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Biomedical subjects

O Axelson

Publications and source records attributed to O Axelson.

At least 127 records · Page 7Linked to original sources
PubMed1988

Formation of 8-hydroxydeoxyguanosine by asbestos and man made mineral fibres.

Samples of rockwool and glass fibre were compared with chrysotile fibres for their capacity to hydroxylate 2-deoxyguanosine to 8-hydroxydeoxyguanosine, a reaction that is mediated by formation of hydroxyl radicals. All three fibres produced 8-hydroxydeoxyguanosine in the absence of H2O2. The chrysotile fibres were most potent and produced about ten times more of the modified nucleoside than rockwool and glass fibre. This investigation shows that not only asbestos but also man made mineral fibres are able to modify nucleosides.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1988

Indoor radon exposure and active and passive smoking in relation to the occurrence of lung cancer.

Exposure to indoor radon and radon daughters is currently attracting great interest as a possible cause of lung cancer. This concern is supported by several studies, most of them relatively small in numbers or weak in the assessment of exposure. This study encompasses 177 persons with lung cancer and 677 noncancer referents, all deceased and with 30 years or more of residency in the same house in an area with radon-leaking alum shale deposits in the central part of southern Sweden. Exposure categories based on building material, type of house, and ground conditions were created, but measurements of the indoor radon daughter concentration were also made for 142 cases and 264 referents. Active and passive smoking was ascertained through questionnaires sent to the next-of-kin. Overall, the lung cancer risk was approximately twofold with regard to the categories of assumed radon daughter exposure for the rural sector of the population but not for the same categories of the urban sector, possibly because of less precise exposure assessment and influence from other factors. Occasional and passive smokers, as well as passive smokers alone, had a particularly increased risk of lung cancer in association with the increased exposure categories.

Adult↗
PubMed1988

Mortality among pyrite miners with low-level exposure to radon daughters.

Mortality among pyrite miners with low-level exposure to radon daughters. Scand J Work Environ Health 14 (1988) 280-285. A cohort mortality study was conducted with regard to a pyrite mine located in central Italy. Exposure to radon ranged from 0.12 to 0.36 working levels (WL) in the work areas; most measurements were around 0.2 WL. The concentration of free silica in the dust was less than 2%. The cohort was determined from company files and included 1,899 subjects. Mortality was studied for the years 1965-1983. The loss to follow-up was less than 2%. The standardized mortality ratio for all causes and all neoplasms was 97 and 107, respectively. That for lung cancer and for nonmalignant respiratory diseases was 131 (95% confidence interval 97-175) and 173 (95% confidence interval 135-231), respectively. It was estimated that the extra cases of lung cancer attributable to radon daughters numbered 13 per 10(6) person-years and working level month in the whole cohort and 21.3 per 10(6) person-years in the subcohort with 10-25 years of exposure.

Adult↗
PubMed1987

Mortality among personnel exposed to diesel exhaust.

Some epidemiological studies have suggested a carcinogenic effect from diesel exhausts and also an increased risk of cardiovascular disease. This cohort study of bus garage employees was undertaken to elucidate further the health effects of diesel exhaust exposure with regard to mortality from cancer and cardiovascular disease. The cohort encompassed 694 men and was followed from 1951 through December 1983. The results showed no significant differences between observed and expected number of deaths in cancer or cardiovascular disease in total or with regard to different degrees of exposure or various requirements of exposure and induction-latency time. The so-called healthy worker effect was relatively weak for cardiovascular disease, but this phenomenon showed no pattern in relation to exposures. The relatively small size of the cohort does not allow for the exclusion of a slightly increased incidence of cancer of certain sites, however.

Cardiovascular Diseases↗
PubMed1987

Pesticides and cancer risks in agriculture.

The work environment in agriculture is complex, with many potentially hazardous exposures, but the overall mortality from cancer and other causes is rather low among farmers. However, several studies have consistently indicated an excess of certain cancer forms. Lymphomas, leukemias, multiple myeloma and also malignancies of connective tissue attract special interest, as being possibly associated with the use of pesticides. Phenoxy acid herbicides may play an etiological role, especially for non-Hodgkin's lymphoma, whereas the findings are more ambiguous for Hodgkin's disease and soft-tissue sarcoma, perhaps indicating an interaction with co-factors. The issue has been controversial for many years, however, and one of its aspects involves the use of phenoxy acids in the Vietnam war. Furthermore, DDT has been associated with lung cancer in mixed exposure situations, and with chronic lymphatic leukemia. Arsenical pesticides may have caused skin cancer in vine-growers. Further studies, especially of specific user groups and producers, may avoid the complex exposure situation in agriculture.

Agricultural Workers' Diseases↗
PubMed1987

Mortality and cancer incidence among workers in an abrasive manufacturing industry.

Earlier epidemiological studies have shown that exposure to aluminium oxide and silicon carbide might carry with it an increased risk of lymphomas, stomach cancer, and non-malignant respiratory disease. To elucidate further this possible hazard, the cancer morbidity and the total mortality pattern was studied among 521 men manufacturing abrasive materials who had been exposed to aluminium oxide, silicon carbide, and formaldehyde. Total dust levels were in the range of 0.1-1.0 mg/m3. The cohort was followed up from 1958 until December 1983. No significant increase was found in total mortality, cancer mortality, or incidence of non-malignant respiratory diseases.

Aluminum Oxide↗
PubMed1987

Mortality in the Swedish glassworks industry.

An earlier, relatively small case-referent study has shown an increased risk for glassworks employees to die from stomach cancer, lung cancer, and cardiovascular disorders. This observation suggested an extended study virtually covering the entire glass-producing industry of Sweden. This new study confirmed the earlier results and, furthermore, an excess risk for colon cancer was also identified. No deviation was found in the cancer mortality pattern for all men in the glass-producing area compared to the whole of Sweden. The grouping of glassworks employees according to type of metal consumption at the glassworks showed the excess risks of stomach cancer, colon cancer, and cardiovascular deaths to relate to glassworks with a high consumption of lead, arsenic, antimony, and manganese. However, the strong correlation of these various metal exposures did not permit any successful separation of the effects of the different metals. For cardiovascular mortality, as for cancer, the glassblowers especially suffered from increased risk. Their exposure might, to a great extent, be oral, involving the glassblower's pipe as a "vector" for the exposure to various metals.

Aged↗
PubMed1986

Silica, silicosis and lung cancer among ceramic workers: a case-referent study.

A case-referent study has been carried out regarding a possible connection between silica exposure and lung cancer (ICD 162) in Central Italy, where the pottery industry has a long tradition. Silicosis among 72 cases of lung cancer and among 314 referents, all deceased, was ascertained through checking the individual files of compensated cases of silicosis. Questionnaires on past employments and smoking habits were blindly administered to the next-of-kin of the deceased subjects. Controlling for age, period of death, and smoking, workers in the ceramic industry were found to have a higher lung cancer risk than workers in other occupations free from silica exposure (Mantel-Haenszel rate ratio = 2.0; 95% confidence interval (CI) = 1.1-3.5). This increased risk was mainly due to a rate ratio of 3.9 (95% CI = 1.8-8.3) for silicotic individuals, while for nonsilicotic ceramic workers it was only 1.4 (95% CI = 0.7-2.8). The result of this study seems to suggest that lung cancer might be merely indirectly associated with exposure to silica through the silicotic process, although the dose may differ for silicotic and nonsilicotic individuals.

Ceramics↗
PubMed1986

Cancer mortality among leather tanners.

Workers were studied at a tannery that operated from 1873 to 1960, once one of the biggest in Scandinavia. The results show a slight numerical increase of deaths from cancer of the stomach and a significant, threefold excess mortality from cancer of the pancreas. Even in view of critical questions about validity it seems likely that this excess might be related to exposure to chemicals in tannery work.

Aged↗
PubMed1986

A review of porphyria and cancer and the missing link with human exposure to hexachlorobenzene.

A literature review shows that porphyria cutanea tarda (PCT), and possibly acute intermittent porphyria also, tend to occur more often than expected among cases of primary liver cancer, especially when cirrhosis is present. Lymphomas and PCT may be related also, although this is less well documented. Furthermore, there is an interesting report on a case of PCT, sarcoma and probable exposure to 2,3,7,8-tetrachlorodibenzo-para-dioxin. Exposure to hexachlorobenzene (HCB) as a cause of cancer in humans does not seem to have been reported, however, but exposure to this compound and other chlorinated aromatics should be included in future observations of PCT and cancer. The possibilities for good epidemiological studies of HCB exposure in relation to cancer and other effects seem to be limited although some guidelines can be given.

Chlorobenzenes↗
PubMed1985

Mortality pattern in a glass producing area in SE Sweden.

Because of discharges, mainly of lead, from glassworks in an otherwise rural and unpolluted area in southeast Sweden the population became concerned about the potential risks of cancer and an epidemiological study was requested. The total and the specific cancer mortality in the three parishes around the glassworks were found to be approximately normal, both by comparison with national death rates and the death rates of another, similarly rural, area. More interesting results, however, were obtained in several case-referent studies also undertaken to study mortality from specific cancer sites and cardiovascular disease with regard to employment in the glassworks. A significant excess of deaths from stomach cancer, especially in glassblowers, lung cancer, and cardiovascular disease was observed among the glassworkers. Occupational exposures in the glassworks, especially to arsenic, may be of aetiological importance.

Cardiovascular Diseases↗
PubMed1985

Dealing with the exposure variable in occupational and environmental epidemiology.

Whereas the outcome variable in epidemiologic research is usually well-defined, the exposure is more diffuse, complex and variable, involving components of both intensity and duration. Usually, the time integral of the intensity has been used as a measure of exposure, e.g. working level months, fibre-years, etc. Toxicological models have suggested, however, that greater importance should be accorded to early exposure in cancer epidemiology, while the recent exposure may be more important as regards the development of some other types of disorders. A simplified approach in cancer epidemiology would be to consider the exposure within a time-window or otherwise allow for induction-latency time. For the practical assessment of exposure, so-called job exposure matrices might be of value, especially if recall bias is suspected, but on the other hand, there is rather little objective indication in the literature that serious recall bias is a major problem in case-referent studies.

Dose-Response Relationship, Drug↗
PubMed1985

The case-referent study--some comments on its structure, merits and limitations.

Case-referent (case-control) studies have become increasingly important in occupational health epidemiology. The concept of study base [Miettinen, Scand J Work Environ Health 8 (1982):suppl 1, 7-14] as referring to the health experience of the study population over time, and a clear recognition of open and closed populations, ie, with or without turnover, make the structure of the case-referent study clearer. The referents should represent the study base in terms of exposure and nonexposure and even with regard to other determinants of the disease under study. Case-referent studies refer to open populations unless nested in cohorts. Matching in cohort studies is straight-forward and creates a symmetrical situation among the exposed and unexposed with regard to the matching factor, but this symmetry is not achieved in case-referent studies, in which matching tends to distort the representativeness of the referents with regard to the study base. This circumstance suggests that matching on determinants of the disease should be maintained in the analysis. However, since the referents are a sample of the base, there might be confounding in the data, which does not exist in the base and vice versa, ie, full control of confounding in case-referent studies is not achievable either through matching or through any other procedure, but a large sample of referents would more properly reflect the distribution of confounders in the base. Using hospital referents, one has to consider possible relations between the referent diseases and the exposure under study, and therefore evaluation of multiple exposures may even require different sets of hospital referents.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiologic Methods↗