摘要:

AbstractTuberculosis (TB) can be transmitted to susceptible healthcare workers via inhalation of droplet nuclei carrying viableMycobacterium tuberculosisbacilli. Several types of respiratory protective devices are compared with respect to efficacy against droplet nuclei penetration: surgical masks, disposable dust/mist particulate respirators (PRs), elastomeric halfmask respirators with high‐efficiency (HEPA) filters, and powered airpurifying respirators (PAPRs) with elastomeric halfmask facepieces and HEPA filters. It is estimated that these devices permit, respectively, 42%, 5.7%, 2%, and 0.39% penetration of droplet nuclei into the facepiece. More limited data for the disposable HEPA filtering‐facepiece respirator suggest that it would allow droplet nuclei penetration of 3% or less, similar to the value estimated for the elastomeric halfmask HEPA filter respirator. Because a respirator wearer's cumulative infection risk depends on the extent of droplet nuclei penetration, the cumulative risk will differ, given use of these different respirators. Hypothetical but realistic “low‐exposure” and “high‐exposure” scenarios are posed that involve, respectively, a 1.6% and a 6.4% annual risk of infection for healthcare workers. For the low‐exposure scenario, the 10‐year cumulative risks given no respirators versus surgical masks versus disposable dust/mist PRs versus elastomeric halfmask HEPA filter respirators versus HEPA filter PAPRs are, respectively, 15%, 6.7%, 0.94%, 0.33%, and .064%. For the high‐exposure scenario, the 10‐year cumulative risks for no respirator use versus use of the same four types of respirators are, respectively, 48%, 24%, 3.7%, 1.3%, and 0.26%. The use of disposable HEPA filtering‐facepiece respirator should permit cumulative risks close to those estimated for the elastomeric halfmask HEPA filter respirator. It is concluded that when an infectious TB patient undergoes a procedure that generates respiratory aerosols, and when droplet nuclei source control is inadequate, healthcare workers attending the patient may need to wear highly protective respirators,

ISSN:0271-3586    

DOI:10.1002/ajim.4700270302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTo confirm the relationship between exposure to coal tar pitch volatiles and bladder cancer among primary aluminum production workers, we carried out a case‐control study among blue‐collar workers who had worked more than 1 year between 1950‐1979 in a major plant using mostly the Soderberg process in the Province of Québec. Cases of bladder cancer (ICD code'l88) diagnosed between 1970‐1979 (n = 69) were mostly included in a previously reported study. To these were added cases diagnosed between 1980‐1988 (n = 69). Each case was matched to three controls on date of birth, date of hiring, and length of service at the company. Smoking habits were assessed from the medical records at the company. Benzene‐soluble matter (BSM) and benzo(a)pyrene (BaP) were used as indicators of environmental exposure to coal tar pitch volatiles in the workplace. The estimated risk for current smokers was 2.63 (95% C.I. 1.29‐5.37). Estimates of risk by occupational exposure were adjusted for smoking. Men who had worked in the Soderberg potrooms were at higher risk of developing the disease, the risk increasing with the time spent in these departments. Similarly, a strong association between risk and cumulative exposure to BSM or to BaP was observed. The risks associated with cumulative exposure to BSM (mg/m3‐years) and to Bap (μg/m3‐years) were described with mathematical models. Using a linear model (1 + bx) and lagging 10 years before the diagnosis. BaP cumulative exposure was a better indicator of risk than BSM cumulative exposure. The risk for each year of exposure to BaP at a concentration of 1 (xg/m3increased by 1.7% (0.8%‐3.2%). Using the same model for BSM, a worker exposed to the current threshold limit value of 0.2 mg/m3for 40 years will sustain a risk of 2.22 (1.56‐3.48). Comparison of risks according to different periods of diagnosis (1970‐1979 vs. 1980‐1988) did not reveal any significant tempora

ISSN:0271-3586    

DOI:10.1002/ajim.4700270303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractFor diagnostic purposes, mineralogical analysis was performed in bronchoalveolar la‐vage fluid and lung tissue from a 58‐year‐old patient previously exposed to asbestos and rare earth dusts. No significant retention of asbestos was demonstrated in lung tissue by light microscopy (asbestos bodies) or transmission electron microscopy analysis (un‐coated fibers). Particles containing rare earth (cerium, lanthanum) and phosphorus were identified in alveolar macrophages in bronchoalveolar lavage fluid, and cerium‐containing particles accounted for 70% of particles observed in the lung tissue. Ultrastructural analysis of lung tissue revealed the presence of particles containing cerium and phosphorus in interstitial macrophages and elastic fibers. These results suggest that rare earth is metabolized and should be considered as biopersistent in the human respiratory tract, since occupational inquiries revealed that exposure to cerium oxide abrasive powder had ceased at least 15 year

ISSN:0271-3586    

DOI:10.1002/ajim.4700270304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractRespiratory symptoms and ventilatory capacity were studied in 63 flour processing male bakery workers in Umtata, Transkei, Southern Africa. The controls were from a bottling plant in the same city. Both groups were black Africans from the Xhosa‐speaking population. The studied population was nonsmoking and no significant difference was noted in age, race, sex, or height between the groups. The exposed workers had significantly lower forced expiratory indices than the control group. Mean percent predicted values of forced expiratory volume in one second (FEV1), forced expiratory ratio (FEV1/FVC x 100), forced mid‐expiratory flow between 25% and 75% of FVC (FMF), forced expiratory flow between the first 200 ml and 1.200 ml of FVC (FEF 200‐1,200), and peak expiratory flow rate (PEF) were, respectively, 11.2%, 20.0%, 31.0%, 27.4%, and 36.1% lower in the exposed group compared with the controls. The prevalence of forced expiratory ratio less than 70% in the exposed group was 37% while in the controls it was 8%. The prevalence of PEF rate less than 5 l/s in the exposed group was 32% while in the controls it was 11%. The exposed workers reported a significantly higher prevalence of respiratory symptoms compared to the controls. The prevalence of nasal symptoms, phlegm, and cough in the exposed workers was 53.9%, 30.1%, and 25.4%, respectively. The present study demonstrated that exposure to flour dust in flour processing workers in the baking industry is associated with significantly lower pulmonary functions and a higher prevalence of respiratory symptoms, and that these workers show signs of airway obstruction, compared to workers not exposed to flour. Flour processing workers have a significant occupationally related respiratory impai

ISSN:0271-3586    

DOI:10.1002/ajim.4700270305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe incidental diagnosis of two cases of silicosis at Messejana Hospital, Fortaleza, capital of Ceará state, triggered a field research conducted with the objective of investigating the incidence of silicosis in pit diggers in four towns in the Ibiapaba Mountain Range, at the state's northwestern area, northeastern Brazil. Out of a universe of 1,050 pit diggers in the area, 366 participated in the study; they were all males ranging in age between 16 and 76 years old (average 39 years). The excavation and the sickening process were described and a dust exposure index in pit diggers (DEIPD) was defined. The study sample indicated a rate of 121 (33.06%) silicotics and possibly silicotics. The radiologic findings were related to the DEIPD and indicated significant prevalence of disease. Furthermore, during the research period, from 1986 to 1989, 30 (34.9%) silicotics died of respiratory failure and wasting of body tissues. The data suggested that these men were afflicted with a severe occupational health problem, possibly scattered throughout a large area in northeastern Brazil, where manual pit excavations occur during the whole year and increase during drought periods

ISSN:0271-3586    

DOI:10.1002/ajim.4700270306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractStructural chromosome aberrations and sister chromatid exchanges (SCEs) in peripheral blood were studied in female workers employed in the shoe‐making industry in two periods: 1987 (group I; N = 38) and 1992 (group II; N = 45). Only 11 of the workers were present in both groups and their results are presented both together and separately. Occupational exposure to benzene and toluene was confirmed through their determination in the working area, blood, and phenol in pre‐ and post‐shift urine. The results were compared with those from the control group (N = 35). Benzene in the working atmosphere was significantly higher in 1987 compared to 1992, but was always lower than the current Croatian permissible concentration of 50 mg m−3(in the near future this value will be changed to 15 mg m−3). A statistically significant difference was also found in biological markers of benzene exposure between the two periods of the investigation. Increased absorption in the first period occurred because of intensified production in 1987, and this decreased significantly in 1992 because of the war in Croatia.The cytogenetic study showed a significant increase in dicentric chromosomes in exposed groups I and II when compared to the control group. Statistically significant higher SCE frequencies were found in group I compared to the control group and also compared to group II. Between exposed group II and the controls no statistically significant difference in SCEs was found. Comparing the same 11 workers present in both periods the results showed no difference in chromosome aberrations between the two periods of examination. SCE frequencies were significantly higher in 1987 when greater benzene absorption occurred, confirmed by biomarkers of benzene exposure.The presented results indicate that genotoxicity may occur in workers exposed to low levels of benzene in the shoe

ISSN:0271-3586    

DOI:10.1002/ajim.4700270307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractWorkers in abattoirs and meatpacking plants have potential for exposure to bovine leukemia virus (BLV) and bovine papilloma viruses (BPV), which are oncogenic in cattle. These workers also have increased exposure to human papilloma viruses (HPV) and certain chemical carcinogens. We investigated whether such a group showed increased risk of cancers. We report mortality results after an additional 9‐year follow‐up of a previously studied group of 5,522 workers in abattoirs and 4,589 workers in meatpacking plants. Excess risk of all cancers combined, cancers of the lung, buccal cavity and pharynx, esophagus, colon, bladder, kidney, and bone was observed. Since factors such as tobacco smoking, alcohol, and diet, which have known associations with some of these cancers, were not taken into account, the significance of these findings is not known, except for lung cancer, for which occupational factors are probably involved. Because some of these findings have been consistently reported before, studies that will control for confounding factors as well are now urgently nee

ISSN:0271-3586    

DOI:10.1002/ajim.4700270308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractHuman respiratory health hazards for people working in livestock confinement buildings have been recognized since 1974. However, before comprehensive control programs can be implemented, more knowledge is needed of specific hazardous substances present in the air of these buildings, and at what concentrations they are harmful. Therefore, a medical epidemiological and exposure‐response study was conducted on 207 swine producers using intensive housing systems (108 farms).Dose‐response relationships between pulmonary function and exposures are reported here. Positive correlations were seen between change in pulmonary function over a work period and exposure to total dust, respirable dust, ammonia, respirable endotoxin, and the interactions of age‐of‐producer and dust exposure and years‐of‐working‐in‐the‐facility and dust exposure. Relationships between baseline pulmonary function and exposures were not strong and therefore, not pursued in this study.The correlations between exposure and response were stronger after 6 years of exposure. Multiple regression models were used to identify total dust and ammonia as the two primary environmental predictors of pulmonary function decrements over a work period. The regression models were then used to determine exposure concentrations related to pulmonary function decrements suggestive of a health hazard. Total dust concentrations ⩾ 2.8 mg/m3were predictive of a work period decrement of ⩾ 10% in FEV1. Ammonia concentrations of ⩾ 7.5 ppm were predictive of a ⩾ 3% work period decrement in FEV1. These predictive concentrations were similar to a previous doseresponse study, which suggested 2.5 mg/m3of total dust and 7 ppm of NH3were associated with significant work period decrements. Therefore, dust ⩾ 2.8 mg/m3and ammonia ⩾ 7.5 ppm should be considered reasonable evidence for guidelines regarding hazardous exposure concentrat

ISSN:0271-3586    

DOI:10.1002/ajim.4700270309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractOn‐site testing of 157 poultry processors disclosed that 50% had three or more abnormal upper extremity findings out of a total of 22 possibles. The average worker had five to six abnormal findings. Impaired pinch strength, decreased vibration sensitivity in the fingertips, and reports of current numbness were the most prevalent. Of workers with signs, 25% reported no symptoms, whereas only 8% of workers reported symptoms but had no signs. The investigators concluded that this measurement method has utility for assessments of worker populations to determine prevalence of CTDs and, potentially, for preclinical detection of these disorders to permit early intervention, reduce medical costs, and minimize disability. The need for accurate measurement to enhance early detection and prevention is discusse

ISSN:0271-3586    

DOI:10.1002/ajim.4700270310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:0271-3586    

DOI:10.1002/ajim.4700270311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY