This study aims to establish the occupational exposure limit （OEL） in the air for workplace of warfarin based on the available toxicological studies and field investigations by using questionnaire and air monitoring...This study aims to establish the occupational exposure limit （OEL） in the air for workplace of warfarin based on the available toxicological studies and field investigations by using questionnaire and air monitoring. The clinical therapeutic dose was used as lowest observed effect level （LOEL）, and no observed effect level （NOEL） was achieved by using a safety factor. The highest concentration of warfarin monitored in the worksite of centrifuge washing, drying and packing were 0.029 mg/m3, 0.052 mg/m3 respectively, which did not exceed the OEL 0.2 mg/m3 recommended by NIOSH and ACGIH. Considering its feasibility for enforcement and protection for workers, we recommend OEL 0.2 mg/m3 of warfarin in China.展开更多
Over the last decade, detrimental effects of human exposure to electromagnetic radiations have received widespread attention. Communications and Information Technology Commission (CITC) in Saudi Arabia has set guideli...Over the last decade, detrimental effects of human exposure to electromagnetic radiations have received widespread attention. Communications and Information Technology Commission (CITC) in Saudi Arabia has set guidelines and launched a national project—in collaboration with academic and research institutions—to perform measurements of the “electromagnetic fields” (EMFs) radiated from base stations of the mobile phone network. In keeping with its mission to address problems of the local community, Electrical Engineering (EE) department at Umm Al-Qura University (UQU) has been commissioned to conduct this project in the western region of Saudi Arabia. The project is concerned with measuring the strength of EMFs around base stations to locate the Maximum Peak Point (MPP). The aim of measurements is to ensure the site compliance with the CITC guidelines for human exposure to Radiofrequency (RF). This paper discusses possible health consequences caused by human exposure to RF radiations. Furthermore, it sum- marizes the results from 20 selective base stations located in Makkah, Madinah, Jeddah, Taif and Yanbu. The results show that EMF levels at all surveyed sites are far below the National Guidelines for public exposure to RF and that the MPPs are found within the distance range suggested in the CITC guidelines. The paper concludes by providing some useful comments and recommendations for RF sites surveyors.展开更多
Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing s...Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 3 1, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk （RR） or odds ratio （OR） and 95% confidence intervals （CI） among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one （RR=13.13, 95% CI 3.18-54.13）, higher in men than that in women （RR=13.92, 95% CI 1.92-100.93）. Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing （RR=28.14, 95% CI 6.43-123.11）, followed by those exposed to pouring （RR-22.23, 95% CI 5.01-98.55） in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employmen展开更多
基金supported by the Occupational Health Standards Program (20100304) from Ministry of Health of China
文摘This study aims to establish the occupational exposure limit （OEL） in the air for workplace of warfarin based on the available toxicological studies and field investigations by using questionnaire and air monitoring. The clinical therapeutic dose was used as lowest observed effect level （LOEL）, and no observed effect level （NOEL） was achieved by using a safety factor. The highest concentration of warfarin monitored in the worksite of centrifuge washing, drying and packing were 0.029 mg/m3, 0.052 mg/m3 respectively, which did not exceed the OEL 0.2 mg/m3 recommended by NIOSH and ACGIH. Considering its feasibility for enforcement and protection for workers, we recommend OEL 0.2 mg/m3 of warfarin in China.
文摘Over the last decade, detrimental effects of human exposure to electromagnetic radiations have received widespread attention. Communications and Information Technology Commission (CITC) in Saudi Arabia has set guidelines and launched a national project—in collaboration with academic and research institutions—to perform measurements of the “electromagnetic fields” (EMFs) radiated from base stations of the mobile phone network. In keeping with its mission to address problems of the local community, Electrical Engineering (EE) department at Umm Al-Qura University (UQU) has been commissioned to conduct this project in the western region of Saudi Arabia. The project is concerned with measuring the strength of EMFs around base stations to locate the Maximum Peak Point (MPP). The aim of measurements is to ensure the site compliance with the CITC guidelines for human exposure to Radiofrequency (RF). This paper discusses possible health consequences caused by human exposure to RF radiations. Furthermore, it sum- marizes the results from 20 selective base stations located in Makkah, Madinah, Jeddah, Taif and Yanbu. The results show that EMF levels at all surveyed sites are far below the National Guidelines for public exposure to RF and that the MPPs are found within the distance range suggested in the CITC guidelines. The paper concludes by providing some useful comments and recommendations for RF sites surveyors.
文摘Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 3 1, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk （RR） or odds ratio （OR） and 95% confidence intervals （CI） among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one （RR=13.13, 95% CI 3.18-54.13）, higher in men than that in women （RR=13.92, 95% CI 1.92-100.93）. Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing （RR=28.14, 95% CI 6.43-123.11）, followed by those exposed to pouring （RR-22.23, 95% CI 5.01-98.55） in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employmen
