Impact of diabetes mellitus onset on sickness absence from work--a 15-year follow-up of the GAZEL Occupational Cohort Study

AIMS

Previous studies do not provide an accurate estimate of the burden of diabetes on sickness absence. The aim of this study was to measure the impact of diabetes onset on absenteeism starting from the earliest occurrence of the disease.

METHODS

The authors used data from a subsample of the French GAZEL cohort of 506 employees with incident diabetes and 2530 matched diabetes-free participants. Medically certified sickness absence data were obtained from company records (1989-2007). Number of sickness absence days and incidence rates of overall and cause-specific absence spells were compared according to diabetes status across three 5-year periods ranging from 10 years before to 5 years after onset of cases' diabetes.

RESULTS

The mean number of sickness absence days was persistently higher in participants with diabetes compared with those without diabetes. This difference increased from 16.4 days (95% confidence interval 7.2-25.5) during the 5-year period preceding diabetes onset to 28.5 days (95% CI 16.1-40.9) during the following 5-year period (P = 0.04). This was due to a steeper relative increase in the incidence of long (but not short) absence spells in participants with diabetes versus those without diabetes [incidence rate ratios 1.33 (95% CI 1.08-1.64) and 1.75 (95% CI 1.43-2.14), respectively; P = 0.02]. Diabetes onset was associated with increased rates of circulatory and metabolic absence spells.

CONCLUSIONS

Onset of diabetes is associated with a substantial increase in sickness absence. This suggests that in addition to its burden on work cessation, diabetes weighs heavily on working ability among people who manage to remain employed.

Job strain in relation to body mass index: pooled analysis of 160 000 adults from 13 cohort studies

BACKGROUND

Evidence of an association between job strain and obesity is inconsistent, mostly limited to small-scale studies, and does not distinguish between categories of underweight or obesity subclasses.

OBJECTIVES

To examine the association between job strain and body mass index (BMI) in a large adult population.

METHODS

We performed a pooled cross-sectional analysis based on individual-level data from 13 European studies resulting in a total of 161 746 participants (49% men, mean age, 43.7 years). Longitudinal analysis with a median follow-up of 4 years was possible for four cohort studies (n = 42 222).

RESULTS

A total of 86 429 participants were of normal weight (BMI 18.5-24.9 kg m(-2) ), 2149 were underweight (BMI < 18.5 kg m(-2) ), 56 572 overweight (BMI 25.0-29.9 kg m(-2) ) and 13 523 class I (BMI 30-34.9 kg m(-2) ) and 3073 classes II/III (BMI ≥ 35 kg m(-2) ) obese. In addition, 27 010 (17%) participants reported job strain. In cross-sectional analyses, we found increased odds of job strain amongst underweight [odds ratio 1.12, 95% confidence interval (CI) 1.00-1.25], obese class I (odds ratio 1.07, 95% CI 1.02-1.12) and obese classes II/III participants (odds ratio 1.14, 95% CI 1.01-1.28) as compared with participants of normal weight. In longitudinal analysis, both weight gain and weight loss were related to the onset of job strain during follow-up.

CONCLUSIONS

In an analysis of European data, we found both weight gain and weight loss to be associated with the onset of job strain, consistent with a 'U'-shaped cross-sectional association between job strain and BMI. These associations were relatively modest; therefore, it is unlikely that intervention to reduce job strain would be effective in combating obesity at a population level.

Cognitive hostility and suicide

OBJECTIVE

To determine whether a specific component of hostility (i.e. cognitive or behavioural) may predict suicide in a prospective design, controlling for depressive mood.

METHOD

In 1993, 14,752 members of the 'GAZ et ELectricité' (GAZEL) cohort (10,819 men, mean age=49.0 years; 3933 women, mean age=46.2 years) completed the Center for Epidemiologic Studies Depression Scale and at least one subscale (i.e. cognitive or behavioural hostility) of the Buss and Durkee Hostility Inventory. Dates and causes of death were obtained annually.

RESULTS

During a mean follow-up of 15.7 years, 28 participants completed suicide (24 men, four women). Suicide was predicted by depressive mood [relative index of inequality (RII) (95% CI)=8.16 (1.97-33.85)] and cognitive hostility [RII (95% CI)=10.76 (2.50-46.42)], but not behavioural hostility [RII (95% CI)=1.37 (0.38-4.97)]. These associations remained significant after adjustment for potential confounders. After mutual adjustment, however, suicide remained significantly associated with cognitive hostility [RII (95% CI)=8.87 (1.52-51.71)] (RII reduction: 34.6%), but no longer with depressive mood [RII (95% CI)=2.03 (0.41-10.07)] (RII reduction: 79.1%).

CONCLUSION

Cognitive rather than behavioural hostility is associated with an increased risk of suicide, independently of baseline depressive mood.

Occupational exposure to solvents and cognitive performance in the GAZEL cohort: preliminary results

BACKGROUND

The impact of occupational exposure to solvents on cognitive ageing remains unclear. We examined whether long-term occupational exposure is associated with poor cognitive performance in late midlife.

METHODS

Participants in the GAZEL cohort, set up in 1989, are employees of the French national electricity and gas company. Data on the working environment were used to create measures of cumulative exposures to solvents using a job-exposure matrix. In 2002-2004, cognitive performance was assessed using the Digit Symbol Substitution Test (DSST) and the Mini Mental State Examination in 5,242 participants (aged 55-65 years).

RESULTS

In cross-sectional analysis using multiple logistic regression, there was a greater risk of poor cognitive performance (DSST score <25th percentile) among those with high exposure to benzene (OR = 1.58; 95% CI 1.31-1.90) and the grouped categories of chlorinated (OR = 1.39; 95% CI 1.3-2.3), aromatic (OR = 1.76; 95% CI 1.08-2.87), and petroleum solvents (OR = 1.50; 95% CI 1.23-1.81).

CONCLUSIONS

These results suggest that occupational exposures to solvents may be associated later in life with cognitive impairment, even after taking into account the effects of education, employment grade, and numerous health factors.

Biomechanical strains and low back disorders: quantifying the effects of the number of years of exposure on various types of pain

OBJECTIVE

To assess the effects of duration of exposure to biomechanical strains on various types of low back pain (LBP).

METHODS

The population study was a random sample from the GAZEL cohort. Durations of exposure to selected biomechanical strains during subjects' working lifetime and potential confounders were assessed in 1996 by self-administered questionnaires. Data on LBP in the previous 12 months were collected in 2001. Relations between various dimensions of LBP and durations of exposure to the biomechanical strains were analysed with multivariate regression models. Polytomous models were built to determine whether some biomechanical strains were specifically associated with some types of LBP.

RESULTS

Analyses were performed separately for men (n = 2218) and women (n = 383). Significant associations were observed (ORs reported are those for 20 years of exposure) between LBP and durations of driving and bending/twisting for men (OR 1.24 and 1.37 respectively); LBP for more than 30 days and duration of exposure to bending/twisting for men and women (OR 2.20 and 2.00 respectively) and duration of driving for women (OR 3.15); LBP radiating to the leg and duration of driving for men (OR 1.43) and bending/twisting for women (OR 1.95); LBP radiating below the knee and duration of exposure to pulling/pushing/carrying for men (OR 1.88). Bending/twisting in both men and women, and driving for women appeared to be stronger risk factors for LBP for more than 30 days. Pulling/pushing/carrying heavy loads appeared to be a risk factor specific for LBP radiating below the knee for men.

CONCLUSION

This study suggests that exposure to biomechanical strains has long-term effects and a dose-response relation with duration of exposure and specific effects for some types of LBP.

Lifelong socioeconomic trajectory and premature mortality (35-65 years) in France: findings from the GAZEL Cohort Study

BACKGROUND

Studies conducted in the UK and Scandinavia show an inverse association between lifetime socioeconomic position and adult mortality. However, there are virtually no data from other countries and few investigations have examined non-cardiovascular mortality in men and women.

METHODS

Lifelong socioeconomic trajectories (father's occupation, own occupation in young adulthood and in mid-life) and premature (< or = 65 years) mortality (all-cause, smoking-related cancer, diseases of the circulatory system and external causes) in the French GAZEL Cohort Study (14,972 men and 5,598 women, followed up between 1990 and 2004) were studied. Hazard ratios (HRs) were estimated using Cox's regression models adjusted for age, marital status, tobacco smoking, alcohol consumption, body mass index, and fruit and vegetable consumption.

RESULTS

Men and women who experienced lifelong disadvantage or downward intergenerational mobility were at high risk of dying prematurely compared with those with a favourable trajectory (age-adjusted HRs for all-cause mortality: cumulative disadvantage: HR 1.61, 95% confidence interval (CI) 1.26 to 2.06 in men and HR 1.95, 95% CI 1.10 to 3.47 in women; downward mobility: HR 1.87, 95% CI 1.35 to 2.58 in men and HR 2.05, 95% CI 1.12 to 3.75 in women). Associations were strongest for mortality due to chronic diseases (smoking-related cancers and diseases of the circulatory system). These associations were partly explained by marital status, body mass index, alcohol consumption, cigarette smoking, and fruit and vegetable consumption.

CONCLUSIONS

In France, where the leading cause of premature death is cancer, lifelong socioeconomic position is associated with the risk of dying before the age of 65 years. Adult factors seem more relevant than childhood socioeconomic circumstances.

Using a representative sample of workers for constructing the SUMEX French general population based job-exposure matrix

BACKGROUND

Job-exposure matrices (JEMs) applicable to the general population are usually constructed by using only the expertise of specialists.

AIMS

To construct a population based JEM for chemical agents from data based on a sample of French workers for surveillance purposes.

METHODS

The SUMEX job-exposure matrix was constructed from data collected via a cross-sectional survey of a sample of French workers representative of the main economic sectors through the SUMER-94 survey: 1205 occupational physicians questioned 48 156 workers, and inventoried exposure to 102 chemicals. The companies' economic activities and the workers' occupations were coded according to the official French nomenclatures. A segmentation method was used to construct job groups that were homogeneous for exposure prevalence to chemical agents. The matrix was constructed in two stages: consolidation of occupations according to exposure prevalence; and establishment of exposure indices based on individual data from all the subjects in the sample.

RESULTS

An agent specific matrix could be constructed for 80 of the chemicals. The quality of the classification obtained for each was variable: globally, the performance of the method was better for less specific and therefore more easy to assess agents, and for exposures specific to certain occupations.

CONCLUSIONS

Software has been developed to enable the SUMEX matrix to be used by occupational physicians and other prevention professionals responsible for surveillance of the health of the workforce in France.

[Use of a job-exposure matrix for the screening of occupational exposure to asbestos]

BACKGROUND

According to a recent French legislation (1995), retired people who have been exposed to an occupational carcinogen can benefit from a specific post-occupational medical follow-up program, supported by the "Caisse Primaire d'Assurance-Maladie" (CPAM), the French health insurance system. However, only very few people presently take access to this social measure. The ESPACES project developed and evaluated a procedure to identify retirees who have been exposed to asbestos during their career, and to inform them about the post-occupational medical follow-up program.

METHODS

This pilot study was performed within the health centers ("Centres d'examens de santé" (CES)) of the health insurance system in a random sample of men who have retired from the six main French administrative divisions between 1994 to 1996. A probability of exposure to asbestos was attributed through a job exposure matrix. Subjects were interviewed in the CES to validate their exposure data. Retired subjects with confirmed exposure to asbestos were referred to their CPAM, to apply for the medical follow-up. The whole process was evaluated through a comparison with control CPAMs, and simulations were performed to assess its sensitivity and specificity, as well as the total number of persons in France who could potentially benefit.

RESULTS

Among the 737 persons classified as exposed by the matrix who came to the CES, the exposure was confirmed for 53.8%, and 143 benefited from the medical follow-up, 17 times more than in a sample of control CPAMs. Based on an annual number of about 250,000 new retirees, simulations showed that a low detection threshold, taking into account the probability and duration of exposure, would yield approximately 25,000 persons coming to the CES, more 6,000 of them benefiting from the follow-up.

CONCLUSION

The proposed detection threshold would allow for a feasible and ethically acceptable generalization, due to the optimization of the false negative and false positive rate.

Evaluation of the quality of coding of job episodes collected by self questionnaires among French retired men for use in a job-exposure matrix

BACKGROUND

and

AIMS

The ESPACES study was intended to identify retirees who may have been, according to their job descriptions, exposed to asbestos during their working lives. As part of this study, we analysed the quality of the occupation and activity sector coding as well as its effect on the subjects' exposure status.

METHODS

The occupation and activity sector for a sample of 450 retired men were coded twice (with the second coder blinded to the first result), according to the international codes for industries (ISIC-1975) and occupations (ISCO-1968). For each series, linking the information about a job episode (dates, ISIC code, ISCO code) with the matrix allowed attribution of a probability of asbestos exposure to each episode and each subject. The asbestos exposure in the two series was compared by the kappa reproducibility coefficient.

RESULTS

The analysis concerned 425 questionnaires. There was at least one difference in the code for either activity sector (ISIC) or occupation (ISCO) in half the episodes (50.2%). The exposure status estimated by the job-exposure matrix did not change between the series for 84.7% of the subjects. The kappa coefficient was 0.64 for all questionnaires, 0.70 when the questionnaire was coded twice by the same coder, and 0.62 when coded by two different coders.

CONCLUSIONS

Despite intra- and inter-differences between coders, the coding of job episodes for the ESPACES study appears satisfactory and hence indicates that the assessment of the subjects' asbestos exposure was assessed without major distortions. This study underlines the usefulness of employing coders specifically trained for this technique.

[Constitution of a bank of biological material in the French Gazel cohort: logistical and practical aspects]

The Gazel cohort was launched in January 1989 among workers of the French national electricity and gas company to form an open and general purpose epidemiological laboratory. More than 20.000 workers (15.000 men, 5.000 women), aged from 35 to 50 volunteered to participate. One of the objectives of this cohort was the constitution of a bank of biological material aiming to collect and preserve various biological samples (serum, plasma, DNA, etc). This paper details the organisation of the bank and presents a feasability study concerning 2.000 volunteers.

Do cardiovascular risk factors in men depend on their spouses' occupational category?

OBJECTIVE

To analyse the relationships between major cardiovascular risk factors in French men and their spouses' occupational category (OC), taking their own OC into account.

DESIGN

A large sample of volunteers working in the French National Electricity and Gas Company (GAZEL). As a check of the robustness, the same analysis was performed in a population-based survey (French multinational MONItoring of trends and determinants in CArdiovascular disease (MONICA) registers).

SETTING

Any site of the company in France. Representative sample from the population of the three registers (Lille, Strasbourg, Toulouse).

PARTICIPANTS

9486 and 534 men respectively, in working activity, living in couple and aged 40 to 50 years.

MAIN OUTCOME MEASURES

Self-reported arterial hypertension, diabetes, hypercholesterolemia, leisure time sedentary lifestyle, smoking status, body mass index (BMI) and alcohol consumption.

RESULTS

In the GAZEL study, diabetes, smoking status, and alcohol consumption in men were associated with their own OC. In contrast, spouses' OC was independently associated with men's hypertension, hypercholesterolemia, sedentary lifestyle, and BMI: men whose spouses were unoccupied or workers have higher risk factors levels. In the MONICA study, the results were mostly comparable, at least for hypercholesterolemia, sedentary lifestyle, smoking status and alcohol consumption.

CONCLUSION

Spouses' OC was independently associated with several cardiovascular risk factors in men. These results might indicate that socioeconomic status of the couple, and not only individual characteristics, should be taken into account for a better understanding of cardiovascular risk.

Socioeconomic, demographic, occupational, and health factors associated with participation in a long-term epidemiologic survey: a prospective study of the French GAZEL cohort and its target population

The purpose of this paper is to examine personal and health factors, both at the beginning of the study and thereafter, associated with participation in the GAZEL cohort, set up in 1989 in a large French company. The authors used logistic regression to analyze the associations between participation and data available for both participants (n = 20,093) and nonparticipants (n = 24,829). Higher participation was associated with male sex, marriage, children, managerial status, and residence in particular regions. Among men, lower participation was associated with sick leave in the year before recruitment and afterwards. During follow-up, participation was negatively associated with several groups of diseases, especially those associated with alcohol consumption. The risk of upper respiratory and digestive tract and lung cancer during follow-up was higher among nonparticipants. The same phenomenon occurred among women, but less markedly, for cancers of the breast and genital organs. During follow-up, mortality among men was higher among nonparticipants, especially for alcohol-related diseases. The association among women was less strong. Among men, but not among women, diseases caused by alcohol, smoking, or dangerous behavior were the primary reason for the health differences observed between participants and nonparticipants. Overall, the most important determinants of participation were cultural factors and lifestyle behaviors.

Validity of self-reported weight and height in the French GAZEL cohort

OBJECTIVE

To examine the validity of self-reported weight and height and the resulting body mass index (BMI), and to explore the associations between demographic, socioeconomic, and health-related factors on the one hand and bias in self-reported weight and height on the other, in order to determine the groups most likely to exhibit bias.

DESIGN

Prospective cohort study.

SUBJECTS

7350 middle-aged subjects, 5445 men and 1905 women, from the GAZEL cohort, who have been followed up since 1989 and work at the French national company Electricité De France-Gaz De France (EDF-GDF) in various occupations.

MEASUREMENTS

Self-reported weight and height were based on information from yearly mailed questionnaires, and measured weight and height, used here as true values, were provided by occupational physicians from 1994 to 1997. Sex, age, marital status, education, occupation, history of ischemic heart disease, and treatment for cardiovascular risk factors were obtained from the mailed questionnaires or from data provided by the Company's personnel and medical departments.

RESULTS

Strong correlations were found between measured and self-reported values, but self-reported weight and height displayed significant systematic errors. Weight was significantly underestimated for men (0.54 kg) and for women (0.85 kg), and height overestimated for men (0.38 cm) and women (0.40 cm). These biases led to significant underestimations of BMI (0.29 and 0.44 kg/m2 for men and women respectively). Consequently, the prevalence of overweight, defined as BMI > 26.9 kg/m2 for women and BMI > 27.2 kg/m2 for men, was also underestimated, by 13% for men and 17% for women. The five factors associated with bias in self-reported weight and height were: overweight status, end-digit preference, age, educational level and occupation.

CONCLUSION

These findings suggest that self-reported weight and height should be treated with caution, because of biases leading to misclassification for overweight and obesity, especially in certain segments of the population.

How is sex considered in recent epidemiological publications on occupational risks?

OBJECTIVES

Although women account for almost half the working population in industrialised countries, a sex bias persists in publications on medical research in general and occupational health in particular. The objective was to review recent publications on how sex is considered in epidemiological studies of occupational health, and to answer the following questions: are men and women studied equally, what are the respective characteristics of the studies which comprise only men, only women, and both, and what strategy of data analysis is chosen by the authors to take account of the sex factor in mixed studies.

MATERIALS

This review was based on publications in six journals during the year 1997, and included all the original articles reporting an epidemiological study of occupational health.

RESULTS

In all, 348 articles were reviewed. In 40 articles (11%), the sex of the study population was not specified. In 177 articles (51%), the study population was mixed. In 108 (31%), the population consisted exclusively of men, and in only 23 (7%), exclusively of women. Even when study populations were mixed, they included fewer women than men. The sex composition of the population was related to the occupational risk factor considered, and also to health outcome. Industrial sector workers, and exposure to chemicals were more likely to be studied in samples of men. Mortality and health outcomes such as neoplasms and cardiovascular diseases were also more often studied among men. Surprisingly, study design differed significantly according to the sex of the population, and prospective studies, cohort studies, and exposed versus non-exposed studies were more often carried out in samples of men. Among the 177 mixed studies, sex was not investigated in over a quarter (27%). In 26 articles (15%), sex was not taken into account, but the authors attempted to justify this decision. In 46 mixed studies (26%), the results were adjusted for sex, and in 46 (26%), the authors gave separate results for men and women. In 11 studies (6%), more complete strategies of data analysis were chosen, including research for interactions or adjustment, followed by stratification.

CONCLUSION

This review of recent publications in occupational health epidemiology showed that women are still less often studied than men, and that the sex factor is not investigated in many mixed studies. The results therefore underline the need for further research on occupational hazards among women, and on sex differences.

Occupational risk factors for lung cancer in the French electricity and gas industry: a case-control survey nested in a cohort of active employees

The main aim of this study was the analysis of occupational lung cancer risk factors in the French national electricity and gas company (Electricité de France-Gaz de France (EDF-GDF)). A case-control survey nested in a cohort of male employees was undertaken. The study population consisted of all male staff who were active at EDF-GDF between January 1, 1978, and December 31, 1989. During this period, 310 cases of lung cancer were identified in the cancer register set up by the medical department of the company. For each case, four age-matched controls who were free of cancer at the time of occurrence of the case's lung cancer were randomly selected. Occupational exposures to 21 chemical agents were assessed for each subject using a job exposure matrix. The associations between lung cancer and the different agents were estimated using conditional logistic regression analysis. After adjustment for various occupational confounding factors, the analysis showed increased lung cancer risks linked to exposure to crystalline silica (highest exposure class: odds ratio = 2.27; 95% confidence interval: 1.10, 4.68) and creosotes (highest exposure level: odds ratio = 2.14; 95% confidence interval: 1.06, 4.31), with significant dose-response relationships for both exposures.

Occupational factors of anxiety and depressive disorders in the French National Electricity and Gas Company. The Anxiety-Depression Group

Very few studies described the prevalence of mental disorders in the workplace by using standard diagnostic criteria. A two-stage case-control study of anxiety and depression was initiated by Electricité de France and Gaz de France, the French Nationwide Company producing electricity and gas, using the General Health Questionnaire with 12 items as a screening test and the Composite International Diagnostic Interview as diagnostic instrument. Its aim was to point out occupational situations that promote the occurrence of anxiety and depression crises. Annual prevalence of depression was estimated at 7.6% in men (95% confidence interval [CI], 5.5 to 9.7) and at 17.9% in women (95% CI, 9.9 to 25.8), and that of anxiety at 9.6% (95% CI, 6.9 to 12.3) in men and 26.3% (95% CI, 17.2 to 35.4) in women. Workers in hazardous occupations were found to be protected from these disorders, whereas supervisory staff tended to be prone to developing them. Important changes in work or in its organization seemed to be risk factors. Extra-professional variables and occupational characteristics were included in a logistic regression model. The odds ratios corresponding to recent job changes and a supervisory position were significantly elevated (odds ratios = 1.7 and 2.4, respectively). These results suggest that some occupational events, such as major changes in work content or organization may cause or precipitate anxiety and/or depressive disorders.

[Psychotropic drug use and associated factors in a professional environment]

Drug use has been evaluated from a study conducted in a large french firm during 1992. The main objective of this study was to estimate prevalence of depressive and anxiety disorders and define professional factors. Psychotropic drug use has been measured by the percentage of subjects reporting their regular or occasional use during the 12 last months. Self-reported resort to medical system and sick leaves for psychiatric reason has been also examined during the same period. Lifetime and 12-month prevalence of depressive and anxiety disorders have been measured with a standardized questionnaire (CIDI, Composite International Diagnostic Interview) according to the criteria for the DSM III-R. A randomized sample of 540 subjects was obtained from two stages procedure. In first, a screening stage on 10,000 employees with the 12-items General Health Questionnaire (GHQ-12). The screened population was stratified on the global score GHQ-12 (> or = 3 and < 3). 270 subjects were randomized in each group and interviewed with CIDI. Occasional and regular psychotropic drug use is respectively 41.1% and 6.8% in women, 16.7% and 3.4% in men. It is much higher after 45 years (regular use: 18.8% in women and 7.6% in men). Only 6% of men and 7% of women with depressive disorders use regularly psychotropic drugs, the occasional use is 27% and 73%. In one third of the cases use regularly psychotropic drug.

Occupational respiratory cancer and exposure to asbestos: a case-control study in a cohort of workers in the electricity and gas industry

Cancers of the pleura, lung, and larynx between 1978 and 1989 among active male workers of Electricité de France-Gaz de France were studied in association with asbestos exposure using a case-control design nested within the cohort of workers of the company. The cohort included about 1,400,000 person-years, corresponding to a mean of 117,000 men per year. Exposure to asbestos and to some potential occupational confounders selected among agents from groups I, IIa, and IIb of the International Agency for Research on Cancer was assessed by a job-exposure matrix specific to the company. During the observation period, 12 cases of pleural cancer, 310 cases of lung cancer, and 116 cases of larynx cancer were registered in the cancer register of the company social security department. Four controls per case, matched for year of birth, were randomly selected among the cohort. Conditional logistic regression was used to estimate the odds ratios. A first analysis was conducted in order to assess the validity of the job-exposure matrix by investigating already known relationships between asbestos exposure and asbestosis. For asbestosis, a strong exposure-response relation was found with an odds ratio (OR) of 57.4 [95% confidence interval (CI): 17.0-194.0] in the highest exposure group. There was an elevated risk of pleural cancer (OR, 4.8, CI, 1.2-19.8). For lung cancer, significant ORs of 2.0 (CI, 1.3-3.2) and 1.9 (CI, 1.2-3.0) were found among the two highest cumulative exposure groups; adjustement for confounders slightly decreased the ORs. Squamous cell neoplasm of the lung was associated with asbestos exposure. The association between larynx cancer and asbestos exposure showed a tendency towards a nonsignificant increase in ORs in the highest cumulative exposure categories; this tendency disappeared when adjusting for occupational confounders. This study showed that occupational exposure to asbestos could increase the risk of pleural and lung cancer in a sector in which exposure levels are not considered to be high compared with other industrial settings.

Conformation of wheat gluten proteins. Comparison between functional and solution states as determined by infrared spectroscopy

The conformation of wheat gluten proteins in their functional hydrated solid state (doughy state) has been studied for the first time using attenuated total reflection infrared spectroscopy. The amide I band of functional gluten proteins reveals that, in addition to beta-turns and alpha-helices, these proteins contain a significant amount of intra- and intermolecular extended beta-sheet structures. It appears that the solubilization of gluten proteins results in a major decrease of the amount of beta-sheet structures accompanied by an increase of the content of the beta-turn and alpha-helical conformations. In addition, the alpha-helices appears to be more distorted in solution than in the functional state. Furthermore, spectra of omega- and gamma-gliadins, which are two types of prolamins of differing amino acid sequence and conformation, confirm the results obtained on the functional protein system. These results suggest that viscoelastic gluten proteins may interact through aligned beta-sheets corresponding to their repetitive domains.