scholarly journals O1C.5 Assessment and assignment of exposure to asbestos for an industrial cohort of chrysotile miners and processors

2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A8.1-A8
Author(s):  
Hans Kromhout ◽  
Eleonora Feletto ◽  
Monika Moissonnier ◽  
Sara J Schonfeld ◽  
Ann Olsson ◽  
...  
Keyword(s):  
Measurement Data ◽  
Quality Measurement ◽  
Dust Exposure ◽  
Job Exposure Matrix ◽  
Asbestos Fibre ◽  
Female Workers ◽  
Exposure Response ◽  
Job Title ◽  
Exposure Levels ◽  
Occupational Cohort

IntroductionHistorical dust concentrations are available for an occupational cohort study of workers active for 12 months or more between 1975 and 2010 in a chrysotile mine and processing factories in Asbest, Russian Federation. Their occupational histories were ascertained back to as early as the 1930s. A cohort specific job-exposure matrix (JEM) to estimate exposure to asbestos dust and fibre was elaborated.MethodsAlmost 1 00 000 recorded dust concentrations were used to develop an asbestos dust JEM and previously derived conversion factors were applied to estimate an asbestos fibre JEM. Where dust concentrations were not available, linear mixed models were used to impute missing data. Both JEMs were applied to the occupational histories of over 30 000 individual workers (over 35% female workers) based on job title and year worked.ResultsAssigned exposures varied over time with higher levels in the earlier years of activity. Approximately 97% of 2 00 000 person-years in the factories and 89% of 3 15 000 person-years in the mine had exposure assigned based on actual measurements. The median cumulative dust exposure for the exposed cohort was almost 50 mg/m3-years, with women slightly lower than men. The median cumulative fibre exposure for was 37 fibres/cm3-years for both men and women.Discussion and conclusionA key strength of this study is the availability of high-quality measurement data covering workers’ occupational histories. The dust and fibre JEMs enable estimation of annual profession-specific exposure levels that will form the basis of quantitative exposure estimates in the study and consequently quantitative exposure-response analyses.

scholarly journals Attenuation of exposure-response curves in occupational cohort studies at high exposure levels

2003 ◽  
Vol 29 (4) ◽  
pp. 317-324 ◽  
Author(s):  
Leslie Stayner ◽  
Kyle Steenland ◽  
Mustafa Dosemeci ◽  
Irva Hertz-Picciotto
Keyword(s):  
Cohort Studies ◽  
Response Curves ◽  
High Exposure ◽  
Exposure Response ◽  
Exposure Levels ◽  
Occupational Cohort

scholarly journals Developing a company-specific job exposure matrix for the Asbest Chrysotile Cohort Study

2021 ◽  
pp. oemed-2021-107438
Author(s):  
Eleonora Feletto ◽  
Evgeny V Kovalevskiy ◽  
Sara J Schonfeld ◽  
Monika Moissonnier ◽  
Ann Olsson ◽  
...  
Keyword(s):  
Cohort Study ◽  
Cumulative Exposure ◽  
Dust Exposure ◽  
Job Exposure Matrix ◽  
Entire Cohort ◽  
Exposure Response ◽  
The Russian Federation ◽  
And Gender ◽  
A Company ◽  
Cumulative Exposures

ObjectivesExposure assessment for retrospective industrial cohorts are often hampered by limited availability of historical measurements. This study describes the development of company-specific job-exposure matrices (JEMs) based on measurements collected over five decades for a cohort study of 35 837 workers (Asbest Chrysotile Cohort Study) in the Russian Federation to estimate their cumulative exposure to chrysotile containing dust and fibres.MethodsAlmost 100 000 recorded stationary dust measurements were available from 1951-2001 (factories) and 1964–2001 (mine). Linear mixed models were used to extrapolate for years where measurements were not available or missing. Fibre concentrations were estimated using conversion factors based on side-by-side comparisons. Dust and fibre JEMs were developed and exposures were allocated by linking them to individual workers’ detailed occupational histories.ResultsThe cohort covered a total of 515 355 employment-years from 1930 to 2010. Of these individuals, 15% worked in jobs not considered professionally exposed to chrysotile. The median cumulative dust exposure was 26 mg/m3 years for the entire cohort and 37.2 mg/m3 years for those professionally exposed. Median cumulative fibre exposure was 16.4 fibre/cm3 years for the entire cohort and 23.4 fibre/cm3 years for those professionally exposed. Cumulative exposure was highly dependent on birth cohort and gender. Of those professionally exposed, women had higher cumulative exposures than men as they were more often employed in factories with higher exposure concentrations rather than in the mine.ConclusionsUnique company-specific JEMs were derived using a rich measurement database that overlapped with most employment-years of cohort members and will enable estimation of quantitative exposure–response.

270. Exposure Levels and Determinants of Flour Dust Exposure in Bakeries

1999 ◽  
Author(s):  
I. Burstyn ◽  
K. Teschke ◽  
K. Bartlett ◽  
S. Kennedy
Keyword(s):  
Dust Exposure ◽  
Exposure Levels ◽  
Flour Dust

Experimental investigation of the air flow in a simplified underhood environment

2021 ◽  
pp. 095440702110597
Author(s):  
Randi Franzke ◽  
Simone Sebben ◽  
Emil Willeson
Keyword(s):  
Flow Field ◽  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Air Flow ◽  
Measurement Data ◽  
Quality Measurement ◽  
Flow Distribution ◽  
Lateral Position ◽  
Reference Case ◽  
Lateral Direction

In this paper, a simplified underhood environment is proposed to investigate the air flow distribution in a vehicle-like set-up and provide high quality measurement data that can be used for the validation of Computational Fluid Dynamic methods. The rig can be equipped with two types of front openings representative for electrified vehicles. Furthermore, it is possible to install differently shaped blockages downstream of the fan to imitate large underhood components. The distance between the blockages and the fan can be varied in longitudinal and lateral direction. The measurements are performed with Laser Doppler Anemometry at a fixed distance downstream of the fan. The results show that the lack of an upper grille opening in the configuration for a battery electric vehicle has a notable impact on the flow field in the reference case without any downstream blockage. However, the differences in the flow field between the two front designs become less when a downstream obstruction is present. The longitudinal and lateral position of the blockages have a minor impact on the flow field compared to the shape of the obstacle itself.

scholarly journals THE EFFECTS OF ENVIRONMENTAL ISSUES ON RESIDENTIAL HOUSE PRICE (IN THE CASE OF ULAANBAATAR CITY)

2018 ◽  
pp. 117-130
Author(s):  
Oyunjargal D ◽  
Byambatseren Ch
Keyword(s):  
Air Quality ◽  
Quality Index ◽  
House Price ◽  
Measurement Data ◽  
Quality Measurement ◽  
Air Quality Index ◽  
Quality Level ◽  
Average Price ◽  
Residential House ◽  
The Impact

The purpose of this research is to determine the impact of the environment, especially the quality of air on house price. In addition, it also includes the research of the linkage between the index of air quality and average price of residential house which located in the most crowded districts of Ulaanbaatar such as Bayangol, Bayanzurkh, Chingeltei, Sukhbaatar, Songinokhairkhan and Khan-Uul. The statistical analysis and statistics determination methods were applied to identify the relationship utilizing the air quality index, determined from the air quality measurement data recorded in 2015-2017, and the average price per square meter of newly built apartment houses in the selected districts. The research findings suggest that there is little direct link between the house prices and air quality level, and the air quality levels of Ulaanbaatar districts do not have a significant impact on the price per square meter. Therefore, the air quality index should not considered as a house price determinant.

MULTI-TONE WAVEFORM MEASUREMENT SYSTEM ENABLING CHARACTERIZATION OF MICROWAVE DEVICES

2014 ◽  
Vol 23 (10) ◽  
pp. 1450141
Author(s):  
MUHAMMAD AKMAL CHAUDHARY ◽  
JONATHAN LEES ◽  
JOHANNES BENEDIKT ◽  
PAUL TASKER
Keyword(s):  
Measurement System ◽  
Measurement Data ◽  
Quality Measurement ◽  
Cost Effective ◽  
Operating Conditions ◽  
Efficient Manner ◽  
Vector Error Correction ◽  
Sampling Oscilloscope ◽  
Rf Components ◽  
Vector Error

This paper presents a fully automated time domain, waveform measurement system, capable of measuring multi-tone waveforms up to a frequency of 14 GHz. Multi-tone waveform measurement capabilities will prove useful in enhancing the understanding of the response of devices under realistic operating conditions, and allow for detailed investigation into device problems leading to memory effects. The system, which is based around a standard sampling oscilloscope, is capable of measuring all four traveling waves simultaneously. It is a cost effective solution, capable of capturing high quality measurement data, it consists of two test sets one to measure RF components of the signal and one to measure IF components, which are then recombined before being measured by the sampling oscilloscope. Vector error correction is applied to the measured data to fully calibrate the system to the device plane, ensuring any dispersion in the connecting hardware is removed. A multi-tone waveform sampling method is employed, ensuring the waveforms are captured in the most efficient manner. Device results are presented showing the multi-tone voltage and current waveforms at the device plane. Some useful applications of the system are demonstrated and explained.

scholarly journals A Graphical Method to Evaluate Exposure-Response Relationships in Epidemiologic Studies Using Standardized Mortality or Morbidity Ratios

Dose-Response ◽  
2005 ◽  
Vol 3 (4) ◽  
pp. dose-response.0 ◽  
Author(s):  
Edwin van Wijngaarden
Keyword(s):  
Cohort Studies ◽  
Graphical Method ◽  
Epidemiologic Studies ◽  
Hypothetical Cohort ◽  
Occupational Epidemiology ◽  
Response Patterns ◽  
Exposure Response ◽  
Occupational Cohort ◽  
Exposure Windows ◽  
Physical Exposures

In occupational epidemiology, exposure-response analyses play an important role in the evaluation of the etiologic relevance of chemical and physical exposures. The standardized mortality or morbidity ratio (SMR) has been commonly used in occupational cohort studies. Statistical approaches to evaluate exposure-response patterns using SMRs have mostly been limited to analyses in which the exposure under investigation is categorized. Here, a graphical method for evaluating exposure-response patterns is presented based on SMR estimates across moving exposure windows. This method is demonstrated using the results of two hypothetical cohort studies. The proposed approach may be useful for graphical exploration of exposure-response trends in situations where the number of observed cases is small.

scholarly journals Relationship between occupational dust exposure levels and mental health symptoms among Korean workers

PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0228853
Author(s):  
Wanhyung Lee ◽  
Jae-Gwang Lee ◽  
Jin-Ha Yoon ◽  
June-Hee Lee
Keyword(s):  
Mental Health ◽  
Dust Exposure ◽  
Mental Health Symptoms ◽  
Health Symptoms ◽  
Occupational Dust Exposure ◽  
Exposure Levels

scholarly journals Validation of an Asbestos Job-Exposure Matrix (AsbJEM) in Australia: Exposure–Response Relationships for Malignant Mesothelioma

2019 ◽  
Vol 63 (7) ◽  
pp. 719-728 ◽  
Author(s):  
Hiroyuki Kamiya ◽  
Susan Peters ◽  
Nita Sodhi-Berry ◽  
Alison Reid ◽  
Len Gordon ◽  
...  
Keyword(s):  
Malignant Mesothelioma ◽  
Proportional Hazards ◽  
Asbestos Exposure ◽  
Occupational Exposures ◽  
Peak Frequency ◽  
Cox Proportional Hazards ◽  
Surveillance Program ◽  
Average Intensity ◽  
Job Exposure Matrix ◽  
Exposure Response

Abstract Objectives An asbestos job-exposure matrix (AsbJEM) has been developed to systematically and cost-effectively evaluate occupational exposures in population-based studies. The primary aim of this study was to examine the accuracy of the AsbJEM in determining exposure–response relationships between asbestos exposure estimates and malignant mesothelioma (MM) incidence (indirect validation). The secondary aim was to investigate whether the assumptions used in the development of the original AsbJEM provided accurate asbestos exposure estimates. Methods The study population consisted of participants in an annual health surveillance program, who had at least 3-month occupational asbestos exposure. Calculated asbestos exposure indices included cumulative asbestos exposure and the average exposure intensity, estimated using the AsbJEM and duration of employment. Asbestos and MM exposure–response relationships were compared between the original AsbJEM and its variations based on manipulations of the intensity, duration and frequency of exposure. Twenty-four exposure estimates were calculated for both cumulative asbestos exposure and the average exposure intensity using three exposure intensities (50th, 75th and 90th percentile of the range of mode exposure), four peak durations (15, 30, 60 and 120 min) and two patterns of peak frequency (original and doubled). Cox proportional hazards models were used to describe the associations between MM incidence and each of the cumulative and average intensity estimates. Results Data were collected from 1602 male participants. Of these, 40 developed MM during the study period. There were significant associations between MM incidence and both cumulative and average exposure intensity for all estimates. The strongest association, based on the regression-coefficient from the models, was found for the 50th percentile of mode exposure, 15-min peak duration and the doubled frequency of peak exposure. Using these assumptions, the hazard ratios for mesothelioma were 1 (reference), 1.91, 3.24 and 5.37 for the quartiles of cumulative asbestos exposure and 1 (reference), 1.84, 2.31 and 4.40 for the quartiles of the average exposure intensity, respectively. Conclusion The well-known positive exposure–response relationship between MM incidence and both estimated cumulative asbestos exposure and average exposure intensity was confirmed. The strongest relationship was found when the frequency of peak exposure in the AsbJEM was doubled from the originally published estimates.

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