Early retirement and non-employment after breast cancer

OBJECTIVE

This study examined whether workplace support, sociodemographic factors and co-morbidity are associated with early retirement or non-employment due to other reasons among breast cancer survivors. We also compared quality of life and chronic symptoms (pain, fatigue, anxiety and depression) among employed, retired and other non-employed breast cancer survivors.

METHODS

We identified breast cancer survivors diagnosed between 1997 and 2002 from either a hospital or a cancer registry in Denmark, Finland, Iceland and Norway (NOCWO study). All patients had been treated with curative intent. Information on employment, co-morbidity and support was collected via a questionnaire. The sample included 1111 working-aged cancer-free survivors who had been employed at the time of diagnosis. We used multinomial logistic regression models to analyse the association of various determinants with early retirement and other non-employment (due to unemployment, subsidized employment or being a homemaker).

RESULTS

Low education, low physical quality of life, co-morbidity and pain were associated with both early retirement and other non-employment after cancer. Other non-employed survivors also rated their mental quality of life as lower and experienced anxiety and fatigue more often than all the other survivors. Moreover, they reported a lower level of supervisor support after their diagnosis than the employed survivors. Retired survivors more often reported weak support from colleagues.

CONCLUSIONS

Differences in ill health and functional status between various groups of non-employed cancer survivors need to be considered when planning policy measures for improving the labour market participation of this population and preventing their early withdrawal from working life.

Work ability of survivors of breast, prostate, and testicular cancer in Nordic countries: a NOCWO study

INTRODUCTION

Cancer can cause adverse effects on survivors' work ability. We compared the self-assessed work ability of breast, testicular, and prostate cancer survivors to that of people without cancer. We also investigated the association of disease-related and socio-demographic factors and job-related resources (organizational climate, social support, and avoidance behavior) with work ability and looked at whether these associations were different for the survivors and reference subjects.

METHODS

Working aged cancer patients diagnosed between 1997 and 2002 were identified from hospital or cancer registries in Denmark, Finland, Iceland, and Norway (Nordic Study on Cancer and Work). A cancer-free reference group was selected from population registries. We collected information on work ability and other factors from 1,490 employed survivors and 2,796 reference subjects via a questionnaire.

RESULTS

The adjusted mean value of work ability was slightly lower among the breast and prostate cancer survivors compared to the cancer-free population. Co-morbidity, chemotherapy, low workplace support, and low organizational commitment were associated with reduced work ability. Avoidance behavior from supervisors or colleagues was only related to work ability among the cancer survivors.

CONCLUSIONS AND IMPLICATIONS

More attention should be paid to assisting cancer survivors in work life, particularly those who have chronic diseases or have undergone chemotherapy. Although most factors affecting the work ability of the survivors and reference subjects were the same, survivors' work ability seemed to be particularly sensitive to avoidance behavior. The results suggest that there is a need to improve communication at the workplace and develop supportive leadership practices in order to avoid isolating behavior towards cancer survivors.

Cancer as the cause of changes in work situation (a NOCWO study)

OBJECTIVE

To investigate the frequency of changes in work situation due to cancer and to analyze the association of physically demanding work, social support from supervisors, colleagues or occupational health services, and disease-related factors, with changing employers due to cancer.

METHODS

Working-aged patients with breast, testicular or prostate cancer, or lymphoma with a good prognosis between 1997 and 2002 were identified from a hospital or cancer registry in four Nordic countries. The registers provided data on the disease-related factors. Information on changes in work situation, received support, and other work-related factors was collected using a questionnaire (response rate 72%). The frequency of changes in work situation was evaluated among a total of 2030 survivors. Further analyses were carried out among 688 survivors using a multivariable logistic regression model, to investigate factors affecting the risk of changing employers due to cancer.

RESULTS

Altogether, 5-10% of cancer survivors had changed employers, occupations or work tasks, 5% had been unemployed, and 9% had retired due to cancer. The physical demands of previous work were the most important reason behind changing employers after cancer. Among women, weak support from supervisors and occupational health personnel increased the risk of changing employers because of cancer.

CONCLUSIONS

A minority of cancer survivors changed employers, occupations, or work tasks because of cancer. Supervisors' support in the form of lightening physically demanding jobs and taking illness into consideration when planning work tasks, and health-care workers' advice on coping at work may help survivors to maintain their jobs.

Respiratory effects of exposure to methacrylates among dental assistants

BACKGROUND

Case reports of occupational asthma in dental personnel have been published, but there is little data on the risk of respiratory disorders related to occupational exposure to methacrylates in dental assistants. The objective of this study was to investigate the relation of exposure to methacrylates to occurrence of respiratory symptoms and diseases among dental assistants.

METHODS

A cross-sectional study of female dental assistants from the membership register of the Finnish Association of Dental Hygienists and Assistants was conducted in the Helsinki metropolitan area. A CATI was carried out to collect information on health and exposures. A total of 799 dental assistants participated (response rate 87%).

RESULTS

Daily use of methacrylates was related to a significantly increased risk of adult-onset asthma (adjusted OR 2.65, 95% CI 1.14-7.24), nasal symptoms (1.37, 1.02-1.84), and work-related cough or phlegm (1.69, 1.08-2.71). Nasal symptoms showed a dose-response relation with increasing years of exposure to methacrylates, and those with >10 years of exposure had also increased risk of hoarseness, dyspnoea, and wheezing with dyspnoea. Dental assistants with a history of atopic diseases were particularly susceptible to exposure to methacrylates, the adjusted OR for adult asthma being in this group 4.18 (95% CI 1.02-28.55) and for nasal symptoms 2.11 (1.08-4.19).

CONCLUSIONS

This study provides new evidence that the risk of adult-onset asthma, nasal symptoms and other respiratory symptoms increase significantly with daily use of methacrylates in dental assistants' work. The results suggest that exposure to methacrylates poses an important occupational hazard for dental assistants.

Increased expression of high mobility group A proteins in lung cancer

High mobility group A (HMGA) proteins play an important role in the regulation of transcription, differentiation, and neoplastic transformation. In this work, the expression of HMGA 1 and 2 in 152 lung carcinomas of mainly non-small-cell histological type has been studied by immunohistochemistry in order to evaluate their feasibility as lung cancer markers. In 17 lung cancer cases, the related bronchial epithelial changes were also studied for HMGA1 and 2 expression. RNA expression of HMGA1a and b isoforms and of HMGA2 was determined by real-time semi-quantitative RT-PCR in 23 lung carcinomas. High expression of HMGA1 and HMGA2 at both mRNA and protein levels was detected in lung carcinomas, compared with normal lung tissue. Nuclear immunostaining for HMGA1 and 2 proteins also occurred in hyperplastic, metaplastic, and dysplastic bronchial epithelium. Increased nuclear expression of HMGA1 and 2 correlated with poor survival (for adenocarcinomas, HMGA1, p=0.006; HMGA2, p=0.05). While the expression of HMGA2 was significantly associated with cell proliferation (p=0.008), HMGA1 expression did not show any association with proliferation or apoptotic index. Sequencing of HMGA2 transcripts from tumours with very high expression showed a normal full-length transcript. As HMGA proteins were expressed in about 90% of lung carcinomas and their expression was inversely associated with survival, they may provide useful markers for lung cancer diagnosis and prognosis.

Influence of radiologists' sex and training on fluoroscopy doses during barium enema

Variables influencing radiation exposure were studied using analysis of covariance in 523 double contrast barium enemas performed by 21 radiology residents (12 female, 9 male). Dose-area products (DAPs) (ns), number of exposures per patient (p < 0.05) and screening times (p < 0.05) were higher for female residents (mean 52.0 Gy cm2, 9.55 exposures and 4.02 min, respectively) than for male residents (mean 41.7 Gy cm2, 8.26 exposures and 3.20 min, respectively). The number of lectures on radiation protection attended by the resident (range 0-20) had no significant effect on these radiation-related variables. Other factors explaining these variables were patient age, diagnosis and anteroposterior thickness. Radiologists' use of ionizing radiation during fluoroscopy may be sex-related. Traditional lecture-based education on radiation protection was not effective with this group; thus, improved methods should be developed to control doses.

Body burden of aluminum in relation to central nervous system function among metal inert-gas welders

OBJECTIVES

The relationship between elevated internal aluminum loads and central nervous system function was studied among aluminum welders, and the threshold level for adverse effect was defined.

METHODS

For 65 aluminum welders and 25 current mild steel welders body burden was estimated, and the aluminum concentrations in serum (S-Al) and urine (U-Al) were analyzed with graphite furnace atomic absorption spectrometry with Zeeman background correction. Referents and low-exposure and high-exposure groups were defined according to an aggregated measure of aluminum body burden, the group median S-Al levels being 0.08, 0.14, and 0.46 micromol/l, respectively, and the corresponding values for U-Al being 0.4, 1.8, and 7.1 micromol/l. Central nervous system functions were assessed with a neuropsychological test battery, symptom and mood questionnaires, a visual and quantitative analysis of electroencephalography (EEG), and P3 event-related potentials with pitch and duration paradigms.

RESULTS

Subjective symptoms showed exposure-related increases in fatigue, mild depression, and memory and concentration problems. Neuropsychological testing revealed a circumscribed effect of aluminum, mainly in tasks demanding complex attention and the processing of information in the working memory system and in the analysis and recall of abstract visual patterns. The visual EEG analysis revealed pathological findings only for aluminum welders. Mild, diffuse abnormalities were found in 17% of the low-exposure group and 27% of the high-exposure group, and mild to moderate epileptiform abnormalities at a frequency of 7% and 17%, respectively.

CONCLUSIONS

Both objective neurophysiological and neuropsychological measures and subjective symptomatology indicated mild but unequivocal findings dose-dependently associated with increased aluminum body burden. The study indicates that the body burden threshold for adverse effect approximates an U-Al value of 4-6 micromol/l and an S-Al value of 0.25-0.35 micromol/l among aluminum welders.

Global burden of disease and injury due to occupational factors

We made estimates of absolute morbidity and mortality due to occupational factors for the world using all available published data as of 1994, and, where no data were available, applying the most appropriate (in terms of similar economy, race, and environment) age-/sex-/diagnosis-specific incidence and mortality rates to known working population distributions. We report results according to economic groupings determined by the World Bank (World Development Report, 1993) and disease and injury groupings according to The Global Burden of Disease project (1997). This was part of a larger study that estimated the total global disease burden. We present aggregate results and analyses by region and disease. We estimate that approximately 100,000,000 occupational injuries (100,000 deaths) and 11,000,000 occupational diseases (700,000 deaths) occur in the world each year. We regard these as very conservative estimates which, although unavoidably crude, can nevertheless provide a basis for health priority planning at global level.

Age-dependent inclusion of sex chromosomes in lymphocyte micronuclei of man

Two-color centromeric FISH was used to study the inclusion of the X and Y chromosomes in micronuclei of cultured lymphocytes from 10 men representing two age groups (21-29 years and 51-55 years). In addition, pancentromeric FISH was separately performed to identify any human chromosomes in micronuclei. One hundred micronuclei per probe were examined from each donor. A higher mean frequency of Y-positive micronuclei was observed in the older men than in the younger men. In both age groups, the X chromosome was micronucleated clearly more often than expected by chance, and the Y chromosome was overrepresented in micronuclei among the older men but not among the younger men. In lymphocytes of four women, X-positive micronuclei were more frequent than they were in men, even after the fact that women have two X chromosomes was taken into account. Similar results were obtained in first-division lymphocytes identified by cytochalasin-B-induced cytokinesis block. In comparison with normal cells, these binucleate cells showed a higher frequency (per 1,000 nuclei) of X-positive micronuclei (in the older men) but a lower frequency of micronuclei harboring autosomes or acentric fragments. In conclusion, the results show that both the X chromosome and the Y chromosome are preferentially micronucleated in male lymphocytes, the Y chromosome only in older subjects. Although the X chromosome has a general tendency to be included in micronuclei, it is micronucleated much more often in women than in men, which is probably the main reason for the high micronucleus frequency in women that has been documented in many previous studies.

Validity of self-reported physical work load in epidemiologic studies on musculoskeletal disorders

OBJECTIVES

This study assessed the validity of self-reported physical work load by questionnaire and logbook against task analysis and observation. It also investigated factors (job type and low-back or neck pain) affecting the self-assessment of physical work load and compared the assessments between the questionnaire and the logbook.

METHODS

A self-administered questionnaire including 10 questions (ordinal scales) on physical work load and musculoskeletal symptoms was filled out by 2756 men in the forest industry. From this population, 36 men were selected for task analysis and observation. Logbooks including 10 continuous variables were analyzed for 386 men.

RESULTS

The Spearman rank correlation coefficients between the self-assessments and observations for the frequency of manual handling, duration of trunk flexion, neck rotation, hand above shoulder level, and squatting or kneeling ranged between 0.42 and 0.55. The correlation coefficients for the questionnaire items were higher in general, and the accuracy better, for those with no low-back pain than for those with pain. The duration of trunk flexion, neck flexion and hand above shoulder level was overestimated in the questionnaires and less so in the logbooks.

CONCLUSIONS

Self-administered questionnaires may help to classify groups with heterogeneous occupational tasks according to some work-load factors. The accuracy of the assessments is not good for studying quantitative exposure-effect relationships, however. The logbook method might give more valid information. The perception of musculoskeletal pain may bias the self-assessment of work load.

The treatment of acute low back pain--bed rest, exercises, or ordinary activity?

BACKGROUND

Bed rest and back-extension exercises are often prescribed for patients with acute low back pain, but the effectiveness of these two competing treatments remains controversial.

METHODS

We conducted a controlled trial among employees of the city of Helsinki, Finland, who presented to an occupational health care center with acute, nonspecific low back pain. The patients were randomly assigned to one of three treatments: bed rest for two days (67 patients), back-mobilizing exercises (52 patients), or the continuation of ordinary activities as tolerated (the control group; 67 patients). Outcomes and costs were assessed after 3 and 12 weeks.

RESULTS

After 3 and 12 weeks, the patients in the control group had better recovery than those prescribed either bed rest or exercises. There were statistically significant differences favoring the control group in the duration of pain, pain intensity, lumbar flexion, ability to work as measured subjectively, the Oswestry back-disability index, and number of days absent from work. Recovery was slowest among the patients assigned to bed rest. The overall costs of care did not differ significantly among the three groups.

CONCLUSIONS

Among patients with acute low back pain, continuing ordinary activities within the limits permitted by the pain leads to more rapid recovery than either bed rest or back-mobilizing exercises.

Rheumatoid factor and HLA antigens in wrist tenosynovitis and humeral epicondylitis

A matched case-referent study was undertaken to assess whether rheumatoid factor (RF) is associated with repeating tenosynovitis or peritendinitis and whether HLA-B27 predisposes to epicondylitis. The study subjects consisted of 25 workers in manually strenuous jobs with a history of at least two episodes of tenosynovitis or peritendinitis in the wrist or forearm, or humeral epicondylitis, and their matched referents. The latex agglutination test was positive in seven of the 23 cases with tenosynovitis and in one of the referents (p = 0.03). The corresponding figures for IgM-RF by enzyme immunoassay were ten and two, respectively (p = 0.008). HLA-B27 antigen was found in five of the 13 workers with epicondylitis and in one worker with no such history (p = 0.13). It is possible that RF-positive repeating tenosynovitis represents an incomplete form of rheumatoid disease.

Psychomotor capacity and occurrence of wrist tenosynovitis

A case-referent study was carried out among meatcutters, sausage markers, and packers in a large meat-processing plant to investigate the association between psychomotor capacity and occurrence of tenosynovitis. Reaction time, movement time, manual dexterity, visual attention and visuospatial ability were measured in 26 cases with a history of two or more episodes of tenosynovitis and 26 referents of similar gender, occupation, age, and job seniority with no episodes of the disease. No differences were found between the cases and the referents in any of the tests of psychomotor capacity. The results suggest that psychomotor capacity, as measured with the tests of this study, is a poor predictor of wrist tenosynovitis.

Lung function impairment following mycoplasmal and other acute pneumonias

We prospectively studied the lung function of 106 consecutive young patients with pneumonia. At the time of hospital admission we observed impaired spirometric function in 48% of the patients. During and following treatment, the frequency of abnormalities in pulmonary function tests decreased rapidly. However, at the 15th day of hospitalization, abnormal ventilatory function was still demonstrated in 21% of the patients. Such prolonged impairment of ventilatory function was significantly more likely to result from pneumonia caused by Mycoplasma pneumoniae than from forms caused by adenovirus or Streptococcus pneumoniae.

Lung function impairment following mycoplasmal and other acute pneumonias

We prospectively studied the lung function of 106 consecutive young patients with pneumonia. At the time of hospital admission we observed impaired spirometric function in 48% of the patients. During and following treatment, the frequency of abnormalities in pulmonary function tests decreased rapidly. However, at the 15th day of hospitalization, abnormal ventilatory function was still demonstrated in 21% of the patients. Such prolonged impairment of ventilatory function was significantly more likely to result from pneumonia caused by Mycoplasma pneumoniae than from forms caused by adenovirus or Streptococcus pneumoniae.

A life-long prospective study on the role of psychosocial factors in neck-shoulder and low-back pain

The predictive value of psychosocial factors in the development of neck--shoulder and low-back symptoms was investigated in a life-long follow-up study of 154 subjects. Measurements taken in adolescence, such as intelligence, alexithymia (low verbal productivity in projective personality tests), social confidence, hobbies, and the socioeconomic status of the family, showed no consistent associations with neck--shoulder or low-back symptoms in adulthood. Of the variables recorded in adulthood, weak mental resources for promoting health (poor sense of coherence) were consistently associated with neck--shoulder pain, whereas low fundamental education predicted low-back symptoms. The results suggest that psychosocial factors in childhood have a minor role as direct predictors of later symptoms.

Anencephaly and maternal common cold

To study the risk of anencephaly related to common cold during pregnancy, a case-control study was made. The series comprised 393 Finnish mothers of anencephalic children and their time-area-matched controls in the period 1964 through 1982. Seventy mothers of anencephalic infants and 17 controls had reported common cold in the first trimester [adjusted odds ratio 4.5; 95% confidence interval (2.2-9.1)]. Reported common cold in the second trimester was not associated with anencephaly. As suggested by our previous cohort study in the same population, a true viral influenza resembling "common cold" might not explain the observed association.

Prevalence of epicondylitis and elbow pain in the meat-processing industry

To determine the etiologic role of strenuous manual tasks in relation to epicondylitis, three clinical cross-sectional examinations were performed on meatcutters (N = 102), sausage makers (N = 125), packers (N = 150), and workers in nonstrenuous tasks (N = 332). The workers in strenuous jobs reported elbow symptoms 1.6-1.8 times as often as those in nonstrenuous jobs. Female sausage makers also showed epicondylar tenderness more often than the women in nonstrenuous jobs. In all the cross-sectional examinations combined, seven cases (0.8%) of epicondylitis were detected in both the strenuous and nonstrenuous jobs. A control for the possible sources of bias (leaving the company, changing task, being on sick leave) did not suggest a marked loss of potential cases of epicondylitis. A major role of strenuous tasks in the etiology of epicondylitis was not shown. However, because the number of clinical cases was small, the power of the study was low.

Incidence of tenosynovitis or peritendinitis and epicondylitis in a meat-processing factory

A 31-month follow-up study on the incidence of clinically ascertained tenosynovitis or peritendinitis in the hand and forearm regions and epicondylitis was conducted among 377 workers in strenuous manual jobs and 338 employees in manually nonstrenuous work in a large meat-processing factory. The clinical diagnosis of tenosynovitis or peritendinitis occurred 143 times and epicondylitis 68 times during the follow-up. The annual incidence of tenosynovitis or peritendinitis was less than 1% for employees in nonstrenuous jobs, 25.3% for female packers, 16.8% for female sausage makers, and 12.5% for male meatcutters. The annual incidence of epicondylitis was about 1% for employees in nonstrenuous jobs, 11.3% for female sausage markers, 7.0% for female packers, and 6.4% for male meatcutters. Workers typically resumed their jobs after returning from sick leave, and job transfers were rare.

Influenza epidemics and anencephaly

To explore the postulated association between maternal influenza and congenital defects of the central nervous system, 14 virologically verified epidemics in Finland, 1969-82, were studied. Mothers of 248 anencephalic children were grouped into those whose first trimester had occurred during an epidemic period and those whose pregnancy had commenced during a non-epidemic period. No significant differences in prevalence of anencephaly were noted in these groups.

Cardiovascular malformations, work attendance, and occupational exposures during pregnancy in Finland

To explore for associations between occupational factors and cardiovascular malformations, information on the parents of 160 infants with cardiovascular malformations and 160 control parents was studied. The case infants had been reported consecutively to the Finnish Register of Congenital Malformations. All mothers were interviewed identically after delivery, using both open and pro forma questions about detailed work tasks, exposures, and leisure activities during pregnancy. The interview information was evaluated blindly. Neither parental occupational titles nor maternal working per se gave new clues to the teratogenic risk; nor did shift working, wearing of personal protective equipment, or the mother's own opinion on exposures during pregnancy. Identified occupational exposures, as categorized by an industrial hygienist, showed no remarkable associations to cardiovascular malformations. Few mothers were exposed substantially to specific occupational hazards. Comparing mothers who used medications in the first trimester with those who did not showed an odds ratio of 2.2 (95% confidence interval 1.3-3.9) when adjusted for potential confounding by multivariate logistic methods.

Facet joint orientation, facet and costovertebral joint osteoarthrosis, disc degeneration, vertebral body osteophytosis, and Schmorl's nodes in the thoracolumbar junctional region of cadaveric spines

The disc degeneration in the thoracolumbar junctional region (T10-L1) of 37 male cadaveric spines was recorded with the use of discography. From 24 of these spines the facet joint orientation and degenerative findings of the facet and costovertebral joints, vertebral bodies (osteophytosis) and discs, and Schmorl's nodes were recorded directly from bones. At T11-12, the most common site for the transitional zone between thoracic and lumbar facet type, there was a marked variation in the orientation of facets. The occurrence of degenerative findings and Schmorl's nodes at the three levels in the region differed. At T10-11, disc degeneration, vertebral body osteophytosis, and Schmorl's nodes were most common (anterior degeneration). At T12-L1, facet and costovertebral joint degeneration were dominant (posterior degeneration). At T11-12, disc degeneration, vertebral body osteophytosis, Schmorl's nodes, and facet and costovertebral joint degeneration all occurred (anterior and posterior degeneration). The results point to a pathoanatomic association between degenerative changes and facet orientation.

Plain radiographic, discographic, and direct observations of Schmorl's nodes in the thoracolumbar junctional region of the cadaveric spine

The perceivability of Schmorl's nodes in plain radiographs and discograms in the thoracolumbar junctional region (T10-L1) of the cadaveric spine was assessed by comparing the radiologic measurements with bone measurements. Schmorl's nodes in bone specimens were encountered in 19 of 24 spines studied. They were more than two times as common between vertebrae T10-11 and T11-12 as between T12 and L1 (P less than 0.01). When the areas of actual Schmorl's nodes exceeded 0.5 cm2 (corresponding to an aperture with a diameter of 0.8 cm), 47% of the nodes were seen in plain lateral radiographs and 68% in discograms. When the area measured 0.5 cm2 or less, only 24% could be perceived in plain lateral radiographs and 23% in discograms. The clinical significance of Schmorl's nodes remains uncertain as long as they are difficult to detect in vivo.

Radiographic vs. direct measurements of the spinal canal of the thoracolumbar junctional region (T10-L1) of the spine

Midsagittal diameter (MSD) and interpedicular distance (IPD) in the thoracolumbar junctional region (T10-L1) of 24 male cadaveric spines were measured both from radiographs and directly from bones after removal of the soft tissues in order to assess the accuracy of plain radiographs. In addition surface areas of the vertebral canals were measured also from bone samples. It was found that the mean difference between bone and radiographic measurements in the IPD on different vertebral levels was 1.0 mm (r = 0.98). The MSD was a more difficult measurement, but the correlation coefficient was still 0.70, the mean difference being 0.7 mm or less. The sum of the MSD and IPD showed good relationship with the cross sectional area of the spinal canal, and the correlation coefficient was 0.77 (P less than 0.001).

Coffee consumption during pregnancy and selected congenital malformations: a nationwide case-control study

Finland leads the world in per capita coffee consumption. To evaluate the hypothesis that coffee consumption during pregnancy is teratogenic, 755 pairs of mothers of malformed children and their controls were personally interviewed soon after delivery. After excluding tea drinkers and pairs with inadequate information, the study group included 706 pairs. Study subjects consisted of mothers of children with 112 defects of the central nervous system, 241 orofacial clefts, 210 structural defects of the skeleton, and 143 cardiovascular malformations. The coffee consumption during pregnancy was similar for the mothers of malformed or non-malformed children. The comparison of the mothers drinking at least four cups of coffee a day during pregnancy with those not consuming coffee at all showed a relative risk point estimate of 1.0 with the 95 per cent confidence limits of 0.7 and 1.3.

Nasal and sinonasal cancer. Connection with occupational exposures in Denmark, Finland and Sweden

A joint Danish-Finnish-Swedish case-referent investigation was initiated in 1977 in order to study the connection between nasal and sinonasal cancer and various occupational exposures. All new cases of nasal and sinonasal cancer were collected from the national cancer registers (Finland and Sweden) or from the hospitals (Denmark). Those still alive who agreed to an interview (N = 167) were individually matched for age and sex with patients with colonic or rectal cancer. A detailed telephone interview was made according to standardized forms. Both cases and referents thought that their condition was the one under study. The exposures were coded blindly by an industrial hygienist. The results showed associations between nasal and sinonasal cancer and exposure to (i) hardwood or mixed wood dust (discordant pairs 14: 2), (ii) softwood dust alone (13:4), (iii) chromium (16: 6), (iv) nickel (12: 5, not significant), (v) welding, flame-cutting and soldering (17: 6), and (vi) lacquers and paints (14: 0). The last finding was probably due to confounding from wood dust exposure. Hardwood dust exposure was associated with adenocarcinoma. Softwood dust exposure alone was associated with epidermoid and anaplastic carcinomas. No associations were found for a number of exposures, including agricultural chemicals, textile dust, asbestos, quartz dust, organic solvents and leather work. Possible exposure to formaldehyde was evenly distributed between the cases and referents.

Nasal cancer and occupational exposures. Preliminary report of a joint Nordic case-referent study

Nasal and sinus paranasal cancers have been associated with several occupational exposures, for example, dust from hardwood, nickel and unspecific agents occurring in the boot and shoe industry. A joint Danish-Finnish-Swedish case-referent investigation was initiated in 1977 to study further the connection between nasal and sinus paranasal cancers and various occupational exposures. All new cases of these cancers were collected from the national cancer registers (Finland & Sweden) or from hospitals (Denmark). Those still alive who agreed to the interview (N = 167) were individually matched for age and sex with patients with colonic or rectal cancer. A detailed telephone interview was performed according to a standardized procedure. Both the cases and referents thought that their condition was the one under study. The exposures were coded blindly by an experienced industrial hygienist. The results showed associations between nasal or sinus paranasal cancer and exposure to hardwood or mixed wood dust (discordant pairs 14/2); softwood dust alone (13/4); chromium 16/6); nickel (12/5, not significant); welding, flamecutting, and soldering (17/16); and lacquers and paints (12/0). Hardwood dust exposure showed a connection with adenocarcinoma. Softwood dust exposure alone was associated with epidermoid and anaplastic carcinomas. No associations were found for a number of exposures, including agricultural chemicals, textile dust, asbestos, quartz dust, organic solvents, and leather work. Possible exposure to formaldehyde was evenly distributed between the cases and referents.

Sauna and congenital defects

To test a recent hypothesis on the causal relationship between sauna-induced hyperthermia and congenital defects, 100 consecutive cases of defects of the central nervous system and 202 cases of orofacial clefts were singled out from the Finnish Registry of Malformations. The mothers and their time-area-matched referents were interviewed for their sauna habits. Almost every pregnant mother (98.5%) had visited the sauna regularly, and yet, the incidence of the CNS defects in Finland is among the lowest ever reported. No differences in the sauna habits were observed between the case and referent mothers. It is concluded that the relatively mild, temporal hyperthermia caused by the sauna should not be considered hazardous for the developing embryo.

Breast cancer incidence: geographical correlations in Finland

Correlation analysis was performed on breast cancer incidence and risk factors in geographical areas of Finland. Breast cancer risk is associated with fertility and taxable income but not with the size of the woman. Trends in risk factors indicate that the rapid increase in the incidence of breast cancer is likely to continue. It is concluded that factors which are reflected by the standard of living and fertility might act independently and not through the nutritional status, for which the size of the woman is an operational indicator.