Occupational risk factors have to be considered in the definition of high-risk lung cancer populations.

BACKGROUND: The aim of this study was to compute attributable fractions (AF) to occupational factors in an area in North-Eastern France with high lung cancer rates and a past of mining and steel industry. METHODS: A population-based case-control study among males aged 40-79 was conducted, including confirmed primary lung cancer cases from all hospitals of the study region. Controls were stratified by broad age-classes, district and socioeconomic classes. Detailed occupational and personal risk factors were obtained in face-to-face interviews. Cumulative occupational exposure indices were obtained from the questionnaires. Attributable fractions were computed from multiple unconditional logistic regression models. RESULTS: A total of 246 cases and 531 controls were included. The odds ratios (ORs) adjusted on cumulative smoking and family history of lung cancer increased significantly with the cumulative exposure indices to asbestos, polycyclic aromatic hydrocarbons and crystalline silica, and with exposure to diesel motor exhaust. The AF for occupational factors exceeded 50%, the most important contributor being crystalline silica and asbestos. CONCLUSION: These AFs are higher than most published figures. This can be because of the highly industrialised area or methods for exposure assessments. Occupational factors are important risk factors and should not be forgotten when defining high-risk lung cancer populations.

Lung cancer mortality and iron oxide exposure in a French steel-producing factory.

OBJECTIVE: To study the possible association between iron oxide exposures and lung cancer risk among workers in a French carbon steel-producing factory. METHODS: 16 742 males and 959 females ever employed for at least 1 year between 1959 and 1997 were followed up for mortality from January 1968 to December 1998. Causes of death were ascertained from death certificates. Job histories and smoking habits were available for 99.7% and 72.3% of subjects, respectively. Occupational exposures were assessed by a factory-specific job-exposure matrix (JEM) validated with atmospheric measurements. Standardised mortality ratios (SMRs) were computed using local death rates (external references). Poisson regressions were used to estimate the relative risks (RRs) for occupational exposures (internal references), adjusted on potential confounding factors. RESULTS: Among males, observed mortality was lower than expected for lung cancer compared to the local population (233 deaths, SMR 0.89, 95% CI 0.78 to 1.01) and higher than expected compared to the French population (SMR 1.30, 95% CI 1.15 to 1.48) No lung cancer excess was observed for exposure to iron oxides (RR 0.80, 95% CI 0.55 to 1.17) and no dose-response relationship with intensity, duration of exposure or cumulative index was found. A significant bladder cancer excess was observed among workers exposed to oil mist (RR 2.44, 95% CI 1.06 to 5.60), increasing significantly with intensity, duration of exposure and cumulative index. CONCLUSION: This study did not detect any relationship between exposure to iron oxides and lung cancer mortality. An excess of mortality from bladder cancer was found among workers exposed to oil mist.

Effects of talc dust on respiratory health: results of a longitudinal survey of 378 French and Austrian talc workers.

OBJECTIVES: The aim of this longitudinal study was to investigate the effects on respiratory health of talc dust, free of asbestiform fibres, at or below airborne concentrations of 2 mg/m(3). METHODS: The respiratory health and dust exposure of all workers with at least 5 years of employment at two talc producing facilities in France and Austria were surveyed between 1988 and 2003. Standard forced expiratory volumes and standard chest x rays were obtained on repeated occasions and recorded using strict quality control procedures. Of a target population of 430 subjects, 378 (88%) were examined at least twice. A quantitative exposure matrix was set up based on 4602 personal exposure measurements of respirable dust and qualitative descriptions of the industrial processes and individual protection devices. RESULTS: The mean duration of follow-up was 14.5 years with a mean estimated talc dust concentration during follow-up of 1.46 mg/m(3). The prevalence of small radiological opacities and lung function parameters were significantly related to cumulative exposure at inclusion but not to exposure during the study period. Overall, the forced expiratory volume in 1 s decreased by 66 ml per 100 years.mg/m(3), which is less than that reported for other types of mineral dusts. CONCLUSIONS: Although early exposure levels to talc as assessed at inclusion were associated with decreased lung function and an increased prevalence of small radiological opacities, there was no evidence of detrimental effects of talc exposure, as assessed within the study period, on lung function and small radiological opacities.

Associations of job, living conditions and lifestyle with occupational injury in working population: a population-based study.

OBJECTIVES: To assess the roles of job demands, living conditions and lifestyle in occupational injury. METHODS: The sample included 2,888 workers, aged > or =15 years, randomly selected from the north-eastern France. The subjects completed a mailed questionnaire. Data were analyzed with adjusted odds ratios (ORa) computed with the logistic model. RESULTS: In total, 9.2% of workers had an injury during the previous 2 years. The high job demands: tasks at height, handling objects, pneumatic tools, other vibrating hand tools, work in adverse climate, physical workload, vibrating platform, machine tools, cold, heat, awkward posture, noise, hammer, and pace had crude odds ratios between 1.81 and 5.25 for injury. A strong exposure-response relationship was found between the cumulated job demands (CJD, defined by their number) and injury: OR 1.88 (95% CI 1.23-2.87) for CJD1, 4.39 (2.98-4.46) for CJD2-3, and 9.93 (6.70-14.7) for CJD > or = 4, versus CJD0. These ORs decreased to 1.68, 3.70, and 7.15 respectively, when adjusted for sex, age, and living conditions/lifestyle confounders; and to 1.54, 2.99, and 5.45 respectively when also adjusted for job category. The following factors had significant ORa: age <30 years (1.54, 1.12-2.12), male (1.64, 1.18-2.30), smoking (1.60, 1.22-2.10), musculoskeletal disorders (1.54, 1.17-2.04), and frequent drug use for fatigue (2.03, 1.17-3.53). The workmen, farmers/craftsmen/tradesmen, and foremen had a 5.7-8.7-fold while the clerks and technicians a 2.7-3.6-fold higher risk compared with upper class. The risk associated with CJD was twofold higher among the workers aged > or =40 or with frequent drug use for fatigue compared with the others. Obesity had ORa 2.05 (1.11-3.78) among the subjects aged > or =40, and excess alcohol use had ORa 2.44 (1.26-4.72) among those free of disease. CONCLUSIONS: This study identified a wide range of job demands and living conditions/lifestyle which predicted injury. Preventive measures should be conducted to reduce job demands and to help workers to be aware of the risk and to improve their living conditions/lifestyle.

Combining expert ratings and exposure measurements: a random effect paradigm.

The aim of this paper is to present a paradigm for combining ordinal expert ratings with exposure measurements while accounting for a between-worker effect when estimating exposure group (EG)-specific means for epidemiological purposes. Expert judgement is used to classify the EGs into a limited number of exposure levels independently of the exposure measurements. The mean exposure of each EG is considered to be a random deviate from a central exposure rating-specific value. Combining this approach with the standard between-worker random effect model, we obtain a nested two-way model. Using Gibbs sampling, we can fit such models incorporating prior information on components of variance and modelling options to the rating-specific means. An approximate formula is presented estimating the mean exposure of each EG as a function of the geometric mean of the measurements in this EG, between and within EG standard deviations and the overall geometric mean, thus borrowing information from other EGs. We apply this paradigm to an actual data set of dust exposure measurements in a steel producing factory. Some EG-specific means are quite different from the estimates including the ratings. Rating-specific means could be estimated under different hypotheses. It is argued that when setting up an expert rating of exposures it is best done independently of existing exposure measurements. The present model is then a convenient framework in which to combine the two sources of information.

Ventilatory function in pre-school children snorers and nonsnorers.

BACKGROUND: The value of flow-volume curves alterations for screening for sleep apnoea is controversial in adults. OBJECTIVE: The purpose of the present study was to assess the possible value of flow-volume curves, in snoring pre-school children to detect upper airway abnormal dynamics. METHODS: We analysed ventilatory function of 190 children aged 5 to 6 years from nine kindergartens in Nancy, France, according to the presence or absence of snoring as declared by their parents. RESULTS: More than half (103 = 54%) of the children never snored; 26 (= 13.7%) snored only with colds, 42 (22.1%) snored occasionally, and 19 (= 10%) snored habitually. The "saw tooth" sign described in adults by Sanders et al in 1981 was absent in all the children in this study, and the height-adjusted forced expiratory volume in one second (FEV1/m2) was similar across the four groups. The height-adjusted peak expiratory flow (PEF/m2) decreased uniformly (but insignificantly) from the group of non-snorer (2.11 +/- 0.381/s/m2) through the group of children snoring with colds. (2.05 +/- 0.37) to the group of children snoring occasionally (1.99 +/- 0.33); no significant decrease was found in the group of habitual snorers (2.06 +/- 0.36). CONCLUSION: In this group of young children, we were unable to find the alteration of the expiratory flow-volume loop described in part of the studies in adults. We cannot, however, exclude an alteration of the inspiratory arm of the loop, as this was not recorded by us. Our results, suggesting a reduction in peak expiratory flow with increase in frequency of snoring need to be validated in a larger population of children.

Relations between occupational exposure to coal mine dusts, erythrocyte catalase and Cu++/Zn++ superoxide dismutase activities, and the severity of coal workers' pneumoconiosis.

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 > or = 4 years at the time of the study (n = 105), or exposed to high dust concentrations for > or = 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 > or = 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 difference 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 effect.

Can the evolution to pneumoconiosis be suspected in coal miners? A longitudinal study.

To assess whether the evolution to pneumoconiosis may be suspected in coal miners, we conducted a 4-yr longitudinal study of 80 dust-exposed miners with chest X-ray findings classified 0/1 or 1/0 according to the International Labor Organization (ILO) classification (exposed to coal mine dust, suspected of pneumoconiosis [ES group]) and two control groups having normal X-rays. The first of these latter two groups included 80 miners with similar exposure to that of the first group (exposure with normal X-rays [EN]), whereas the second group consisted of markedly less exposed miners (no exposure with normal X-rays [NN]). The protocol comprised a questionnaire on respiratory symptoms and smoking, assessment of cumulative coal-mine-dust exposure, X-rays, computed tomographic (CT) scans, and lung-function tests. The study was conducted in 1990 and 1994 by the same medical team. At the end of the follow-up, 24 members of the ES group had worsened X-ray findings, and 10 of them had X-ray findings classified as 1/1 or greater. In the EN and NN groups, six and one subjects, respectively, had worsened X-ray findings. At the first examination, subjects who developed pneumoconiosis had significantly lower values for FEV1/FVC ratio, maximum midexpiratory flow (MMEF), and maximal forced expiratory flow at 25% of vital capacity (FEF25%), and higher CT-scan micronodule scores. This latter score and FEF25% were significantly associated with the evolution to pneumoconiosis in the ES group, and scanner micronodule score and MMEF were significantly associated with this in all three groups combined. Worsening findings on X-ray and change to pneumoconiosis must be controlled in coal miners. The findings in this study offer the possibility of identifying miners who especially need follow-up and monitoring.

Asymmetry correction equations for hand volume, grip and pinch strengths in healthy working people.

Assessments of oedema and decrease in hand strength are useful for patients with a hand lesion. This study examined the asymmetry of the arms and determined the estimates of the unknown prior to lesion values for hand volume, grip strengths assessed with a Jamar dynamometer (GS[J]) and a Collins dynamometer (GS[C]), and pinch strength with a Jamar pinch gauge (PS) in 100 healthy working people. Hand volume, GS(J), GS(C) and PS of the dominant hand were respectively 3.6 +/- 4.1%, 6.6 +/- 9.2%, 11.7 +/- 11.2%, and 8.0 +/- 13.2% higher than those of the non-dominant hand (p < 0.001). Very good estimates were obtained with the values of the contralateral arm for all the indices studied. The correlation coefficient equalled 0.95 for hand volume, 0.91 for GS(J), 0.83 for GS(C), and 0.72 for PS. These estimates allow us to evaluate the evolution of oedema and hand strengths in patients with hand injury, especially to determine whether they could return to work as they are mostly manual workers with demanding jobs.

The single-breath nitrogen test in coal miners: factors associated with failure to perform.

The single-breath nitrogen washout (SBN2) test was used, along with spirometry, in the baseline examination of a longitudinal study in a cohort of active coal miners from North-eastern France. The procedure was computerized, allowing the technician to coach and encourage the subject, and excluding computation errors. While all miners performed satisfactory spirometry, a significant number were unable to meet the National Heart and Lung Institute recommendation concerning a 10% agreement of vital capacities. When the limits were set at +/-12%, 57 miners (24.2%) were still classified as failing to perform. When compared to those who succeeded, those failing proved to be significantly older, had more cumulated dust exposure, a higher prevalence of chronic cough and sputum, and a trend for more micronodulation on the chest radiographs. The ventilatory function did not differ between the two groups. These results confirm previous data on spirometric test failure concerning older age and respiratory symptoms, extending them to the SBN2 test. The present study further indicates that dust exposure and roentgenologic pneumoconiosis nodulation are associated with failure to perform the SBN2 test.

Comparison between estimates of hand volume and hand strengths with sex and age with and without anthropometric data in healthy working people.

Edema and hand strength measurements are useful for the recovery assessment of patients with a hand lesion. This work determined and compared estimates of hand volume, grip strengths (measured with a Jamar and a Collins dynamometer), and pinch strength (with a Jamar pinch gauge) in terms of sex and age with or without anthropometric indices in healthy working people. The sample included 100 subjects from within the staffs of two rehabilitation centres. For both grip strengths, multiple linear regression models including body height, weight, and arm muscle area were very good (multiple correlation coefficient R of about 0.84) and clearly better than those obtained with sex and age only. For pinch strength, the best estimate was obtained with sex and arm muscle area (R of 0.76); for hand volume, the model with sex, body height, and weight provided the best result (R of 0.93). These findings suggested that anthropometric indices easy to measure must be taken into account to estimate hand volume and hand strengths.

[Unidimensionality of a functional measure for patient with an injured upper limb]. / Unidimensionnalité d'une mesure fonctionnelle pour des malades ayant une lésion du membre supérieur.

The construction of an instrument including a number of tests requires an analysis of its structure and its unidimensionality (which allows calculation of global score), and the determination of the difficulty level of various tests. This study examined a tool including 67 tests designed to evaluate the functional ability of patients with an injured upper limb. The patients seen in a rehabilitation centre during 12 months (173 subjects) were evaluated by the occupational therapists familiar with the tool. The statistical analyses were made using the principal component analysis method (PCAM), the Cronbach's coefficient and the Rasch model. The PCAM showed 3 principal factors which explained 44%, 10% and 4% of the total variance respectively in the case of patients with injured dominant limb. The predominance of the first axis and the high ratio of first by second eigenvalues suggested the unidimensionality of the tool. The Cronbach's value of 0.97 attested the good congruence of the items. The results obtained with the Rasch model seemed to be consistent with the hypothesis of the unidimensionality of the tool. This analysis also provided the difficulty scale of various tests. Similar results were obtained in patients with injured non dominant limb or with all the sample. The methods used provide complementary results.

Personality self-representations of patients with hand injury, and its relationship with work injury.

This study compared the personality self-representations of 288 hand injured patients with those of 959 young people (15-25 years old) randomly selected from the general population (noted GP), and with those of 336 unemployed people of all ages in professional training (U) in Lorraine (north-eastern France). The relationship between patients' personality self-representations and injury was also investigated. Personality self-representations included 14 questions: in your own opinion are you sociable?, at ease with others?, serious?, careful?, dynamic?, optimistic?, worried?, irritable?, clumsy?, solitary?, organised?, ambitious?, do you have a sense of responsibility?, and many plans? The patients had similar self-representations to GP except for the items non clumsy (odds ratio adjusted on age and sex OR = 2.40, p < 0.05) and optimistic (OR = 1.70, but 0.05 < p < 0.10). The frequencies of non irritable, non clumsy and non solitary people were higher in patients than in the U group (OR about 2.40, p < 0.01). By contrast, the other items were more favourable for the U group except for the items sociable, organised and having many plans. Self-representation items were significantly related to some socio-demographic data. The work injured workmen having one or more previous work injuries during the last five years were more at ease with others than the other subjects. Among the work injured workmen who had had no previous work injury during this time, the people aged 29 or less (the highest risk age class) were more optimistic than the others (71% vs 49%, p < 0.05); a difference was also found for the items at ease with others, careful, dynamic, and non worried, but it was not significant possibly due to the small number of subjects. The sum of these five items differed between the two age groups (3.29 +/- 1.49 vs 2.55 +/- 1.68, p < 0.05). These simple items would provide an interesting approach in terms of personality which could explain in part the excess of work injuries in young people, though the work requirement still seemed to be the highest risk factor.

Forced oscillation technique (FOT): a new tool for epidemiology of occupational lung diseases?

The aim of this study was to evaluate the usefulness of the forced oscillation technique (FOT) in the assessment of occupation-related airway changes. The forced oscillation technique and conventional lung function tests were applied in 80 underground coalface workers, aged 35-48 yrs, with chest roentgenogram films classified 0/1 or 1/0 according to the International Labour Office (ILO) classification (G group), and two control groups matched for age and smoking habits. The first control group, was made up of face-workers having normal chest radiographs, whilst the second comprised underground non-face-workers with normal chest radiographs. Spirometric, plethysmographic and transfer factor of the lungs for carbon monoxide single-breath (TL,CO,sb) indices revealed no significant differences between the three groups. As regards the forced oscillation technique, a higher value of resistance/frequency slope (Pa.L-1.s2) was found in the G group compared with the control groups; 2.11 vs 1.06 in the face-workers, and 1.58 in the underground workers. In all three groups, the forced oscillation technique indices (mean resistance (R), resistance at zero frequency (RO), resistance/frequency slope (S), and resonant frequency (fo)) were found to be higher in subjects having a decreased forced expiratory volume in one second (FEV1) (< or = 90% predicted) or a mildly obstructive pattern of ventilatory function, even though this did not reach statistical significance in each of the groups. These findings together with the feasibility and acceptability of the forced oscillation technique would suggest that it may be a suitable tool for epidemiological studies of occupational respiratory diseases.

[Respiratory symptoms and function of coal miners presenting radiological pulmonary abnormalities]. / Symptômes et fonction respiratoires des mineurs de charbon présentant des anomalies radiologiques pulmonaires.

Respiratory symptoms and lung function of 80 coal workers suspected of pneumoconiosis (pulmonary X-rays classified 0/1 or 1/0 according to International Labour Organisation classification) who worked for at least 10 years at face work (Ts) were studied in comparison with two control groups matched by age (+/- 2 years), height (+/- 5 cm), weight (+/- 10 kg) and smoking habits: the Tn group constituted by 80 coal workers who worked for at least 10 years at face work with normal pulmonary X-rays, and the HTn group constituted by 80 underground miners who worked mainly out of face work with normal pulmonary X-rays. The frequencies of cough, expectoration, chronic bronchitis or dyspnoea were significantly higher in Ts group than in the two others. The one-second forced expiratory volume to vital capacity ratio (FEV1/VC) was lower, closing volume to vital capacity (CV/VC) or to total lung capacity ratios (CV/TLC) were higher in Ts group than in the control groups. Unexpectedly, vital capacity (VC), one-second forced expiratory volume (FEV1), total lung capacity (TLC), compliance, diffusing capacity (DLCO) referred to alveolar volume (VA) were higher. In Ts group, the small rounded opacities were noted in the top part of the lung (56.9%), the irregular ones were distributed on the entire lung (65.5%). There were no relation between the category of small opacities and respiratory symptoms or lung function.