Biomedical subjects

L Hagmar

Publications and source records attributed to L Hagmar.

At least 91 records · Page 5Linked to original sources

PubMed1995

High consumption of fatty fish from the Baltic Sea is associated with changes in human lymphocyte subset levels.

Fatty fish from the Baltic Sea accumulate immunotoxic persistent organochlorine compounds. In a previous study we found inverse correlations between such fish consumption and natural killer (NK) cell levels in a Swedish population. The present study concerns 68 Latvian subjects with high, low or intermediate fish consumption. High fish consumption correlated positively with B cell levels and CD4+/CD8+ ratios, but negatively with levels of cytotoxic (CD8+) T cells. Furthermore, NK cell levels correlated inversely with plasma selenium, one of several strong correlates with fish intake. A high fish diet includes a set of possible immunomodulating agents. It is presently not possible to pinpoint the cause for the observed subset deviations or to establish their possible biological importance.

Adult↗

PubMed1995

Radiographic changes and lung function in relation to activity of the glutathione transferases theta and mu among asbestos cement workers.

Experimental data indicate that active oxygen species may be casually involved in the development of asbestos-related disease. Thus, it was hypothesized that individual differences in glutathione transferase activity, which may affect the ability to inactivate molecules formed in relation to oxidative stress, could influence the biological response to asbestos exposure. We could, however, not demonstrate an increased risk for radiographic changes or reduced lung function among asbestos cement workers deficient for glutathione transferase theta (GSTT1), glutathione transferase mu (GSTM1), or having a combined deficiency of enzyme activity.

Aged↗

PubMed1995

A prospective study of cancer incidence in a cohort examined for allergy.

In order to assess the association between atopy and cancer risk, a cohort of 6593 skin-prick-tested patients was established. Among atopic subjects, no overall increased cancer risk was found, but the incidence of both breast cancer (standardized incidence ratio (SIR) 2.50, 95% CI 1.01-5.16) and malignant lymphomas (SIR 4.40, 95% CI 1.20-11.3) was significantly enhanced. Atopic subjects with asthma showed a decreased overall cancer risk (SIR 0.73, 95% CI 0.27-1.60), as compared with the other asthmatic subjects (SIR 1.46, 95% CI 1.03-2.04). The cancer risk for subjects with rhinitis was near unity (SIR 1.11), irrespective of whether the subjects were atopic or not. An almost significant risk increase for cancer was observed among subjects with urticaria (SIR 1.70, 95% CI 0.99-2.80). Our results support neither the original hypothesis of an overall cancer protective effect of atopy, nor that of an opposite effect; rather, they strengthen the view that the association between atopic diseases and cancer is complex.

Adolescent↗

PubMed1995

Radiological changes in asbestos cement workers.

OBJECTIVE: To explore associations between exposure to asbestos cement dust and radiographic findings in lung parenchyma and pleura. METHODS: Radiographs from 174 blue collar workers and 29 white collar workers from an asbestos cement plant formed one part of the study. Progression of small opacities was further studied in those 124 blue collar workers, for whom two radiographs taken after the end of employment were available. The median readings from five readers who used the full ILO 1980 classification were used. As exposure indices, time since start of employment, duration of employment, cumulative exposure, and average intensity of asbestos exposure were used. The influence of age and smoking was also considered in multiple logistic regression analyses. RESULTS: Small opacities (profusion > or = 1/0) were closely correlated with time related exposure variables, and showed weaker association with intensity based exposure variables. The odds ratio (OR) for small opacities was equal to 2.8 (90% CI 1.2, 6.7) in the > 30 f(fibre)-y/ml group, compared with those in the 0-10 f-y/ml group. Progression of at least two minor ILO categories after the end of employment was seen in 20%. Also, pleural thickening was closely related to time. By contrast, costophrenic angle obliterations were not associated with the time related variables, but closely associated with the intensity of asbestos exposure, and tended to occur during employment. The OR was 4.5 (90% CI 1.3, 15) in the > 2 f/ml group, compared with those in the 0-1 f/ml group. CONCLUSIONS: In these workers, exposed mainly to chrysotile but also to small amounts of amphibole, the risk of radiographically visible parenchymal abnormality was substantially increased and strongly dependent on time related exposure variables. Progression was found long after the end of exposure. The findings on costophrenic angle obliterations, supposed to be sequelae of benign pleural effusions, were consistent with an immediate reaction triggered by intense asbestos exposure.

Adult↗

PubMed1995

Mortality and cancer incidence among secondary lead smelter workers.

OBJECTIVES: To examine the mortality pattern and the cancer incidence in a cohort of long term smelter workers exposed to lead. METHODS: The cohort consists of 664 male lead battery workers, employed for at least three months in 1942-87. From 1969 the values of all blood lead samples repeatedly obtained from these workers every two to three months, have been collected in a database. The expected mortality and morbidity 1969-89 was estimated from the county rates, specified for cause, sex, five-year age groups, and calendar year. Individual exposure matrices have been calculated and used for dose-response analyses. RESULTS: The total cohort showed an increased overall mortality (standardised mortality ratio (SMR) 1.44; 95% confidence interval (95% CI) 1.16-1.79), an increased mortality from ischaemic heart diseases (SMR 1.72; 95% CI 1.20-2.42) and all malignant neoplasms (SMR 1.65; 95% CI 1.09-2.44). These risk estimates were unaffected or slightly decreased when applying a latency period of 15 years, and no dose-response pattern was shown. The non-significantly raised cancer incidence in the gastrointestinal tract (11 malignancies) in the total cohort, increased to a barely significant level in the quartile with the highest cumulative lead exposure (standardised incidence ratio (SIR) 2.34, 95% CI 1.07-4.45). No clear dose response pattern was evident when further subdividing the data into those first employed up to 1969 v those first employed after 1969 when the blood lead monitoring programme started. The risk estimate for malignancies in the gastrointestinal tract was not related to latency time. The cancer incidence was not increased at other sites. CONCLUSIONS: A slightly increased incidence of gastrointestinal cancers was found in workers exposed to lead and employed before 1970. The lead cohort also showed an increased mortality from ischaemic heart diseases. These risk estimates did not show a dose-response pattern and were not associated with latency time. The results must also be interpreted with caution because of limited numbers, and lack of dietary and smoking data.

Adult↗

PubMed1995

Cancer incidence in Swedish sterilant workers exposed to ethylene oxide.

OBJECTIVES: To assess the risk of cancer, especially leukaemia, in a cohort of sterilant workers exposed to ethylene oxide (EtO). METHODS: A cohort of 2170 workers employed for at least one year in two plants that produce disposable medical equipment sterilised with EtO has previously been established. The results of an update with four more years of observation are presented. The cancer incidence was assessed for the periods 1976 to 1990 and 1972 to 1990 and cause specific standardised incidence ratios (SIRs) were calculated. Individual cumulative exposure to EtO, expressed as ppm-years, was estimated and used in exposure-response analyses. RESULTS: Six lymphohaematopoietic tumours were observed (SIR 1.78, 95% confidence interval (95% CI) 0.65-3.88), of which two were leukaemias (SIR 2.44; 95% CI 0.30-8.81). When those with cumulative exposures to EtO below the median value (0.13 ppm-years) were excluded, and a minimum of 10 years induction latency period was applied, the incidence ratio for leukaemia increased further (SIR 7.14, 95% CI 0.87-25.8), but was still not significantly enhanced. CONCLUSIONS: The risk estimate for leukaemia increased, but non-significantly, with time since start of exposure, and with cumulative exposures to EtO above the median value. The subjects with leukaemia had, however, only slightly higher cumulative exposure estimates for EtO than the average cohort member. Nevertheless, the present results may add some minor evidence for an association between EtO and an increased risk of leukaemia.

Cohort Studies↗

PubMed1995

Fish consumption and exposure to persistent organochlorine compounds, mercury, selenium and methylamines among Swedish fishermen.

OBJECTIVES: This study assessed dietary habits and exposure to selenium, persistent organochlorine compounds, methylmercury, and methylamines among Swedish fishermen. METHODS: Two hundred and fifty randomly selected subjects from a cohort of 2896 fishermen from the Swedish east coast (Baltic Sea) and 8477 fishermen from the west coast (Skagerrak and Kattegatt) were interviewed along with 250 referents. Subgroups of fishermen and referents from different coastal areas were also selected for blood and urine sampling. RESULTS: The interview data showed that fishermen ate almost twice as much fish as the 250 referents from the general population. The blood levels of mercury were twice as high, and the plasma selenium levels were 10-15% higher in the fishermen than in the referents. There was, however, no difference between the fishermen's cohorts with respect to these variables. Fishermen from the east coast ate more fatty fish than fishermen from the west coast, and they also had higher blood levels of persistent organochlorine compounds such as polychlorinated biphenyls and polychlorinated dibenzo p-dioxins and furans (present in fatty fish species in the Baltic Sea) than both the westcoast fishermen and the referents. CONCLUSIONS: A cohort of Swedish eastcoast fishermen might be a suitable study base for epidemiologic studies on the mortality and cancer morbidity associated with dietary exposure to persistent organochlorine compounds.

Animals↗

PubMed1995

Mortality and cancer incidence among Swedish fishermen with a high dietary intake of persistent organochlorine compounds.

OBJECTIVES: The objective of this study was to determine mortality and cancer incidence in two cohorts of Swedish fishermen with different dietary intakes of persistent organochlorine compounds. METHODS: The following two cohorts of Swedish fishermen were established: a cohort of 2896 subjects from the Swedish east coast (on the Baltic Sea), and a cohort of 8477 subjects from the Swedish west coast. Mortality and cancer incidence were studied in these cohorts and comparisons were made both with the regional populations and between the cohorts. RESULTS: The incidences of stomach and squamous cell skin cancers among the eastcoast fishermen were elevated as compared with those of the regional population [standardized incidence ratio (SIR 1.6, 95% confidence interval (95% CI) 1.0-2.4 and SIR 2.3, 95% CI 1.5-3.5 respectively] and with the westcoast cohort (IRR 2.2, 95% CI 1.3-3.5 and IRR 1.9, 95% CI 1.2-3.1, respectively), while that of colon cancer was decreased. Moreover, mortality from multiple myelomas was increased among the eastcoast fishermen as compared with that of the general population [standardized mortality ratio (SMR) 3.1, 95% CI 1.2-6.4) and the westcoast fishermen (IRR 3.2, 95% CI 1.2-8.7). A 12% decreased mortality in ischemic heart disease was found for the eastcoast cohort. A slight, but significant increase in such deaths was noted among the westcoast fishermen. CONCLUSIONS: High consumers of fatty fish, contaminated with organochlorine compounds, had an increased risk for stomach and skin cancer. They also had a suggestive decrease in mortality from ischemic heart diseases.

Animals↗

PubMed1995

Cancer incidence among pharmaceutical workers.

OBJECTIVES: A cluster of cancers at one plant in a pharmaceutical company in Sweden was the initiator for this work, which describes the cancer incidence among the laboratory and production workers at this company. METHODS: The investigation is a retrospective cohort study. All employees with possible exposure to chemical, pharmacological, or biological agents and employment for at least six months at the company during 1960-1990 were included. Standardized incidence ratios (SIR) were calculated with the local county population as reference. RESULTS: The total cancer incidence was close to the expected. In a subcohort consisting of the highest exposed employees, an SIR of 3.5 [95% confidence interval (95% CI) 1.5-6.8] was found for urothelial tumors, while there were no urothelial tumors among the workers with the lowest exposure. An evaluation of the exposures among the subjects with urothelial tumors revealed no association with specific exposures in the workplaces. There was also a statistically significant increase in the risk for acute leukemia (SIR 4.5, 95% CI 1.2-12 ). With a 10-year induction-latency period in the calculations, the elevated risk was smaller and not significant. Although the numbers were small, there were also statistically significant overrisks for cancer of the peritoneum, the lip, and the pleura. CONCLUSIONS: A significant increase in the risk for urothelial tumors was found among pharmaceutical workers. All but one of those with urothelial tumors were smokers, but confounding from smoking could probably not explain the risk increase.

Acute Disease↗

PubMed1995

Decreased birthweight among infants born to women with a high dietary intake of fish contaminated with persistent organochlorine compounds.

OBJECTIVES: The purpose of the study was to assess reproductive outcomes, especially birthweight, and the consumption of fatty fish from the Baltic Sea, contaminated with persistent organochlorine compounds, among women from the Swedish east coast. MATERIAL AND METHODS: Cohorts of fishermen's wives from the Swedish east and west coasts were established and linked to the Swedish Medical Birth Register for 1973-1991; 1501 children were born in the eastcoast cohort and 3553 in the westcoast cohort. Comparisons were made with regional populations and between the cohorts. Dietary interviews were made with 69 randomly selected women from the cohorts and 69 referents. RESULTS: The women interviewed from the east- and westcoast cohorts ate locally caught fish more than twice as often as their referents. Compared with the regional population, the women in the eastcoast cohort gave birth to an increased number of infants with low birthweights (< 3000 g), whereas the opposite was seen in the westcoast cohort. Infants in the eastcoast cohort had significantly lower birthweights than infants from the westcoast cohort (median 3530 versus 3610 g, P < 0.001). Even after adjustment for potential confounders, eastcoast affiliation showed an increased risk for low birthweight (odds ratio 1.44, 95% confidence interval 1.18-1.76). The effect was more conspicuous for boys (odds ratio 1.95) and heavy smokers (odds ratio 3.00). CONCLUSIONS: The present data support, but do not prove, an association between a high consumption of contaminated fish from the Baltic Sea and an increased risk for low birthweight.

Adolescent↗

PubMed1995

Mortality and cancer incidence among women with a high consumption of fatty fish contaminated with persistent organochlorine compounds.

OBJECTIVES: The purpose of this study was to assess cancer incidence and cardiovascular mortality among women with a high dietary intake of fatty fish from the Baltic Sea (on the Swedish east coast), contaminated with persistent organochlorine compounds. MATERIAL AND METHODS: Cohorts of fishermen's wives from the Swedish east (1989 subjects) and west (6605 subjects) coasts were established. The mortality and cancer incidence were studied in these cohorts, and comparisons were made with respective regional populations and between the cohorts. Dietary interviews were made with 200 randomly selected cohort women and equally many women from the general population. The interviewed east- and westcoast cohort women ate locally caught fatty fish at least twice as often as their referents. RESULTS: Compared with that of the regional population, the breast cancer incidence was higher than expected in the eastcoast cohort [standardized incidence ratio (SIR) 1.29, 95% confidence interval (95% CI) 0.96-1.71], whereas it was lower in the westcoast cohort (SIR 0.89; 95% CI 0.77-1.04). When a direct comparison was made between the two cohorts, the eastcoast women displayed an increased breast cancer incidence (incidence rate ratio 1.35, 95% CI 0.98-1.86). No obvious difference was seen between the two cohorts concerning cardiovascular mortality. CONCLUSIONS: The results support, but do not prove, the hypothesis of an association between exposure to a mixture of persistent organochlorine compounds through fish consumption and an increased risk for breast cancer.

Adult↗

PubMed1994

Cancer risk in humans predicted by increased levels of chromosomal aberrations in lymphocytes: Nordic study group on the health risk of chromosome damage.

Cytogenetic assays in peripheral blood lymphocytes (PBL) have been used extensively to survey the exposure of humans to genotoxic agents. The conceptual basis for this has been the hypothesis that the extent of genetic damage in PBL reflects critical events for carcinogenic processes in target tissues. Until now, no follow-up studies have been performed to assess the predictive value of these methods for subsequent cancer risk. In an ongoing Nordic cohort study of cancer incidence, 3182 subjects were examined between 1970 and 1988 for chromosomal aberrations (CA), sister chromatid exchange or micronuclei in PBL. In order to standardize for the interlaboratory variation, the results were trichotomized for each laboratory into three strata: low (1-33 percentile), medium (34-66 percentile), or high (67-100 percentile). In this second follow-up, a total of 85 cancers were diagnosed during the observation period (1970-1991). There was no significant trend in the standardized incidence ratio with the frequencies of sister chromatid exchange or micronuclei, but the data for these parameters are still too limited to allow firm conclusions. There was a statistically significant linear trend (P = 0.0009) in CA strata with regard to subsequent cancer risk. The point estimates of the standardized incidence ratio in the three CA strata were 0.9, 0.7, and 2.1, respectively. Thus, an increased level of chromosome breakage appears to be a relevant biomarker of future cancer risk.

Adult↗

PubMed1994

Parameters of immunological competence in subjects with high consumption of fish contaminated with persistent organochlorine compounds.

Consumption of fatty fish species, like salmon and herring, from the Baltic Sea is an important source of human exposure to persistent organochlorine compounds, e.g. polychlorinated dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Many of these compounds show immunotoxic and hepatotoxic effects in animals. We have now studied immunological competence, including lymphocyte subsets, in 23 males with a high consumption of fish from the Baltic Sea and in a control group of 20 males with virtually no fish consumption. The high consumers had lower proportions and numbers of natural killer (NK) cells, identified by the CD 56 marker, in peripheral blood than the non-consumers. Weekly intake of fatty fish correlated negatively with proportions of NK cells (rs = -0.32, P = 0.04). There were also, in a subsample of 11 subjects, significant negative correlations between numbers of NK cells and blood levels of a toxic non-ortho-PCB congener (IUPAC 126; rs = -0.68, P = 0.02) and a mono-ortho congener (IUPAC 118; rs = -0.76, P = 0.01). A similar correlation, in 12 subjects, was seen for p,p'-DDT (rs = -0.76, P = 0.01). The corresponding negative correlation, in 13 subjects, with blood levels of PCDD/Fs was not significant (rs = -0.57, P = 0.07). No significant association was seen between organic mercury in erythrocytes and NK cells. Fish consumption was not associated with levels of any other lymphocyte subset. Neither were there any correlations with plasma immunoglobulins or liver enzyme activities. Our study indicates that accumulation of persistent organochlorine compounds in high consumers of fatty fish may adversely affect NK cell levels.

Adult↗

PubMed1994

Aromatic DNA adducts, micronuclei and genetic polymorphism for CYP1A1 and GST1 in chimney sweeps.

Aromatic DNA adducts in total white blood cells, cytochrome P450 (CYP) class 1A1 and glutathione transferase (GST1) class mu genotypes and micronuclei in T- and B-lymphocytes were studied in 69 full-time chimney sweeps and 35 controls, all male subjects. The sweeps had a higher (22%) but statistically non-significant increase in the level of DNA adducts as compared to the controls when all individuals independent of genotype were compared. The non-inducible CYP1A1 genotype, m1/m1, lacking a MspI restriction site at the 3' end of the gene, was associated with significantly higher adduct levels in the sweeps. Among the 26 sweeps with the combined genotype m1/m1 and GST1(-), a statistically significant 60% increase in median adduct levels was observed as compared with those 14 control subjects with the corresponding genotype. Smoking also showed a significant effect on the level of adducts. The effect on DNA adducts by sweeping, smoking and genotype appeared to be additive and independent of each other. DNA adducts in sweeps were moderately but statistically significantly correlated with micronuclei in both T- and B-lymphocytes. The correlation between adduct levels and micronuclei was most marked in T-lymphocytes of individuals lacking the GST1 gene.

Adult↗

PubMed1994

Genetic polymorphism for glutathione-S-transferase mu in asbestos cement workers.

OBJECTIVE: To investigate whether a lack of glutathione-S-transferase mu (GSTM1) activity was related to an increased risk for adverse outcome after asbestos exposure. METHODS: A study was made of 78 male former asbestos cement workers, with retrospective cohort data on exposure, radiographical findings, and lung function. Venous blood samples were obtained for the analysis of GSTM1 polymorphism by the polymerase chain reaction technique. Chest x ray films were classified according to the International Labour Organisation (ILO) 1980 classification. Vital capacity (VC) and forced expiratory volume during 1 s (FEV1) were determined. Individual estimates of asbestos exposure were calculated, and expressed as duration of exposure, average exposure intensity, and cumulative dose. Data on smoking were obtained from interviews. RESULTS: The lung function in the study group was reduced, compared with reference equations. 23% of the workers had small opacities > or = 1/0, 29% circumscribed pleural thickenings, 14% diffuse thickenings, and 12% obliterated costophrenic angles. 54% of the workers were GSTM1 deficient. They were comparable with the other workers in age, follow up time (median 30 years), and duration of exposure (median 18 years), but had a slightly higher cumulated dose (median 18 v 10 fibre-years) than the others. Neither in radiographical changes nor lung function variables were there any differences between the different GSTM1 groups. The findings were similar when smoking habits and estimated asbestos exposure were taken into account. CONCLUSIONS: We could not show that lack of GSTM1 activity was related to an increased risk for radiographical or lung function changes in a group of asbestos cement workers, followed up for a long period after the end of exposure.

Aged↗

PubMed1994

Asbestos, cement, and cancer in the right part of the colon.

OBJECTIVE: The aim was to investigate associations between exposure to mineral fibres and dust, and cancer in subsites within the large bowel. DESIGN: Pooled retrospective cohort studies. SUBJECTS AND SETTINGS: Blue collar workers, employed for at least one year in different trades; asbestos cement or cement workers (n = 2507), other industrial workers (n = 3965), and fishermen (n = 8092). MAIN OUTCOME MEASURES: Standardised incidence ratios (SIRs, national reference rates) were calculated for cause specific cancer morbidity between 1958 and 1989. The observation period began 15 years after first employment. RESULTS: The asbestos cement and cement workers had a slightly increased risk of colorectal cancer (SIR 1.5; 95% confidence interval (95% CI) 1.1-2.0). This was due to an increase only in the right part of the colon (SIR 2.5; 95% CI 1.6-3.8). The ratio of right (7th revision of the International Classification of Diseases ICD-7) 1530-1531)/left (ICD-7 1532-1533) colon cancer among the asbestos cement and cement workers of 4.8 differed significantly from the ratio both among the other blue collar workers (0.4) and among the fishermen (1.5). As the sensitivity and accuracy was insufficient, mortality data did not show the excess of cancers in the right part of the colon. CONCLUSIONS: An increased incidence of cancer in the right part of the colon was evident in the asbestos cement and cement workers. The distribution of cancers within the colon was noticeably different from that in other blue collar workers, indicating that our findings cannot be explained by socioeconomic confounding factors. A detailed and appropriate disease classification, based on incidence data, is necessary in order not to obscure or underestimate effects of exposure in epidemiological studies on colorectal cancer.

Asbestos↗

PubMed1994

Cancer incidence and mortality among Swedish leather tanners.

OBJECTIVES: The aim was to study the incidence of cancer among Swedish leather tanners. METHODS: A cohort of 2026 subjects who had been employed for at least one year between 1900 and 1989 in three Swedish leather tanneries, was established. The cancer incidence and mortality patterns were assessed for the periods 1958-89 and 1952-89 respectively, and cause-specific standardised incidence and mortality ratios (SIRs and SMRs) were calculated. RESULTS: A significantly increased incidence of soft tissue sarcomas (SIR 4.27, 95% confidence interval (95% CI) 1.39-9.97) was found, based on five cases. Excesses, (not statistically significant) was also found for multiple myelomas (SIR 2.54, 95% CI 0.93-5.53), and sinonasal cancer (SIR 3.77, 95% CI 0.46-13.6). CONCLUSIONS: The increased incidence of soft tissue sarcomas adds support to previous findings of an excess mortality in this diagnosis among leather tanners. A plausible cause is exposure to chlorophenols, which had occurred in all three plants. The excess of multiple myelomas may also be associated with exposure to chlorophenol. The association between incidence of cancer and specific chemical exposure will be elucidated in a cohort-based case-referent study.

Cause of Death↗

PubMed1994

Exposure to mixtures and congeners of polychlorinated biphenyls.

There are 209 congeners of polychlorinated biphenyls (PCBs), the metabolism and toxicity of which vary by congeners. Use of PCBs is now restricted, but environmental contamination and human exposure persist. Analysis for "total PCBs" in biological samples gives limited information; congener-specific analysis is far more informative, but more complicated. Concentrations of congeners in serum/plasma, adipose tissue, or milk are useful biomarkers of exposure. Lipids may contain similar concentrations and congener patterns, but these vary between exposures and are different from those of the corresponding exposure mixtures; hence, analysis of lipids cannot be used to identify the original exposure. Some non- and mono-ortho congeners may attain a coplanar conformation, which renders them capable of a dioxin-like action. Toxic equivalency factors (TEFs) have been used to sum that risk as toxic equivalents (TEQs), which are considerably different from congener concentrations. No reliable data have been developed on the relationship between concentrations of "total PCBs" or congeners in biological samples and effects of PCBs on human health, mainly because of the various analytical procedures involved and confounding exposures.

Adipose Tissue↗