Occupational and environmental exposures and nonspecific lung disease--a review of selected studies

Selected studies show that nonspecific lung diseases are a major occupational and environmental health hazard. Exposure to mineral dusts (such as cement and brown coal) and organic dusts (cotton, hemp and flour) as well as manganese and gaseous irritants causes significant upper respiratory tract injury. Possible additive effects of mixed exposures, combined exposure to dusts and gaseous irritants of the upper respiratory tract, individual susceptibility, and mechanisms of nonspecific respiratory effects of exposures are considered. Interpretation of the results is difficult due to uncontrolled confounding. Measures for preventing lung impairments include exposure reduction and preemployment examination of workers.     

Potential health hazards from lead shielding

Uncoated metallic lead is widely used as radiation shielding in research and development, nuclear medicine and radiology, and various manufacturing processes. The common use of lead shielding, however, may present an insidious health hazard due to lead dust. Field and laboratory measurements were collected to evaluate the distribution and removal of lead from radiation shielding material as well as to measure airborne exposures during large shielding emplacement projects. The data indicate that lead is readily dispersed from visibly oxidized as well as freshly-cleaned shielding, but that a single coating of polyurethane can reduce lead removal by nearly three orders of magnitude. Although 8-hour time-weighted average exposures for workers constructing lead shielding structures were nearly all below the Occupational Safety and Health Administration's action level of 30 micrograms/m3 (due to short work periods), the distribution of airborne lead concentrations during this kind of work demonstrates a potential for overexposure.     

Cytogenetic and molecular analysis of cellular atypical mesoblastic nephroma

An epidemiological survey was carried out on 332 workers in a nitrogen fertilizer factory exposed to various levels of NO, NO2, NO3- and NH3. The population was divided into six groups as a function of the atmospheres in the different workshops and compared with a control group recruited outside the factory. We investigated the relations between the exposures of the different groups and serum levels of three nitrogen-containing derivatives involved in arginine metabolism: nitrates, creatinine and urea. The workers most exposed to the hydrogenated and oxygenated compounds of nitrogen were found to have the highest serum nitrates. Further analysis of the results showed that inhaled nitrogen oxides and ammonia were only partly responsible for the circulating nitrates. The excess nitrates were thought to have an endogenous origin due to inflammatory reactions induced by the pollutants, especially ammonia. In addition, we showed that the workers from the two groups exposed to both NO and NH3 had significantly elevated levels of serum creatinine (P < 0.001). The excess creatinine was thought to have derived from the interaction of the exogenous NO with arginine metabolites.     

Rapid detection of different RNA respiratory virus species by multiplex RT-PCR: application to clinical specimens

Inconsistent findings from recent mortality studies of workers exposed to magnetic fields have led to calls for more detailed understanding of exposure distributions and metrics in various industries. The authors undertook personal monitoring at an automobile transmission plant to (a) learn if magnetic field exposure differences were present, (b) make assignments for a brain cancer study, and (c) compare two exposure indices. A wide range of average exposures occurred (i.e., 0.016-4.6 microtesla). Within-day variability was also large, and it reached 4 orders of magnitude for some workers. Unexpectedly, demagnetizers were found among the strong sources that contributed to elevated exposures. The authors used conventional summary measures to assign job groups to exposure categories, and they used a new index of exposure irregularity to make alternative assignments. These new assignments appeared to differ from the original ones with respect to work time in each exposure group (i.e., 54% of the work time fell into different exposure categories).     

Some occupational exposures as risk factors for malignant lymphomas

BACKGROUND: Malignant lymphomas (Hodgkin disease [HD] and non-Hodgkin lymphoma [NHL]) have been subject to several epidemiologic studies and found to be associated with various environmental exposures, especially solvents, wood, and phenoxy herbicides. METHODS: Various determinants for HD and NHL were evaluated in a case-referent study encompassing 31 cases of HD, 93 cases of NHL, and 204 referents, all alive. Information on these determinants, mainly occupational exposures, was obtained by mailed questionnaires. RESULTS: Crude odds ratios were increased for various occupational exposures, i.e., exposures to solvents, pesticides, metal fumes, welding, and fresh wood, and nursing. Further analyses based on logistic regression indicated exposure to phenoxy herbicides and fresh wood among sawmill workers, lumberjacks, and paper pulp workers to be significant risk factors for HD. Welding, working as a lumberjack, nursing, and ex-smoking were associated with a significantly increased risk for NHL. Radiographic examinations were negatively associated with HD, as was office work for NHL. CONCLUSIONS: The results were mainly in agreement with the findings of earlier studies, but diverging associations also appeared.     

Should infection control practitioners do follow-up of staff exposures to patient blood and body fluids?

BACKGROUND: The purpose of this study was to determine the efficiency of a joint infection control/occupational health program for the follow-up of accidental blood or bloody body fluid exposures in health care workers. METHODS: A comprehensive staff follow-up program for all blood exposures with known patient sources was initiated in 1989, consisting of patient follow-up by the Infection Control Department (risk assessment for hepatitis B virus [HBV] and [HIV] infection and obtaining of consent for HIV testing) and staff follow-up by the Occupational Health Department. In 1992 a mailed survey was conducted to examine exposure follow-up policies and responsibilities in large teaching hospitals across Canada. RESULTS: A total of 924 blood exposures with known patient sources were reported between January 1989 and December 1993. HIV and HBV screening was obtained for 67.9% and 87.6% of patients assessed as at low risk and 82.3% and 92.2% of those assessed as at high risk for infection, respectively. Two previously unknown HIV-seropositive patients were identified, one of whom had been classified as at low risk (one of 530 [0.19%] patients at low risk who underwent screening). Primary reasons for screening being missed were patient discharge (46.3%) or communication problems (18.0%). The requirement for informed written consent before HIV screening accounted for the difference in completed HIV and HBV screens. Results of the hospital survey indicated that 40.8% of Canadian hospitals follow up all patients who are involved in blood exposures; however, most hospitals still rely on the physician to obtain consent (87.6%). CONCLUSIONS: Use of ICPs to screen patients involved in staff blood exposures during regular hours may be the most efficient method of follow-up, particularly if supplemented by a backup team of health professionals on nights and weekends. Although screening all patients for HBV/HIV may detect patients with undisclosed high-risk behaviors, institutions must decide whether the practice is cost-effective in areas of low prevalence.     

Left ventricular perimysial collagen fibers uncoil rather than stretch during diastolic filling

Workers in the pulp and paper industry are exposed to different substances, such as hydrogen sulfide and other reduced sulfur compounds, chlorine, chlorine dioxide, sulfur dioxide, terpenes, and paper dust. The exposure level depends on the process, i.e., sulfite, sulfate, groundwood, bleachery, or paper production. Hitherto, exposures have been poorly described and more studies are certainly needed. Workers with repeated exposure peaks to chlorine, e.g., bleachery workers, seem to have an impaired lung function and an increased prevalence of respiratory symptoms. Exposure to high levels of paper dust, (> 5 mg/m3) causes impaired lung function. Therefore, exposure to respiratory irritants is an important, and probably overlooked, occupational risk among certain groups of pulp and paper workers. Some studies indicate that sulfate workers with high exposure to reduced sulfur compounds have an increased mortality due to ischemic heart disease. However, before any definite conclusions can be drawn, the impact of important confounders, such as shift-work and smoking habits have to be further evaluated.     

Ethical guidelines for physician compensation based on capitation

The effectiveness of one particular shrouded tool type in capturing composite dust generated during dry machining operations was tested. The effectiveness of the shrouded tool was measured by comparing exposures during identical operations done by the same workers. The operation was conducted by dividing the time into two equal portions, one using an unshrouded tool and the other with same tool shrouded. The operations included sanding and grinding operations of fibrous glass/epoxy composite materials. Unshrouded short-term exposures ranged from 2.17 mg/m3 to 50.81 mg/m3. There was a significant reduction in exposure using the shroud (paired t-test, p = 0.005). The effect of a shroud on respirable dust exposures was inconclusive, because of the limited amount of respirable dust collected in these short-term samples.     

Clinical and endocrine diagnosis of pheochromocytoma

A cross-sectional study of 63 current and former aluminum potroom workers and 37 comparison workers was conducted to evaluate for evidence of neurological dysfunction, including tremor from long-term exposures to aluminum using sensitive quantitative measures of arm/hand and leg tremor. Signs of upper extremity tremor were also evaluated by neurological examination and compared with the quantitative measures of arm/hand tremor. Both arm/hand and leg tremor were measured using fatiguing test conditions, but no statistically significant differences due to exposure to aluminum were present between the potroom workers and the comparison workers. The neurological examination also showed no statistically significant differences between the groups on the evaluation of signs of tremor. These results do not support the findings of Best-Pettersen et al., who reported evidence of increased tremor in aluminum workers using the static steadiness test in the Halstead-Reitan battery. Differences between the studies that may have contributed to the contrasting results are discussed. In addition, techniques are presented for using microcomputer-controlled devices to evaluate tremor in both the visible (1-6 Hz) and nonvisible (7-18 Hz) frequencies of the tremor spectrum.     

Pertinent consumer issues in choosing a counseling professional.

In Study 1, 43 counselors (with MAs and PhDs), psychiatrists, clinical psychologists, and social workers completed a questionnaire evaluating issues in the literature as to their pertinence to the consumer in choosing a counseling professional. The most and the least pertinent issues are presented, as assessed by counseling professionals and clients. Counselors and psychiatrists were compared in their rankings. A significant positive correlation was found between the 2 groups. Study 2 utilized 39 17–61 yr old clients of counseling professionals in 4 categories: counselors (MA and PhD), psychiatrists, clinical psychologists, and social workers. Clients also completed the same questionnaire as in Study 1. Five items that differed significantly among clients' responses in the 4 professional counseling groups are presented. Results from both studies indicate the presence of general unifying concepts pertinent to consumer evaluation of potential counseling professionals. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Medical surveillance of the lead exposed worker. Current guidelines

1. The "lead standards" established by OSHA for general industry in 1978 and the construction industry in 1993 require employers and clinicians to follow very specific guidelines for protecting lead exposed workers. Depending on the level of exposure, medical surveillance may be legally required. 2. Lead affects multiple body systems and can cause permanent damage. Low level exposures that in the past were thought safe are now considered hazardous as new information emerges about the toxicity of lead. 3. Lead poisoning, if undetected, often results in misdiagnosis and costly care. Adults are exposed to lead in many different workplace settings. All clinicians caring for lead exposed workers need to be informed about the health effects of lead, employer and physician responsibilities, and worker rights. 4. Occupational and environmental health nurses can help identify workers at risk and prevent lead poisoning by education and early intervention through collaboration with the workers, the employer, the company physician, and other health and safety professionals.     

Health survey of former workers in a Norwegian coke plant: Part 2. Cancer incidence and cause specific mortality

OBJECTIVES: A Norwegian coke plant that operated from 1964 to 1988 was investigated to ascertain whether the male workers in this plant had increased morbidities of cancer or increased mortality from specific causes, particularly associated with specific exposures at the coke plant. METHODS: Personal data on all the employees of the plant were obtained from the plant's archives. With additional data from the Norwegian Bureau of Statistics we identified 888 male former workers at the plant. Causes of death were obtained from the Norwegian Bureau of Statistics, and cancer diagnoses from the Norwegian Cancer Registry. The results were compared with national averages adjusted for age. Specific exposures were estimated with records of actual measurements done at the plant and interviews with former workers at the plant. RESULTS: A significant excess of stomach cancer (standardised incidence ratio (SIR) 2.22, 95% confidence interval (95% CI) 1.01 to 4.21) was found. Mortality from ischaemic heart disease and sudden death was positively associated with work in areas which entailed peak exposures to CO. When considering work in such areas the past 3 years before death, the association was significant (p = 0.01). The last result is based on only two deaths. CONCLUSIONS: Considering the short follow up time and the small size of the cohort the results should be interpreted with a certain caution. The positive results would justify a re-examination of the cohort at a later date.     

Religiosity as a protective or prognostic factor of depression in later life; results from a community survey in The Netherlands

OBJECTIVES: This study explored the possibility of using urinary 1-naphthol excretion as a marker of complex exposure among workers handling creosote. METHODS: Urine specimens of 6 workers from a creosote impregnation plant, where railroad ties were impreganted with coal tar creosote, were collected during 1 workweek, and the concentration of 1-naphthol was determined. 1-Naphthol in spot urine samples of 5 occupationally nonexposed male smokers was used as the background reference. Concurrently, naphthalene and 10 different polycyclic aromatic hydrocarbons (PAH) were determined in personal air samples. RESULTS: The mean airborne exposure of the workers was 1.5 mg/m3 for vaporous naphthalene, 5.9 micrograms/m3 for particulate PAH and 1.4 micrograms/m3 for PAH with 4-6 aromatic rings. The mean urinary concentration of 1-naphthol at the end of the workshift was 20.5 (range 3.5-62.1) mumol/l, whereas the referents' urinary concentration was below the detection limit (0.07 mumol/l). Airborne naphthalene correlated fairly well with 1-naphthol when measured at the end of the shift (r = 0.745). CONCLUSIONS: This method of analysis for 1-naphthol is sufficiently sensitive for measuring low occupational exposures to naphthalene. Low background exposures are, however, unlikely to result in detectable urinary levels of 1-naphthol. Since naphthalene is the most abundant compound in creosote vapor, urinary 1-naphthol determination serves well as a biological marker of exposure to vaporous creosote. Urinary 1-naphthol alone is not, however, a suitable marker for inhalatory or cutaneous exposure to PAH originating from creosote.     

Varicella zoster virus in the health care setting: risk and management

1. Varicella zoster poses a threat to clients and staff in health care settings because of its ease of transmission and incidence of complications in those over age 20, neonates, and the immunocompromised. 2. Risk surveillance of personnel via a comprehensive screening program will establish the pool of seronegative (or "at risk") health care workers. 3. Clear policies on restricting client admission or visitors, and work restrictions for health care workers related to varicella will aid in preventing outbreaks in the health care setting. 4. Prompt follow up of exposures is best accomplished using an established protocol for loss control.     

Gender differences in job strain, social support at work, and psychological distress.

Using the demand-control-support model of job strain, the authors examined gender differences in the relationship between psychosocial work exposures and psychological distress in a cross-sectional sample of 7,484 employed Canadians. Compared with low-strain work, high-strain and active work were associated with a significantly higher level of distress in both men and women. Differences in psychological distress in relation to psychosocial work exposures were greater for men than for women. Low social support was associated with higher distress across all categories of job strain, and the combined effect of low social support and high job strain was associated with the greatest increase in distress. This pattern was similar in men and women. This study suggests that psychosocial work exposures may be a more significant determinant of psychological well-being in male workers compared with female workers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asbestos: current knowledge and perspectives

Diseases due to asbestos inhalation are not only a concern for occupational physicians, but also for general practicioners and pneumologists. The real or supposed risk has extended beyond the factories employing "primary asbestos workers" to thousands of people exposed to this material or simply working in buildings insulated with asbestos. The spectrum of asbestos-related diseases has changed: asbestosis (parenchymal fibrosis due to asbestos) tends to disappear, whereas the incidence of pleural lesions, which can be associated with lower cumulative exposures, increases. Patients with asbestos related diseases do not die any more from respiratory failure but from late neoplastic complications, such as mesothelioma and lung cancer. The lack of interest and of training in occupational medicine leads to an underrecognition and an underestimation of cancers due to asbestos by the physicians. Recent progresses in CT imaging and evaluations of exposure to fibers through mineralogical analysis of lung samples have led to improve the diagnostic approach of fiber-related diseases.     

Metabolic and functional consequences of successive no-flow and sustained low-flow ischaemia; a 31P MRS study in rat hearts

Sawmill workers in British Columbia (B.C.), Canada, have been exposed to chlorophenate fungicides which are known to be contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Due to concern about the potential of these workers to have significant body burdens of PCDD/Fs, and the absence of measurements in these workers, a single-compartment pharmacokinetic model was developed to estimate the concentration of PCDD/Fs in the fat tissue of the sawmill workers. Data from a large cohort of B.C. sawmill workers and literature-based data on chlorophenate exposures and PCDD/F concentrations in chlorophenates were used in Monte Carlo simulations to predict a PCDD/F body burden distribution. The median concentrations of HxCDF and HpCDF predicted using the model for the B.C. sawmill worker population exceeded the range measured in unexposed populations. PeCDF and OCDF concentrations exceeded the range measured in unexposed populations at the 70th percentile of the model-predicted distribution, and PeCDD at the 90th percentile. The primary limitation of the model was the scarcity of input data about actual dermal and inhalation exposures to chlorophenates.     

Sex and ethnic differences in the use of power.

Hypothesized that women and Chicanos would make less internal and more external attributions for their own successful performance than would Anglo males. 40 Chicano male, 40 Chicano female, 40 Anglo male, and 40 Anglo female undergraduates participated as managers in an industrial simulation study. Ss were randomly assigned to 1 of 4 experimental conditions: designated powers vs unspecified powers, and supervision of male or female workers. Following the managerial task, Ss completed a questionnaire assessing their own performance and that of their workers. All Anglos devalued their workers as a function of controlling power and attributed workers' performance to external factors. All Ss tended to use their power to persuade workers. Males attempted to influence workers to a greater degree than did females. The predicted sex differences in terms of attribution were evident only among Anglos. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monitoring liver disorders in vinyl chloride monomer workers using greyscale ultrasonography

Recognition that vinyl chloride could be hepatotoxic led to a survey of workers to determine whether changes had been induced by past exposure, and to evaluate standard liver function tests as monitors of early liver abnormalities. Standard liver function tests were found to be unsuitable for the detection of such abnormalities in the population at risk. Of 487 workers examined, 102 (20-9%) had abnormalities on initial testing but only two were finally shown to have portal hypertension; in both cases, thrombocytopaenia provided the first diagnostic evidence since liver function tests were normal. Furthermore, 40 (35-7%) of 112 control subjects had initial test abnormalities. A sample of 19 workers with various exposures to vinyl chloride monomer were examined blind by greyscale ultrasonography. Five with minimal or no exposure were confirmed as normal but 12 of the remainder had abnormalities. These consisted of an enlarged portal vein (seven instances), splenomegaly (eight), and changes in hepatic texture (seven). Five of these 12 cases had previously been considered normal. It was concluded that greyscale ultrasonography had many advantages over standard methods for screening workers exposed to hepatotoxic chemicals, and should be the subject of a large scale evaluation.     

Sleepiness as measured by modified multiple sleep latency testing varies as a function of preceding activity

Although female breast cancer rates are lower in China than in Western countries, rates have been rising rapidly in China. This increase may be due to changes in established breast cancer risk factors, but it is possible that exposure to occupational and environmental carcinogens in Shanghai also have contributed to the rise in incidence. We used data collected by the Shanghai Cancer Registry and the Chinese Third National Census to study the risk of breast cancer by occupation and by occupational exposures. Standardized incidence ratios (SIRs) were used to compare observed cases to expected numbers of cases, based on the incidence rates for Shanghai and the number of women in each occupation according to the 1982 census. Statistically elevated SIRs for breast cancer were seen for a number of professional occupational categories, with the greatest risk seen among scientific research workers (SIR = 3.3). Administrative clerks, political and security personnel, and makers of rubber and plastics products also had significant excesses. Significant deficits of risk were seen for the categories of production and related workers, construction workers, and transportation equipment operators. For specific occupations, the highest SIRs were observed among doctors of Chinese-Western medicine (SIR = 14.7, 95% CI = 5.9-30.3) and doctors of Chinese medicine (SIR = 7.2, 95% CI = 4.4-11.4). We also found excesses among teachers at each level of education, librarians, clerical workers, electrical and electronic engineers, nurses, lab technicians, accountants and bookkeepers, rubber manufacturing products makers, weavers, and knitters. SIRs were significantly elevated for high probability of exposure to organic solvents (SIR = 1.4). For benzene exposure, we found significant excesses for overall exposure (SIR = 1.1) and for medium level of exposure (SIR = 1.3). There was no evidence of an association between risk and electromagnetic fields (EMF) exposure. Based on a small number of exposed, SIRs were elevated for both medium probability and high level of exposure to pesticides. The elevations in occupations reported here support some previous reports. Our finding of an increased risk associated with benzene also has been reported previously; the finding for organic solvents is new. However, the literature on the risk of breast cancer related to occupational exposures is limited and there is no consistent body of literature for any of the exposures studied here. Further, many comparisons were made and the problem of multiple hypothesis testing cannot be ignored in a survey such as ours.