bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of an industrial cohort and verification of its completeness using a complicated system of plant records
Authors: Andjelkovich Dragana A. , Levine Richard J.
Published: April 2007

The published literature on occupational mortality studies seldom describes the manner in which cohorts were assembled and efforts made to ensure that all, or nearly all, eligible persons had been enumerated. Researchers must struggle unassisted through a morass of plant records, often not knowing how to utilize important sources of information to the fullest extent. This paper describes the identification of a cohort of over 8,700 foundry workers and the verification of its completeness using existing plant data sources. By understanding the techniques for manipulating data sources in this investigation, researchers may gain insight into the use of materials available to them.
Risk of ischemic heart disease among primary aluminum production workers
Authors: Thériault Gilles P. , Tremblay Claude G. , Armstrong Ben G.
Published: April 2007

The risk of ischemic heart disease (IHD) has been studied in relation to working conditions encountered in a primary aluminum smelter employing over 6,000 men. During the period 1975‐1983, 306 new cases of IHD were identified which were matched with 575 referents. A logistic regression analysis was performed to adjust for differences in smoking habits, high blood pressure, hyperglycemia, hypercholesterol‐emia, and obesity. Results from this showed that white collar workers had a significantly lower risk of IHD (odds ratio 0.47, 95% confidence interval 0.31‐0.70). Among blue collar workers, a significantly higher risk was observed for workers in the reduction division of the plant (OR 1.72, CI 1.09‐2.97) including, in particular, Soderberg (OR 1.71, CI 1.07‐2.72) and prebake (OR 2.26, CI. 1.27‐4.02) potroom workers. The risk of IHD did not increase with the length of time worked in these occupations. The search for associations (among blue collar workers) of risk with nine specific contaminants (benzene soluble material, fluoride, total dust, sulfur dioxide, carbon monoxide, thermal stress, noise, physical load, and mental load) proved inconclusive, with no association reaching statistical significance.
Spontaneous Abortion in Women Employed in Plastics Manufacture
Authors: McDonald Alison D. , Lavoie Jacques , Côté Rosanne , McDonald J. Corbett
Published: April 2007

An analysis was made of 193 current and previous pregnancies of women employed at time of conception in the plastics industry, derived from a survey of work and pregnancy in 56,012 women in Montreal, 1982–84. The ratio of observed to expected spontaneous abortions, corrected by logistic regression for seven nonoccupational confounding variables, was elevated (1.27), but not significantly (90% confidence interval [CI] 0.91–1.72), in women engaged in process work. The ratio was significantly raised (1.58, 90% CI 1.02–2.35) in women whose work included the processing of polystyrene. Nonsignificant excesses in women working with polyolefine (1.30) and polyvinyl (1.39) were present only when exposure also included other types of plastic; no excess was observed in women whose work did not include polystyrene. The number of women (17) exposed to polyurethane was too small for any conclusion to be drawn about this group.
Cross‐sectional and longitudinal changes in pulmonary function associated with automobile pollution among bridge and tunnel officers
Authors: Evans R. Gregory , Webb Karen , Homan Sharon , Ayres Stephen M.
Published: April 2007

This study investigated the effects of emissions from the internal combustion engine on pulmonary function and respiratory symptoms in men collecting tolls and directing traffic in areas with high levels of air pollution. Bridge and tunnel officers (BTOs) were administered pulmonary function tests and respiratory questionnaires for up to 11 consecutive years (n = 944). Carboxyhemoglobin levels were also measured. Regression coefficients on year tested were calculated on 466 individuals (49% of all BTOs) tested at least 3 years. The tunnel workers had significantly lower FEV1s (forced expiratory volume at one second) and FVCs (forced vital capacity), respiratory symptoms, and higher carboxyhemoglobin levels than the bridge workers. BTOs working over 20 years had the lowest mean pulmonary function values, the steepest slopes, and the most respiratory symptoms. We believe that the data show an association between working as a bridge and tunnel officer and decreased pulmonary function and increased respiratory symptoms, but it was not readily evident whether the effects were of clinical importance.
Alveolar Fiber Load in Asbestos Workers and in Subjects With No Occupational Asbestos Exposure: An Electron Microscopy Study
Authors: Chiappino Gerolamo , Friedrichs Karl H. , Rivolta Giuseppe , Forni Alessandra
Published: April 2007

The alveolar fiber load was evaluated by bronchoalveolar lavage and by scanning and transmission electron microscopy (SEM and TEM) in 50 subjects with or without occupational exposure to asbestos. The concentration of asbestos fibers in bronchoalveolar lavage was significantly higher in the groups of people currently and formerly occupationally exposed, compared to the concentration found in people only exposed environmentally, despite wide interindividual variation within the groups. Nonasbestos inorganic fibers were present in all groups, but the concentrations did not differ significantly. Both in people occupationally exposed and in those only environmentally exposed, the alveolar load consisted mainly of ultrashort and ultrathin fibers, which can be studied only with TEM. In fact, the percentage of fibers >5 μm long was only around 15% in the occupationally exposed and was minimal in those only environmentally exposed. The geometric mean diameters of asbestos fibers retained in the alveoli ranged from 0.05 μm for chrysotile to 0.15 μm for amphiboles.
Increased Risks of Soft Tissue Sarcoma, Malignant Lymphoma, and Acute Myeloid Leukemia in Abattoir Workers
Authors: Pearce Neil , Smith Allan H. , Reif John S.
Published: April 2007

This paper presents a review and further analysis of a series of New Zealand case‐control studies which have found elevated risks for soft tissue sarcoma (STS), non‐Hodgkin's lymphoma (NHL), and acute myeloid leukemia (AML) in abattoir workers. The first published study involved 82 cases of STS (ICD 171) and found a relative risk of 2.8 (90% confidence interval 1.3–6.3). Interviews with an additional 51 cases reported here revealed a relative risk of 1.6 (90% confidence interval 0.9–3.0). Two further studies involved interviews with 100 cases of the category of NHL involving lymphosarcoma and reticulosarcoma (ICD 200) and 83 cases of other NHL (ICD 202). Relative risk estimates were 1.8 (90% confidence interval 1.1–2.9) and 1.7 (90% confidence interval 1.0–2.8), respectively. A study of 150 cases of AML (ICD 205.0) found a relative risk of 2.5 for abattoir workers (90% confidence interval 1.3–4.7). Finally, a United States cohort study found a standardized mortality ratio of 2.4 (90% confidence interval 0.8–5.4) for Hodgkin's disease (ICD 201) and 2.2 (90% confidence interval 0.8–4.5) for cancer of other lymphatic tissue (ICD 202, 203, 208) among abattoir workers. Abattoir workers are potentially exposed to oncogenic viruses, including bovine leukemia virus. Some workers may also be exposed to the animal carcinogen 2,4,6‐trichlorophenol when treating pelts.
Occupational Asthma Due to Toluene Diisocyanate Among Velcro‐Like Tape Manufacturers
Authors: Wang Jung‐Der , Huang Ping‐Hung , Lin Jia‐Ming , Su Shyh‐Young , Wu Min‐Chien
Published: April 2007

During September‐November, 1985, four employees of a factory were seen at the occupational clinic complaining of cough, shortness of breath, and wheezing. All four worked in the same area of the factory where an adhesive containing toluene diisocyanate (TDI) was applied to velcro‐like tape during manufacturing. To confirm the diagnosis of TDI‐induced asthma and determine the prevalence among workers, 38 workers were interviewed and examined (84%) in the factory. Air samples were also taken from several areas in the factory to determine the TDI concentration. For analysis, the factory was divided into three areas based on the concentration of TDI: low (0.012 ± 0.002 ppm), medium (0.021 ± 0.006 ppm), and high (0.047 ± 0.054 ppm). The distribution of workers with symptoms of asthmatic bronchitis was highly associated with TDI concentration (p < 0.001). After stopping work for a period of 10 days, workers in areas with a high concentration of TDI showed marked improvement in pulmonary function tests (PFTs). After isolation of the exposure site, improvement of the ventilation system, and substitution of the TDI with less volatile diphenylmethane diisocyanate (MDI), air concentration of isocyanates was usually below 0.007 ppm. Three of the four clinically overt asthma cases went back to work without any difficulty. The PFTs of affected workers showed a significant improvement 5 months later. We conclude that TDI was responsible for the occupational asthma among velcro‐like tape manufacturers and that the TDI‐induced impairment of pulmonary functions was at least partially reversible.
Exposure to Organic Solvents and Hypertensive Disorders of Pregnancy
Authors: Eskenazi Brenda , Bracken Michael B. , Holford Theodore R. , Grady James
Published: April 2007

The present investigation compares the frequency of adverse pregnancy complications and outcomes in 90 women who worked with various organic solvents during pregnancy and in 180 unexposed matched (2:1) subjects. Solvent‐exposed women were approximately four times more likely to develop preeclampsia, a disorder of pregnancy characterized by hypertension, edema, and proteinuria (unconditional adjusted RR = 3.9, 95% CI = 2.5, 5.4). That hypertension alone, without edema or proteinuria, was also more likely to be reported in solvent‐exposed women (unconditional adjusted RR = 3.0, 95% CI = 0.9, 9.9) lent additional support to the association of solvent exposure and hypertensive disorders of pregnancy. Because preeclampsia is thought to be associated primarily with glomerular lesions, our findings, although in need of replication with a larger sample size, may be biologically plausible given the growing literature associating solvent exposure with renal disease. Solvent‐exposed women were more likely to have cardiovascular complications and to deliver by cesarean section; however, given the specific type of complications and reason for cesarean, it is unlikely that these findings were directly related to solvent exposure. Other pregnancy complications such as threatened abortion and vaginal bleeding, and poor neonatal growth and maturity, were not more common in the exposed group.
Bladder tumors in two young males occupationally exposed to MBOCA
Authors: Ward Elizabeth , Halperin William , Thun Michael , Grossman H. Barton , Fink Burton , Koss Leopold , Osorio Ana Maria , Schulte Paul
Published: April 2007

MBOCA (4,4′ methylenebis (2‐chloroaniline) is a structural analogue of benzidine and is carcinogenic in mice, rats, and dogs. MBOCA has not yet been demonstrated to be carcinogenic in humans and is not regulated as an occupational carcinogen in the United States. We report two noninvasive papillary tumors of the bladder identified in a screening study of 540 workers exposed to MBOCA during its production at a Michigan chemical plant from 1968 to 1979. Both tumors occurred in men under 30 years old who had never smoked. Although the prevalence of grade 1‐2 tumors among asymptomatic males in this age group is unknown, the incidence of clinically apparent tumors on U.S. males aged 25‐29 is only 1 per 100,000 per year. The detection of the two tumors in young, nonsmoking males is consistent with the hypothesis that MBOCA induces bladder neoplasms in humans.
Obstructive and restrictive ventilatory impairment in polyvinylchloride fabrication workers
Authors: Ernst Pierre , De Guire Louise , Armstrong Ben , Thériault Gilles
Published: April 2007

Responses to a standardized respiratory symptom questionnaire, spirometry, and crossshift decreases in lung function between 70 current employees of a polyvinylchloride (PVC) fabrication plant and a control group consisting of 48 men employed in a vegetable packing plant were compared. FEV1/FVC was significantly lower in the PVC workers. Cross‐shift drops in Vmax75 of 15% or more were also more prevalent in the exposed group (p = .01). When examining the association between months of work within the exposed workforce and spirometric indices of airway obstruction, no relationship could be demonstrated. However, an inverse dose‐response relationship was seen between level of FVC and duration of employment, suggesting a restrictive impairment. While the specific exposures have not been identified, it appears that employment in PVC fabrication may be associated with both obstructive and restrictive ventilatory effects.
Leukemias and occupation in Sweden: A registry‐based analysis
Authors: Linet Martha S. , Malker Hans S. R. , McLaughlin Joseph K. , Weiner Jan A. , Stone B. J. , Blot William J. , Ericsson Jan L. E. , Fraumeni Joseph F.
Published: April 2007

A linked‐registry was used to examine systematically, on a national basis, the leukemia incidence in Swedish men by industry and occupation. New associations were observed for chronic lymphocytic leukemia among cloth and pattern cutters and for chronic myelocytic leukemia among brewery workers and motor mechanics. A number of additional findings were consistent with previous observations in other countries. Although etiologic inferences are limited when using linked‐registry data, this hypothesis‐generating study may provide new clues to the occupational determinants of specific forms of leukemia.
Asbestos fibers in human pulmonary and extrapulmonary tissues
Authors: Huang Jian , Hisanaga Naomi , Sakai Kiyoshi , Iwata Masamitsu , Ono Yuichiro , Shibata Eiji , Takeuchi Yasuhiro
Published: April 2007

The association between asbestos fibers in human lung tissues and those in other extrapulmonary organs was studied by analysing three autopsied cases, one of whom had a high pulmonary asbestos burden, one an intermediate burden, and one a low burden. The amount, types and sizes of asbestos fibers in the tissues of lung, liver, spleen, pancreas, kidney, and gastrointestinal tract were identified and measured by transmission electron microscopy equipped with an energy dispersive X‐ray analyser. The following results were obtained: 1) The concentrations of asbestos fibers in extrapulmonary organs tended to increase with that in lung tissues. 2) The types of fibers identified in lungs were approximately consistent with those in other organs. 3) A relatively large range of fiber length was observed in both lungs and other organs. The findings extend and support previous light microscopic studies comparing asbestos bodies in various organs, and may imply that persons with high levels of asbestos in their lungs are also likely to have the same types and high levels of asbestos in their other tissues.
Using multiple cause of death coding in occupational mortality studies
Authors: Milham Samuel
Published: April 2007

Conventional occupational mortality analysis, using underlying cause of death coding, underestimates the contribution of those chronic diseases which are mentioned on the death certificate but which usually do not appear as underlying cause of death. Proportionate occupational mortality analysis, using all the mentioned causes on the Washington State male death records 1968‐1984, identified an excess of rheumatoid arthritis in farmers, and asbestosis in plumbers, pipefitters, and steamfitters.
Lung function in workers exposed to soft paper dust
Authors: Järvholm Bengt , Thorén Kjell , Brolin Inger , Ericsson Jens , Morgan Ulf , Tylen Ulf , Bake Björn
Published: April 2007

In a cross‐sectional study, 13 nonsmoking men with heavy exposure to paper dust were compared with 14 unexposed men, mainly office workers, employed at the same paper mill. They were studied using questionnaries, physical examinations, pulmonary function studies, and chest radiographs.

Among those exposed there was an increased lung elastic recoil pressure (Pel) compared with controls which was significant (p < 0.05) at the maximal level of total lung capacity (100% TLC). Furthermore, among the exposed workers there was also a significantly (p < 0.05) decreased residual volume (RV). Two of the exposed men underwent lung biopsies, one of which showed fibrotic alveolar walls. Among the exposed there was also a significant (p < 0.05) predominance of symptoms from the lower respiratory tract.

We suggest that the observed pulmonary function impairment taken together with the histological examination of the lung biopsies are signs of a nonspecific reaction to high levels of paper dust.
The use of geometric and arithmetic mean exposures in occupational epidemiology
Authors: Seixas Noah S. , Robins Thomas G. , Moulton Lawrence H.
Published: April 2007

In constructing quantitative measures of exposure for the study of chronic occupational disease, researchers have generally used a cumulative exposure calculated as the sum of the products of period‐specific exposure concentrations and the time each individual spent in each exposure category. There has been some disagreement and lack of clarity about the use of the geometric or arithmetic mean of exposure for this calculation. This paper explores the difference in the use of the two measures and defines a relative bias introduced with the geometric vs. the arithmetic mean. The magnitude of the bias is calculated in two linear models of possible exposure‐response relationships. The theoretical basis for the choice of one mean over the other is then explored. It is suggested that when adopting a linear exposure response model, the arithmetic mean is the more appropriate measure. In other models, such as a linear‐log (outcome is proportional to the logarithm of exposure) model, the geometric mean would be more appropriate.
Effects of exposure to ethylene glycol ethers on shipyard painters: II. Male reproduction
Authors: Welch Laura S. , Schrader Steven M. , Turner Terry W. , Cullen Mark R.
Published: April 2007

To determine whether 2‐ethoxyethanol (2‐EE) and 2‐methoxyethanol (2‐ME) affected the reproductive potential of exposed men, we examined the semen of 73 painters and 40 controls who work in a large shipyard. An industrial hygiene survey was performed to characterize the work environment. The men supplied information on demographic characteristics, medical conditions, personal habits, and reproductive history; underwent a physical examination; and provided a semen sample. Semen samples were analyzed for pH, volume, turbidity, liquidity, viability by stain exclusion and hypo‐osmotic stress, sperm density and count per ejaculate, motility using a videotape technique, morphology, and morphometry. Serum was analyzed for testosterone, FSH, and LH. The industrial hygiene survey revealed that the painters were exposed to 2‐EE at a time‐weighted average (TWA) of 0–80.5 mg/m3 with a mean of 9.9 mg/m3, and to 2‐ME at a TWA of 0–17.7 mg/m3 with a mean of 2.6 mg/m3. Painters had an increased prevalence of oligospermia and azoospermia and an increased odds ratio for a lower sperm count per ejaculate, while smoking was controlled. This finding is consistent with prior animal studies and with one human study. Potential biases and confounding of the data are discussed.
Effect of exposure to ethylene glycol ethers on shipyard painters: III. Hematologic effects
Authors: Welch Laura S. , Cullen Mark R.
Published: April 2007

Hemoglobin, hematocrit, red cell indices, total and differential white blood cell counts, and platelet count were measured in shipyard painters and control subjects as part of a cross‐sectional, observational study of the effects of ethylene glycol ethers. Although the means of all variables were comparable between the groups, a significant proportion of painters were anemic (10%) and granulocytopenic (5%); none of the controls were affected. Review of company records documented that most of these abnormalities were acquired during employment; preexisting disease and other exposure could not explain the findings. These findings are consistent with prior animal studies and human case reports. Potential biases and confounding of the data are discussed.
Occupational health services in South African manufacturing industries: A pilot survey
Authors: Sitas F. , Davies J. C. A. , Kielkowski Danuta , Becklake Margaret R.
Published: April 2007

A pilot survey of the distribution and content of occupational health services in South African manufacturing industries was carried out in the Germiston area of the Witwatersrand using the records of the Workmens' Compensation Commissioner as a sampling frame. All establishments with 50 or more workers and a stratified random sample of smaller ones (495 in all) were contacted. The overall response rate was 56% and was positively related to work force size, the larger establishments showing higher response rates. The offering of health services, defined minimally as at least a part‐time nurse or doctor employed on the premises, was reported in 11% of work places employing 52% of the work force and was also positively related to work force size. Seventeen percent of establishments had ever monitored environmental conditions, and all classes of industry in the study area fell short of government recommendations. The advantages of the study approach used here, based on a countrywide sampling frame and a mail questionnaire, include 1) the relatively modest cost; 2) the creation of an information framework to which can be added additional information obtained from other sources e.g., factory visits; and 3) the use of a database for sampling that is countrywide, regularly updated, and versatile, with the potential for extending the observations with a similar (geographic) or different focus, for instance, by industrial class or work force size.
Lung cancer among dutch coal miners: A case‐control study
Authors: Meijers J. M. M. , Swaen G. M. H. , Slangen J. J. M. , van Vliet C.
Published: April 2007

A case‐control study was conducted in the southern part of The Netherlands to investigate the risk of lung cancer in coal miners; 381 age‐matched pairs of primary lung cancer cases and controls, diagnosed between 1972 and 1988, were selected from the pathology department of the University Hospital in the region. Information about past employment in coal mines was obtained through the registers of the collaborative pension fund for Dutch miners. 20% of the cases were (at some time) employed in coal mining, compared with 21% of the controls (odds ratio 0.95; 95% confidence interval: 0.65–1.38). 9% of both cases and controls had an underground work history (odds ratio 0.96; 95% confidence interval: 0.56–1.65). The duration of underground coal mining did not differ substantially between cases and referents (average duration: respectively 117 and 108 months). No relation between specific histologic tumor cell types and coal mining could be demonstrated. The study gives no indication that workers in Dutch coal mines have an increased risk of developing lung malignancies.
Occupational biohazards: A review
Authors: Dutkiewicz Jacek , Jabloński Leon , Olenchock Stephen A.
Published: April 2007

There are at least 193 important biological agents that show infectious, allergenic, toxic, or carcinogenic activities in the working population. These agents are viruses, bacteria, fungi, plant substances, invertebrate animals (mostly arthropods), and substances derived from vertebrate animals. At least 20 large occupational groups are exposed to these biohazards. The risk is greatest among health care and laboratory workers who are threatened by human pathogens and among agricultural workers who are at risk from dust‐borne biological allergens and toxins and by parasitic worms in warm climates. There is growing evidence that biohazards are also important risk factors for many other professions, including woodworkers, workers of textile plants, sewage and compost workers, miners and renovators. Some suggestions for research and prevention for reducing the occupational risks from biohazards are discussed.
Railroad workers with pleural plaques: I. Spirometric and nitrogen washout investigation on smoking and nonsmoking asbestos‐exposed workers
Authors: Hjortsberg Ulf , Ørbaek Palle , Arborelius Måns , Ranstam Jonas , Welinder Hans
Published: April 2007

Eighty‐seven workers exposed to asbestos in a railroad car repair shop, with characteristic asbestos‐induced pleural plaques, underwent extensive lung‐function examination. Vital capacity (VC) showed the greatest reduction among the static lung volumes, with an asymmetrical distribution of one‐fourth of the subjects below 80% of the predicted value. Logistic regression demonstrated VC to be sufficient for optimal discrimination of asbestos‐exposed subjects from a group of matched controls. No further discriminationry power was gained by additional spirometric measures, lung mechanics, blood gas analysis, or diffusing capacity. Smoking had an influence on dynamic but not on static lung volumes. In conclusion, reduced static lung volumes among smoking asbestos‐exposed workers with pleural plaques should, in the absence of other lung diseases, be mainly attributed to the asbestos exposure.
Asbestos‐related pleural plaques and lung function
Authors: Oliver L. Christine , Eisen Ellen A. , Greene Reginald , Sprince Nancy L.
Published: April 2007

The present study examines the association between asbestos‐related pleural plaques and lung function in a group of workers with occupational exposure to asbestos. Exposure, smoking, and respiratory histories, chest radiographs, flow‐volume loops, and single breath DLCOs were obtained on 383 railroad workers. A score based on the ILO‐1980 classification system was used to quantify the extent of plaquelike thickening. In order to eliminate potential confounders, we excluded from final analysis subjects with diffuse pleural thickening (n = 10) or small irregular opacities classified as profusion 0/1 or greater (n = 6) on chest radiograph. Definite pleural plaques were observed in 22.6%. The single breath DLCO was similar in the groups with and without plaques (p = 0.0550). Decrement in FVC and the occurrence of pulmonary restriction were associated with the presence of definite plaques (p = 0.0306 and 0.0431, respectively) and with quantitative pleural score (p = 0.0135 and 0.0126), controlling for duration of asbestos exposure and smoking. A test for trend revealed an association between level of diagnostic certainty (none, suspect, definite) for pleural plaques and these measures of lung function (p < 0.02). Our findings reveal an association between asbestos‐related pleural plaques and decrement in lung function as measured by FVC and criteria for pulmonary restriction.
Acute nonlymphatic leukemia among deck officers on coastal tankers: A report of two cases
Authors: Nilsson Ralph I. , Carneskog Jan , Järvholm Bengt G. , Nordlinder Rolf G.
Published: April 2007

Deck officers on coastal tankers may be exposed to high concentrations of cargo vapors during loading and tank‐cleaning operations. Two cases of acute nonlymphatic leukemia are described. Both men had worked as chief officers on coastal tankers transporting benzene and other petroleum products.
B cell neoplasms and occupational asbestos exposure
Authors: Schwartz David A. , Vaughan Thomas L. , Heyer Nicholas J. , Koepsell Thomas D. , Lyon Joseph L. , Swanson G. Marie , Weiss Noel S.
Published: April 2007

To evaluate the etiologic role of asbestos exposure in B cell neoplasms, we compared the estimated level of occupational exposure to asbestos of cases with chronic lymphocytic leukemia (CLL; N = 429) and multiple myeloma (MM; N = 698) with that of controls (N = 1,683). Cases were identified through four population‐based cancer registries in the U.S. and controls were randomly selected from the same geographic areas. Exposure to asbestos was assessed by classifying each job held by a subject into one of four categories, based on the estimated intensity of exposure to asbestos.

Evidence was found for a modest increasing risk of CLL with increasing asbestos exposure. Relative to persons with no known occupational exposure to asbestos, the risk for CLL was 1.1 (95% confidence interval (CI) = 0.8–1.6) for low, 1.2 (CI = 0.8–1.8) for medium, and 1.4 (CI = 0.8–2.3) for high peak asbestos exposure (p value for trend = 0.13). The association was strongest in white study subjects and in those individuals exposed 10 to 19 years prior to the interview. No association was observed between MM and occupational exposure to asbestos in the entire study population or within specific subgroups.

Given the pattern of immunologic abnormalities that occur with increased frequency in asbestos‐exposed persons, our observation of an association between occupational asbestos exposure and CLL deserves attention in subsequent studies.
Encephalopathy: An uncommon manifestation of workplace arsenic poisoning?
Authors: Morton William E. , Caron Gordon A.
Published: April 2007

This report describes two cases of chronic encephalopathy associated with occupational exposure to arsenic fumes from hot pressurized impregnation of wood. Both cases displayed symptoms of cognitive impairment with onset 14–18 months after start of occupational exposure to arsenic fumes. Laboratory confirmation was provided by elevated urine arsenic levels. One patient was hospitalized for apparent psychiatric reasons. Neuropsychologic testing of one case showed typical and relatively mild impairments of new learning, recent memory, and concentration in addition to the psychological symptoms. Symptoms in both cases disappeared following cessation of exposure and return of urine arsenic excretion to normal levels. In future studies of workers exposed to arsenic, documentation of mild impairment of cognitive function should be sought using neurobehavioral test batteries.
Cumulative arsenic exposure and lung cancer in smelter workers: A dose‐response study
Authors: Järup Lars , Pershagen Göran , Wall Stig
Published: April 2007

The cause‐specific mortality was followed through 1981 in a cohort of 3,916 male Swedish smelter workers employed for at least 3 months from 1928 through 1967. Arsenic levels in the air of all workplaces within the smelter were estimated for three different time periods. Using this exposure matrix and detailed information of the work history, cumulative arsenic exposure could be computed for each worker. Standardized mortality ratios (SMRs) were calculated for several dose categories using age‐specific mortality rates from the county where the smelter was situated. A positive dose‐response relationship was found between cumulative arsenic exposure and lung cancer mortality with an overall SMR of 372 (304–450, 95% confidence interval). The lung cancer mortality was related to the estimated average intensity of exposure to arsenic but not to the duration. No positive dose‐response relationship was found between arsenic and ischemic heart disease or cerebrovascular disease. There was also no evident dose‐response relationship between estimated exposure to sulfur dioxide and lung cancer.
Improvement in the occupational health program in a finnish construction company by means of systematic workplace investigation of job load and hazard analysis
Authors: Mattila Markku
Published: April 2007

The aim of the present study was to improve an occupational health program by means of systematic workplace investigations. The 8‐month study was done at three building sites of one construction firm. The method for workplace investigations was a simple job hazard analysis of chemical hazards, physical hazards, physical work load, mental stress, and risk of injury, each factor being rated on a three‐point scale. Information was gathered by observations, interviews, and a worker questionnaire. Occupational health and safety personnel and worker representatives dealt with problems cooperatively. Together they assessed occupational loads and hazards, whereafter the occupational health and safety personnel devised an occupational health care program and proposed preventive measures. The workplace investigation method proved to function well. It improved the occupational health care program, produced an overall analysis of occupational hazards, and dramatically increased the number and quality of proposed preventive measures. The new method was evaluated to be clearly superior to previous practices and was implemented at moderate cost. The study showed that attention to issues of environmental and occupational health can effectively prevent health impairment even in difficult settings such as construction work. More research is needed for effective utilization of information accumulated by systematic workplace investigations.
Cholinesterase activity depression among California agricultural pesticide applicators
Authors: Ames Richard G. , Brown Stephanie K. , Mengle Donald C. , Kahn Ephraim , Stratton James W. , Jackson Richard J.
Published: April 2007

Cholinesterase activity measurements for 542 California agricultural pesticide applicators under medical supervision during the first 9 months of 1985 were analyzed. Twenty‐six workers, 4.8% of the sample, had cholinesterase values at or below the California threshold values for removal from continued exposure to cholinesteraseinhibiting pesticides (60% of baseline for red blood cell cholinesterase and 50% of baseline for plasma cholinesterase activity). Eight of these 26 workers, 31.5%, had pesticide‐related illnesses. Pesticides most frequently associated with cholinesterase depressions exceeding California threshold values included mevinphos (Phosdrin), oxydemeton methyl (Metasystox‐R), methomyl (Lannate), and acephate (Orthene); these pesticides included organophosphates in toxicity categories I and II and one carbamate in toxicity category I.
Fatal occupational injuries in California, 1972–1983
Authors: Goldberg Robert Leonard , Bernstein Leslie , Garabrant David H. , Peters John M.
Published: April 2007

Prior reports have indicated that the crude incidence of fatal occupational accidents in California has substantially declined since at least 1972. We tested the hypothesis that this observation was an artifact of demographic shifts in the workforce towards lowerrisk age groups and industries. Review of worker's compensation data from 1972 to 1983 identified 2,483 fatal injuries among males. Crude rates declined by an average of 7.0% annually (p<.005). Age and industry adjustment reduced this decline to 6.7% annually, but the trend was still significant (p<.005). Thus, the decline in fatal injury rates is not artifactual and will require further study to explain. In a separate analysis, age‐specific death rates were found to follow a bimodal pattern in most industries with the highest rates observed at the extremes of age. These results conflict with those of several previous studies. However, these studies did not adjust for the prevalence of part‐time work schedules among younger employees.
Self‐reported musculoskeletal complaints among garment workers
Authors: Sokas Rosemary K. , Spiegelman Donna , Wegman David H.
Published: April 2007

One hundred forty‐four sewing machine operators answered questionnaires concerning occupational history and musculoskeletal symptoms adapted from the National Health and Nutrition Examination Survey. They were matched for age within 5 years, race, and sex with persons completing the HANES I Augmentation Survey, and the prevalence of self‐reported musculoskeletal morbidity was compared. Operators complained significantly more often of knee pain (prevalence odds ratio [POR] = 1.84, p = .0001) and knee swelling (POR = 9.98, p < .00001), although they were no more likely to have had knee surgery. Similar increases were reported for upper‐back pain (POR = 2.13, p = .002) joint ache, and joint swelling (both were significant for fingers, wrists, elbows, and shoulders at p < .05 levels). No differences in low‐back pain or in hospitalization for joint conditions were noted.

Ergonomic redesign of sewing machines needs to address knee and upper‐back movements as well as the arm. wrist, and finger movements.
Organophosphate exposure inhibits non‐specific esterase staining in human blood monocytes
Authors: Mandel Jack S. , Berlinger Norman T. , Kay Neil , Connett John , Reape Martin
Published: April 2007

The objective of this study was to investigate the association between exposure to triaryl phosphate and monocyte nonspecific esterase staining activity in workers from a plant in Nitro, West Virginia. A cross‐sectional study design was used to identify the exposed plant employees, and both a plant and a general population group. In addition to completing a questionnaire for each participant, 30 cc of blood were drawn and analyzed using four techniques, two morphological and two enzymatic. These procedures included a Technicon D‐90 autoanalyzer, a Technicon H‐6000 autoanalyzer, a manual enzymatic using alpha naphthyl butyrate, and a manual morphologic using Wright‐Giesma stain. The results showed a decrease in nonspecific esterase staining with the Technicon D‐90. No significant effect on monocyte numbers or esterase positivity was found with the other three techniques.
Design and conduct of occupational epidemiology studies: I. design aspects of cohort studies
Authors: Checkoway Harvey , Pearce Neil , Dement John M.
Published: April 2007

Cohort and case‐control studies are two standard approaches for investigating the etiology of occupational diseases. This paper, which is the first of a four‐part series, contains a review of the design features of occupational cohort studies. Topics discussed include the basic features of prospective and historical cohort studies, options for defining the cohort, disease incidence ascertainment, and considerations involved in planning an occupational cohort study. Subsequent papers in this series will focus on data analysis of occupational cohort studies and the design and analysis of occupational case‐control studies.
Design and conduct of occupational epidemiology studies: II. Analysis of cohort data
Authors: Checkoway Harvey , Pearce Neil , Dement John M.
Published: April 2007

This paper reviews strategies and statistical methods for analyzing data from occupational cohort studies. Emphasis is placed on the common methods for grouped data analysis involving external and internal comparison populations. Analysis procedures reviewed are standardized mortality ratio, standardized rate ratio, and Mantel‐Haenszel techniques for estimating relative risks. Methods for control of confounding, assessment of effect modification, and allowance for disease latency are discussed. These concepts and procedures are illustrated with data from an historical cohort mortality study of workers from an asbestos textile plant.
Design and conduct of occupational epidemiology studies: III. Design aspects of case‐control studies
Authors: Pearce Neil , Checkoway Harvey , Dement John
Published: April 2007

Currently available approaches for the design of occupational case‐control studies are reviewed. An accompanying paper reviews methods of analysis. We commence by drawing a distinction between cohort‐based and registry‐based studies. Methods for selecting cases and controls are then reviewed, including cumulative incidence and incidence density sampling, matching, sources of controls, and issues in control selection. Finally, the advantages and disadvantages of the case‐control approach are summarized.
Design and conduct of occupational epidemiology studies: IV. The analysis of case‐control data
Authors: Pearce Neil , Checkoway Harvey , Dement John
Published: April 2007

This paper reviews the basic methods of analysis of data from case‐control studies. The standard analytic methods are outlined first for a single stratum. The discussion is then extended to stratified analysis, multiple exposure levels, and analyses allowing for disease induction and latency periods. Finally, logistic regression is discussed as an extension of the more basic forms of analysis. The methods are illustrated with data from a study of lung cancer among asbestos textile plant workers.
Relationship of lung geometry to the development of pleural abnormalities in insulation workers exposed to asbestos
Authors: Delfino Ralph , Ernst Pierre , Bourbeau Jean
Published: April 2007

The relationship of respiratory airway and airspace geometry to radiographic evidence of pleural abnormality consistent with asbestos exposure was studied in 178 construction insulators. Lung geometry was assessed from tracings of radiographic shadows, and the measures taken were tracheal length and diameter, subcarinal angle, right and left lung lengths, and upper, middle, and lower lung widths. Important modifying variables—age, height, weight, exposure estimates, and smoking history—were included in a logistic regression model to test the significance of the lung geometry measurements as predictors of the presence or absence of pleural abnormality. No such relationships were found. Neither were there any differences in prevalence or severity of pleural disease between the right and left sides which might have been found if airway geometry were a significant determinant of asbestos pleural disease. These results do not support the hypothesis that lung geometry is a host risk factor for the development of asbestos‐related pleural disease.
Understanding comorbidity: A twin study of reading disability and attention‐deficit/hyperactivity disorder
Authors: Willcutt Erik G. , Pennington Bruce F. , Olson Richard K. , DeFries John C.
Published: April 2007

A community sample of twins in which at least one member of each pair exhibited significant reading difficulties (99 monozygotic and 80 dizygotic pairs) or symptoms of attention‐deficit/hyperactivity disorder (ADHD; 83 monozygotic and 78 dizygotic pairs) was used to test the etiology of comorbidity between reading disability (RD) and ADHD. Univariate analyses revealed moderate to high heritability for all measures of reading difficulty and ADHD. Subsequent bivariate analyses indicated that the relation between reading difficulties and inattention symptoms is primarily attributable to common genetic influences, whereas bivariate heritability estimates were not significant for hyperactivity‐impulsivity and any of the reading measures. Reading difficulties and ADHD symptoms were more highly heritable if the proband met criteria for both disorders versus RD or ADHD alone, suggesting that future molecular genetic analyses of comorbid RD + ADHD may facilitate the identification of susceptibility genes for RD, ADHD, and their comorbidity. © 2007 Wiley‐Liss, Inc.
Neurocognitive deficits in first‐episode schizophrenic patients and their first‐degree relatives
Authors: Ma Xiaohong , Wang Qiang , Sham Pak C. , Liu Xiehe , Rabe‐Hesketh Sophia , Sun Xueli , Hu Junmei , Meng Huaqing , Chen Wai , Chen Eric Y.H. , Deng Wei , Chan Raymond C.K. , Murray Robin M. , Collier David A. , Li Tao
Published: April 2007

Some neuropsychological abilities, particularly those affecting memory, attention and executive function, are impaired amongst both schizophrenic patients and their unaffected relatives, implying that these deficits are at least partly genetic in origin. However neuropsychological performance can be altered by medication, and has rarely been examined in first onset, drug naive patients. The objective of this study was to determine whether selected neurocognitive abilities are impaired in first‐onset schizophrenic patients and their relatives compared to controls. We examined attention and speed of information processing, memory and learning, verbal function, visuoconstructive abilities and executive function in 207 first‐episode schizophrenic patients (163 of whom were drug naïve), 322 of their first‐degree relatives and 133 unrelated normal controls. The data were subjected to multilevel modeling to compare neurocognitive performance between schizophrenic probands, relatives and controls while taking into account potential correlations among members of the same family; age, gender, and years of education were included as covariates. Of the three groups, schizophrenic patients performed poorest at all neuropsychological tests, suggestive of a broad range of neurocognitive deficits. Their first‐degree relatives showed a narrower pattern of poor performance at Digit Symbol, Digit Span, Trail Making, Verbal Fluency test, Tower of Hanoi, and WCST‐M tests. Our findings show that selected neurocognitive deficits especially attention and executive function are impaired in the families of schizophrenic patients. These patterns of neurocognitive deficits may represent “endophenotypes” denoting varying degrees of vulnerability to schizophrenia and may be of value in future molecular genetic studies. © 2007 Wiley‐Liss, Inc.
Association analysis of GABA receptor subunit genes on 5q33 with heroin dependence in a Chinese male population
Authors: Loh E.W. , Tang N.L.S. , Lee D.T.S. , Liu S.I. , Stadlin Alfreda
Published: April 2007

GABAA receptor subunit genes clustered on 5q33 play a role in the development of alcoholism and methamphetamine use disorder without psychosis. The present study explored the possible contribution of the same subunit genes to the development of heroin dependence. Single nucleotide polymorphisms (SNPs) of the GABAA receptor subunits GABRB2, GABRA6, GABRA1, and GABRG2 were examined in 178 male Han Chinese heroin‐dependent and 170 male control subjects. A significant difference in allele frequency for the SNP rs211014 in the GABAAγ2 receptor subunit gene between cases and controls was identified (P = 0.015). A possible mechanism for the involvement of the GABA receptor subunit genes on 5q33 in the development of heroin dependence is discussed. © 2007 Wiley‐Liss, Inc.
A meta‐analysis of association studies between the 10‐repeat allele of a VNTR polymorphism in the 3′‐UTR of dopamine transporter gene and attention deficit hyperactivity disorder
Authors: Yang Binrang , Chan Raymond C.K. , Jing Jin , Li Tao , Sham Pak , Chen Ronald Y.L.
Published: April 2007

The association between the 10‐repeat allele of the dopamine transporter gene (DAT) and attention deficit hyperactivity disorder (ADHD) is uncertain. This study aimed to conduct a meta‐analysis of the association between the 10‐repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3′‐untranslated region (UTR) of the DAT1 gene and ADHD. We pooled up 18 published transmission disequilibrium test (TDT) studies between the 40‐base pair VNTR polymorphism in the3′‐UTR of the DAT1 gene and ADHD. It included a total of 1,373 informative meioses, 7 haplotype‐based haplotype relative risk (HHRR) studies, and 6 case‐control‐based association studies. There were statistically significant evidences for heterogeneity of the odds ratio in TDT and HHRR studies (P < 0.10), but not in case‐control studies. The results of random effects model showed small but significant association between ADHD and the DAT1 gene in TDT studies (OR = 1.17, 95% CI = 1.05–1.30, chi‐square = 8.11, df = 1, P = 0.004), but not in HHRR and case‐control studies. The 10‐repeat allele of a VNTR polymorphism in the 3′‐UTR the DAT1 gene has a small but significant role in the genetic susceptibility of ADHD. These meta‐analysis findings support the involvement of the dopamine system genes in ADHD liability variation. However, more work is required to further identify the functional allelic variants/mutations that are responsible for this association. © 2006 Wiley‐Liss, Inc.