the dual-energy linac. Thus, a shielding advantage was found when the linac was operated without the flattening filter. This translates into a reduction in occupational exposure and/or the cost and space of shielding.

Respiratory health of road-side vendors in a large industrialized city

The literature reports a high prevalence of respiratory symptoms associated with exposure to motor vehicle exhaust emissions and people exposed to vehicle emissions are at risk of reduced lung function and cardiovascular performance. Although the effect of traffic emissions is a known risk to respiratory health, retailers are often situated along major roads in a busy urban environment to maximise customers. Shop assistants in an air-conditioned environment should be less exposed to traffic fumes and their lung function should be better preserved compared to 'unprotected' vendors exposed directly to vehicle emissions. The lung function of these two groups of workers has not previously been compared. The aims of this study are to determine if there is a difference in the concentration of respirable particles of diameter less than 10 micrometers (PM10) inside and outside air-conditioned shops along a busy major road; and to compare the lung function parameters, blood lead levels and respiratory symptoms between road-side vendors directly 'exposed' to traffic fumes and vendors working in 'protected' air-conditioned shops along the same road. Roadside vendors (n=33) and adjacent shop assistants (n=31) were recruited for the study in a district known to have high emissions and pollution measures. All subjects were asked to complete a questionnaire providing the frequency of their respiratory symptoms. Spirometry pulmonary function tests were conducted and exhaled carbon monoxide levels (ECO), oxygen saturation and blood lead levels (BLL) were measured. PM10 level was concurrently measured in the subject's working environment. Pulmonary function data and ECO levels collected from a cohort of university staff aged > or = 30 years (n=92) at a university campus were included for comparison. The concentration of particulate matter (PM10) at the roadside (210 +/- 70 microg/m3) was significantly higher than inside the shops (130 +/- 40 microg/m3). There was no difference in lung function parameters or BLL between the groups, however the forced vital capacity of both groups of vendors was significantly lower than a 'control' cohort of academic institution personnel (n=92). This study illustrated that while the level of pollution improved with air conditioning, this may not be sufficient to prevent respiratory consequences. Our data suggests that a reduction in occupational exposure is not enough to protect these workers. Air-conditioned work environment is insufficient to protect the respiratory system against the adverse effects of exposure to vehicle emissions. The overwhelming effect of exposure during travel to and from work and at home cannot be underestimated. More stringent guidelines to control pollution appear necessary to protect the respiratory health of both shop-keepers and road-side vendors and further studies to explore the effect on respiratory health of the exposure to pollutants associated with commuting to and from work are warranted.

Environmental and Chemical Toxins and Psychiatric Illness

Back to table of contents Previous article Next article Book ReviewsFull AccessEnvironmental and Chemical Toxins and Psychiatric IllnessMartin K. Williams, M.D.Martin K. WilliamsSearch for more papers by this author, M.D.Published Online:1 Mar 2003https://doi.org/10.1176/appi.ps.54.3.411AboutSectionsView EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail Many years ago, my grandfather told me stories of his service in France during World War I. He talked about the enemy's use of poisonous gas as a weapon and still had his old gas mask to show me. Recently, I have had many memories of that gas mask.James S. Brown, Jr., M.D., has completed a timely form of community service for psychiatric caregivers in his thorough overview of potential psychiatric symptoms in Environmental and Chemical Toxins and Psychiatric Illness. Dr. Brown notes in his introduction that chemical exposures became a part of daily life during the 20th century. Many products that are within arm's reach as you read these words have the potential for causing harm: gasoline, correction fluid, and insecticides.With the development of poison control centers and the Occupational Health and Safety Administration, there has been a reduction of occupational exposures, but most of the mass poisonings with psychiatric sequelae have occurred since the 1960s—for example, Chernobyl, Love Canal, the Tokyo subway poisonings, and the Gulf War.Early in his text, Dr. Brown points out the differences between technological and natural disasters. He isolates nuances from a psychodynamic perspective in the roles of perception and interpretation, bias, and litigation in terms of how these differences may affect the patient's presentation and symptom clusters. I found the early chapter on community and individual stress reactions to be the most useful part of the book. There is a well-reasoned discussion of mass hysteria, especially as it relates to industrial settings. Many clinicians who practice at institutional sites will find this section relevant to the rumors that fly around such facilities in relation to the new cleaning solutions that have a different odor, or whether certain buildings are associated with higher frequencies of employee health problems.The remainder of the book includes chapter-by-chapter reviews of various classes of potential toxins and their psychiatric sequelae. They are well written and concise and provide tables of high-risk occupations and work sites along with symptom clusters. Unfortunately, many of the symptoms are diverse and nonspecific, but review of this text will help clinicians avoid errors of omission. One especially strong point is an extensive list of references and resources at the end of each chapter, clearly grouped to aid readers in finding what they need quickly.Finally, I would be remiss if I failed to point out Dr. Brown's close attention to the cultural issues that are intrinsically bound to many of the chemical toxins and potential exposures identified in his text. For example, in the South, medical schools are able to provide students with ready examples of organophosphate poisonings. Such poisonings occur in the South with some regularity because of the rural nature of the area and the large number of migrant workers, who often are unable to read the labels of the insecticides they are using. In addition, patients who are practicing folk medicine may have exposure to various toxins, including mercury. Identification of chemical exposures as a possible source of psychiatric symptoms will occur only if the informed clinician thinks to look for them.Dr. Williams is chief of psychiatry at Cherry Hospital in Goldsboro, North Carolina.by James S. Brown, Jr., M.D.; Washington, D.C., American Psychiatric Publishing Inc., 2002, 320 pages, $45 softcover FiguresReferencesCited byDetailsCited ByNone Volume 54Issue 3 March 2003Pages 411-411 Metrics History Published online 1 March 2003 Published in print 1 March 2003

Avoidable mortality in Europe 1955-1994: a plea for prevention.

OBJECTIVE: To analyse trends of avoidable mortality in Europe, emphasising causes of death amenable to primary prevention through reduction of exposures, secondary prevention through early detection and treatment, and tertiary...

An engineer's perspective of the intervention research workshop.

As an engineer practicing in the area of engineering controls for the reduction of occupational exposures to hazardous agents, the Intervention Research Workshop studies appeared to be effective for the studied situations, yet the models may not be applicable across a wide range of intervention possibilities. A more generic model might be more appropriate, perhaps a business model. Dr. W. Edwards Deming has proposed a model for the production of goods and services. If we can view interventions as products which need to be sold to potential customers, perhaps this type of model would be more effective across a wide range of intervention strategies.

Intervention study on the influence of reduction of occupational exposure to styrene on sister chromatid exchanges in lymphocytes.

An intervention study was performed on 28 workers exposed by inhalation to styrene in the reinforced plastics industry and 20 controls not occupationally exposed to the compound. The workers involved were 14 laminators exposed to a time-weighted average of approximately 40 ppm styrene and 14 formers exposed to an average of about 10 ppm styrene. Ambient air monitoring data and the concentration of mandelic acid in the urine were used for the assessment of exposure. From each subject, peripheral blood lymphocytes were analysed for sister chromatid exchanges (SCEs). In the laminators, the mean SCE frequency was significantly higher than in the controls in both the group of smokers (9.59 +/- 0.77 SCEs/cell vs 7.23 +/- 1.00 SCEs/cell) and the group of non-smokers (10.25 +/- 1.08 SCEs/cell vs 5.98 +/- 0.60 SCEs/cell). The mean SCE frequency of the formers (7.42 +/- 128 SCEs/cell in smokers) did not differ statistically from the controls (7.23 +/- 1.00 SCEs/cell in smokers). No evaluation was made for non-smoking formers since all but one worker in this group were smokers. In order to comply with a lowering of the occupational exposure limit (MAK value) for occupational exposure to styrene in the Federal Republic of Germany from 100 ppm to 20 ppm, considerable technical and hygienic improvements were made at the work site of the laminators. This intervention led to a reduction of average exposure of these workers by inhalation from 40 ppm to approximately 20 ppm. One year after these improvements were made, a second investigation was performed. In all but one of the laminators, the concentration of mandelic acid in urine had dropped considerably. The SCE frequency in blood lymphocytes of the laminators had likewise dropped significantly to 7.74 +/- 0.59 SCEs/cell in the non-smokers. In the smokers, it was also lower than on the first occasion (9.02 +/- 1.19), yet statistical evaluation was not possible due to insufficient numbers. Overall, the results of the intervention study show that the lowering of the occupational exposure limit for styrene to 20 ppm in Germany was justified and that a reduction of occupational exposure to the chemical has led to a prevention of adverse cytogenetic effects.

Cancer of respiratory organs among workers at a nickel refinery in Norway.

In a previous report (Pedersen et al., 1973) an excess risk of respiratory cancer among Norwegian nickel workers was demonstrated. The number of cancer cases was relatively small for the study of temporal changes in exposure. In this report the number of cancer cases increased by 70% through an extended follow-up to 1979, and the results published previously were confirmed. Data on smoking habits of the employees at the nickel refinery have now become available. The interaction between smoking and occupational nickel exposure is assessed by comparing the excess risk of lung cancer caused by smoking in the study group and in a sample of the general population. It is shown that the interaction is closer to being additive than multiplicative. This observation has methodological implications for studying temporal changes in occupational exposure. These implications are discussed. No substantial reduction in occupational exposure at the nickel refinery can be observed as far as lung cancer is concerned. For nasal cancer, however, the risk is much smaller among those employed around 1960 than among those employed around 1930. The difference in trend of occupational risk for the two types of cancer cannot be explained by the data presented.