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Biomedical subjects

I Lundberg

Publications and source records attributed to I Lundberg.

At least 73 records · Page 4Linked to original sources
PubMed1997

Increased risk of lung cancer among male professional drivers in urban but not rural areas of Sweden.

OBJECTIVES: To study the risk of lung cancer in different subgroups of professional drivers in urban and rural areas of Sweden. METHODS: Information on occupation and geographical region was obtained from the Swedish census of 1970 and data on the incidence of lung cancer between 1971 and 1984 from the National Swedish Cancer Registry. Professional drivers were separated into bus, taxi, and long and short distance lorry drivers. Comparisons of cumulative incidence of lung cancer were made between each particular group of drivers and gainfully employed men in the same region. RESULTS: Taxi drivers, and long and short distance lorry drivers in Stockholm County showed increased relative risks (RRs) of lung cancer with the highest risk among the short distance lorry drivers (RR 2.0, 95% confidence interval (95% CI) 1.5 to 2.6). These categories of drivers also showed increased risks in the other two large conurbations in Sweden. In the rest of the country (mainly rural areas) there were no increased RRs for any category of driver. The RR for bus drivers was not increased in any region. After adjustment for assumed differences in smoking habits the RRs remained significantly increased for lorry drivers in Stockholm but not for other groups of drivers in other areas. However, the RRs remained numerically higher in large conurbations than in rural regions for all groups of drivers. CONCLUSIONS: These findings suggest that some factors present in the urban environment play a substantial part in the excess of lung cancer among short distance lorry drivers in urban areas of Sweden. Exposure to motor exhaust fumes may have contributed to this excess.

Adult↗
PubMed1997

Evaluation of the Q16 questionnaire on neurotoxic symptoms and a review of its use.

OBJECTIVES: The questionnaire 16 (Q16) is commonly used to study prevalences of neurotoxic symptoms among workers exposed to organic solvents. It has also been recommended that exposed workers reporting more than six symptoms should be referred for further examination of possible chronic toxic encephalopathy. It would be useful to know whether symptoms reported in the questionnaire also reflect impairment of similar functions measured with objective or semiobjective methods in a formerly highly exposed group. METHODS: 135 painters and 71 carpenters answered the Q16, were interviewed about symptoms compatible with an organic brain damage, and took a battery of psychometric tests. A subsample of 52 painters and 45 carpenters were interviewed for psychiatric diagnosis according to Diagnostic and Statistical Manual for Mental Disorders, 3rd version (DSM III) and their vibration thresholds in hands and feet were measured. The entire group was followed up in the register of diagnoses at early retirement 1971-93. The lifetime exposure to organic solvents was assessed. Current exposure to organic solvents was found to be low or none. RESULTS: The prevalence of people with more than six symptoms in the Q16 rose with increasing cumulative exposure to solvents. The sensitivity of the questionnaire (more than six symptoms) to detect people who were assessed to exhibit symptoms compatible with an organic brain damage was only 38%. One of seven people who had retired early with a diagnosis compatible with a chronic toxic encephalopathy, and two of five people with a psychiatric diagnosis compatible with this condition, had more than six symptoms in the Q16. The agreement between Q16 replies and psychometric test results, as well as other examinations, was low. CONCLUSIONS: The notable exposure-response relation indicates that the questionnaire is useful for comparison of groups with different exposures to organic solvents. There was low agreement between the number of symptoms on the questionnaire and the assessment of symptoms compatible with organic brain damage, as well as psychiatric, or early retirement diagnoses compatible with chronic toxic encephalopathy. The questionnaire does not seem useful for screening of patients with chronic toxic encephalopathy in groups without ongoing exposure to organic solvents.

Aged↗
PubMed1996

Exposure to styrene and mortality from nervous system diseases and mental disorders.

Chronic low-dose exposure to solvents has been associated in epidemiologic studies with chronic neurotoxicity, but the evidence is not consistent. Styrene causes acute disturbances in the central and peripheral nervous systems. To determine if exposure to styrene may contribute to chronic diseases of the central nervous system, the authors examined mortality from nervous system diseases, mental disorders, and suicide in relation to styrene exposure in an international historical cohort study. The cohort involved 35,443 workers employed during 1945-1991 in the reinforced plastics industry, where high exposures to styrene occur. Indicators of exposure were reconstructed through job histories and environmental and biologic monitoring data. Poisson regression was used for internal comparisons. Mortality from diseases of the central nervous system (27 deaths) increased with time since first exposure, duration of exposure, average level of exposure, and cumulative exposure to styrene. A quadratic model described best the dose-response shape for cumulative exposure and duration of exposure with the highest risks at around 300 ppm-years and 5 years, respectively, and a subsequent decrease in risk in the highest exposure categories. Mortality from epilepsy increased monotonically with all styrene exposure indicators, while associations for degenerative diseases of the central nervous system were generally weaker. Mortality from mental disorders and suicide decreased with increasing duration of exposure and cumulative exposure, while there was no trend with time since first exposure and average exposure to styrene. These findings suggest that, in addition to the known acute effects, exposure to styrene may contribute to chronic diseases of the central nervous system.

Cause of Death↗
PubMed1996

Neuropsychological verbal tests may lack "hold" properties in occupational studies of neurotoxic effects.

OBJECTIVES: In epidemiological studies of neurotoxic effects neuropsychological tests are often applied to assess possible functional changes. In these studies tests presumed to be resistant to neurotoxic effects, "hold tests", are often used to adjust performance in tests presumed to be sensitive to neurotoxic effects, "nonhold tests", in assessment of pre-exposure ability. This conception is based on experience from the examination of patients with organic brain disorders. For this adjustment to be valid hold tests should change comparatively little over time and should not change differently in groups of people with different exposures to neurotoxic agents. METHODS: These assumptions were examined in 71 carpenters and 135 painters divided in three subgroups according to level of cumulative exposure to organic solvents. The results were noted from two verbal tests (test A, which involved following verbal instructions and test C, word comprehension), which were performed at conscription (age 18-20). The tests resemble hold tests used in occupational studies. The same tests were performed again at the age of 45-60 together with a conventional synonym test (SRB 1), often used in occupational studies. RESULTS: In the three tests given at the time of the investigation some differences were found between the carpenters and the subgroups of painters. The painters with low exposure tended to perform better than the carpenters in all three tests and the heavily exposed painters tended to perform less well in the tests. These differences were not present at the age of 18-20. In one of the conscription tests painters with different cumulative exposure to organic solvents developed differently over time. There was little improvement among painters with heavy and intermediate exposure and obvious improvement among painters with low exposure. The results in the other conscription test showed similar tendencies. CONCLUSIONS: The results indicate that the hold tests examined do not meet basic criteria for hold tests used in occupational studies. Thus adjustments for conventional verbal tests seem inappropriate in such studies. It is possible that other presumed hold tests may meet the criteria but our results suggest that such tests also should be evaluated before being used as hold tests in working populations.

Adolescent↗
PubMed1996

Exposure to styrene and mortality from nonmalignant respiratory diseases.

A cohort of 34,560 men and 6128 women employed in 660 European factories manufacturing reinforced plastic products, followed up originally to assess the risk of cancer, was used to assess the risk of non-malignant respiratory diseases associated with exposure to styrene. Mortality from pneumonia was associated with intensity of exposure to styrene, but this may have been due to chance. Mortality from bronchitis, emphysema, and asthma was not associated with styrene exposure.

Cohort Studies↗
PubMed1996

Exposure to styrene and mortality from nonmalignant diseases of the genitourinary system.

OBJECTIVES: A historical cohort study was carried out to investigate mortality from nonmalignant diseases of the genitourinary system among workers in the reinforced plastics industry, where high workroom concentrations of styrene are encountered. METHODS: The external comparisons in this report were based on an average of 12.6 years of retrospective follow-up of 35 443 workers who were first employed in the reinforced plastics industry during 1945-1991 and were known to have been exposed to styrene in their work. For the internal comparisons, 2641 subjects with incomplete occupational histories were excluded, leaving 32 802 subjects. Previous individual exposure histories to styrene were reconstructed through job histories and environmental and biological monitoring data. RESULTS: Mortality from nonmalignant diseases of the genitourinary system (N = 20) was associated with average exposure to styrene (P for trend 0.05). Weaker increasing trends in risk were seen for time since first exposure and cumulative exposure, while no increase was identified for duration of exposure. There was a significant increasing trend in mortality from nephritis and nephrosis (N = 5), associated with an increasing average level of exposure to styrene (P for trend 0.03). No clear trend was observed for time since first exposure, duration of exposure, or cumulative exposure. CONCLUSIONS: In this large cohort study of workers exposed to styrene, mortality from nonmalignant diseases of the genitourinary system increased as the average intensity of exposure increased. This finding indicates that other data should be scrutinized.

Air Pollutants, Occupational↗
PubMed1995

Development of a questionnaire in Spanish on neurotoxic symptoms.

A questionnaire in Spanish (with yes/no answers) was developed in order to study effects of neurotoxic agents in groups of workers in Nicaragua. Since many workers in Latin America are illiterate, the questions were read to the subjects. The questionnaire initially contained 34 questions, which were reduced to 16 after studying whether the questions were interpreted in the intended way by the subjects, whether the answers were reasonably reproducible over a 3-week period, and whether the questions discriminated between groups exposed to different neurotoxic agents (mercury, lead, organic solvents, and organophosphate insecticides) and nonexposed groups. In total, 851 male workers in Nicaragua and Venezuela participated in the evaluation. The questionnaire is submitted for use in the monitoring of groups exposed to neurotoxic agents, particularly in Latin America. The authors welcome further evaluation.

Adolescent↗
PubMed1995

Analysis of cytokine expression in muscle in inflammatory myopathies, Duchenne dystrophy, and non-weak controls.

We investigated the profiles of cytokine mRNA expression in muscle in 15 cases of inflammatory myopathy (IM) (5 each of polymyositis, inclusion body myositis, and dermatomyositis) and in 10 controls (5 of Duchenne dystrophy and 5 non-weak subjects). Expressions of the predominantly T cell-derived cytokines (interleukin (IL)-2, IL-4, IL-5, and interferon-gamma (IFN-gamma), of the predominantly macrophage-derived cytokines (IL-1, IL-6, and tumor necrosis factor-alpha (TNF-alpha)), as well as cytokines that can be of either T cell or macrophage origin (granulocyte-macrophage colony stimulating factor (GM-CSF) and transforming growth factor beta 1 (TGF-beta 1) and TGF-beta 2), were monitored by the reverse transcriptase-PCR method. The expression of T cell cytokine mRNAs for IL-2, IL-5, and IFN-gamma was generally weak or inconsistent. IL-4 mRNA expression was consistently moderate to strong in polymyositis but generally weak or absent in the other IMs. The expression of macrophage cytokine mRNAs for IL-1 alpha and IL-1 beta was weak or absent in all cases. Variable TNF-alpha mRNA expression was observed in 12 of 15 IM cases and faint or weak expression in 5 of 10 controls. Very strong GM-CSF expression was detected, but only on boosted PCR, in 12 of 15 cases of IM but in none of the controls. IL-6 was expressed only weakly or inconsistently. In contrast to the variable expression of several of the above mentioned cytokine mRNAs, all IM specimens strongly expressed TGF-beta 1 mRNA and 12 of 15 strongly expressed TGF-beta 2 mRNA. Thus, with the exception of IL-4 expression in polymyositis, a similar pattern of cytokine mRNA expression exists in the different types of IMs. Moreover, this pattern resembles that detected in non-weak and DD controls, although expression is generally weaker in the non-weak controls. The findings suggest that in IM muscle a sustained secretion of cytokines by T cells or of IL-1 by macrophages is not a prerequisite for operation of the immune effector response and that muscle may not be the site of ongoing sensitization.

Actins↗
PubMed1995

Cancer incidence and mortality of patients with suspected solvent-related disorders.

OBJECTIVE: The aim of this study was to study the incidence of cancer and deaths from cancer and other diseases among patients referred to the 11 clinics of occupational medicine in Sweden between 1967 and 1987 for examination because of exposure to organic solvents. METHODS: The cohort comprised 5791 persons, 5283 men and 508 women. Information about cancer incidence and causes of death was collected from the Cancer Register of the National Board of Health and Welfare and the National Death Register of Statistics Sweden, respectively. The expected values were calculated from the national death rates and incidence rates of cancer. RESULTS: The overall mortality rate was close to expected, but the mortality rate was decreased for diseases of the circulatory system [standardized mortality ratio (SMR) 0.7, 95% confidence limit (95% CI) 0.5-0.9] and increased for suicide (SMR 2.0, 95% CI 1.2-3.2). The total cancer incidence was slightly elevated [standardized incidence ratio (SIR) 1.2, 95% CI 0.99-1.4], and some specific cancer sites showed an increased incidence, although the lower confidence limits surpassed one. Malignancies of the lymphohematopoietic system and cancer of the uterine cervix had an increased risk (SIR 1.9, 95% CI 1.2-3.2, and SIR 3.7, 95% CI 2.2-6.2, respectively). Patients with presumerably high solvent exposure had an SIR of 1.4 for all malignancies (95% CI 0.9-2.1) and those with presumerably low exposure had an SIR of 1.1 (95% CI 0.9-1.4). CONCLUSIONS: The study showed an increased risk for malignancies of the hematopoietic system and the uterine cervix among patients originally examined with regard to solvent-induced disorders. There was also an increased risk of suicide and a decreased risk of death from diseases of the circulatory system. There was no increased risk for deaths from mental or neurological disorders.

Adult↗
PubMed1995

Neuropsychiatric function of housepainters with previous long-term heavy exposure to organic solvents.

Neuropsychiatric effects were examined among 206 men, of whom 135 had been house painters and 71 had been house carpenters, affiliated with their respective trade unions for at least 10 years before 1970. Their lifetime organic solvent exposure was evaluated through the aid of an interview. Relevant potential confounding factors were accounted for in the statistical analysis. Neuropsychiatric symptoms compatible with chronic toxic encephalopathy were more common among the painters than among the carpenters, and these symptoms became increasingly prevalent with increasing cumulative solvent exposure. On only one of 12 psychometric tests, block design, did the painters perform worse than the carpenters, and in this test the painters' performance deteriorated with increasing cumulative exposure. For the majority of the psychometric tests, and for the coordination tests, there were no differences between the painters and carpenters, but the painters with "low" exposure tended to show better, and "heavily" exposed painters worse, results than the carpenters. The 52 painters with the heaviest cumulative exposures and 45 carpenters were examined for psychiatric diagnosis according to DSM-III, with electroencephalography and auditory evoked potential, P-300. Three painters and two carpenters had diagnoses compatible with an organic mental disorder. There were no overall differences between the painters and carpenters, either for the visually examined electroencephalograms or the P-300 latencies. The excess of neuropsychiatric symptoms among the painters was probably causally linked to solvent exposure. However, these symptoms seemed only rarely, if ever, serious enough to entail a psychiatric diagnosis. Concerning other outcomes, the investigation may not lead to a determination of whether the exposure-response relationship among the painters, with no difference between the entire group of painters and carpenters, is caused by solvent exposure or by selection factors within the group of painters.

Adult↗
PubMed1994

Liver function tests and urinary albumin in house painters with previous heavy exposure to organic solvents.

The serum activities or concentrations of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), alkaline phosphatase (ALP), albumin, gamma-glutamyl transpeptidase (GGT), bilirubin (BIL), cholic acid (CHOL), chenodeoxycholic acid (CHENO), and transferrin with isoelectric point 5.7, and the urinary excretion of albumin were determined among male current or former house painters (n = 135) and house carpenters (n = 71) who had worked in their trades for at least 10 years before 1970. Workers who showed a value above the 90th percentile among the carpenters in at least one of the tests ASAT, ALAT, GGT, BIL, CHOL, or CHENO were regarded as showing "possible signs of liver dysfunction". Each participant's lifetime solvent exposure was evaluated by interview. The painters were divided into categories with low, intermediate, and heavy cumulative exposure during life (LTSE) or during the most exposed year (MEYSE). All participants stated none or slight recent exposure. The prevalence of possible signs of liver dysfunction increased with solvent exposure category according to LTSE as well as MEYSE with a numerically higher risk estimate in the heavy exposure category for MEYSE than for LTSE. ALP activity increased with exposure category according to both exposure estimates. This increase seemed to be due to an interaction between exposure to solvents and current or previous long term intake of medicines potentially toxic to the liver. None of these results was affected by whether or not the subjects had been exposed to solvents during the year before the investigation. The exposure to solvents was not significantly related to any other outcome variable. It is concluded that long term heavy exposure to solvents may elicit changes in conventional liver function tests indicative of a mild chronic effect on the liver. The findings also suggest that heavy solvent exposure during short time periods is a more likely cause of the findings than lifetime cumulative solvent exposure and that an interaction between solvent exposure and medicines potentially harmful to the liver may be important in the causation of the effects.

Aged↗
PubMed1994

Occupation, occupational exposure to chemicals and rheumatological disease. A register based cohort study.

The cumulative incidence of rheumatoid arthritis (RA) was compared between different occupations, and between different exposure groups based on a job-exposure matrix (JEM). The study population comprised those subjects who in 1980 lived in one of 13 Swedish counties, were born between 1905 and 1945, and who had stated the same occupation in the censuses of 1960 and 1970, a total of 375,035 men and 140,139 women. The study population was followed concerning hospital care for rheumatoid arthritis in 1981-1983 by lineage to the Swedish Hospital Discharge Register. In general there were rather small differences in the relative risk of RA in different exposure groups and different occupations. Most of the occupations associated with an increased risk of RA were occupations in which it was possible to work when the disease was present, i.e. cost accountants, estimating clerks and working proprietors in the retail trade. However, an increased relative risk of RA was also observed in some occupations where selection of RA patients out of heavy work should have biased genuinely increased relative risks towards unity. Such occupations were farmers, upholsterers, lacquerers, concrete workers, and hair-dressers. Substantial handling of organic solvents, according to the JEM, was associated with an increased relative risk.

Adult↗
PubMed1994

Cancer mortality in a historical cohort study of workers exposed to styrene.

OBJECTIVES: The goal of this study was to determine whether exposure to styrene is associated with an increased risk for neoplasms of the lymphatic and hematopoietic tissues. METHODS: A historical cohort study was conducted in Denmark, Finland, Italy, Norway, Sweden, and the United Kingdom. It involved 40,688 workers ever employed in the reinforced plastics industry, where high exposure to styrene occurs. Exposure to styrene was reconstructed through job histories and environmental and biological monitoring data. Cause-specific national death rates were used as the reference. Poisson regression was applied for internal comparisons. RESULTS: Among the exposed workers, no excess was observed for mortality from all neoplasms. Mortality from neoplasms of the lymphatic and hematopoietic tissues increased with time since first exposure and average level of exposure to styrene, but was not consistently associated with duration of exposure or with cumulative exposure. CONCLUSIONS: These findings leave open the possibility of an excess risk of neoplasms of the lymphatic and hematopoietic tissues among workers exposed to styrene.

Cohort Studies↗
PubMed1993

Dyslexia, left-handedness, and immune disorders.

OBJECTIVE: To illuminate a possible three-way association between dyslexia, immune disorders, and left-handedness. Geschwind's, Behan's, and Galaburda's hypotheses have been of special interest in this connection. DESIGN: Statistical analysis based on general assessment of the prevalence of the three aforementioned conditions. PARTICIPANTS: There were 734 children included from a total of 1165 in grade 6 (about 12 years of age) in the municipality of Stavanger, Norway. SETTING: Educational and demographic statistics indicate that the municipality of Stavanger is representative of the national population at large regarding the three conditions examined. MAIN OUTCOME MEASURES: A screening test with high reliability and validity was used to assess reading ability. It measured word recognition and phonological decoding. The questionnaires that recorded the students' handedness and immune disorders were filled in by the parents. Handedness was assessed by a Norwegian version of the Oldfield Inventory. A questionnaire concerning allergies and asthma was used to assess the prevalence of immune disorders. RESULTS: The bivariate analyses disclosed a significant association between handedness and dyslexia and a significant but weak association between handedness and immune disorders. No significant association was found between dyslexia and immune disorders. A triadic analysis yielded the following: 66.7% of the left-handed dyslexic children had immune disorders (P > .05); 42.1% of the left-handed children with immune disorders had dyslexia (P < .01); and 32% of the dyslexic children with immune disorders were left-handed (P < .05). CONCLUSIONS: There seems to be some association between dyslexia, left-handedness, and immune disorders. Of the three factors, handedness seems to be the most important association. The findings lend some support to the one interpretation of the hypotheses of Geschwind, Behan, and Galaburda.

Adolescent↗
PubMed1993

Mortality and cancer incidence among PVC-processing workers in Sweden.

The mortality pattern and the cancer incidence were investigated among 717 men who had been employed for at least 3 months during 1964-1974 in three Swedish PVC-processing plants. The mortality was followed 1964-1986 and the cancer incidence 1964-1984. Expected figures were calculated from Swedish national rates. Among Swedish citizens, the observed mortality and cancer incidence was close to the expected in most diagnoses. Among immigrants, mostly from Finland, there was a marked excess of circulatory deaths. This finding was probably due to the higher incidence of coronary mortality in Finland compared to Sweden. In the whole cohort, five cases of malignant melanoma had occurred as compared to 1.5 expected (SMR = 3.4, 95% confidence limit 1.1-7.9). This may be due to chance but merits further investigation since an increased incidence of malignant melanoma has previously been found among Norwegian PVC-manufacturing workers.

Chemical Industry↗
PubMed1993

Cancer mortality in an international cohort of workers exposed to styrene.

Increased risks for leukaemia and lymphoma have been suggested in studies of workers exposed to styrene in the rubber and plastics industry. A historical cohort study was conducted in Denmark, Finland, Italy, Norway, Sweden and the United Kingdom involving 40,683 workers employed in the reinforced plastics industry, where high exposure to styrene occurs. Exposure to styrene was reconstructed through job histories, environmental and biological monitoring data and production records of the plants in the study. Cause-specific national death rates were used as the reference. Among exposed workers, no excess was observed for mortality from all causes (2195 deaths, standardized mortality ratio [SMR], 95; 95% confidence interval [CI], 91-99), from all neoplasms, from lung cancer or from other major epithelial cancers. Mortality from neoplasms of the lymphatic and haematopoietic tissues was not elevated (50 deaths; SMR, 96; CI, 71-126) and was not consistently associated with length of exposure. The rate of mortality from leukaemias and lymphomas increased with time since first exposure. Among subjects who had been exposed for more than one year, a two-fold risk was observed 20 years after first exposure (eight deaths; SMR, 197; CI, 85-387). These results are inadequate to exclude the possibility that styrene causes leukaemia and lymphoma.

Cohort Studies↗