[Is the socioeconomic deprivation EPICES score useful in obstetrics?]. / Intérêt de l'échelle d'évaluation de la précarité EPICES en obstétrique.

OBJECTIVES: To describe a validated and multifactorial deprivation score to study the relationship between socioeconomic deprivation and perinatal risks. PATIENTS AND METHODS: The index of deprivation EPICES (Evaluation of Precarity and Inequalities in Health Examination Centers) was used to characterize the deprivation status of 234 women in post-partum in comparison with perinatal morbidity. The cutoff value of 30.7 was the threshold to define deprivation. RESULTS: Two hundred and eight patients were included in this retrospective study from whom 48 (23%) had a score of deprivation higher than 30.7. Maternofetal morbidity was more severe in deprived patients. DISCUSSION AND CONCLUSION: The current results show that the EPICES score could be a useful obstetrical tool for the identification of deprived women during pregnancy.

Potentially inappropriate drug prescription in the elderly in France: a population-based study from the French National Insurance Healthcare system.

BACKGROUND: Inappropriate prescribing is a known risk factor for adverse drug event occurrence in the elderly. In various countries, several studies have used insurance healthcare databases to estimate the national prevalence of potentially inappropriate medications (PIM) in the elderly, as defined by explicit PIM lists. Recently, a representative sample of the French National Insurance Healthcare database, known as the "Echantillon Généraliste des Bénéficiaires" (EGB), was created, making it possible to assess the quality of drug prescription in France. Our objective was to evaluate the prevalence and the regional distribution of PIM prescription in the elderly aged 75 years and over in France, using the French PIM list and the EGB database. METHODS: The list of drugs reimbursed to patients aged 75 years and over from 1 March 2007 to 29 February 2008 was extracted from the EGB. Drugs were classified as inappropriate using the French PIM list. A PIM user was defined as a person receiving at least one PIM reimbursement during the study period. Interregion variability was estimated from logistic regression. RESULTS: In 53.6% (95% CI: 53.0-54.1) of the elderly aged 75 years and over, at least one PIM was given during the study period. The three main drug groups identified were cerebral vasodilators (19.4%), drugs with antimuscarinic properties (19.3%), and long half-life benzodiazepines (17.8%). There was an important disparity in PIM prescription among the French regions. In 14 out of 22 regions, the risk of PIM prescription was significantly elevated. This geographical variation differed for the different drug groups. CONCLUSION: PIM prescription in the elderly is a major and worrying problem in France. As in other countries, recent accessibility of the National Insurance Healthcare database makes it possible to create local indicators that the regional health agencies could use to manage public health policy in closer alignment to the needs of the patients within each French region.

[Job insecurity, unemployment and health: results from the health examination centers of the French General Health Insurance]. / Santé et instabilité professionnelle : résultats issus des centres d'examens de santé de l'assurance-maladie.

BACKGROUND: Job insecurity has increased over the last 30 years. Socioeconomic changes have led to various insecure employment categories, including fixed term employment, part time employment and government sponsored jobs. This study was aimed at investigating relationships between employment status and health. METHODS: The study population was composed of 767,184 people, aged 26 to 59 years, examined between 2003 and 2005 in the Health Examination Centers of the French General Health Insurance. Employment status was defined using insecure employment (combining permanent/fixed-term contracts and part-time/full time), government sponsored jobs and duration of unemployment (from <6 months to > or =3 years). Health indicators were poor perceived health, smoking, lack of gynecological follow-up, obesity, untreated caries and high blood pressure. Data were analysed by logistic regression (odds ratios [OR]) adjusted on age, occupational social class and education level, the reference category being permanent full time contracts (OR=1). RESULTS: Significant level-dependent relations with health were observed between non permanent versus permanent employments, part time versus full time. Most OR of unemployed people were higher than those of having employment and increased with duration of unemployment. For example, for poor perceived health in men, OR ranged between 1.00 and 1.68 (95%CI 1.57-1.78) according to job insecurity categories, and between 1.75 (95%CI 1.67-1.83) and 2.80 (95%CI 2.72-2.89) according to duration of unemployment. For obesity in women, OR increased from 1.00 to 1.48 (95%CI 1.37-1.60) in active women and from 1.35 (95%CI 1.27-1.44) to 1.77 (95%CI 1.70-1.84) in unemployed. CONCLUSIONS: This study showed quantitative relationships between job insecurity, unemployment and health. In particular, workers having government-sponsored jobs and long-time unemployed people were at high risk of health problems.

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.

[Comparison of the individual deprivation index of the French Health Examination Centres and the administrative definition of deprivation]. / Comparaison du score individuel de précarité des centres d'examens de santé, EPICES, à la définition socio- administrative de la précarité.

In French Health Examination Centres, populations in deprived situation were usually defined by administrative criteria The aim of the study was to investigate whether EPICES, a new individual index of deprivation, was more strongly related to health status than an administrative classification. The EPICES score was calculated on the basis of 11 weighted questions related to material and social deprivation. Participants were 197, 389 men and women, aged over 18, encountered in 2002 in French Health Examination Centres. Relationships between health status, health-related behaviours, access to health care, EPICES and the administrative classification of deprivation were analyzed by logistic regression. The associations between EPICES and the study variables were stronger than those observed for the administrative definition. The comparison also showed socially disadvantaged people with poor health identified by the EPICES score who were not by the administrative classification. These results showed that the EPICES score can be a useful tool to improve the identification of deprived people having health problems associated to deprivation.

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.

A mortality study among workers in a French aluminium reduction plant.

OBJECTIVE: A mortality study on the association between lung cancer and occupational exposure to polycyclic aromatic hydrocarbons (PAHs) was carried out in a French aluminium reduction plant. This study updated a previous mortality study. METHOD: The historical cohort included every male worker who had been employed in the plant for at least 1 year between 1950 and 1994. Workers were followed-up for mortality from 1968 to 1994. Causes of death were obtained from death certificates. Standardised mortality ratios (SMRs) and 95% confidence intervals (CI) were computed using regional mortality rates as external reference to compare observed and expected numbers of deaths, adjusted for gender, age and calendar time. RESULTS: The cohort comprised 2,133 men, of whom 335 died during the follow-up period. The observed mortality was lower than expected for all causes of death (SMR = 0.81, CI 0.72-0.90) and for lung cancer (observed = 19, SMR = 0.63, CI 0.38 0.98). No lung cancer excess was observed in workshops where PAH exposure was likely to have occurred, and no trend was observed according to duration of exposure and time since first exposure. This low lung cancer mortality could be partly explained by a marked healthy worker effect and a possible negative confounding by smoking. An excess was observed for bladder cancer (observed = 7, SMR = 1.77, CI 0.713.64) in the whole cohort, that was higher among workers employed in workshops where PAH exposure was likely to have occurred (observed = 6, SMR = 2.15, CI 0.79-4.68). In addition, an SMR higher than unity was observed for "psychoses and neuro-degenerative diseases" (observed = 6, SMR = 2.39, CI 0.88-5.21), that could not be related to occupational aluminium exposure. CONCLUSION: No lung cancer risk was detected. Non-significant excesses were observed for bladder cancer and for psychoses and neuro-degenerative diseases.

Lung cancer mortality in a site producing hard metals.

OBJECTIVES: To study the mortality from lung cancer from exposures to hard metal dust at an industrial site producing hard metals--pseudoalloys of cobalt and tungsten carbide--and other metallurgical products many of which contain cobalt. METHODS: A historical cohort was set up of all subjects who had worked for at least 3 months on the site since its opening date in the late 1940s. A full job history could be obtained for 95% of the subjects. The cohort was followed up from January 1968 to December 1992. The exposure was assessed by an industry specific job exposure matrix (JEM) characterising exposure to hard metal dust from 1 to 9 and other possibly carcinogenic exposures as present or absent. Smoking information was obtained by interview of former workers. Standard lifetable methods and Poisson regression were used for the statistical analysis of the data. RESULTS: Mortality from all causes was close to the expected (standardised mortality ratio (SMR) 1.02, 399 deaths) whereas mortality from lung cancer was significantly increased among men (SMR 1.70; 46 deaths, 95% confidence interval (95% CI) 1.24 to 2.26). By workshop, lung cancer mortality was significantly higher than expected in hard metal production before sintering (SMR 2.42; nine deaths; 95%CI 1.10 to 4.59) and among maintenance workers (SMR 2.56; 11 deaths; 95%CI 1.28 to 4.59), whereas after sintering the SMR was lower (SMR 1.28; five deaths; 95%CI 0.41 to 2.98). The SMR for all exposures to hard metal dust at a level >1 in the JEM was in significant excess (SMR 2.02; 26 deaths; 95%CI 1.32 to 2.96). The risks increased with exposure scores, duration of exposure, and cumulative dose reaching significance for duration of exposure to hard metal dust before sintering, after adjustment for smoking and known or suspected carcinogens. CONCLUSION: Excess mortality from lung cancer was found among hard metal production workers which cannot be attributed to smoking alone. This excess occurred mostly in subjects exposed to unsintered hard metal dust.

Risk of lung cancer in workers producing stainless steel and metallic alloys.

OBJECTIVES: The mortality of workers involved in the production of stainless and alloyed steel from 1968 to 1992 was studied, in order to investigate the risk of lung cancer due to exposure to metals, i.e. iron oxides, chromium and/or nickel compounds. METHODS: The study design was a historical cohort mortality study and a nested case-control study concerning lung cancer. Standardized mortality ratios (SMRs) were computed using regional mortality rates as an external reference for comparing observed and expected numbers of deaths, adjusting for age, sex and calendar time. Conditional logistic regression was used to estimate odds ratios (ORs). Occupational exposure was assessed through the complete job histories of cases and controls and a specific job-exposure matrix. RESULTS: The cohort comprised 4,288 male and 609 female workers. The observed overall mortality was significantly lower than expected [649 deaths; SMR = 0.91; 95% confidence interval (CI) 0.84-0.98]. No significant SMR was observed for mortality from lung cancer (54 deaths; SMR = 1.19; CI 0.88-1.55). The case-control study was based on 54 cases and 162 individually matched controls. Smoking habits were available for 71%. No lung cancer excess was observed for exposure to (1) metals and/or their compounds, i.e. iron (OR = 0.94, CI 0.48-1.86), chromium and/or nickel (OR = 1.18, CI 0.62-2.25), and cobalt (OR =0.64, CI 0.33-1.25), (2) acid mists (OR = 0.43, CI 0.17-1.10), and (3) asbestos (OR = 1.00, CI 0.54-1.86). With respect to exposure to polycyclic aromatic hydrocarbons (PAHs) and silica, which are often found together in workplaces, (1) high and statistically significant lung cancer excesses were observed, the ORs being 1.95 (CI 1.03-3.72) and 2.47 (CI 1.28-4.77) respectively, (2) quantitative exposure parameters revealed upward trends reaching statistical significance (P < 0.05), and (3) adjustments for tobacco consumption did not reveal any confounding factors from smoking. CONCLUSION: This study failed to detect any relationship between lung cancer and exposure to iron, chromium, nickel and/or their compounds. High and statistically significant relative risks, along with increasing trends, were observed for simultaneous exposure to PAHs and silica.

Occupational cancer in France: epidemiology, toxicology, prevention, and compensation.

This article is a description of the current situation in France with regard to occupational cancer: research, prevention, and occupation. Toxicologic experiments are carried out using (italic)in vitro(/italic) and (italic)in vivo(/italic) tests, particularly using transgenic mice. Several epidemiologic studies have been conducted over the last decades: population-based case-control studies; mortality studies and cancer incidence studies carried out in historical cohorts of workers employed in the industry; and case-control studies nested in occupational cohorts. French ethical aspects of toxicologic and epidemiologic studies are described. The results thus obtained are used to establish regulations for the prevention and the compensation of cancers attributable to occupational exposure. This French regulation for prevention of occupational cancer involves several partners: (italic)a(/italic)) the states authorities, including labor inspectors, responsible for preparing and implementing the labor legislation and for supervising its application, particularly in the fields of occupational health and safety and working conditions; (italic)b(/italic)) the Social Security Organisation for the analysis of present or potential occupational risks based on tests, visits in plants, complaints or requests from various sources, and statistics. These activities are performed within the framework of the general French policy for the prevention of occupational cancer. This organization includes the National Institute for Research and Safety, particularly involved in research in the various fields of occupational risks--animal toxicology, biologic monitoring, exposure measurements epidemiology, psychology, ergonomy, electronic systems and machineries, exposure to chemicals, noise, heat, vibration, and lighting; and (italic)c(/italic)) companies where the regulation defines the role of the plant manager, the occupational physician, and the Health, Safety and Working Conditions Committee (comprising the manager, employees' representatives, the occupational physician, and the safety department) in dealing with any problem regarding safety, occupational hygiene, and working conditions. These organizations along with medical practitioners are involved with the compensation of occupational cancers. The regulation for compensation includes the tables of occupational cancer, the possibility of recognition of a cancer case when the requirements of the tables are not met, and the postprofessional follow-up of workers exposed to a carcinogenic agent.

[Survey of the effects of smoking in an occupational cohort study. Value and limits of a new method]. / Prise en compte des effets du tabagisme dans les études de cohortes professionnelles. Intérêt et limites d'une nouvelle méthode.

BACKGROUND: This paper proposes a method to take smoking into account in occupational cohort studies when a lung cancer excess is observed and no information on smoking is available. METHODS: The model consists in assessing the proportion of smokers in the study cohort on the basis of (i) the relative risk observed for lung cancer (P1), and (ii) relative risks due to other smoking related diseases (P2). If P1 is higher than P2, it is concluded that the observed lung cancer excess is unlikely to be due to smoking. RESULTS: The model was applied to nine epidemiological studies, of which five showed a lung cancer excess (ranged between 1.12 et 1.32). The P2 proportions of four of these five studies ranged between 0.29 and 0.46, and were lower than P1 that ranged between 0.57 and 0.69. These differences reached statistical significance. These results suggest that occupational lung cancer risks might have existed. The model was validated by applying to cohorts without lung cancer excess and to cohorts of smokers and non smokers. The robustness was assessed using different values of the basic parameters: proportion of smokers in the general population and risks due to smoking for smoking related diseases. CONCLUSION: This model is an assessment of the relative importance of smoking and occupational factors in occupational cohort studies, in the absence of information on smoking.

Lung cancer risk in hard-metal workers.

An industry-wide mortality study on the association between lung cancer and occupational exposure to cobalt and tungsten carbide was carried out in the French hard-metal industry. This case-control study was nested in the historical cohort of workers ever employed in this industry's 10 facilities, most of which are located in eastern France. Workers were followed up from 1968 to 1991. Occupational exposure was assessed using a job-exposure matrix that provided semiquantitative scores for 320 job periods. These scores were significantly correlated with the levels of cobalt measured in 744 historical air samples. In this cohort, which comprised 5,777 males and 1,682 females, the death rate from lung cancer was significant (63 deaths, standardized mortality ratio=1.30, 95% confidence interval (CI) 1.00-1.66) when compared with national death rates. Sixty-one cases and 180 controls were included in the study. When the exposures during the last 10 years were ignored, a twofold lung cancer risk was observed among workers simultaneously exposed to cobalt and tungsten carbide (odds ratio (OR)=1.93, 95% CI 1.03-3.62) adjusted for other cobalt exposure (OR=2.21, 95% CI 0.99-4.90). The odds ratios increased with cumulative exposure (first quartile, OR=1.00; second quartile, OR=2.64; third quartile, OR=2.59; fourth quartile, OR=4.13) and, to a lesser degree, with duration of exposure (one decade, OR=1.00; two decades, OR=1.61; three decades, OR=2.77; four decades, OR=2.03). Adjustments for smoking and for exposures to known or suspected carcinogens did not change the results, yet the odds ratio for smoking (3.38) was lower than expected, suggesting the possibility of some misclassification. Occupational risk was highest among smokers. This study supports the hypothesis that workers who manufacture hard metals have an increased mortality from lung cancer due to simultaneous exposure to cobalt and tungsten carbide.

[Mortality in the French paper and pulp industry]. / Une étude de mortalité dans l'industrie française du papier et de la pâte à papier.

BACKGROUND: The objective was to describe a possible cancer mortality risk in relation with the occupational exposure within an International study co-ordinated by the International Agency for Research on Cancer. METHODS: An epidemiological cohort study was set up to assess the mortality in four French pulp and paper companies. The four cohorts were followed up from January 1st 1968 to December 31st 1992. The causes of death were ascertained by matching with the national file of causes of death. RESULTS: The full cohort consisted in 5,529 men and 876 women. The total numbers of subjects deceased between 1968 and 1992 were respectively 708 and 34. Causes of death could be traced for 98%. The observed mortality was significantly lower than the expected for all causes of deaths (SMR = 0.86) as well for all deaths by cancer (SMR = 0.87). The analysis by departments showed an excess mortality by cancer of the pancreas in the wood preparation department (SMR = 3.14) as well as in the paper production department (SMR = 2.04). CONCLUSIONS: In absence of any prior hypothesis, it is difficult to assign an occupational origin to these observed excesses. The future results of the international study will enable us to interpret these results more precisely.

Cancer mortality among magazine printing workers.

OBJECTIVE: After an inquiry from the employees of an offset printing plant, a historical cohort study was conducted to investigate cancer mortality among these workers. METHODS: The cohort comprised 262 men, who contributed 2771 person-years of observation. 16 deaths were identified during the follow up period (1980-91). Expected numbers of deaths were derived from age specific regional rates. Standardised mortality ratios (SMR) and 95% confidence intervals (95% CIs) were calculated. RESULTS: An increased cancer mortality was found after 10 years of employment (SMR 213, 95% CI 98 to 405, based on nine deaths), mainly due to a high mortality from lung cancer (SMR 381, 95% CI 104 to 975, four deaths), and from oesophageal cancer (SMR 1049, 95% CI 216 to 3065, three deaths). For workers with at least 20 years since the start of employment, the SMR was 262 (95% CI 105 to 540) for all cancer sites, 447 (95% CI 92 to 1306) for lung cancer, and 1094 (95% CI 132 to 3952) for oesophageal cancer. The increased cancer mortality was concentrated among pressmen. CONCLUSION: Although based on small numbers, the findings suggest an increased risk of cancer among these workers, which should be further investigated.

A meta-analysis of epidemiologic studies of lung cancer in welders.

OBJECTIVE: A meta-analysis of epidemiologic studies was carried out on lung cancer risk among shipyard, mild steel, and stainless steel welders, and the role of asbestos exposure and smoking was considered. METHODS: The meta-analysis consisted of calculating combined relative risks (RR) and their variances through a logarithm transformation of published RR values and a weighing using the inverted variance of each RR. RESULTS: The literature provided 18 case-referent and 31 cohort studies. The combined RR values were 1.38 [observed 1028, 95% confidence interval (95% CI) 1.29-1.48] for "all or unspecified welding categories", 1.30 (observed 305, 95% CI 1.14-1.48) for shipyard welders, and 1.35 (observed 173, 95% CI 1.15-1.58) for nonshipyard welders. Similar combined RR values (RR) were observed for mild steel welders (combined RR 1.50, observed 137, 95% CI 1.18-1.91) and stainless steel welders (combined RR 1.50 observed 114, 95% CI 1.10-2.05). No significant heterogeneity was discerned between studies of any welding or study design category. A marked healthy worker effect may also lead to an underestimation of the standardized mortality ratio for lung cancer among stainless steel welders. Furthermore, welders of any category are likely to be exposed to asbestos. Welders also seem to smoke more than the general male population, and therefore the hypothesis of tobacco overconsumption among welders could not be discarded. CONCLUSIONS: A 30-40% increase in the RR of lung cancer among welders cannot be explained by hexavalent chromium and nickel exposure among stainless steel welders. The combination of the carcinogenic effects of asbestos exposure and smoking may account for part of the lung cancer excess observed.

[Development of a job-exposure matrix in the heavy-metal industry in France]. / Elaboration d'une matrice emplois-expositions dans l'industrie productrice de métaux durs en France.

A job exposure matrix (JEM) was developed by a committee of experts using the DELPHI method, in the French hard metal industry, in order to assess occupational exposures to cobalt along with tungsten carbide resulting from the industrial process. This JEM is part of a nested case-control study, carried out within the historical cohort of workers ever employed in these factories, aimed at assessing lung cancer risk. The committee included 8 experts: hygienists, chemical engineers, occupational physicians and epidemiologists. The JEM was developed in four stages: (i) visit of factories, (ii) definition of lines (job-periods) and columns (exposures) of the JEM, (iii) definition of coding procedures, (iv) coding the cells of the JEM. This last stage used a method derived from the DELPHI method. Throughout the study period 1945-1994. 320 job-periods and 21 agents were defined. A quantitative assignment (level 0 to level 9) along with a frequency code (1 to 3) was attempted for 4 agents, whereas only a qualitative assignment (non exposed/exposed, i.e. 0/l) was done for the other agents. An additional probability code (1 to 3) was assigned to all agents. This procedure led to 46 columns and 14,720 cells in the JEM. When applying the DELPHI method, the consensus of the committee was obtained for 85% of all cells after the first individual assignment of experts, 88% after the second individual assignment and 100% after the third assignment by the experts all together. In order to validate the JEM, these expert assignments will be brought together with the results of exposure measurements that were performed in some workplaces of these factories. The JEM will also be linked with the data base of the case-control study for the exposure assessment of cases and controls.

Survey of the respiratory health of the workers of a talc producing factory.

OBJECTIVES: To assess the effect of an occupational exposure to talc dust on respiratory health. METHODS: 166 talc millers from a French factory underwent spirometry and filled in a standardised respiratory questionnaire during their annual medical visit in 1989. A full sized chest radiograph taken in 1987 for the subjects hired before 1982 was also available, for the others a radiograph taken when hired was used. Radiography was repeated in 1992 for all subjects still active at this date (n = 139). The occupational exposure to talc dust was characterised for each workplace with 1440 personal samples collected since 1986 and by semiquantitative estimates of the historical exposure. RESULTS: The geometric mean (range) of estimated exposure was 1.87 (0.5 to 50) mg/m3 and the estimated cumulative exposure at the date of spirometry was > 150 y mg/m3 for 41 subjects. After adjustment for smoking in a linear model the standardised residual values of both forced vital capacity and forced expiratory volume in one second decreased significantly with increasing exposure. The prevalence of dyspnoea also increased after adjustment for smoking categories and age in a logistic regression. The prevalence of small radiological opacities was significantly related to age and to the exposure after adjustment for age and smoking categories. The incidence of new opacities between the two radiographs (11 new opacities with a profusion higher than 0/1) was significantly related to smoking (10 out of 11 are smokers) but not to the exposure. CONCLUSION: This study shows an effect of high levels of talc dust both on functional variables and on the prevalence of small radiological images, but provides no clear evidence about the possible effect of present levels of exposure.

Mortality from cardiovascular diseases among potash miners exposed to heat.

We assessed mortality rates in a cohort of French potash miners between 1977 and 1987. The cohort comprised all workers of a potash mine active on January 1, 1977, or subsequently hired, with at least 3 years of employment. We compared the mortality of the subcohort exposed to heat from underground work (U) with the mortality of those who had never worked underground (D). The overall mortality was low [standardized mortality ratio (SMR) = 0.89, based on 570 deaths] and was lower among underground workers (age-standardized mortality rate = 660 per 100,000 person-years, 266 deaths) than among daylight workers (age-standardized mortality rate = 710 per 100,000 person-years, 304 deaths). Mortality from ischemic heart diseases (IHD) was higher for underground workers than for daylight workers (relative risk = 1.6). As exposure to heat decreased over time, we analyzed the mortality according to period of hire: within underground workers, we observed a downward trend for mortality from IHD which contrasted with a stable mortality from IHD among daylight workers. Among subjects who left for medical reasons, IHD mortality was five times greater in the heat-exposed group compared with daylight workers. The data are consistent with an increased risk of ischemic heart diseases from a hot environment that is offset by a strong healthy worker effect.