bluuebunny/crossref_metadata_2025 huggingface dataset:
A cross sectional study of the independent effect of occupation on lung function in British coal miners.
Authors: Lewis S , Bennett J , Richards K , Britton J
Published: December 2008

BACKGROUND: Chronic bronchitis and emphysema are now recognised complications of occupational exposure to coal dust, and since 1992 compensation has been available for miners with impaired lung function provided that they also have x ray film evidence of pneumoconiosis. However, many miners with heavy exposure to coal dust and impairment of lung function therefore do not qualify for compensation because they do not have simple pneumoconiosis. In the present study attempts were made to determine whether coal mining is an independent risk factor for impairment of lung function in a group of Nottinghamshire miners with no evidence of simple pneumoconiosis, by comparing these men with a group of local controls who were not occupationally exposed. METHOD: Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were obtained on 1286 miners with no evidence of pneumoconiosis on x ray film. Lung function data were also obtained from a random sample of 567 men aged between 40 and 70 living in a district of Nottingham and who had never worked in the mining industry or in any other dusty occupation. Multiple linear regression in SPSS was used to estimate the mean independent effect of mining on FEV1 and FVC after adjustment for age, height, and smoking, in all miners and controls, and in a subgroup of men of 45 and under. In men of 45 and under, the independent effects of mining and smoking on the probability of a deficit of one litre or more from modelled predicted FEV1 values were computed with logistic regression in EGRET. RESULTS: There was a significant mean effect of mining on FEV1 after adjustment for age, height, and smoking of -155 ml (95% confidence interval (95% CI) -74 to -236 ml, P < 0.001), but the size of effect was inversely related to age such that in men of 45 and under the estimated mean effect of mining was -251 ml (95% CI -140 to -361 ml, P < 0.001). In this subgroup of younger men, 4.7% of miners and 0.7% of controls had a deficit of one litre or more from predicted FEV1 values, and in logistic regression, there was a marginally significant independent effect of both smoking (P = 0.05) and mining (P = 0.07) for a deficit of this magnitude. CONCLUSIONS: Occupational exposure to coal dust is associated with a small mean deficit in lung function even in the absence of simple pneumoconiosis, and independently from the effects of smoking. The requirement that miners should have evidence of pneumoconiosis to qualify for compensation for impaired lung function is therefore unjustified.
Predicting duration of sleep from the three process model of regulation of alertness.
Authors: Akerstedt T , Folkard S
Published: December 2008

OBJECTIVES: Irregular working hours severely disturb sleep and wakefulness. This paper presents a modification of the quantitative (computerised) three process model of regulation of alertness to predict duration of sleep in connection with irregular sleep patterns. METHODS: The model uses a circadian "C" (sinusoidal) and homeostatic "S" (exponential) component (the duration of previous periods awake and asleep), which are summed to yield predicted alertness (on a scale of 1-16). It assumes that waking from sleep will occur at a given alertness level (S' + C') when recuperation is complete. Variables of electroencephalographic duration of sleep from two studies of irregular sleep were used to model the S and C variables in a regression approach to maximise prediction. The model performance was cross validated against published field and laboratory data. RESULTS: The model parameters were defined with a high degree of precision R2 = 0.99 and the validation yielded similar values R2 = 0.98-0.95, depending on the acrophase. The paper also describes a simplified graphical version of the computation model seen as a two dimensional duration of sleep nomogram. CONCLUSION: The model seems to predict group means for duration of sleep with high precision and may serve as a tool for evaluating work and rest schedules to reduce risks of sleep disturbances.
Occupational risk factors for female breast cancer: a review.
Authors: Goldberg M S , Labrèche F
Published: December 2008

OBJECTIVES: Although progress has been made in identifying personal risk factors and in improving treatment for female breast cancer, incidence rates continue to increase. With women now occupying a sizable fraction of the workforce, it is worth inquiring whether there are occupational risk factors for breast cancer. This is a review of occupational studies on female breast cancer. METHODS: Suitable reports and published articles with associations of female breast cancer and occupation were identified from technical reports, by searching the MEDLINE bibliographic data base, and by reviewing each paper on cancer that was published in 20 major journals during the period from about 1971-94. RESULTS: A total of 115 studies were identified; 19 studies relied exclusively on data collected for administrative purposes, and there were four incident case-control studies and 92 cohort studies. Although data for individual industries, occupations, and exposures were sparse, there was limited evidence of an association with employment in the pharmaceutical industry and among cosmetologists and beauticians. Associations were also found for chemists and occupations with possible exposure to extremely low frequency electromagnetic fields, but potential methodological weaknesses preclude drawing any definite conclusions. There was little support for increased risks among textiles workers, dry cleaning workers, and nuclear industry workers. CONCLUSIONS: Few high quality occupational studies directed specifically toward women have been carried out to allow the unambiguous identification of occupational risk factors for breast cancer. It is suggested that investigations that account for non-occupational risk factors and that assess exposure in a more detailed way be carried out. One strategy already suggested is to conduct population based, case-control studies in which subjects are interviewed about their occupational histories and exposure to chemical and physical agents which are then attributed from the job descriptions by a team of experts. These studies can then be supplemented when necessary with cohort studies of specific populations.
Investigation on neurotoxicity of occupational exposure to cyclohexane: a neurophysiological study.
Authors: Yuasa J , Kishi R , Eguchi T , Harabuchi I , Kawai T , Ikeda M , Sugimoto R , Matsumoto H , Miyake H
Published: December 2008

OBJECTIVES: To examine the effect of occupational exposure to cyclohexane on the peripheral nervous system. METHODS: A nerve conduction study was performed on 18 workers exposed to cyclohexane in a luggage factory and on age and sex matched occupationally unexposed controls. 12 workers had been exposed to n-hexane (median 2.8 years) before the start of exposure to cyclohexane. To confirm the effect of exposure, a follow up study was performed on nine workers one year after the first study. The mean exposure to cyclohexane was 1.2 years in the first study. A symptom survey was performed. The exposure was measured by air sampling of the breathing zone of each worker. The urinary metabolite cyclohexanol was also monitored. RESULTS: The concentration of airborne cyclohexane ranged from 5 to 211 ppm. The urinary concentration of cyclohexanol ranged from 0.12 to 1.51 mg/l. There was a strong correlation between the cyclohexane exposure in personal air and urinary cyclohexanol. No differences were found in nerve conduction velocities (NCV) between workers exposed to cyclohexane and age and sex matched controls. The results of the follow up study showed significant improvements in peroneal motor NCV (P < 0.01) and sural sensory NCV (P < 0.05) and in ulnar motor distal latency (MDL, P < 0.05) and peroneal MDL (P < 0.05) compared with the first study. Although the past n-hexane exposure affected the first neurophysiological study, the effect had disappeared in the second study, one year later. CONCLUSION: Occupational exposure to the concentrations of cyclohexane experienced in this study had no adverse effects on the peripheral nervous system.
Distribution and determinants of personal exposure to nitrogen dioxide in school children.
Authors: Linaker C H , Chauhan A J , Inskip H , Frew A J , Sillence A , Coggon D , Holgate S T
Published: December 2008

OBJECTIVES: To assess the distribution of personal exposures to nitrogen dioxide (NO2) in school children, and to investigate factors that might influence personal exposure. METHODS: NO2 exposures were assessed by use of passive diffusion tubes for 46 children aged 9-11 years, selected from two Southampton schools. The tubes were worn for seven days, and parallel measurements were made with static samplers in the child's kitchen, living room, classroom, and playground. Information about potential exposures was collected by questionnaire. RESULTS: Personal exposures to NO2, averaged over seven days, ranged from 11 to 257 micrograms/m3 (6 to 137 ppb) with a geometric mean of 36 micrograms/m3 (19 ppb). Exposures correlated with concentrations of NO2 recorded in the home, but the relation was far from exact. Factors associated with increased personal exposure included the use of gas appliances in the home, living with one or more smokers, and travel to school by means other than a car. However, together these variables only explained a small part of the variation in personal exposures. CONCLUSIONS: These findings reinforce the need for personal monitoring of exposure in studies investigating potential health effects of NO2 in children.
Glutathione transferase activity and formation of macromolecular adducts in two cases of acute methyl bromide poisoning.
Authors: Garnier R , Rambourg-Schepens M O , Müller A , Hallier E
Published: December 2008

OBJECTIVES: To determine the activity of glutathione transferase and to measure the S-methylcysteine adducts in blood proteins, after acute inhalation exposure to methyl bromide. To examine the influence of the polymorphism of glutathione-S-transferase theta (GSTT1) on the neurotoxicity of methyl bromide. METHODS: Two workers acutely exposed to methyl bromide with inadequate respiratory protective devices were poisoned. Seven weeks after the accident, blood samples were drawn from both patients, for measurement of glutathione transferase activity in erythrocytes (conjugator status--that is, GSTT1 phenotype) and measurement of binding products of methyl bromide with blood proteins. Conjugator status was determined by a standard procedure. The binding product of methyl bromide, S-methylcysteine, was measured in globin and albumin. RESULTS: Duration and intensity of exposure were identical for both patients as they worked together with the same protective devices and with similar physical effort. However, one patient had very severe poisoning, whereas the other only developed mild neurotoxic symptoms. The first patient was a "conjugator" with normal glutathone transferase activity, whereas this activity was undetectable in the erythrocytes of the second patient, who consequently had higher concentrations of S-methylcysteine adduct in albumin (149 v 91 nmol/g protein) and in globin (77 v 30 nmol/g protein). CONCLUSIONS: Methyl bromide is genotoxic and neurotoxic. Its genotoxicity seems to be the consequence of the alkylating activity of the parent compound, and conjugation to glutathione has a protective effect. The data presented here suggest a different mechanism for methyl bromide neurotoxicity which could be related to the transformation of methylglutathione into toxic metabolites such as methanethiol and formaldehyde. If such metabolites are the ultimate toxic species, N-acetylcysteine treatment could have a toxifying rather than a detoxifying effect.
Incidence of cancer among Norwegian boiler welders.
Authors: Danielsen T E , Langård S , Andersen A
Published: December 2008

OBJECTIVES: The cancer incidence among 2957 boiler welders was investigated. The subjects were registered electrical welders from 1942 to 1981. A subcohort of 606 stainless steel welders was studied separately. METHODS: The investigation was a historical prospective cohort study based on a national registry. The loss of follow up was 4.9%. RESULTS: There were 625 deaths (659 expected). There were 269 cancer cases (264 expected). An excess of lung cancer was found; 50 cases v 37.5 expected. There were three cases of pleural mesotheliomas v 1.1 expected. The subcohort of stainless steel welders had six cases of lung cancer v 5.8 expected, and one case of pleural mesothelioma v 0.2 expected. CONCLUSIONS: The welders in the study were assumed to represent a qualified work force. These welders had a small excess risk of lung cancer. The excess risk did not seem to be associated with stainless steel welding. Smoking and asbestos exposure were potential confounders.
Dust exposure, respiratory symptoms, and longitudinal decline of lung function in young coal miners.
Authors: Carta P , Aru G , Barbieri M T , Avataneo G , Casula D
Published: December 2008

OBJECTIVES: To study the role of dust exposure on incidence of respiratory symptoms and decline of lung function in young coal miners. METHODS: The loss of lung function (forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow (MEF), carbon monoxide transfer factor (TLCO)) with time and the incidence of respiratory symptoms in 909 Sardinian coal miners (followed up between 1983 and 1993 with seven separate surveys) has been compared with the past and current individual exposures to respirable mixed coal dust. Multiple linear and logistic regression models were used simultaneously controlling for age, smoking, past occupational exposures, and other relevant covariates. RESULTS: According to the relatively low dust exposures experienced during the follow up few abnormal chest x ray films were detected. In the cross sectional analysis of initial data, significant associations between individual cumulative exposure to dust, decrements in FEV1 and MEFs, and increasing prevalence of respiratory symptoms were detected after allowing for the covariates included in the model. The yearly decline of FVC, FEV1, and single breath carbon monoxide transfer factor (TLCO/VA) was still significantly related to the individual exposure to dust experienced during the follow up, even after allowing for age, smoking, initial cumulative exposure to dust, and initial level of each functional variable. In logistic models, dust exposure was a significant predictor of the onset of respiratory symptoms besides age and smoking. CONCLUSIONS: The results show that even moderate exposures to mixed coal dust, as in our study, significantly affect lung function and incidence of symptoms of underground miners. Although the frequency of chest x ray examination might be fixed at every three or four years, yearly measurements of lung function (spirometry, MEFs, and TLCO) are recommended for evaluation of the respiratory risk from the coal mine environment to assess the need for further preventive interventions.
Lung cancer in asbestos cement workers in Denmark.
Authors: Raffn E , Villadsen E , Engholm G , Lynge E
Published: December 2008

OBJECTIVES: To study the relative and absolute risks of main types of lung cancer in a cohort of asbestos cement workers from Denmark. METHOD: A cohort of 7887 men and 576 women employed between 1928 and 1984 was compiled from the personnel files of Danish Eternit Production. The cohort was followed up for deaths, emigrations, and incident cancer cases during the period 1943-90. The observed number of lung cancer cases in the cohort was compared with the expected number based on incidences for the Danish population. Internal comparison was made with Poisson modelling. RESULTS: A total of 226 lung cancer cases were observed (223 men and three women). The standardised incidence ratio (SIR) for all lung cancer among men was 1.7 (observed number 223, expected number 129.7, 95% confidence interval (95% CI) 1.5-2.0). The SIRs were raised for all main types of lung cancer; adenocarcinoma 2.6, squamous cell carcinoma 1.7, and anaplastic carcinoma 1.5. The higher SIR for adenocarcinomas was found particularly with a latency period of 25 years or more. Among the 93 excess lung cancer cases, 36 were squamous cell carcinomas and 32 were adenocarcinomas. CONCLUSION: Asbestos cement work is associated with an increased risk of lung cancer of all main types. During the first 25 years after the start of employment this excess risk is shared almost equally between the different histological types of lung cancer, but the risk of adenocarcinomas is clearly higher after this point.
Occupational exposure to poultry and prevalence of antibodies against Marek's disease virus and avian leukosis retroviruses.
Authors: Choudat D , Dambrine G , Delemotte B , Coudert F
Published: December 2008

OBJECTIVES: To compare the prevalence of antibodies against Marek's disease herpes virus (MDV) and against avian leukosis viruses type C (ALV) in groups of workers exposed to poultry and in unexposed groups. METHODS: Antibodies directed against avian viral proteins were detected by enzyme linked immunosorbent assay in 549 subjects. Exposure to chickens was high in two subgroups: farmers on intensive chicken farms and workers at chicken slaughterhouses. One subgroup, traditional farmers on dairy or pig farms with poultry, had moderate exposure to poultry. Another subgroup, farmers and slaughterhouse workers on quail farms, had high exposure to quails. Three subgroups were not exposed to chickens: farmers on dairy or pig farms without poultry, workers at cattle slaughterhouses, and white collar workers. Also, MDV antibodies were tested after serum sample adsorption with chicken antigens in 134 serum samples. RESULTS: The prevalence of antibodies against MDV was significantly higher in the exposed subgroups than in unexposed groups (odds ratio (OR) 6.17; 95% confidence interval (95% CI) 3.91-9.75). No association was found between seroprevalence and age. However, higher prevalence was found among women and was related to duration of exposure to chickens. The concentration of antibodies from a few subjects remained very high after adsorption. Significant differences between the men and women were found for the prevalence of antibodies for ALV but were not related to exposure to chickens. CONCLUSIONS: The prevalence of antibodies against MDV was significantly higher among workers exposed to chickens and was related to sex and duration of exposure. The higher prevalence of antibodies against avian oncogenic viruses found among women compared with men may be induced by differences in exposure or by genetic factors. The meaning of these high titres could be related to the presence of MDV in humans. Because the involvement of animal oncogenic viruses in human cancer is indicated by epidemiological and some experimental studies, the integration of viral DNA in human cells needs to be investigated.
A bibliometric study of the trend in articles related to epidemiology published in occupational health journals.
Authors: Takahashi K , Hoshuyama T , Ikegami K , Itoh T , Higashi T , Okubo T
Published: December 2008

OBJECTIVES--To study the role assumed by epidemiology in occupational health literature and characterise its change over the years. METHODS--A bibliometric study was conducted with a MEDLINE search to evaluate 9024 articles published in eight representative occupational health journals for the period 1980-93. Articles related to epidemiology were found by descriptors indexed in the articles and their numbers and proportions among all published articles was tabulated for the study period. RESULTS--The proportion of source items indexed by epidemiology as a descriptor increased over threefold from 7.9% (42/534) in 1980 to over 25% after 1990. Epidemiology was indexed most frequently as a subheading associated with other descriptors-for example, occupational diseases-epidemiology. Cohort studies had the largest increase in the descriptors that indicated epidemiological type of studies during the period studied. CONCLUSION--Epidemiology is assuming increasing importance in occupational health literature. This was shown quantitatively and qualitatively by the use of descriptors in the MEDLINE database.
Creatine kinase activities in brain and blood:possible neurotoxic indicator of acrylamide intoxication.
Authors: Matsuoka M , Matsumura H , Igisu H
Published: December 2008

OBJECTIVES--To examine whether the activities of creatine kinase (CK) correlate with neurological disturbances caused by acrylamide. METHODS--The activities of CK and other enzymes reported to be inhibited by acrylamide in the brain and plasma, and landing foot spread (LFS) were measured in mice and rats intoxicated with acrylamide. RESULTS--Activity of CK was suppressed by acrylamide in the brain of mice in parallel with the neurological dysfunction measured by LFS. No clear alterations were found in glyceraldehyde-3-phosphate dehydrogenase, neuron-specific enolase, and lactate dehydrogenase activities over the experimental period (eight days for the exposure and 43 days for the recovery). In rats, among the plasma enzymes examined, suppression of CK activity was most notable, but thyroid activity was not affected. CONCLUSIONS--Among the enzymes so far examined, the CK activities in the brain and blood seem to be the most sensitive indicators of acrylamide intoxication.
Relation of cumulative exposure to inorganic lead and neuropsychological test performance.
Authors: Lindgren K N , Masten V L , Ford D P , Bleecker M L
Published: December 2008

OBJECTIVES--To determine if measures reflecting chronic occupational lead exposure are associated with performance on neuropsychological tests. METHOD--467 Canadian male lead smelter workers (mean (SD) age 43.4 (11.00) years, education 9.8 (3.18) years, years of employment 17.7 (7.43), and current blood lead concentration (B-Pb) 27.5 (8.4) micrograms dl-1) were given a neuropsychological screening battery. Time weighted average (TWA) and time integrated blood levels (IBL) were developed from B-Pb records obtained through regular medical monitoring (mean (range) TWA 40.1 (4.0-66.4) micrograms dl-1, mean IBL 765.2 (0.6-1625.7) micrograms-y dl-1). 14 neuropsychological variables were included in three multivariate analyses of covariance, with each exposure variable as the grouping variable (high, medium, and low) and age, education, score on a measure of depressive symptoms, and self reported alcohol use as the covariates. Groups did not differ in history of neurological conditions. RESULTS--Neither the B-Pb, TWA, nor IBL was significant by multivariate analyses of covariance (MANCOVA). When years of employment, a suppressor variable, was included as a covariate, IBL exposure groups differed significantly on digit symbol, logical memory, Purdue dominant hand, and trails A and B. CONCLUSIONS--A dose-effect relation was found between cumulative exposure (IBL) and neuropsychological performance at a time when current B-Pb concentrations were low and showed no association with performance.
Glioma and occupational exposure in Sweden, a case-control study.
Authors: Rodvall Y , Ahlbom A , Spännare B , Nise G
Published: December 2008

OBJECTIVES: The aim of the study was to analyse whether any job titles, industrial codes, and certain occupational exposures were associated with an increased risk of glioma. METHODS: A population based case-control study of incident primary brain tumours in adults was carried out in Uppsala, Sweden in the period 1987-90. The study included 192 cases of glioma and 192 matched controls. It also included cases with other tumours of the central nervous system with matched controls. Information from all 343 controls was used in this study. Information was collected by means of a questionnaire that was sent to all subjects. An occupational hygienist reviewed the questionnaires for self reported exposures to substances and assessed whether these reported exposures were plausible or not in the corresponding occupation. RESULTS: The kappa coefficient for those classified by the two methods ranged between 0.46 and 0.88, and they were almost the same for cases and controls. For men exposed to solvents a relative risk (RR) of 2.6 (95% CI 1.3 to 5.2) was found. For men exposed to pesticides the RR was 1.8 (95% CI 0.6 to 5.1), and for plastic materials the RR was 3.6 (95% CI 1.0 to 12.4). For men employed in forestry and logging the RR was 2.2 (95% CI 0.9 to 5.3) and in basic metal industries 2.0 (95% CI 1.0 to 4.0). CONCLUSION: An increased risk of glioma was associated with use of solvents, pesticides, and plastic materials but this should be interpreted with some caution.
Mesothelioma in a community in the north of England.
Authors: Edward A T , Whitaker D , Browne K , Pooley F D , Gibbs A R
Published: December 2008

OBJECTIVES: To find the numbers of mesotheliomas in Calderdale over the period 1966-94 and determine their relation to asbestos exposure, pathology, and mineral fibre burden within the lungs of affected subjects. METHODS: Cases were entered into the study if the subject has been diagnosed with mesothelioma after postmortem and histopathological examinations. Occupational data were obtained mainly from the case records of the Cape Asbestos medical officer, hospital, and medical practitioner and from death certificates. Analyses of the mineral fibres were performed with transmission electron microscopy and energy dispersive x ray spectrometry. RESULTS: 73 mesotheliomas were diagnosed from 1966 to 1994. Forty four were associated with exposure at the Acre Mill factory, which manufactured asbestos products. Concentrations of amphibole asbestos fibres were found to be raised above controls in 31 out of 32 cases associated with Acre Mill exposure, in 10 out of 12 other cases exposed to asbestos and eight out of 17 cases not exposed to asbestos. CONCLUSIONS: There was a high number of mesotheliomas in Calderdale. More than half of the cases were associated with occupation at the Acre Mill factory and were associated with exposure to amphibole asbestos, predominantly crocidolite. No cases associated with neighbourhood exposure to asbestos were identified.
Comparison of dust related respiratory effects in Dutch and Canadian grain handling industries: a pooled analysis.
Authors: Peelen S J , Heederik D , Dimich-Ward H D , Chan-Yeung M , Kennedy S M
Published: December 2008

OBJECTIVES: Four previously conducted epidemiological studies in more than 1200 grain workers were used to compare exposure-response relations between exposure to grain dust and respiratory health. METHODS: The studies included Dutch workers from an animal feed mill and a transfer grain elevator and Canadian workers from a terminal grain elevator and the docks. Relations between forced expiratory volume in one second (FEV1) and exposure were analysed with multiple regression analysis corrected for smoking, age, and height. Exposure variables examined included cumulative and current dust exposure and the numbers of years a subject was employed in the industry. Sampling efficiencies of the Dutch and Canadian measurement techniques were compared in a pilot study. Results of this study were used to correct slopes of exposure-response relations for differences in dust fractions sampled by Dutch and Canadian personal dust samplers. RESULTS: Negative exposure-response relations were shown for regressions of FEV1 on cumulative and current exposure and years employed. Slopes of the exposure-response relations differed by a factor of three to five between industries, apart from results for cumulative exposure. Here the variation in slopes differed by a factor of 100, from -1 to -0.009 ml/mg.y/m3. The variation in slopes between industries reduced to between twofold to fivefold when the Dutch transfer elevator workers were not considered. There was evidence that the small exposure-response slope found for this group is caused by misclassification of exposure and a strong healthy worker effect. Alternative, but less likely explanations for the variation in slopes were differences in exposure concentrations, composition of grain dust, exposure characteristics, and measurement techniques. CONCLUSION: In conclusion, this study showed moderately similar negative exposure-response relations for four different populations from different countries, despite differences in methods of exposure assessment and exposure estimation.
Interferences of urinary tract infection in the measurement of urinary nitrous oxide.
Authors: Apostoli P , Gelmi M , Alessio L , Turano A
Published: December 2008

OBJECTIVES: To investigate the effective role of micro-organisms in producing N2O. METHODS: The N2O in either urine samples inoculated with 24 microbial strains or urine samples from patients with urinary tract infections were measured. RESULTS: Gram negative bacilli generally produced high amounts of nitrous oxide (N2O), whereas Gram positive cocci and yeasts did not. The production of N2O depends on the incubation time and follows exponential kinetics, reaching a plateau at 48 hours. Furthermore, the results of urinocultures agreed well with N2O concentrations found in urine samples: samples negative for bacteria were found to contain very low concentrations of N2O whereas those positive--for example, for Enterobacteriaceae--gave highest N2O values. CONCLUSION: The urinary tract infections caused by Gram negative bacilli are important confounding factors in biological monitoring practices of exposure to inhalation anaesthetics. The current methods adopted to avoid these factors (urine acidification, storage of samples at 4 degrees C) are not good enough because of the relative acid tolerance of some strains and the production of N2O directly into the bladder.
Lung cinescintigraphy in the dynamic assessment of ventilation and mucociliary clearance of asbestos cement workers.
Authors: Di Lorenzo L , Mele M , Pegorari M M , Fratello A , Zocchetti C , Capozzi D
Published: December 2008

OBJECTIVES: To verify in vivo whether lung cinescintigraphy confirms the effect of asbestos on the patency of the smallest airways and on the efficiency of mucociliary clearance in asbestos cement workers. METHODS: 39 male subjects were examined: 30 asbestos cement workers and nine workers never exposed to occupational respiratory irritants. All subjects had a chest radiograph (International Labour Organisation (ILO) 1980); standard questionnaire on chronic bronchitis; spirometry; arterial blood gas analysis; carbon monoxide transfer factor (TLcosb); pulmonary O2 and CO2 ductances (DuO2, DuCO2); electrocardiogram; and lung cinescintigraphy after radioaerosol inhalation for the measurement of mucociliary clearance time in vivo in the smallest ciliated airways and for the assessment of radioaerosol deposition in alveoli (alveolar deposition index). RESULTS: Apart from nine non-exposed subjects, the 30 asbestos cement workers were so classified on the basis of chest radiography: nine of them as healthy exposed, 10 with pleural plaques, and 11 with asbestosis. The four groups had similar ages, work seniority, and smoking habits. Exercise dyspnoea was significantly more frequent in asbestos cement workers. Lung function variables of workers with effects related to asbestos were significantly lower than the other two groups. The PaO2, TLcOsb and DuO2 mean values were significantly lower in exposed workers than non-exposed. The mean PacO2 value was significantly higher in the asbestosis group than in the other three groups. Workers with effects related to asbestos showed a significantly lower alveolar deposition index and a significantly higher mucociliary clearance time than the other two groups. Subjects with asbestosis showed similar differences from those with pleural plaques. CONCLUSIONS: Lung cinescintigraphy confirms in vivo the effects of asbestos on bronchiolar and alveolar patency and on efficiency of mucociliary clearance in the smallest ciliated airways. Finally, lung cinescintigraphic variables are able to discriminate workers with asbestosis from those with pleural plaques.
Exposure to hydrogen fluoride: an experimental study in humans of concentrations of fluoride in plasma, symptoms, and lung function.
Authors: Lund K , Ekstrand J , Boe J , Søstrand P , Kongerud J
Published: December 2008

OBJECTIVES: To study the absorption of inhaled hydrogen fluoride (HF) by measuring plasma fluorides and HF concentrations in the breathing zone during exposure to HF. A possible dose-effect relation was investigated by following airway symptoms and lung function-that is, forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)-during and after exposure to HF. METHODS: 20 healthy, male volunteers were exposed for one hour to constant HF concentrations that ranged from 0.2 to 5.2 mg/m3; these concentrations are known to occur among potroom workers in the primary aluminium industry. Plasma fluorides were analysed before, during, and after exposure. Symptoms from the eyes and the upper and lower airways were registered and graded from 1 to 5 with a standardised questionnaire. RESULTS: The total symptom score was significantly increased at the end of exposure for all the subjects as a group (P < 0.01) and for the group exposed to HF below the present Norwegian standard for total fluorides 0.6 mg/m3 (P = 0.05). No change was detected in FEV15 although a significant decrease was found in FVC in the group exposed to fluorides below the hygienic standard (n = 9) and for the entire group (n = 23). Almost all the symptoms had disappeared four hours after the end of exposure. Symptom scores from the upper airways were significantly correlated with the HF concentration (r = 0.62, P = 0.002), the change in plasma fluoride concentration (delta C) (r = 0.51, P = 0.01), and the maximum plasma fluoride concentration (Cmax) (r = 0.42, P = 0.05). A significant correlation was also found between the total symptom score for airways and the HF concentration. CONCLUSIONS: The present study showed a strong relation between inhaled HF and concentrations of fluoride in plasma. Upper airway and eye symptoms occurred after one hour of exposure to HF even when below the Norwegian hygienic standard for fluorides.
Transient increase of serum Clara cell protein (CC16) after exposure to smoke.
Authors: Bernard A , Hermans C , Van Houte G
Published: December 2008

OBJECTIVES: Smoke inhalation is a well known cause of airways injury in firefighting personnel. The aim of this study was to evaluate whether toxic effects of smoke on the respiratory tract can be detected by measuring Clara cell protein (CC16), a recently described serum marker of lung function. METHODS: CC16 was measured by a sensitive latex immunoassay in the serum of six voluntary firefighters from a chemical plant who had inhaled smoke from the combustion of polypropylene for about 20 minutes. The protein was measured immediately after the fire and 10 days later. The values were compared with those of six control workers examined simultaneously. RESULTS: The mean (SD) concentration of CC16 in the serum of firefighters after the fire (54.4 (34.9) micrograms/l) was significantly higher than that of controls (19.5 (11.7), P = 0.04). 10 days later, serum CC16 from firefighters had returned to the concentrations found in controls (15.9 (2.76) v 17.7 (12.5)). With the values at day 10 as a baseline, the rise of serum CC16 was estimated at 328% on average (range 100%-564%). These changes were found in the absence of any functional sign of lung impairment. CONCLUSION: Acute exposure to smoke results in a transient increase of CC16 in serum due most likely to an increased permeability of the bronchoalveolar/blood barrier. Serum CC16 seems potentially to be a new biomarker for the early detection of acute airways injury caused by smoke.
Concentration of cadmium in rice and urinary indicators of renal dysfunction.
Authors: Nakashima K , Kobayashi E , Nogawa K , Kido T , Honda R
Published: December 2008

OBJECTIVES: (1) To examine the relation between concentrations of cadmium (Cd) in rice and urinary concentrations of indicators of renal dysfunction and the prevalence of abnormalities in urine in areas polluted by Cd. (2) To establish the maximum allowable concentration of Cd in rice from these findings. METHODS: The target population consisted of 1703 inhabitants (832 men and 871 women) aged over 50 years who consumed home grown rice and had lived in the same hamlet in areas polluted by Cd in the Kakehashi River basin in Ishikawa Prefecture, Japan for at least 30 years. The correlation coefficients between concentrations of Cd in rice and several urinary substances, the prevalence of abnormalities in urine and sex in hamlets polluted by Cd were calculated. Finally, regression analysis was performed for significant indicators to calculate the maximum allowable concentration of Cd in rice based on values in a control group. CONCLUSIONS: Significant correlations between concentration of Cd in rice and concentrations of urinary beta 2-microglobulin, metallothionein, glucose, and aminonitrogen were established. Similarly, there were significant correlations between concentration of Cd in rice and the prevalence of beta 2-microglobulinuria, metallothioneinuria, glucosuria, proteinuria, proteinuria with glucosuria, and aminonitrogenuria. The highest maximum allowable concentration of Cd in rice calculated for these indicators was 0.34 ppm/l and 0.29 ppm/g creatinine. Both values are lower than 0.4 ppm, the tentative limit prescribed by the Japanese government.
Outcome determinants for isocyanate induced occupational asthma among compensation claimants.
Authors: Tarlo S M , Banks D , Liss G , Broder I
Published: December 2008

OBJECTIVES: To compare the outcome of occupational asthma (OA) induced by isocyanates in Ontario (where a surveillance programme for exposed workers has been in place for over 15 years), with the outcome of OA induced by other work agents. METHODS: Compensated OA claims during the period 1984-88 in Ontario were retrospectively reviewed in a standardised way. RESULTS: 136/235 compensated claims were attributed to isocyanates. Compared with other causes of OA, those attributed to isocyanates had a shorter latent period before onset (5.9 v 7.9 years, P < 0.05), shorter duration of symptoms before diagnosis (2.0 v 3.0 years, P < 0.05), and less associated atopy (43% v 58%, P < 0.05). Outcome at a mean of 1.9 years after initial assessment was significantly better in those with OA induced by isocyanates; 73% cleared or improved v 56% with other causes of OA (P < 0.05). Ten subjects with OA induced by isocyanates stayed at the same work; none cleared and four had worsened at follow up. A better outcome in OA induced by isocyanates was associated with early diagnosis (P < 0.05), and early removal from isocyanates after the onset of asthma. CONCLUSIONS: The outcome in the group with OA induced by isocyanates is similar to previous follow up studies. However, it is better than the outcome in our comparison group with OA due to other causes, perhaps because of earlier diagnosis in the group with OA induced by isocyanates. This may be attributable to the medical surveillance of workers exposed to isocyanates in Ontario, either directly from the surveillance assessments, or indirectly by increasing awareness of the condition.
Occupational asthma due to porcine pancreatic amylase.
Authors: Aiken T C , Ward R , Peel E T , Hendrick D J
Published: December 2008

A case of occupational asthma in a 41 year old histopathology laboratory technician attributable to a powder preparation of the porcine pancreatic enzyme amylase is reported. The diagnosis was confirmed by a double blind, placebo controlled, inhalation challenge study which showed immediate and late asthmatic reactions associated with a significant increase in airway responsiveness to methacholine.
Injuries after falls at work in the United Kingdom and Sweden with special reference to fractures in women over 45.
Authors: McNamee R , Kemmlert K , Lundholm L , Cherry N M
Published: December 2008

OBJECTIVES: To describe the relation with age of risk of reported injury after a fall among women at work in two countries, the United Kingdom and Sweden, with particular emphasis on fractures, and to interpret these data. METHODS: Rates of accidents compiled under the national reporting regulations of each country during a two year period were described by age, sex, cause (fall on the level, fall from a height, other), and occurrence of fracture, with emphasis on the relative risk (RR) in workers aged 45 years and over compared with those aged under 45. For fractures (major fractures only in the United Kingdom) among women, RRs were calculated for all occupations, with the three digit occupational classification schemes of each country. Summary RRs for older versus younger women, directly standardised for occupation, were derived. RESULTS: Among women, RRs for injury after a fall on the level and fall from a height were 2.77 and 1.77 respectively in Sweden and 2.28 and 1.54 in the United Kingdom. When restricted to fractures, the RRs became 4.75 and 3.66 respectively in Sweden and 3.35 and 1.97 in the United Kingdom. Standardisation for occupation gave RRs for fractures of 4.87 and 3.75 in Sweden and 3.43 and 2.16 in the United Kingdom. Almost all occupational groups with enough fractures for analysis showed an excess of fractures related to falls among older women. A different age pattern was seen for all injuries or fracture after other types of accidents and for all types of accident in men. CONCLUSION: It is argued that, for fractures at least, the results for women are unlikely to be due to reporting bias and unlikely to be explained by a greater exposure to workplace hazards among older women. Whether there is an increased risk of falling, as distinct from sustaining a fracture, is not clear. The generality of the increased risk suggest that efforts should be made to minimise hazards in all occupational sectors, particularly those using many women.
Occupational exposure to carcinogens and risk of lung cancer: results from The Netherlands cohort study.
Authors: van Loon A J , Kant I J , Swaen G M , Goldbohm R A , Kremer A M , van den Brandt P A
Published: December 2008

OBJECTIVES: To investigate risk of lung cancers associated with common established carcinogenic occupational exposures (asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes) in a prospective cohort study among the general population, and to estimate the proportion of lung cancer cases attributable to these occupational exposures. METHODS: A prospective cohort study on diet, other lifestyle factors, job history, and cancer risk that started in 1986 in The Netherlands on 58,279 men, aged 55-69 years. Based on information about job history obtained from a self-administered questionnaire, case by case expert assessment was carried out to assign to each study subject a cumulative probability of occupational exposure for each carcinogenic exposure. For analysis, a case-cohort approach was used, in which the person-years at risk were estimated from a randomly selected subcohort (n = 1688). After 4.3 years of follow up, 524 lung cancer cases with complete job history were available. RESULTS: After adjustment for age, each of the other occupational exposures, and for smoking habits and intake of vitamin C, beta-carotene, and retinol, significant associations were found between risk of lung cancer and cumulative probability of occupational exposure to asbestos (relative risk (RR) highest/no exposure = 3.49, 95% confidence interval (95% CI) 1.69 to 7.18, trend P < 0.01 or paint dust (RR highest/no exposure = 2.48, 95% CI 0.88 to 6.97, trend P < 0.01). The population attributable risks (PARs) for the four exposures based on the multivariately adjusted RRs for ever exposed versus never exposed workers were calculated. The PAR of lifetime occupational exposure to asbestos was calculated to be 11.6%. CONCLUSIONS: This prospective cohort study among the general population showed that occupational exposure to asbestos or paint dust is associated with higher RRs for lung cancer. This study shows that after adjustment for smoking and diet about 11.6% of the cases of lung cancer in men is attributable to lifetime occupational exposure to asbestos.
Bronchial reactions to exposure to welding fumes.
Authors: Contreras G R , Chan-Yeung M
Published: December 2008

OBJECTIVES: To study the airway response and its mechanism to welding fumes in six welders with respiratory symptoms. METHODS: Methacholine and welding challenge tests were carried out. The concentration of welding fumes during the exposure test was measured. On two subjects who developed bronchoconstricition to welding challenge, additional tests were carried out including prick, patch, and inhalation challenges with metal salt solutions. RESULTS: Three subjects developed immediate bronchial reaction to exposure to welding fume; one to mild steel and stainless steel welding, another to mild steel and galvanised welding, and one only to galvanised welding. They all had a moderate to pronounced degree of non-specific bronchial hyperresponsiveness. The concentration of fumes during welding tests, particularly to galvanised welding, was high. An inhalation challenge test with zinc chloride salt solution in two subjects who reacted to galvanised welding was negative. Prick and patch tests with zinc chloride were also negative. CONCLUSION: The airway response to welding in these subjects is non-specific and is due to irritation rather than to sensitisation.
Assessment of potential damage to DNA in urine of coke oven workers: an assay of unscheduled DNA synthesis.
Authors: Roos F , Renier A , Ettlinger J , Iwatsubo Y , Letourneux M , Haguenoer J M , Jaurand M C , Pairon J C
Published: December 2008

OBJECTIVES: A study was conducted in coke oven workers to evaluate the biological consequences of the exposure of these workers, particularly production of potential genotoxic factors. METHODS: 60 coke oven workers and 40 controls were recruited in the same iron and steel works. Exposure to polycyclic aromatic hydrocarbons (PAHs) was assessed by job and measurement of 1-hydroxypyrene (1OHP) in urine samples. An unscheduled DNA synthesis assay was performed on rat pleural mesothelial cells used as a test system to evaluate the effect of the workers' filtered urine on the DNA repair capacity of rat cells to determine whether DNA damaging agents are present in the urine of these workers. RESULTS: Urinary concentrations of 1OHP ranged from 0.06 to 24.2 (mean (SD) 2.1 (3.6)) mumol/mol creatinine in exposed coke oven workers, and from 0.01 to 0.9 in controls (0.12 (0.15)). These high concentrations in coke oven workers reflected recent exposure to PAHs and were in agreement with the assessment of exposure by job. No significant difference was found between coke oven workers and controls in the DNA repair level of rat cells treated with urine samples. However, the rat cell repair capacity decreased with increasing 1OHP concentrations in the exposed population (r = -0.28, P < 0.05). CONCLUSIONS: As high concentrations of 1OHP were found in the urine of some workers, a more stringent control of exposures to PAHs in the workplace is required. Exposure to PAHs was not associated with a clear cut modification of the urinary excretion of DNA damaging factors in this test, as shown by the absence of increased unscheduled DNA synthesis in rat cells. However, impairment of some repair mechanisms by urinary constituents is suspected.