bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of construction workers repeatedly exposed to chlorine over a three to six month period in a pulpmill: II. Follow up of affected workers by questionnaire, spirometry, and assessment of bronchial responsiveness 18 to 24 months after exposure ended.
Authors: Bhérer L , Cushman R , Courteau J P , Quévillon M , Côté G , Bourbeau J , L'Archevêque J , Cartier A , Malo J L
Published: December 2008

OBJECTIVE--The aim was to determine the prevalence of persistent respiratory symptoms and bronchial hyper-responsiveness due to reactive airways dysfunction syndrome in a population of construction workers at moderate to high risk of developing the syndrome, at an interval of 18 to 24 months after multiple exposures to chlorine gas during renovations to a pulp and paper mill. DESIGN AND PARTICIPANTS--71 of 289 exposed workers (25%) were identified on the basis of an exposure and the onset of respiratory symptoms shortly after this event (moderate to high risk). A standardised respiratory questionnaire was first presented, followed by spirometry and a methacholine inhalation test on those whose questionnaire suggested the persistence of respiratory symptoms. RESULTS--64 of 71 (90%) subjects completed the respiratory questionnaire at the time of the follow up. The questionnaire suggested a persistence of respiratory symptoms in 58 of the 64 workers (91%). Of the 58 subjects, 51 underwent spirometry and assessment of bronchial responsiveness. All of them used bronchodilators as required (not regularly) and four required inhaled anti-inflammatory preparations. Sixteen had bronchial obstruction (forced expiratory volume in one second) (FEV1 < 80% predicted) and 29 showed significant bronchial hyper-responsiveness. CONCLUSION--Of the subjects (n = 71) who were at moderate to high risk of developing reactive airways dysfunction syndrome after being exposed to chlorine and were seen 18 to 24 months after exposure ended, 58 (82%) still had respiratory symptoms, 16 (23%) had evidence of bronchial obstruction, and 29 (41%) had bronchial hyper-responsiveness.
Airways obstruction, coal mining, and disability.
Authors: Lapp N L , Morgan W K , Zaldivar G
Published: December 2008

It has recently been suggested that the inhalation of coal in the absence of complicated coal workers' pneumoconiosis (CWP) or smoking can lead to disabling airways obstruction. The cause of such obstruction has been variously attributed to emphysema or bronchitis. The frequency of significant airways obstruction in a group of United States coal miners seeking compensation for occupationally induced pulmonary impairment was therefore determined. In a sample of 611 "Black Lung" claimants there was only one subject who was a non-smoker and who in the absence of other non-occupationally related diseases,--for example, asthma and bronchiectasis--had sufficient airways obstruction to render it difficult for him to carry out hard labour. An alternative explanation for his reduced ventilatory capacity other than coal dust or smoking may be available. If the inhalation of coal dust in the absence of smoking and complicated CWP ever induces sufficient ventilatory impairment to preclude a miner from working, it is indeed rare.
Pleural mesothelioma and exposure to asbestos: evaluation from work histories and analysis of asbestos bodies in bronchoalveolar lavage fluid or lung tissue in 131 patients.
Authors: Pairon J C , Orlowski E , Iwatsubo Y , Billon-Galland M A , Dufour G , Chamming's S , Archambault C , Bignon J , Brochard P
Published: December 2008

Exposure to asbestos was evaluated in 131 patients with pleural malignant mesothelioma in the Paris area between 1986 and 1992 using data from a detailed specific questionnaire and light microscopy analysis of the retention of asbestos bodies in bronchoalveolar lavage fluid or lung tissue. Probable or definite exposure to significant levels of asbestos dust was identified in only 48 (36.6%) subjects, and significant asbestos body counts (above 1 asbestos body/ml in bronchoalveolar lavage fluid or 1000 asbestos bodies/g of dry lung tissue) were found in only 45 (34.3%) subjects. Overall 50 subjects had experienced exposure to only low levels of asbestos or no exposure at all and showed no significant retention of asbestos bodies in the biological sample analysed. Previous studies have shown that light microscopy may be useful in the identification of subjects with previous exposure to asbestos. In this study, apart from cases with obvious exposure to asbestos, a large group of subjects seemed to have a history of exposure or lung retention of asbestos bodies suggestive of very low levels of cumulative exposure, similar to those described in the general population.
Chronic interstitial nephropathy after plasma cutting in stainless steel.
Authors: Petersen R , Mikkelsen S , Thomsen O F
Published: December 2008

Chromium is nephrotoxic in experimental animals. In subjects with acute chromium intoxication acute nephritis has been reported and renal function has been affected in chromium exposed workers with a high urinary chromium concentration. Chronic kidney disease after long term occupational exposure to chromium has, however, not been reported previously. A case report is presented concerning a 48 year old man who was diagnosed with chronic interstitial nephropathy. He had worked for nine years as a plasma cutter of stainless steel and had thereby been exposed to smoke containing chromium. At the time of diagnosis his blood chromium concentration was seven times higher and his urinary chromium concentration six times higher than reference values. Taking into account the nephrotoxicity of chromium and the high chromium burden of this patient it is considered likely that his exposure to smoke from plasma cutting of stainless steel was the cause of his chronic interstitial nephropathy.
Differences in the effects of two hexachlorobiphenyls on superoxide generation by polymorphonuclear leucocytes stimulated by N-formyl-methionyl-leucyl-phenylalanine and phorbol myristate acetate.
Authors: Iwata M , Nishihara Y , Watanabe Y , Miyahara M , Saeki K
Published: December 2008

The effects of hexachlorobiphenyls (HCBs) on superoxide (O2-) generation by guinea pig polymorphonuclear leucocytes were examined. 2,3,6,2',3',6'-HCB by itself had only a weak inductive effect on O2- generation. This compound, however, enhanced O2- generation stimulated by N-formyl-methionyl-leucyl-phenylalanine (FMLP) about twofold, but not the generation induced by phorbol myristate acetate (PMA). On the other hand, 3,4,5,3',4',5'-HCB suppressed O2- generation stimulated by both FMLP and PMA. The inhibitory potency of this compound was far greater with PMA (ID50, 5 microM) than with FMLP (ID50, 40 microM).
Impairment of lipoglycoprotein metabolism in rat liver cells induced by 1,2-dichloroethane.
Authors: Cottalasso D , Barisione G , Fontana L , Domenicotti C , Pronzato M A , Nanni G
Published: December 2008

BACKGROUND--1,2-Dichloroethane (DCE) is a volatile liquid readily absorbed through dermal, digestive, or inhalatory routes. After inhalation or oral administration to rats, death occurs within a narrow range of concentrations (six hour LC50 = 5100 mg/m3). Exposure to single high doses of DCE resulted in adverse effects on the central nervous system, liver, kidneys, adrenals, and lungs. The liver showed fatty changes and hepatocellular necrosis with haemorrhage. These injuries are probably related to changes in several cell functions and constituents. Therefore, it was decided to investigate whether DCE was capable of impairing the secretion of hepatocellular lipoglycoproteins acting both at the level of the Golgi apparatus and endoplasmic reticulum. METHODS--Isolated hepatocytes of Wistar rats were prelabelled with two precursors of lipoglycoproteins 3H-Na-palmitate and 14C-glucosamine, and then exposed to concentrations of DCE from mean (SD) 4.4 (0.03) to 6.5 (0.02) mM for different durations ranging from five to 60 minutes. To measure lipid and sugar bound radioactivity, a preliminary separation of cell homogenate, cytosol, total microsomes, Golgi apparatus, and lipoglycoproteins secreted into cell suspension medium was carried out. RESULTS--After five minutes of exposure, DCE did not induce obvious changes in cell viability or lactic dehydrogenase leakage, but a significant (p < 0.01) depletion of reduced glutathione content was seen (40.10 (4.3) nM/10(6) cells). Furthermore, the cells poisoned by DCE started to show noticeable accumulation of 3H-Na-palmitate in the Golgi apparatus after five minutes (5103 (223) dpm/10(6) cells) and in the microsomes after 15 minutes (85,470 (7190) dpm/10(6) cells). There was a simultaneous significant increase in 14C-glucosamine content in the Golgi apparatus (690 (55) dpm/10(6) cells) and the microsomes (15,975 (2035) dpm/10(6) cells). The specific radioactivity of lipid and sugar moieties incorporated in secreted lipoglycoproteins was already significantly reduced after only five minutes of exposure (480 (57) dpm/10(6) cells for lipids, and 315 (45) dpm/10(6) cells for sugars). CONCLUSIONS--Overall, DCE, like other haloalkanes, produces a block of secretion of hepatocellular lipoglycoproteins as early as five minutes after poisoning. The simultaneous percentage increases into Golgi apparatus and microsomes of lipid and sugar bound radioactivity suggest that lipid retention at the sites of processing of lipoglycoproteins would probably play an important part in the early stages of cellular accumulation of fat after exposure to DCE.
Research priorities in occupational medicine: a survey of United Kingdom medical opinion by the Delphi technique.
Authors: Harrington J M
Published: December 2008

An attempt to achieve an agreed set of priorities for research in occupational medicine was undertaken by the Delphi technique. Fifty three senior practitioners of occupational medicine in academe (25) and industry or government (28) were canvassed about their views and choices for priority activity. Forty six (86%) responded to the initial enquiry and 48 (91%) provided rank order choices from a second, more detailed questionnaire. The first priority for more research on the natural history of work related ill health identified musculoskeletal disorders of the back and upper limbs followed by asthma, accidents, skin disorders, vibration induced disease, suicide and depression, and finally hearing loss. The second priority area was audit and particularly the need for its use in occupational health screening procedures. Environmental impact of industrial activity was third with the community health effects being more important than individual health effects. Stress related disease was fourth with emphasis on risk factors. The fifth area was neuropsychological effects of work exposures particularly the need for more research on diagnostic tests. Other assorted areas of concern were the cost effectiveness of occupational health, risk assessment, reproductive hazards, the effects of pharmacological agents, and the development of biomarkers as early evidence of an exposure effect. The remarkable degree of unanimity on the issues and choices and the general agreement between physicians from academe and industry on what constitute the priorities warrants further discussion and positive action.
An investigation of brain tumours and other malignancies in an agricultural research institute.
Authors: Daly L , Herity B , Bourke G J
Published: December 2008

A historical cohort study was carried out in an agricultural research institute in the Republic of Ireland to investigate a perceived excess of cancer deaths among employees. The objectives of the study were (a) to confirm whether or not total or cause specific death rates among selected employees were higher than expected based on national figures, and to quantify any excess, and (b) to identify centres and employee grades associated with any excess risk. The cohort comprised all administrative, research, and technical staff employed for at least two years between 1960 and 1980, giving a final total for analysis of 1323 employees. Employment history was categorised by place of work and employment grade. Deaths among the cohort were identified and causes of deaths verified. Overall the cohort had a lower than expected mortality compared with national rates (O/E = 0.67). Female deaths were too few for analysis but, among the male employees, there was an excess of all cancers (O/E = 1.24; 95% confidence interval (95% CI) 0.8-1.9), in particular brain cancer (O/E = 4.69; 95% CI 1.2-11.4) and bladder cancer (O/E = 9.31, 95% CI 1.9-27.2). The pattern of brain tumour deaths was consistent with an occupational aetiology but it was not possible to identify specific exposures associated with the excess. All four cases occurred among research workers in the plant and soil science area. The pattern of bladder cancers was difficult to interpret. The authors are at present participating in a multicentre study to further investigate cancer risk in laboratory workers.
A case-control study of chronic neuropsychiatric disease and organic solvent exposure in automobile assembly plant workers.
Authors: Nelson N A , Robins T G , White R F , Garrison R P
Published: December 2008

A case-control study of chronic neurological and psychiatric disease and occupational exposure to solvents was carried out in eight automobile assembly plants. Cases included 299 subjects who were granted medical disability retirement in 1980-8. Two control groups were selected, the first from those granted retirement in the same period because of medical disability from causes unrelated to solvent exposure. The second included hourly employees from the plant population. In these facilities, solvent exposures tended to be short term and low level, although common: the average duration of exposure was 2.3 years; about 41% experienced at least one day of exposure. Of those exposed, 46% had less than one year of exposure. Results for all psychiatric disease combined (273 cases) suggested that cases had lower exposures than either control group, regardless of how exposure was expressed. Results could not be explained by conventional confounding exposures or characteristics or by usual manifestations of the healthy worker effect. By contrast, chronic neurological disease, and multiple sclerosis in particular, seemed to be associated with exposure, although few cases were identified and observed increases in risk were not statistically significant.
Mortality in uranium miners in west Bohemia: a long-term cohort study.
Authors: Tomásek L , Swerdlow A J , Darby S C , Placek V , Kunz E
Published: December 2008

A cohort of 4320 uranium miners in West Bohemia who started work at the mines during 1948 to 1959 and worked there for at least four years were followed up to the end of 1990 to determine cause specific mortality risks in relation to exposures in the mines. The miners had experienced high radon exposures, on average 219 working level months during their uranium mining careers, for which detailed measurements were available. They had also been exposed to high arsenic levels in one of the two major mines, and to dust. New follow up methods, not previously used for occupational cohorts in Czechoslovakia, were utilised. By the end of follow up 2415 (56%) of the cohort were known to have died. Overall mortality was significantly raised compared with that in the general population (relative risk (RR) = 1.56, 95% confidence interval (95% CI) 1.50-1.63), with significantly raised risks of lung cancer (RR = 5.08, 95% CI 4.71-5.47), accidents (RR = 1.59, 95% CI 1.34-1.87), homicide (RR = 5.57, 95% CI 2.66-10.21), mental disorders (RR = 5.18, 95% CI 2.83-8.70), cirrhosis (RR = 1.51, 95% CI 1.16-1.94), and non-rheumatic circulatory diseases (RR = 1.16, 95% CI 1.08-1.25). The relative risk of lung cancer was greatest four to 14 years after entry to the mines. Relative risks for homicide and accidents were raised up to 25 years from entry but not after this. Substantial significantly raised risks at 15 to 24 years after entry occurred for cirrhosis, non-rheumatic circulatory diseases,a nd pneumonia and other respiratory infections. Sizeable significantly raised risks at 25 and more years after entry, but not earlier, were present for mental disorders, tuberculosis, and non-malignant non-infectious respiratory conditions. No specific causes showed risks significantly related to age at entry to mining. Risk of lung cancer was significantly positively related to radon exposure, estimated arsenic exposure, and duration of work in the mines, but no other cause was significantly positively related to these variables. The raised risk of lung cancer in uranium miners, which is well established, is related aetiologically to radon exposure, and in the present cohort it may also in part have been due to exposure to arsenic. The raised risks of accidents, tuberculosis, and non-infectious respiratory diseases have also been seen in other uranium mining cohorts, and are likely to reflect the dangerous and dusty working conditions and the confined spaces in which work occurred. The cirrhosis and homicide deaths probably related to the lifestyle associated with mining. The raised risk of circulatory diseases does not seem to be related to radon or arsenic exposure; its causes are unclear. The use of multiple follow up methods was found to be mortality in the cohort.
Exposure to stainless steel welding fumes and lung cancer: a meta-analysis.
Authors: Sjögren B , Hansen K S , Kjuus H , Persson P G
Published: December 2008

Stainless steel welding is associated with exposure to metals including hexavalent chromium and nickel. This study is a meta-analysis of five studies of stainless steel welders and the occurrence of lung cancer. Asbestos exposure and smoking habits have been taken into account. The calculated pooled relative risk estimate was 1.94 with a 95% confidence interval of 1.28-2.93. This result suggests a causal relation between exposure to stainless steel welding and lung cancer.
Fibrogenic effect of wollastonite compared with asbestos dust and dusts containing quartz.
Authors: Cambelová M , Juck A
Published: December 2008

The distribution of length and diameter and the aspect ratio of crocidolite asbestos, a mineral substitute for asbestos (wollastonite), a manmade mineral fibre (glass wool), and synthetic fibres (polypropylene and polyacrylonitrite) were determined by light microscopy with phase contrast and, for crocidolite, also with transmission electron microscopy. The synthetic organic fibres and manmade mineral fibre used were of a size exceeding that considered respirable. Respirable materials were given to rats by the intratracheal method and after exposure for a standard time interval the main indices of fibrogenic effects--the total hydroxyproline content, the wet weight of the lung, and the total lipid content in the lung--were estimated. For wollastonite there was a significant increase in these variables in comparison with the controls. The fibrogenicity was considerably less than that of crocidolite and quartz.
The presence of 1-naphthol in the urine of industrial workers exposed to naphthalene.
Authors: Bieniek G
Published: December 2008

1-Naphthol at concentrations ranging from 0.4 to 34.6 mg/l was found in urine collected directly after the end of the work shift from a group of industrial workers employed in distillation of naphthalene oil. The maximum excretion was found one hour after the end of the shift and the mean excretion rate was 0.57 mg/h. Coke plant workers exposed to naphthalene and other aromatic and polycyclic hydrocarbons also had 1-naphthol in their urine. Mean values were 0.89 mg/l (working with new technology) and 4.86 mg/l (working with old technology) and the excretion rates were 0.19 and 0.31 mg/h respectively. The maximum excretion was shifted to two to three hours after the end of the exposure. For non-exposed subjects the mean urinary 1-naphthol concentration was 120 micrograms/l and the excretion rate was 7.0 micrograms/h.
Occupational asthma in salbutamol process workers.
Authors: Agius R M , Davison A G , Hawkins E R , Newman Taylor A J
Published: December 2008

Occupational asthma after exposure to salbutamol in the pharmaceutical industry has not been previously reported. The occurrence of occupational asthma is described in two pharmaceutical process workers who were likely to have inhaled doses appreciably in excess of the therapeutic dose range. The findings do not lead to an unequivocal conclusion on the mechanism of the asthma but it was probably a pharmacological consequence of high exposure.
Respiratory symptoms and ventilatory function in confectionery workers.
Authors: Zuskin E , Mustajbegovic J , Schachter E N , Kern J
Published: December 2008

Respiratory symptoms and ventilatory capacity were studied in a group of 288 workers (259 women and 29 men) employed in a confectionery plant. A group of workers (96 women and 31 men) not exposed to confectionery manufacture were also studied as controls. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers, being greatest for confectionery workers exposed to the dust of flour, talc, and starch and the vapours of alcohol. Chronic bronchitis was reported by 7% of the women and 21% of the men, and chest tightness was reported by 27% of women and 66% of men. There was a high prevalence of acute irritative symptoms during the workshift in all groups of confectionery workers, especially for cough, dyspnoea, burning and dryness of the throat, and eye irritation. For all groups of confectionery workers there were statistically significant across shift reductions in ventilatory capacity, being most pronounced for maximum flow rate at 50% of the control vital capacity (FEF50; range 4.6-13.0%) and at 25% of the control vital capacity (FEF25; range 4.7-22.3%). Preshift values of FEF50 and FEF25 were significantly lower than predicted values. The data suggest that some workers employed in confectionery plants may develop acute and chronic respiratory symptoms associated with changes in lung function.
Relations between respiratory symptoms and sickness among workers in the animal feed industry.
Authors: Post W K , Burdorf A , Bruggeling T G
Published: December 2008

OBJECTIVE--The survey aimed at studying the associations between prevalent respiratory symptoms in an occupational population and sickness absence due to respiratory disorders. METHODS--A cross sectional survey among male workers in an animal feed mill was conducted. A total of 303 production workers and 102 office clerks completed a questionnaire on respiratory complaints, smoking habits, and occupational history. The questionnaire was used to identify workers with respiratory symptoms in the past 12 months. During this period all spells of sickness absence were recorded. Causes of sickness were classified in broad categories encompassing respiratory symptoms, influenza, musculoskeletal disorders, and others. RESULTS--Logistic regression analysis showed that workers with respiratory complaints experienced a higher sickness absence than those without respiratory complaints. Adjusted for age and smoking the odds ratio (OR) for sickness prevalence was 1.9 among office clerks and 2.6 among blue collar workers. Smoking increased the risk on sickness absence with ORs of 2.4 and 1.6, respectively. When restricting the analysis to sickness due to respiratory complaints, subjects with respiratory complaints had significantly higher risks for absence prevalence and absence rate than those without respiratory complaints. There were no differences in sickness absence between workers with asthma like complaints and those with chronic bronchitis like complaints. CONCLUSION--The clear associations between respiratory complaints and prevalence and rate of respiratory sickness absence indicate that workers with respiratory complaints are at risk of temporary disability and, thus, may experience a reduced ability to cope with routine activities at work.
Biological monitoring of workers exposed to cobalt metal, salt, oxides, and hard metal dust.
Authors: Lison D , Buchet J P , Swennen B , Molders J , Lauwerys R
Published: December 2008

OBJECTIVE--The aim was to examine the relation between environmental and biological (blood and urine) indices of exposure to different chemical forms of cobalt. METHODS--A cross sectional study was undertaken in workers exposed to cobalt metal, oxides, and salts in a refinery and to a mixture of cobalt and tungsten carbide in a hard metal producing plant. RESULTS AND CONCLUSION--Although biological monitoring of workers exposed to cobalt oxides showed higher blood and urine concentrations than in non-exposed subjects, these indices poorly reflected the recent exposure level. By contrast, when exposure was to soluble cobalt compounds (metal, salts, and hard metals), the measurement of urine or blood cobalt at the end of the workweek could be recommended for the assessment of recent exposure. An eight hour exposure to 20 or 50 micrograms/m3 of a soluble form of cobalt would lead to an average concentration in a postshift urine sample collected at the end of the workweek of 18.2 or 32.4 micrograms of cobalt/g creatinine, respectively.
Determinants of benzo(a)pyrenediol epoxide adducts to haemoglobin in workers exposed to polycyclic aromatic hydrocarbons.
Authors: Ferreira Júnior M F , Tas S , dell'Omo M , Goormans G , Buchet J P , Lauwerys R
Published: December 2008

OBJECTIVE--The aim was to assess the determinants of benzo(a)pyrenediol epoxide adducts to haemoglobin (BaPDE-Hb) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS--This was a study of the correlations between the concentrations of PAHs in air, 1-hydroxyprene in urine, and BaPDE-Hb adduct concentration in the blood in 206 men working in steel foundries and one graphite electrode producing plant, taking into consideration confounding factors such as smoking and dietary habits. RESULTS--BaPDE-Hb adduct concentration was correlated (r = 0.26; p = 0.0002) with the airborne PAH concentration and was influenced by tobacco consumption but not by dietary habits. Benzo(a)-pyrene concentration in air, 1-hydroxypyrene concentration in urine, and duration of exposure to PAHs were not associated with the adduct concentration. CONCLUSION--Although environmental exposure to PAHs was statistically associated with BaPDE-Hb adduct concentration, differences between individual subjects in the metabolism of benzo(a)pyrene probably play an important part in determining the amount of BaPDE-Hb adducts formed.
Pleural plaques and exposure to mineral fibres in a male urban necropsy population.
Authors: Karjalainen A , Karhunen P J , Lalu K , Penttilä A , Vanhala E , Kyyrönen P , Tossavainen A
Published: December 2008

OBJECTIVES--The study aimed to evaluate the risk of pleural plaques according to the degree of past exposure to asbestos, type of amphibole asbestos, and smoking, as well as to estimate the aetiologic fraction of asbestos as a cause of plaques among urban men. METHODS--The occurrence and extent of pleural plaques were recorded at necropsies of 288 urban men aged 33 to 69 years. The pulmonary concentration of asbestos and other mineral fibres was analysed with scanning electron microscopy. The probability of past exposure was estimated from the last occupation. RESULTS--Pleural plaques were detected in 58% of the cases and their frequency increased with age, probability of past occupational exposure to asbestos, pulmonary concentration of asbestos fibres, and smoking. The risk of both moderate and widespread plaques was raised among asbestos exposed cases, and the risk estimates were higher for widespread plaques than for moderate plaques. The age adjusted risk was higher for high concentrations of crocidolite/amosite fibres than for anthophyllite fibres. The aetiologic fraction of pulmonary concentration of asbestos fibres exceeding 0.1 million fibres/g was 43% for widespread plaques and 24% for all plaques. The median pulmonary concentrations of asbestos fibres were about threefold greater among cases with widespread plaques than among those without plaques. No increased risk of pleural plaques was associated with raised total concentrations of non-asbestos fibres. CONCLUSION--The occurrence of pleural plaques correlated closely with past exposure to asbestos. The risk was dependent on the intensity of exposure. Due to methodological difficulties in detecting past exposures to chrysotile and such low exposures that may still pose a risk of plaques, the aetiologic fractions calculated in the study probably underestimate the role of asbestos.
Relation between lung asbestos fibre burden and exposure indices based on job history.
Authors: Takahashi K , Case B W , Dufresne A , Fraser R , Higashi T , Siemiatycki J
Published: December 2008

Lung asbestos burden was compared with exposure indices derived from job history interviews in 42 male subjects originating from the Montréal Case-Control Study project, 12 of whom had documented asbestos exposed job histories. Job interview data consisting of a chronological timetable of job histories were translated into detailed exposure indices by an expert group of hygienists and chemists. Total and individual asbestos fibre type concentrations were quantified by transmission electron microscopy with fibre identification by energy dispersive chi ray spectrometry after deparaffinisation of tissue blocks and low temperature plasma ashing. Geometric mean or median asbestos content was higher in subjects with an asbestos exposed job history than those without for retained dose of amosite, total commercial amphiboles, and total asbestos fibre. Except for crocidolite fibre diameter, which was significantly less in the lungs of exposed workers, no consistent differences were found in measurements of fibre dimension for any fibre type. Subgroups of subjects exposed to silica, metals, or smokers and non-smokers without significant occupational exposure showed varying patterns of lung asbestos fibre type deficit compared with the asbestos exposed subgroup. There was an overall trend for higher lung asbestos content proportional to higher exposure indices for asbestos representing concentration, frequency, and reliability. These exposure indices as well as duration of exposure (in years) were independent predictors of total asbestos content in regression analyses when combined in a model with age. Stepwise regression indicated that exposure concentration was the most important variable, explaining 32% of the total variation in total asbestos content. Smoking, whether expressed in ever or never smoked dichotomy or in smoked-years, had no relation to lung asbestos content in this model.
Transient changes in the pulmonary function of welders: a cross sectional study of Monday peak expiratory flow.
Authors: Donoghue A M , Glass W I , Herbison G P
Published: December 2008

OBJECTIVES--The aim was to compare the peak expiratory flow (PEF) of welders and non-welders over a 12 hour period from the start of work on Monday. METHODS--The two study groups consisted of 20 welders and 20 non-welders, all men who had essentially never smoked, with no significant difference in age, height, ethnicity, or baseline spirometry between the groups. The PEF was measured for each welder before the start of work and 15 minutes, 30 minutes, and 1, 2, 4, 7, and 12 hours after the start of welding. The same method was applied to the non-welders, for whom a proxy time for the start of welding was used. RESULTS--The percentage change in baseline PEF was calculated for each subject at each of the recording times. The welder and non-welder group means for these results were significantly different at 15 minutes (p = 0.028). Also, the group mean for maximum fall in PEF (at any of the recording times during the 12 hour period) was significantly greater for the welders (p = 0.011). 50% of the welders (10/20), but only 5% of the non-welders (1/20), experienced a fall in PEF in excess of 5% (p = 0.0046). 25% of the welders (5/20) experienced drops of greater than 5% within the first 15 minutes. CONCLUSION--The results are suggestive of an immediate type reaction in welders, similar to that seen in some cases of occupational asthma, although not so severe. Studies to determine if these reactions reflect non-specific bronchial hyper-responsiveness would be useful. It is recommended that future studies also undertake breathing zone measurements to relate the response to particular constituents of the welding plume, especially the gases ozone and nitrogen dioxide.
Age and adjustment to night work.
Authors: Härmä M I , Hakola T , Akerstedt T , Laitinen J T
Published: December 2008

OBJECTIVE--The study was designed to examine the effects of age on sleep and the circadian rhythms during consecutive night shifts. METHODS--Two groups of letter sorters (19-29 (n = 7) and 53-59 (n = 7) years of age were studied in a sleep laboratory under closely controlled conditions. After two baseline days, circadian adjustment to three night shifts was monitored by continuous measurement of rectal temperature, salivary melatonin, and sleep-wakefulness during the night shifts. RESULTS--Age was significantly related to the adjustment to night work of rectal temperature minimum and of self rated sleepiness. Young subjects delayed their temperature phase and decreased sleepiness more than the older subjects. Age was also significantly related to an increase of alertness and to the feeling of being refreshed after the day sleep. Although there were basic differences in sleep duration and structure between the age groups, the latter did not change across the night shifts. CONCLUSION--Aging decreases the ability to recover after several, but not after the first night shift.
Traumatic work related fatalities in commercial fishermen in Australia.
Authors: Driscoll T R , Ansari G , Harrison J E , Frommer M S , Ruck E A
Published: December 2008

OBJECTIVES--To describe the types and circumstances of traumatic work related fatalities in Australian commercial fishermen. METHODS--Work related traumatic fishing fatalities were studied as part of a larger study of all work related traumatic fatalities in Australia from 1982 to 1984. Data on 47 cases were obtained from inspection of coroners' files. RESULTS--The incidence of fatality of 143/100,000 person-years was 18 times higher than the incidence of fatality for the entire workforce, and considerably higher than that of the mining and agricultural workforces. 68% of decedents drowned and 13% died from physical trauma. Rough weather, non-seaworthy vessels, inadequate use of personal flotation devices, and inexperience were associated with many of the fatal incidents. DISCUSSION--Improved vessel and equipment maintenance, better training of workers, greater use of personal flotation devices, and development of improved clothing and personal flotation devices are recommended.
Occupational exposure to hydrocarbons and chronic pancreatitis: a case-referent study.
Authors: McNamee R , Braganza J M , Hogg J , Leck I , Rose P , Cherry N M
Published: December 2008

OBJECTIVES--To investigate the hypothesis that hydrocarbon exposure is a risk factor for chronic pancreatitis. METHODS--102 cases of chronic pancreatitis and 204 age and sex matched referents were interviewed about their occupational histories, alcohol and cigarette consumption, and diet. Exposure to hydrocarbons was inferred from interview responses by four assessors who were blind to disease state, and these data were then summarised by a cumulative hydrocarbon exposure (CHE) score. RESULTS--After adjustment for alcohol, cigarettes, dietary antioxidants, and social class, odds ratios for low CHE scores were 1.20 (90% CI: 0.62-2.35) and 2.67 (90% CI: 1.22-5.87) for high scores. A test for trend with level of exposure among only those who had exposure scores > 0 gave p = 0.09. Analysis by type of hydrocarbon was limited to four exposures for each of which there were at least 20 exposed patients. The adjusted OR for paint solvents (any level) was 0.96 (90% CI: 0.48-1.93); for diesel exhaust fumes OR = 2.66 (90% CI: 1.05-6.73); for petrochemicals OR = 1.82 (90% CI: 0.80-4.11); and for chlorinated solvents OR = 1.49 (90% CI: 0.58-3.81). CONCLUSIONS--These results support the original hypothesis. Further studies are needed to confirm or refute the findings here and to clarify the types of hydrocarbon involved.
Cumulative exposure to inorganic lead and neurobehavioural test performance in adults: an epidemiological review.
Authors: Balbus-Kornfeld J M , Stewart W , Bolla K I , Schwartz B S
Published: December 2008

OBJECTIVES--To evaluate the current evidence that cumulative exposure to inorganic lead is associated with decreased performance in neurobehavioural tests in adults. METHODS--21 unique studies were reviewed from 28 published manuscripts. An algorithm was developed to determine the usefulness of each study on the basis of exposure assessment, control of confounding variables, methods of subject selection, test conditions, and data analysis. Highest emphasis was placed on the use of cumulative measures of exposure or absorption. RESULTS--Only three studies used a measure of cumulative exposure to or absorption of lead, and two others used duration of exposure as a surrogate for cumulative exposure. All other studies used a measure that did not adequately estimate cumulative exposure to lead, most often current blood lead concentration. 20 of the studies controlled for age as a confounding variable, although in several studies the possibility for residual confounding by age remained. 16 studies controlled for intellectual ability before exposure; all of them used educational level for this purpose. Of the five studies that used direct or surrogate measures of cumulative exposure to or absorption of lead, two were thought to be of low usefulness because of inadequate duration of exposure. The three remaining studies found stronger associations of neurobehavioural performance with recent exposure measures than with those of cumulative exposure. CONCLUSION--The current scientific literature provides inadequate evidence to conclude whether or not cumulative exposure to or absorption of lead adversely affects performance in neurobehavioural tests in adults. The current evidence is flawed because of inadequate estimation of cumulative exposure to or absorption of lead and inadequate control for age and intellectual ability before exposure.
Radiological changes in asbestos cement workers.
Authors: Jakobsson K , Strömberg U , Albin M , Welinder H , Hagmar L
Published: December 2008

OBJECTIVE--To explore associations between exposure to asbestos cement dust and radiographic findings in lung parenchyma and pleura. METHODS--Radiographs from 174 blue collar workers and 29 white collar workers from an asbestos cement plant formed one part of the study. Progression of small opacities was further studied in those 124 blue collar workers, for whom two radiographs taken after the end of employment were available. The median readings from five readers who used the full ILO 1980 classification were used. As exposure indices, time since start of employment, duration of employment, cumulative exposure, and average intensity of asbestos exposure were used. The influence of age and smoking was also considered in multiple logistic regression analyses. RESULTS--Small opacities (profusion > or = 1/0) were closely correlated with time related exposure variables, and showed weaker association with intensity based exposure variables. The odds ratio (OR) for small opacities was equal to 2.8 (90% CI 1.2, 6.7) in the > 30 f(fibre)-y/ml group, compared with those in the 0-10 f-y/ml group. Progression of at least two minor ILO categories after the end of employment was seen in 20%. Also, pleural thickening was closely related to time. By contrast, costophrenic angle obliterations were not associated with the time related variables, but closely associated with the intensity of asbestos exposure, and tended to occur during employment. The OR was 4.5 (90% CI 1.3, 15) in the > 2 f/ml group, compared with those in the 0-1 f/ml group. CONCLUSIONS--In these workers, exposed mainly to chrysotile but also to small amounts of amphibole, the risk of radiographically visible parenchymal abnormality was substantially increased and strongly dependent on time related exposure variables. Progression was found long after the end of exposure. The findings on costophrenic angle obliterations, supposed to be sequelae of benign pleural effusions, were consistent with an immediate reaction triggered by intense asbestos exposure.
Respiratory health of young shipyard welders and other tradesmen studied cross sectionally and longitudinally.
Authors: Chinn D J , Cotes J E , el Gamal F M , Wollaston J F
Published: December 2008

OBJECTIVE--To assess the effectiveness of current measures for protecting shipyard welders and caulker/burners (WCBs) from the respiratory effects of fumes. METHODS--Shipyard tradesmen born after 1953 (cohort 1), and 181 older men, subjects of a previous study (cohort 2), were assessed, then followed up after an average interval of 6.7 years. The respiratory associations with shipyard trades were assessed cross sectionally and longitudinally and an estimate made of the likely effects of selection bias. Cohort 1 comprised 90% of the 462 eligible WCBs and 239 other tradesmen; there were 31 exclusions. At follow up 139 of 146 men still in the shipyard and 43% of those who had left were reassessed. The lapses were mainly due to migration. All members of cohort 2 were followed up for respiratory symptoms (from MRC questionnaire), were recorded, and indices reflecting all aspects of lung function were measured. RESULTS--At the initial assessment and independent of smoking, trade as a WCB was associated with increased prevalences of chronic cough, phlegm, and wheeze, a reduced transfer factor, and an enhanced age related deterioration in peak expiratory flow (measured cross sectionally). Continued work as a WCB was associated with enhanced deterioration in lung function despite some amelioration of respiratory symptoms; the deterioration was influenced by whether or not exhaust ventilation had been used for every weld. The effects of fume on forced expiratory volume, flow-volume curvilinearity, mean transit time, and moment ratio were independent of and at least as large as those due to smoking. Enhanced deterioration in peak expiratory flow was confined to WCBs who smoked. These effects of trade, but not those of smoking, were nearly independent of atopy. CONCLUSION--In WCBs the working practices over the period of the study did not prevent the development of mild respiratory impairment. In WCBs who used exhaust ventilation at all times, the impairment seemed to reverse by discontinuation of exposure. Thus existing hygiene measures should be applied rigorously. The biological effectiveness of these and any other necessary supplementary measures should be assessed by long term monitoring of forced expiratory volume and peak expiratory flow.
New method for an occupational dust challenge test.
Authors: Lin F J , Chen H , Chan-Yeung M
Published: December 2008

OBJECTIVES--Specific challenge tests with a suspected allergen in the workplace are standard to confirm the diagnosis of asthma. Facilities for sophisticated exposure tests are available only in a few institutions. A pilot study was carried out that used a novel approach for an occupational dust challenge test with a rotahaler. METHODS--Nine consecutive patients were enrolled in this study. Six of these proved to have asthma to red cedar by challenge tests with plicatic acid. They were challenged with a maximum dosage of 80 mg of red cedar dust and spruce dust (control) with a rotahaler on separate days in a single blinded manner. A positive reaction was defined as a fall in the forced expiratory volume in one second (FEV1) or the peak expiratory flow (PEF) after a challenge test of > or = 20% below the baseline value. RESULTS--Three of the six patients who reacted to plicatic acid also had a positive response to red cedar dust delivered through a rotahaler. All three patients with a negative response to challenge with plicatic acid also showed a negative response to red cedar dust. CONCLUSIONS--This pilot study showed that a positive challenge test with a rotahaler to deliver red cedar dust was specific in the diagnosis of red cedar asthma but a negative response could not rule out the diagnosis. The rotahaler has merits of being easy to operate, safe, inexpensive, and readily available. The usefulness of this method and its reproducibility have to be examined in a series of patients.
Repeatability and validity of a field kit for estimation of cholinesterase in whole blood.
Authors: London L , Thompson M L , Sacks S , Fuller B , Bachmann O M , Myers J E
Published: December 2008

OBJECTIVES--To evaluate a spectrophotometric field kit (Test-Mate-OP) for repeatability and validity in comparison with reference laboratory methods and to model its anticipated sensitivity and specificity based on these findings. METHODS--76 farm workers between the age of 20 and 55, of whom 30 were pesticide applicators exposed to a range of organophosphates in the preceding 10 days, had blood taken for plasma cholinesterase (PCE) and erythrocyte cholinesterase (ECE) measurement by field kit or laboratory methods. Paired blinded duplicate samples were taken from subgroups in the sample to assess repeatability of laboratory and field kit methods. Field kits were also used to test venous blood in one subgroup. The variance obtained for the field kit tests was then applied to two hypothetical scenarios that used published action guidelines to model the kit's sensitivity and specificity. RESULTS--Repeatability for PCE was much poorer and for ECE slightly poorer than that of laboratory measures. A substantial upward bias for field kit ECE relative to laboratory measurements was found. Sensitivity of the kit to a 40% drop in PCE was 67%, whereas that for ECE was 89%. Specificity of the kit with no change in mean of the population was 100% for ECE and 91% for PCE. CONCLUSION--Field kit ECE estimation seems to be sufficiently repeatable for surveillance activities, whereas PCE does not. Repeatability of both tests seems to be too low for use in epidemiological dose-response investigations. Further research is indicated to characterise the upward bias in ECE estimation on the kit.
Exposure assessment in industry specific retrospective occupational epidemiology studies.
Authors: Seixas N S , Checkoway H
Published: December 2008

Quantitative estimation of exposure for occupational epidemiology studies has received increasing attention in recent years and, as a result, a body of methodological literature has begun to take form. This paper reviews the generic issues in the methodology of exposure assessment, particularly methods for quantitative retrospective assessment studies. A simple framework, termed an exposure data matrix (EDM), for defining and analysing exposure data is proposed and discussed in terms of the definition of matrix dimensions and scales. Several methods for estimation, interpolation, and extrapolation, ranging from subjective ratings to quantitative statistical modelling are presented and discussed. The various approaches to exposure assessment based on the EDM concept are illustrated with studies of lung disease among coal miners and other dust and chemically induced chronic occupational diseases. The advantages of validated statistical models are emphasised. The importance of analysis and control of errors in exposure assessments, and integration of the exposure assessment and exposure-response processes, especially for emerging occupational health issues, is emphasised.