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Among many short-term, subchronic, and chronic toxicology studies with ammonium perfluorooctanoate (PFOA), the gastrointestinal tract has not been identified as a target organ for PFOA-related toxicity in laboratory animals where the corresponding serum PFOA concentrations typically approach several orders of magnitude higher than the general human population. These lack of gastrointestinal tract-related findings were in direct contrast to an epidemiological observation where a positive trend was observed for ulcerative colitis, an idiopathic chronic inflammatory condition of the gut, in a Mid-Ohio River community whose drinking water contained higher levels of PFOA. This study was conducted to perform a histological reevaluation of large intestine sections in laboratory animals from 2 long-term toxicological studies: one was with Sprague Dawley rats that received ammonium PFOA in their diet for 2 years and the other one was with cynomolgus macaques that received daily capsules of ammonium PFOA for 6 months. In both studies, there was a lack of histological evidence of treatment-related inflammatory lesions that was suggestive of the occurrence of ulcerative colitis in these laboratory animals even under the most rigorous treatment schedules. These findings do not offer support for the biological plausibility of the epidemiological associations reported.

Bladder cancer is the fourth and ninth most common cancer in men and women, respectively, in the United States. An estimated 74,690 people (56,205 men and 18,484 women) will be diagnosed with and 15,210 men and women will die from bladder cancer in 2014.1 Recognized risk factors for bladder cancer include increased age, male sex, white race, smoking, family history, urinary tract infections, drugs, personal history of bladder cancer, and occupational exposures.2 Estimates suggest that between 5% and 25% of bladder cancer incidence is attributable to occupational exposures.3 Consequently, interest has mounted for implementation of bladder cancer screening among high-risk populations including industrial workers exposed to bladder carcinogens in the workplace. Epidemiologic studies of aluminum smelter workers have demonstrated an association between coal tar pitch volatiles (CTPVs) generated during aluminum reduction and bladder cancer.4–8 Coal tar pitch volatiles contain many low molecular weight polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are lipophilic nonpolar chemicals comprising two or more benzene rings formed as a result of pyrolytic processes, in particular the incomplete combustion of organic materials.6 Some PAHs in CTPV are recognized carcinogens.9 Benzo(a)pyrene (BaP), a specific carcinogenic PAH, and benzene soluble materials (BSM), which include all PAHs present and other benzene soluble compounds, have consistently been found in CTPV10,11; therefore, BaP and BSM are often used as surrogates or indicator compounds for the presence of PAHs in the work environment. Theriault reported on a bladder cancer screening program consisting of annual urine cytology initiated in a cohort of current aluminum smelter workers with at least a 10-year history of CTPV exposure associated with aluminum smelting and later expanded to include workers with at least 5 years of exposure.12 Results of this screening program showed trends toward a higher proportion of early-stage bladder cancer at diagnosis (77% vs 67%) and an increased 5-year survival (rate ratio, 0.54; confidence interval [CI], 0.20 to 1.48) after the screening program was instituted; however, these differences were not statistically significant, and the authors concluded that these results did not encourage an optimistic view of screening effectiveness in the population. Similar to the aforementioned study, most earlier screening protocols for bladder cancer primarily included testing for blood in the urine (hematuria) and/or urine cytology. Unfortunately, hematuria has a relatively low sensitivity and specificity, whereas urinary cytology, although highly specific, has poor sensitivity.13,14 Cystoscopy, although very accurate and considered the criterion standard for the detection of bladder tumors, is an invasive and expensive procedure with complications including intense discomfort as well as bleeding, infections, and mechanical lesions.15 Given these limitations, the focus has turned to identification of more sensitive and specific molecular markers for detection and surveillance of bladder cancer.16–19 One of the earlier tumor markers commercially developed and approved by the United States Food and Drug Administration for bladder cancer surveillance was the ImmunoCyt test (subsequently commercialized under two names: ImmunoCyt/uCyt+). This immunofluorescence assay uses three monoclonal antibodies directed against transitional cell carcinoma antigens in exfoliated cells for the detection of cellular markers that are relatively specific for bladder cancer.20 In a study assessing the sensitivity and specificity of 18 bladder tumor markers including ImmunoCyt/uCyt+, the authors concluded that ImmunoCyt/uCyt+ was one of the six promising markers for surveillance of patients for recurrent bladder cancer.21 Another report comparing ImmunoCyt/uCyt+ alone and in combination with urine cytology to five other commercially available urine tumor markers concluded that the combination of ImmunoCyt/uCyt+ with urine cytology offered a superior sensitivity to the other tests.22 Although the primary focus of many reports assessing various biomarkers to screen for bladder cancer has been on surveillance of bladder cancer recurrence in patients, a few studies have used different combinations of biomarkers for surveillance of high-risk occupational cohorts. In one recent study, bladder cancer screening was instituted in 76 workers exposed to 4, 4-methylenebis (2-chloroaniline) (MBOCA), a synthetic chemical used in the production of castable polyurethane parts. Ninety-two other workers who were not involved in the MBOCA manufacturing process served as controls. Urine occult blood tests, urine cytology, tests for tumor marker nuclear matrix protein 22 (NMP22), which uses two mononuclear antibodies, and abdominal ultrasonography were performed in all participants. This study identified one worker with confirmed bladder cancer; however, the prevalence of atypical urine cells, the NMP22 tumor marker, and positive occult blood were not significantly different between the MBOCA-exposed workers and nonexposed workers.23 In another study, a prospective cohort of 1323 male workers with former exposure to aromatic amines was screened for bladder cancer between 2003 and 2010. Using a combination of annual tests for hematuria, quantitative determination of NMP22, UroVysion test (a fluorescence in situ hybridization assay that assesses chromosomal instability in urothelial cells), and urine cytology, 15 bladder tumors were detected in 14 participants.24 Between 2006 and 2008, 171 male workers from an Italian coke plant with a median exposure duration to PAHs of 16 years were screened for bladder cancer using a medical protocol that included urine analysis, urine cytology, and urine ImmunoCyt/uCyt+. Workers with positive results on at least one of the urinary markers underwent urinary ultrasonography and cystoscopy. Overall, 12% of the workers tested positive on at least one urinary marker. Nevertheless, evidence of bladder cancer was not confirmed by cystoscopy and ultrasonography. The authors reported a specificity of urine analysis, cytology, and ImmunoCyt/uCyt+ of 98%, 96%, and 92%, respectively. Although no increased risk for bladder cancer was seen among the coke workers evaluated, the result was considered preliminary because of reported study limitations, including the small number of workers enrolled in the surveillance program, the analysis based on only one assessment with no follow-up available, and the relatively short duration of PAH exposure in these workers.25 We present the results of a bladder cancer surveillance program conducted between January 2000 and December 2010 in a cohort of aluminum smelter workers in the United States who were employed by a single company. Our objective in this report was to establish the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the bladder cancer screening protocol in the context of the observed risk of bladder cancer in the cohort under surveillance.

Objectives To look for an association between acoustic neuroma (AN) and participation in a hearing conservation programme (HCP) and also for an association between AN and possible occupational risk factors in the aluminium industry. Methods We conducted a case–control analysis of a population of US aluminium production workers in 8 smelters and 43 other plants. Using insurance claims data, 97 cases of AN were identified between 1996 and 2009. Each was matched with four controls. Covariates included participation in a HCP, working in an aluminium smelter, working in an electrical job and hearing loss. Results In the bivariate analyses, covariates associated with AN were participation in the HCP (OR=1.72; 95% CI 1.09 to 2.69) and smelter work (OR=1.88; 95% CI 1.06 to 3.36). Electrical work was not significant (OR=1.60; 95% CI 0.65 to 3.94). Owing to high participation in the HCP in smelters, multivariate subanalyses were required. In the multivariate analyses, participation in the HCP was the only statistically significant risk factor for AN. In the multivariate analysis restricted to employees not working in a smelter, the OR was 1.81 (95% CI 1.04 to 3.17). Hearing loss, an indirect measure of in-ear noise dose, was not predictive of AN. Conclusions Our results suggest the incidental detection of previously undiagnosed tumours in workers who participated in the company-sponsored HCP. The increased medical surveillance among this population of workers most likely introduced detection bias, leading to the identification of AN cases that would have otherwise remained undetected.

Objectives This study expands previous research comparing injury risk for women and men in a cohort of 24 000 US aluminium manufacturing workers in 15 facilities from 2001 to 2010. Methods We compared injury rates (all injury, first aid, medical treatment, restricted work and lost work time) by sex and by job and sex. Using a mixed effect modelling approach, we calculated ORs and 95% CIs adjusting for age, job tenure, ethnicity and year as fixed effects and person, job and plant as random effects. Additionally, we modelled the data stratified by plant type to examine potential differences in injury risk between smelter (generally recognised as more hazardous) and fabrication production environments. Results Risk of injury was higher for women in four out of the five injury outcomes: all injuries combined (OR: 1.58, CI 1.48 to 1.67), injuries requiring first aid (OR: 1.61, CI 1.54 to 1.70), injuries requiring medical treatment (OR: 1.18, CI 1.03 to 1.36) and injuries requiring restricted work (OR: 1.65, CI 1.46 to 1.87). No difference in the risk of lost time injury by sex was found in this cohort. Analyses stratified by plant type showed similarly elevated injury risk for women, although the risk estimates were higher in smelters than fabrication plants. Conclusions To our knowledge, this is the largest single-firm study examining injury risk by sex with sufficient data to appropriately adjust for job. We show a consistently higher injury risk for women compared with men in the smelting and fabrication environments.

Objectives This study aimed to examine the effect of an ergonomic hazard control (HC) initiative, undertaken as part of a company ergonomics standard, on worker injury risk. Methods Using the company’s ergonomic hazards database to identify jobs with and without ergonomic HC implementation and linking to individual job and injury histories, injury risk among person-jobs with HC implementation (the HC group) was compared to those without HC (NoHC group) using random coefficient models. Further analysis of the HC group was conducted to determine the effect of additional ergonomic hazards controlled on injury risk. Results Among 123 jobs at 17 plant locations, 347 ergonomic hazards were quantitatively identified during the study period. HC were implemented for 204 quantified ergonomic hazards in 84 jobs, impacting 10 385 persons (12 967 person-jobs). No HC were implemented for quantified ergonomic hazards in the remaining 39 jobs affecting 4155 persons (5046 person-jobs). Adjusting for age, sex, plant origin, and year to control for any temporal trend in injury risk, the relative risk (RR) for musculoskeletal disorder (MSD) was 0.85 and the RR for any injury or MSD was 0.92 in the HC compared to NoHC group. Among the HC group, each ergonomic hazard controlled was associated with risk reduction for MSD and acute injury outcomes (RR 0.93). Conclusion Systematic ergonomic HC through participatory ergonomics, as part of a mandatory company ergonomics standard, is associated with MSD and injury risk reduction among workers in jobs with HC implemented.

Several adverse pregnancy outcomes were reported among female laboratory workers in a North American aluminum smelter. To determine whether these outcomes were associated with any occupational exposure at the plant, a cross-sectional survey was undertaken.Rates of miscarriage, premature singleton birth, and major congenital anomaly occurring during employment were compared with a reference group comprised of all pregnancies that occurred before employment.Among female workers, the excess of congenital anomalies among female laboratory workers that defined the initial cluster was observed, but no specific pattern was found.On the basis of these analyses, the increase in congenital anomalies could not be attributed to occupational exposures at the smelter nor could potential exposure likely explain the diverse anomalies described.

OBJECTIVE: This study was designed to determine whether injury risk among manufacturing workers was related to hours worked during the previous week. METHODS: A case-crossover design was utilized to contrast hours worked prior to an injury shift with those worked prior to a non-injury shift for hourly workers. Paired t-tests were used to determine significance of the difference. Conditional logistic regression was used to assess dose-response. RESULTS: Hours worked prior to injury significantly exceeded hours during the control week. Workers who worked more than 64 hr in the week before the shift had an 88% excess risk compared to those who worked 40 hr or fewer, P < 0.05. CONCLUSION: The study provides evidence that injury risk is related to time worked during the previous week. Control of overtime in manufacturing may reduce risk of worker injury. Language: en

Purpose Hearing is an important sense for physicians, making communication and stethoscope use possible, yet not much is known about the impact of hearing loss on professional function. The purpose of this study was to explore hearing-related issues affecting physicians. Materials and methods We administered a hearing test and questionnaire to 107 physicians and medical students. Results The proportion of physicians reporting trouble with their hearing increased with age, reaching almost 100% in those older than 60 years. Audiometric hearing loss also increased with age. Perceived hearing trouble was significantly associated with audiometric hearing loss, yet 46% of physicians with hearing loss described their hearing as good. Older physicians more frequently reported difficulty communicating with patients, staff, and colleagues owing to hearing problems ( P = .007). Reported stethoscope difficulties did not significantly increase with age; there was no association with hearing thresholds. No physician reported use of electronic stethoscopes or hearing aids. Noise exposures were common, yet 51% of respondents never used hearing protection. Younger physicians were less likely to use protection ( P = .002). Conclusion Physicians lose hearing with age but may not notice or report the loss. Physician hearing loss is associated with difficulty communicating with patients, staff, and colleagues. Neither age nor hearing level predicts problems with stethoscope use; possible explanations include a training effect or denial. Many physicians, especially younger ones, never use hearing protection around noise. Strategies to recognize and reduce the impact of hearing loss on professional function throughout a physician's career deserve greater attention.

Respiratory disorders, including occupational and environmental lung diseases, are prevalent. Physicians are frequently called upon to determine impairment and aid in the assessment of disability caused by these conditions, either as the treating physician or as an independent medical examiner. In this article we reviewed the role of physicians in determining the presence and severity of pulmonary disorders. A comprehensive clinical assessment and appropriate standardized tests, to objectively characterize the severity of impairment, are the key elements of the evaluation. This assessment may also include the physician's opinion regarding causative factors. Finally, disability determination is made by nonclinicians, through administrative means, based on the degree of impairment and a review of circumstances specific to the individual. Knowledge of these components of disability evaluation will help physicians to better serve their patients and supply appropriate data to the adjudicating system.

Aluminum use and primary aluminum production results in the generation of various particles, fumes, gases, and airborne materials with the potential for inducing a wide range of lung pathology. Nevertheless, the presence of diffuse parenchymal or interstitial lung disease related to these processes remains controversial. The relatively uncommon occurrence of interstitial lung diseases in aluminum-exposed workers--despite the extensive industrial use of aluminum--the potential for concurrent exposure to other fibrogenic fibers, and the previous use of inhaled aluminum powder for the prevention of silicosis without apparent adverse respiratory effects are some of the reasons for this continuing controversy. Specific aluminum-induced parenchymal diseases described in the literature, including existing evidence of interstitial lung diseases, associated with primary aluminum production are reviewed.

Given the burden of occupational illnesses and injuries in the United States, family physicians should understand the role workplace exposures may play in patients' chief concerns. Incorporating employment screening questions into patients' intake questionnaires is an efficient means of identifying potential occupational causes of symptoms. Recommended questions include what kind of job patients have; whether their symptoms are worse at work; whether they are or have been exposed to dust, fumes, chemicals, radiation, or loud noise; and whether they think their health problems may be related to their work. These questions are especially important when the diagnosis or etiology is in doubt. Depending on patients' responses to the screening questions, a more detailed occupational history may be appropriate. It can be useful to ask about routine tasks performed during a typical work shift, as well as anything out of the ordinary (e.g., a change in routine, an injury or accident). The occupational history should include information about alcohol and tobacco use, second or part-time jobs, military service, hobbies, and home environment. Patients with suspected occupational illnesses or injuries may benefit from referral to an occupational medicine specialist for a more detailed assessment and follow-up.

The objective of the study was to determine if female workers in a heavy manufacturing environment have a higher risk of injury compared with males when performing the same job and to evaluate sex differences in type or severity of injury. By use of human resources and incident surveillance data for the hourly population at 6 US aluminum smelters, injuries that occurred from January 1, 1996, through December 21, 2005, were analyzed. Multivariate logistic regression, adjusted for job, tenure, and age category, was used to calculate odds ratios and 95% confidence intervals for female versus male injury risk for all injuries, recordable injuries, and lost work time injuries. The analysis was repeated for acute injuries and musculoskeletal disorder-related injuries separately. Female workers in this industry have a greater risk for sustaining all forms of injury after adjustment for age, tenure, and standardized job category (odds ratio = 1.365, 95% confidence interval: 1.290, 1.445). This excess risk for female workers persisted when injuries were dichotomized into acute injuries (odds ratio = 1.2) and musculoskeletal disorder-related injuries (odds ratio = 1.1). This study provides evidence of a sex disparity in occupational injury with female workers at higher risk compared with their male counterparts in a heavy manufacturing environment.

Physicians are frequently involved in the assessment of impairment and disability as the treating physician, in consultation, or as an independent medical examiner. The key elements of this assessment include a comprehensive clinical evaluation and appropriate standardized testing to establish the diagnosis, characterize the severity of impairment, and communicate the patient's abilities, restrictions, and need for accommodation. In some cases, a functional capacity evaluation performed by a physical or occupational therapist or a neuropsychological evaluation performed by a neuropsychologist may be required to further clarify the functional capacity of the patient. The results of the impairment evaluation should be communicated in clear, simple terms to nonmedical professionals representing the benefits systems. These individuals make the final determination on the extent of disability and eligibility for benefits and compensation under that particular benefits system.

To determine whether beryllium-related disease exists among aluminum smelter workers.A total of 1278 employees from four aluminum smelters determined to have significant beryllium exposure based on 5 years of sampling were invited to participate in medical surveillance that included a respiratory symptoms questionnaire, spirometry, and blood beryllium lymphocyte proliferation test.Of these, 734 employees participated in the program. Beryllium exposure from 965 personal samples ranged from 0.002 to 13.00 microg/m time-weighted average, with a median of 0.05 microg/m, geometric mean of 0.05 microg/m, and arithmetic mean of 0.22 microg/m. Only two employees had confirmed beryllium sensitization (0.27%).There is evidence of beryllium sensitization among aluminum smelter workers. When compared with beryllium-exposed workers in other industries, aluminum smelter workers had lower rates of sensitization. The low beryllium sensitization rate observed may be related to work practices and the properties of the beryllium found in this work environment.

Background Employer administrative files are an underutilized source of data in epidemiologic studies of occupational injuries. Methods Personnel files, occupational health surveillance data, industrial hygiene data, and a real-time incident and injury management system from a large multi-site aluminum manufacturer were linked deterministically. An ecological-level measure of physical job demand was also linked. This method successfully created a database containing over 100 variables for 9,101 hourly employees from eight geographically dispersed U.S. plants. Results Between 2002 and 2004, there were 3,563 traumatic injuries to 2,495 employees. The most common injuries were sprain/strains (32%), contusions (24%), and lacerations (14%). A multivariable logistic regression model revealed that physical job demand was the strongest predictor of injury risk, in a dose dependent fashion. Other strong predictors of injury included female gender, young age, short company tenure and short time on current job. Conclusions Employer administrative files are a useful source of data, as they permit the exploration of risk factors and potential confounders that are not included in many population-based surveys. The ability to link employer administrative files with injury surveillance data is a valuable analysis strategy for comprehensively studying workplace injuries, identifying salient risk factors, and targeting workforce populations disproportionately affected. Am. J. Ind. Med. 50:676–686, 2007. © 2007 Wiley-Liss, Inc.

In this study, the authors examined the distribution and odds of occupational injury among hourly employees of a US aluminum manufacturing company by body mass index (weight (kg)/height (m)(2)). In 2002, height and weight data on 7,690 workers at eight plants were extracted from medical records from annual physicals, and body mass index was categorized. Information on traumatic injuries recorded between January 1, 2002, and December 31, 2004, was obtained from a company injury surveillance system. Twenty-nine percent of the employees (n = 2,221) sustained at least one injury. Approximately 85 percent of injured workers were classified as overweight or obese. The odds of injury in the highest obesity group as compared with the ideal body mass index group were 2.21 (95% confidence interval: 1.34, 3.53), after adjustment for sex, age, education, smoking, physical demands of the job, plant process and location, time since hire, time in the job, and significant interaction terms. Injuries to the leg or knee were especially prevalent among members of this very obese group. Research findings support an association between body mass index and traumatic workplace injuries among manufacturing employees. Workplace safety personnel might consider adding policies or programs that address weight reduction and maintenance as part of ongoing comprehensive workplace safety strategies.

Exposures to respiratory irritants encountered in aluminum smelters in Europe, Australia, and New Zealand have been suggested as the cause of "potroom asthma." However, there remains disagreement in North America regarding the existence of this entity. This study was designed to assess whether asthma occurs excessively among potroom workers and if so, delineate dose-response relationships for possible causal risk factors. The asthma incidence ratio between potroom and nonpotroom workers after adjusting for smoking was 1.40. Although bivariate analyses showed a relationship between asthma incidence and exposure to total fluoride, gaseous fluoride, particulate fluoride, sulfur dioxide, and smoking, only the effects of gaseous fluoride (relative risk [RR] = 5.1) and smoking (RR = 7.7) remained significant in a multivariate model. Potroom asthma appears to occur at the studied U.S. aluminum smelters at doses within regulatory guidelines.

No Abstract. Keywords: international medical graduates, graduate medical education, educational commission for foreign medical graduates (ECFMG), residency, USA Archives of Ibadan Medicine 2005, Vol. 6(1): 46-49

Background An inverse relationship between experience and risk of injury has been observed in many occupations. Due to statistical challenges, however, it has been difficult to characterize the role of experience on the hazard of injury. In particular, because the time observed up to injury is equivalent to the amount of experience accumulated, the baseline hazard of injury becomes the main parameter of interest, excluding Cox proportional hazards models as applicable methods for consideration. Methods Using a data set of 81,301 hourly production workers of a global aluminum company at 207 US facilities, we compared competing parametric models for the baseline hazard to assess whether experience affected the hazard of injury at hire and after later job changes. Specific models considered included the exponential, Weibull, and two (a hypothesis-driven and a data-driven) two-piece exponential models to formally test the null hypothesis that experience does not impact the hazard of injury. Results We highlighted the advantages of our comparative approach and the interpretability of our selected model: a two-piece exponential model that allowed the baseline hazard of injury to change with experience. Our findings suggested a 30% increase in the hazard in the first year after job initiation and/or change. Conclusions Piecewise exponential models may be particularly useful in modeling risk of injury as a function of experience and have the additional benefit of interpretability over other similarly flexible models.

Background The practice of using medical service claims in epidemiologic research on hypertension is becoming increasingly common, and several published studies have attempted to validate the diagnostic data contained therein. However, very few of those studies have had the benefit of using actual measured blood pressure as the gold standard. The goal of this study is to assess the validity of claims data in identifying hypertension cases and thereby clarify the benefits and limitations of using those data in studies of chronic disease etiology. Methods Disease status was assigned to 19,150 employees at a U.S. manufacturing company where regular physical examinations are performed. We compared the presence of hypertension in the occupational medical charts against diagnoses obtained from administrative claims data. Results After adjusting for potential confounders, those with measured blood pressure indicating stage 1 hypertension were 3.69 times more likely to have a claim than normotensives (95% CI: 3.12, 4.38) and those indicating stage 2 hypertension were 7.70 times more likely to have a claim than normotensives (95% CI: 6.36, 9.35). Comparing measured blood pressure values identified in the medical charts to the algorithms for diagnosis of hypertension from the claims data yielded sensitivity values of 43-61% and specificity values of 86–94%. Conclusions The medical service claims data were found to be highly specific, while sensitivity values varied by claims algorithm suggesting the possibility of under-ascertainment. Our analysis further demonstrates that such under-ascertainment is strongly skewed toward those cases that would be considered clinically borderline or mild.