Abstracf. Three techniques for studying nasal mucociliary clearance have been compared in 20 normal subjects, aged 19 to 26. Three different tracers used were deposited on Acta Otolatyngol9l

A previous study on 536 retired coke oven plant workers in Lorraine Collieries (France) reported an excess of deaths from lung cancer (standardised mortality ratio (SMR) = 251) compared with the French male population. Occupational exposures during working life were retraced for each subject, but the number of deaths during the observation period was small, and smoking habits were known only for dead subjects. In 1988, the cohort was re-examined (182 deaths occurred between 1963 and 1987) and smoking habits were determined for all the subjects. This study confirmed the excess of lung cancer (SMR = 238, p < 0-001). It showed an excess of mortality from all causes (SMR = 141, p < 0-001), overall cancers (SMR = 133, p < 0 05), and cardiovascular diseases (SMR = 133, p < 0-05). A significant excess of deaths was found for subjects who worked near the ovens for all causes (145, p < 0-01), lung cancer (SMR = 252, p < 0-01), colon cancer (SMR = 381, p < 0-05), and cardiovascular diseases (SMR = 155, p < 0-05). A significant excess mortality was also found from all causes (176, p < 0-05) and stomach cancer (SMR = 538, p < 0-01) in subjects who worked in byproducts, from lung cancer (SMR = 433, p < 0-001) in those in the workshops, and from cirrhosis of the liver and alcoholism (SMR = 360, p < 0-01) in those underground; but, due to small numbers, these figures were not robust. An excess of mortality from all INSERM U 115 "Sante au Travail et Sante Publique: A Patris causes (SMR = 163, p < 0-01), lung cancer (SMR = 228, p < 0-05), and cardiovascular diseases (SMR = 179, p < 0-01) was shown also for non-exposed or slightly exposed subjects. The fact that, on the whole, mortality of various exposed groups was similar to that of non-exposed or slightly exposed workers may be explained in part by the selection at hiring and the healthy worker effect. As an increased risk of lung cancer was noted among subjects who worked in the old generations of plant compared with the other workers (although the relative risk was not significant) it is concluded that the role of occupational hazards could not be excluded. (British Journal of Industrial Medicine 1993;50:127-135) The effect ofoccupational hazards in coke oven plants (notably of polycyclic aromatic hydrocarbon from the ovens, coal dusts, tar, etc) on mortality has been extensively investigated.`'3' A previous study carried out in 1983 on 536 retired workers from the two coke oven plants of Houilleres du Bassin de Lorraine (Lorraine Collieries) reported a significant excess of mortality from lung cancer (SMR = 251, p < 0 01) with reference to the French male population.' The small number of deaths found during the observation period (1963-82) did not allow a full analysis of the effect ofoccupational exposures. Also, smoking habits were known only for dead subjects. In 1988, the cohort was re-examined, and smoking habits were determined for all the cohort members. A question of interest was whether there was an increased risk, notably for lung cancer, in the old generations...

A cross sectional study was conducted on 513 employees at three hard metal plants: 425 exposed workers (351 men, 74 women) and 88 controls (69 men, 19 women). Cough and sputum were more frequent in workers engaged in "soft powder" and presintering workshops compared with controls (12-5% and 16X5% v 3 5%). Spirometric abnormalities were more frequent among women in sintering and finishing workshops compared with control women (56-8% v 23-8%) and abnormalities of carbon monoxide test were more frequent in exposed groups than in controls; this difference was more pronounced in women (31[4% v 5-6%) than in men (18-5% v 13%). No significant correlation was observed between duration ofexposure and age adjusted lung function tests. Slight abnormalities of chest radiographs (0/1, 1/1 according to ILO classification) were more frequent in exposed men than controls (12-8% v 1-9%) and mostly in soft powder workers. In subjects with abnormal chest radiographs FVC, FEV1 and carbon monoxide indices (fractional uptake of CO or CO transfer index or both) were lower compared with those with normal chest radiographs. Although relatively mild, the clinical, radiological, and functional abnormalities uncovered call for a regular supervision of workers exposed to hard metal dust.The industrial use of hard metal tools began in Germany in 1922. Owing to their hardness and resistance to wear and high temperatures they are used to make cutting tools, drill tips, and armament components. Their qualities are due mainly to tungsten carbide which, with cobalt (Co), constitutes the essential part of this alloy. They are produced according to the powder metallurgy technique in specialised factories in relatively large quantities (in France 300 tons a year at present).About 20 years later, hard metals were suspected of being responsible for bronchopulmonary disorders, first in Germany, then in the other industrialised countries. Despite a certain heterogeneity of the symptoms and signs, the condition progresses towards a diffuse pulmonary fibrosis and leads to severe respiratory insufficiency. Except for sporadic case reports, the frequency and intensity of clinical and functional respiratory disorders which can be observed among a group of workers exposed to hard metal dust are not well known. Thus a cross sectional survey was conducted among a group of 425 workers exposed to hard metal dusts and of 88 controls who worked in three factories.

Objectives-To better understand the relations between occupational exposure, blood antioxidant enzyme activities, total plasma antioxidant concentration, and the severity of coal workers' pneumoconiosis (CWP). Methods-Blood samples were obtained from miners without CWP exposed to low dust concentrations for >4 years at the time of the study (n = 105), or exposed to high dust concentrations for >14 years at the time of the study (n=58), and from retired miners with CWP (n=19). Miners without CWP were classified into three subgroups according to their estimated cumulative exposure to dust. Chest x ray films were obtained for each miner. Miners were classified in five subgroups according to their International Labour Organisation (ILO) profusion grades. Univariate tests were completed by multiple linear regression analyses. Results-The estimated cumulative exposure to dust was strongly positively related to erythrocyte catalase activity and strongly negatively related to Cu ++ /Zn ++ SOD activity only in miners exposed to high dust concentrations for >14 years at the time of the study (F tests p=0.006 and p=0.004 respectively). Moreover, catalase activity was strongly related to the severity of CWP expressed as five subgroups of ILO profusion grades (F test p=0.003); the greatest diVerence in the mean values was found between the group of 1/1 to 1/2 ILO profusion grades and the group of 2/1 to 3/3 ILO profusion grades. Conclusion-These results are in good agreement with the hypothesis that production of reactive oxygen species may be an important event in the exposure to coal mine dusts and the severity of CWP. Erythrocyte catalase and Cu ++ /Zn ++ SOD activities are more closely related to recent exposure to high dust concentrations than to cumulative exposure, and could be considered as biological markers of exposure rather than as markers of early adverse biological eVect. (Occup Environ Med 1998;55:533-540)

Cedex, and Lormines, 57703 Hayange, France ABSTRACr Eleven hundred and nine iron mine workers aged 35 to 55 with normal chest radiographs were submitted to a pulmonary examination consisting of a questionnaire, a clinical examination, and pulmonary function testing including an acetylcholine challenge test. A positive response (decrease of FEV, of more than 10%) was observed in 210 subjects (Ace+). The remaining 899 had a negative response (Ace-). Bronchitis, asthma, dyspnoea, and obstructive syndrome were more frequent in the Ace+ group. Five years later, 820 subjects were reexamined: occasional cough and sputum and chronic bronchitis appeared more frequently among subjects without symptoms at the first examination but with a positive acetylcholine challenge test. The obstructive syndrome was more often observed and regressed more rarely in the Ace+ group. The results confirm the use of a test of bronchial hyperreactivity as a means of identifying subjects at risk from chronic obstructive lung disease.The concept that bronchial hyperreactivity was important in the evolution of chronic obstructive lung disease (COLD) was introduced by Dutch investigators.' 2 Pharmacodynamic tests using acetylcholine, metacholine, or histamine may be used to evaluate the degree of hyperreactivity.36 Initial work by Tiffeneau et a13-6 on the ventilatory effect of acetylcholine concerned asthmatic subjects during remission. It is now known, however, that bronchial hyperreactivity may occur not only in asthma but also in other conditions as a response to inhaled irritants and infections. The mechanism of this hyperreactivity is complex and not yet fully understood; nevertheless, it remains a criterion to be taken into account when evaluating the diagnosis and prognosis of COLD, the decrease in forced expiratory volume in one second (FEV,) being correlated with the degree of methacholine reactivity as was pointed out by Barter and Campbell7 and Minette8 in their longitudinal studies of bronchitic patients.In 1973 a recommendation was made by the working group on "functional respiratory tests in

An epidemiological, cross-sectional study was conducted in order to assess non-neoplasic effects on the lung due to chronic exposure to arc welding fumes and gases. The study involved 346 arc welders and 214 control workers from a factory producing industrial vehicles. These workers (welders and controls) had never been exposed to asbestos. Respiratory impairments were evaluated by using a standardized questionnaire, a clinical examination, chest radiophotography and several lung function tests (spirometry, bronchial challenge test to acetylcholine, CO transfer tests according to the breath-holding and the steady-state methods, N2 washout test). The only significant differences between the welders overall compared to the controls were a slightly higher bronchial hyper-reactivity to acetylcholine and a lower lung diffusing capacity for CO in the welders. However, non-specific, radiologic abnormalities (reticulation, micronodulation) and obstructive signs were more frequent in the most exposed welders (welding inside tanks) than in welders working in well ventilated workplaces. The nature of the metal welded (mild-steel, stainless steel, aluminium) did not seem to have an influence on respiratory impairments. In the mild-steel welders, respiratory symptoms (dyspnoea, recurrent bronchitis) and obstructive signs were more frequent in the welders using a manual process than in the welders involved with the semi-automatic process (MIG). For all the workers (welders and controls), smoking had a markedly adverse effect on respiratory symptoms and lung function. Moreover, smoking seemed to interact with welding since CO lung transfer was more impaired in smoking welders than in smoking controls.

The respiratory health of 138 arc welders and 106 control subjects in the same company was studied in 1981 and in 1986. Most of the subjects welded mild steel using the Metal Inert Gas (MIG) process. The controls were workers in the same company, not exposed to any known pulmonary risk. The welders and controls in the analysis had not changed their professional activity nor their smoking habits during these five years. The examinations consisted of a questionnaire on respiratory symptoms, a thoracic auscultation, a chest X-ray and lung function tests: flow-volume curve and steady state CO transfer test. The examinations in 1986 confirmed the risk of non specific radiological impairment (pulmonary reticulo-micronodulation) and of obstruction in the small bronchi, which had already been observed in 1981 in the arc welders in this company. These impairments did not seem to have evolved more than in the controls, but do however justify regular surveillance of the respiratory health of arc welders.

An increased mortality from lung and stomach cancer was found in previous studies on Lorraine iron miners. A detailed analysis, however, was not possible due to the lack of data for survivors. In this study the cohort included 1178 workers selected at random from all the 5300 working miners aged between 35 and 55 at the start of the follow up period, which ranged from 1975 to 1985. Occupational exposures and tobacco consumption, lung function tests, and respiratory symptoms were assessed for each subject in 1975, 1980, and 1985. This study confirmed the excess of lung cancer (standardised mortality ratio (SMR) = 389, p < 0.001) and of stomach cancer (SMR = 273, p < 0.05). There was no excess of lung cancer in non-smokers and moderate smokers (<20 pack-years) or the miners who worked only at the surface or underground for less than 20 years. A significant excess (SMR = 349, p < 0.001) was found in moderate smokers when they worked underground for between 20 and 29 years. Heavy smokers (over 30 pack-years) or subjects who worked underground for more than 30 years experienced a high risk: SMR = 478 (p < 0-001) for moderate smokers who worked underground for over 30 years; 588 (p < 0.001) for heavy smokers who worked underground for between 20 and 29 years; and 877 (p < 0.001) for heavy smokers who worked underground for over 30 years. This showed an interaction between smoking and occupational exposure. The excess mortality from lung cancer was because there were some subjects who died young (from 45 years old).Comparison with the results of a previous study showed that additional hazards produced by diesel engines and explosives increased the mortality from lung cancer. The SMR was higher than 400 (p < 0-001) from 45 years old instead of from 56 years. A relation was found between a decrease in vital capacity (VC), forced expiratory volume in one second (FEV1) and of FEVJIVC and mortality from all causes and from lung cancer in heavy smokers or men who had worked underground for more than 20 years. Respiratory symptoms were related to mortality from lung cancer among smokers (moderate and heavy) who worked underground for more than 20 years. It is considered that the risk of lung cancer in the Lorraine iron miners was mainly due to dust, diesel engines, and explosives although the role of low exposure to radon daughters could not be totally excluded.