bluuebunny/crossref_metadata_2025_split huggingface dataset:
Associations between disease and occupation: Hypotheses generated from the national mortality followback survey
Authors: Reviere Rebecca , Schneider Scott , Woolbright Kathy 
Published: April 2007

AbstractThis study uses the National Mortality Followback Survey of 1986 to identify the top five Sentinel Health Events Occupational [SHE(O)s], the five leading causes of death, and to ascertain the primary occupations and industries associated with these. We found that, as expected, cardiovascular diseases were four of the five leading causes of death overall. In addition, the SHE(O) responsible for most deaths was cancer of the trachea, bronchus, and lung, followed by renal failure, bladder cancer, myeloid leukemia, and liver cancer. We employed proportionate mortality ratios to analyze the relationship between industry and occupation and category of mortality. In brief, we validated findings by other researchers; for example, farmers were at lower risk of cancer of the trachea, bronchus, and lung, and workers in eating/ drinking places had excess risk of liver cancer. We also hypothesize other relationships, such as between motor vehicle dealers and bladder cancer.
Quantitative comparison of asbestos and talc bodies in an individual with mixed exposure
Authors: Dodson Ronald F. , O'Sullivan Michael , Corn Carolyn J. , Hammar Samuel P. 
Published: April 2007

AbstractTissue from an individual with a history of exposure to asbestos and other dust was referred for particulate analysis. The digested material was reviewed by light microscopy to establish the numbers of ferruginous bodies per gram of tissue. Typical asbestos bodies were found at levels consistent with occupational exposure. A second type of elongated ferruginous body was formed on a thicker transparent core which suggested the minerals were sheet silicates. The number of ferruginous bodies with nonasbestos cores was over four times the number of asbestos cored ferruginous bodies.Electron microscopy was used to confirm the core composition of both populations and also to establish the levels of uncoated fibers. The nonasbestos ferruginous bodies were predominantly formed on talc.
Comparison of neurobehavioral function in workers exposed to a mixture of organic and inorganic lead and in workers exposed to solvents
Authors: Bolla Karen I. , Schwartz Brian S. , Stewart Walter , Rignani Joellen , Agnew Jacqueline , Ford D. Patrick 
Published: April 2007

AbstractThe neurobehavioral effects of lead (organic and inorganic) and organic solvents were compared in 386 U.S. workers (52 reference, 190 lead, and 144 solvent workers). The association between neurobehavioral test performance and duration of exposure to lead or solvents was also examined and compared. The neurobehavioral test battery consisted of examiner and computer‐administered neurobehavioral tests, a test of olfactory function, and questionnaires that assessed neuropsychiatric symptoms. Adjusted mean differences on the neurobehavioral test scores were estimated by comparing the exposed group to the referent group using linear regression and adjusting for premorbid intellectual ability, age, and race. Both lead and solvents were associated with diminished neurobehavioral performance in all neurobehavioral areas tested. Specifically, while lead and solvent exposure had the same magnitude of adverse effects on tests of manual dexterity, lead exposure was associated with greater adverse effects on memory and learning tests but with less adverse effects on executive/motor tests and on a test of olfaction than solvent exposure. An elevated number of neuropsychiatric symptoms was reported by 7% of the referent group, 43% of the lead group, and 15% of the solvent group. For exposure duration of ⩾10 years, more neurobehavioral decrements were found in the solvent group relative to the lead group. However, for exposure duration of ⩽18 years, the lead group showed more decrements than the solvent group. Overall, these data suggest differences in neurobehavioral functioning between the lead (organic and inorganic) and solvent exposed workers examined in this study.
Insulation, asbestos, smoking habits, and lung cancer cell types
Authors: Muscat Joshua E. , Stellman Steven D. , Wynder Ernst L. 
Published: April 2007

AbstractThe association between occupational exposure to asbestos and histological type of lung cancer was analyzed in a multicenter hospital‐based case‐control study (2,871 male cases and 5,240 male controls) conducted from 1981‐1991. Twenty‐two percent of cases and 18% of controls were employed in asbestos‐related occupations for at least 1 year. Most of these asbestos jobs were in the construction field. The odds ratio (OR) among current smokers was 1.0 [95% confidence intervals (CI) 0.9 to 1.3]; for ex‐smokers, the OR was 1.4 (95% CI 1.1 to 1.6). In contrast, 10% of cases and 5% of controls self‐reported that they were chronically exposed to asbestos for at least 1 year. Self‐reported asbestos exposure was significantly related to all lung cancer cell types among smokers and ex‐smokers, although a trend in the ORs with duration of self‐reported exposure was not found for current smokers. Among 48 cases and 52 controls reporting distinct exposure to building insulation, the OR was 2.2 (95% CI 1.2 to 4.3) for current smokers, and 1.8 (95% CI 0.9 to 3.6) for ex‐smokers, compared to subjects who were not exposed to building insulation and asbestos. A nonsignificant association with self‐reported exposure to asbestos was observed for a small number of never smokers (eight of 83 nonsmoking cases, OR = 2.0, 95% CI 0.9 to 4.6). When examining these results and their causal implications, possible misclassification and reporting biases need to be considered.
Subclinical neurotoxicity of mercury vapor revealed by a multimodality evoked potential study of chloralkali workers
Authors: Chang Yang‐Chyuan , Yeh Ching‐Ying , Wang Jung‐Der 
Published: April 2007

AbstractPattern visual, brainstem auditory, and somatosensory evoked potential (EP) studies were performed on 26 chloralkali workers. The intensity of mercury vapor exposure in these workers was estimated from the individual working history. Mercury levels in blood, urine, and hair were determined with atomic absorption spectrometry. The EP findings were compared with those from individually matched normal subjects. In brainstem auditory and somatosensory EP studies, prolonged neural conduction times in the central nervous system (CNS) were found in workers exposed to mercury vapor. In the pattern visual EP study, mercury workers had higher interpeak amplitudes. Findings of this study suggested that chronic exposure to mercury vapor would affect the CNS functions. A multimodality EP study is a useful adjunct in evaluation of chronic mercury neurotoxicity, especially in an epidemiological study.
Does regression analysis of lung function data obtained from occupational epidemiologic studies lead to misleading inferences regarding the true effect of smoking?
Authors: Attfield Michael D. , Hodous Thomas K. 
Published: April 2007

AbstractExposure‐response studies of the relationship between ventilatory function and dust exposure in workers are often quantified using linear regression methods. In coal miners, this technique has indicated that average effects of smoking and moderate dust exposure are roughly equivalent. However, the validity of direct comparison of the average effects of smoking and dust exposure has been questioned, the argument being that smoking causes severe effects in a minority, but leaves the remainder largely unaffected. This hypothesis was studied by examining distributions of FEV1 in a group of working coal miners where mean effects associated with both smoking and dust exposure have been detected. Overall, the results suggest that comparison of average effects of smoking and dust exposure derived from linear regression analysis is valid and not misleading.
Mechanisms, chemical carcinogenesis, and risk assessment: Cell proliferation and cancer
Authors: Huff James 
Published: April 2007

AbstractMechanisms of carcinogenesis—and in particular chemically associated carcinogenicity—have attracted considerable scientific and public attention in the last decade. Much insight has been gained that will lead to more reasoned and better prevention, intervention, and treatment for the reduction of environmentally caused cancers. However, there seems to be an exaggerated tendency to embrace “mechanisms” not yet fully characterized, completely tested, unequivocally proven, and consensus accepted. More than 100 agents and exposure circumstances have been identified as causally or strongly associated with human cancers; for many the evidence was discovered first in experimental animals. More chemicals have been uncovered as carcinogenic in experimental animals, with as yet no or little available information in exposed human populations. Additional and expanded mechanistic and epidemiological studies should further elucidate the relevance of these agents to adverse human health effects, including cancers. Claims are being posed that certain chemical‐specific “mechanisms” in experimental systems are irrelevant to humans, and thus chemicals thought to be aberrantly carcinogenic in animals would present no cancer hazard to exposed humans. Nonetheless before undeniable proof becomes available, we must continue to proceed with sensitive and responsible caution. This commentary offers a central and personal view of one such mechanism: cell proliferation and cancer.
Respiratory protection and the risk of Mycobacterium tuberculosis infection
Authors: Nicas Mark 
Published: April 2007

AbstractTuberculosis (TB) can be transmitted to susceptible healthcare workers via inhalation of droplet nuclei carrying viable Mycobacterium tuberculosis bacilli. 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, such as HEPA filter PAPRs.
Estimation of risk of developing bladder cancer among workers exposed to coal tar pitch volatiles in the primary aluminum industry
Authors: Tremblay Claude , Armstrong Ben , Thériault Gilles , Brodeur Jules 
Published: April 2007

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/m3 increased 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/m3 for 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 temporal changes on risk estimates.
Biopersistence of cerium in the human respiratory tract and ultrastructural findings
Authors: Pairon Jean‐Claude , Roos Frédérique , Sébastien Patrick , Chamak Brigitte , Abd‐Alsamad Issam , Bernaudin Jean‐François , Bignon Jean , Brochard Patrick 
Published: April 2007

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 years earlier.
Respiratory symptoms and pulmonary function in flour processing workers in the baking industry
Authors: Shamssain Mohammad H. 
Published: April 2007

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 impairment.
Silicosis in brazilian pit diggers: Relationship between dust exposure and radiologic findings
Authors: Holanda Márcia Alcǎntara , Holanda Marcelo Alcǎntara , Felismino Pedro Henrique , Pinheiro Valéria Góes Ferreira 
Published: April 2007

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.
Possible genotoxicity in low level benzene exposure
Authors: Karačić Višnja , Skender Ljiljana , Bosner‐Cucančić Branka , Bogadi‐Sare Ana 
Published: April 2007

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 industry.
Cancer mortality among workers in abattoirs and meatpacking plants: An update
Authors: Johnson Eric S. , Dalmas Dawn , Noss John , Matanoski Genevieve M. 
Published: April 2007

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 needed.
Respiratory dysfunction in swine production facility workers: Dose‐response relationships of environmental exposures and pulmonary function
Authors: Donham Kelley J. , Reynolds Stephen J. , Whitten Paul , Merchant James A. , Burmeister Leon , Popendorf William J. 
Published: April 2007

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 concentrations in this work environment.