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Biomedical subjects

O Axelson

Publications and source records attributed to O Axelson.

At least 145 records · Page 8Linked to original sources
PubMed1984

Clinical studies of psychoorganic syndromes among workers with exposure to solvents.

Exposure to organic solvents is common in industry. In Sweden, patients being evaluated for suspected solvent-related diseases now constitute the largest group of patients seen at many clinics of occupational medicine, largely replacing classical occupational disorders. The findings in 128 consecutive patients with solvent exposure have been reviewed for the period 1978-1981. The duration of exposure was 9 years or more for those with a diagnosis of psychoorganic syndrome (POS). "Incipient" POS was seen after a minimum exposure of 3 years duration. Patients with POS also had an increased frequency of polyneuropathy in comparison to those without any signs of POS. It was not possible to link these abnormalities with particular solvent exposure. Clinical chemistry tests were normal except for liver function tests in a few patients.

Adult↗
PubMed1984

Risk factors of coronary heart disease among personnel in a bus company.

A cohort of all the men employed in a bus company was undertaken to elucidate possible adverse health effects of diesel exhaust exposure. The results showed that the most heavily exposed group (bus garage workers) had a fourfold increase in risk of dying from cardiovascular disease, even after correction for smoking, and allowing for at least 10 years of exposure and 15 years or more of induction-latency time. The findings are in accordance with the hypothesis of a possible connection between exposure to carbon monoxide and cardiovascular disease.

Carbon Monoxide Poisoning↗
PubMed1984

Room for a role for radon in lung cancer causation?

Reduced ventilation due to energy saving has focussed interest on a potential lung cancer risk from increased indoor concentrations of alpha-emitting radon and radon daughters, escaping from building materials and from the ground. Some preliminary studies now also indicate a hazard to be present as related to radon daughter exposure in homes. However, the indoor radon daughter levels have probably been continuously increasing for half a century, especially in colder climates, due to the introduction of central heating instead of stoves and open fire places, reducing thermal ventilation. Furthermore, in our time, many people have got additional exposure through extended indoor work time instead of earlier outdoor activities in farming etc. The steeply increasing lung cancer rates over the past decades as well as the various oddities affecting the relationship between smoking and lung cancer, e.g. the urban-rural difference in lung cancer risk, also after standardization for smoking, the influence of immigration on lung cancer morbidity as well as the varying rates over the world and other observations, would obtain simple explanations by taking radon daughter exposure into account in addition to smoking. Then, also some curious and hitherto unexplained "inverse" relationships between lung cancer and inhalation of cigarette smoke or bronchitis in air-polluted areas, respectively, would become understandable.

Animals↗
PubMed1984

Radon in homes--a possible cause of lung cancer.

An earlier case-referent study [Scand j work environ & health 5 (1979) 10-15] has indicated a possible relationship between lung cancer and exposure to radon and radon daughters in dwellings. Indoor radon concentrations seem to depend on both building material and leakage of radon from the ground. This new study, in a rural area, is a further attempt to elucidate the etiology of lung cancer, taking into consideration type of house and ground conditions, as well as smoking habits. Although the choice of a rural study population helped to eliminate various confounding exposures in the urban environment, it limited the size of the study because of the rareness of lung cancer in rural populations. Long-term residents, 30 years or more in the same houses, were studied, and again an association was found between lung cancer and estimated exposure to radon and radon daughters in homes. The data also seem to indicate the possibility of a multiplicative effect between smoking and exposure to radon and radon daughters in homes, but there was also some confounding between these factors in the data.

Adult↗
PubMed1984

Mortality from cardio-cerebrovascular diseases among dynamite workers--an extended case-referent study.

Increased mortality from cardio-cerebrovascular diseases among male dynamite workers was reported in 1977 and was supported two years later by findings in a small cohort study from another Swedish dynamite population. The excess risk was confined to those with long-term employment. The original case-referent study comprised the years between 1955-1975 and the register of deaths and burials in the parish around the dynamite factory was used as the source of subjects. The same register has now been used for the time period 1976-1980. We have used identical requirements for this extension as in the original study, i.e., confined to men with more than one year of employment and aged 36-70. Cases were those who died from ischaemic heart diseases and cerebrovascular diseases according to WHO classification rules and referents those who died from all other diseases remaining after the primary exclusions. 102 men had died in the parish during the extension period. 15 were excluded. There were 36 deaths from heart diseases, 12 from cerebrovascular diseases and 39 referent diagnoses. Six of the "heart-cases", three of the "c-v-cases" and six of the referents were exposed. The Mantel-Haenszel estimation of the risk ratio for cerebrovascular diseases during the period 1955-80 is 2.9 (95% confidence interval 0.9-6.4) and 2.7 for cardio-vascular diseases (1.4-5.4). Among 25 men exposed more than 20 years only one died from anything else but a cardio-cerebrovascular disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

On the problem of controlling confounding in case-referent studies.

Individuals in various exposure categories constitute an epidemiological study population and its health experience over time can be taken as the base of the study, which is either open with a turnover of individuals (deaths, migrations etc) or closed, when encompassing only originally defined individuals. In cohort studies all individuals are known in terms of membership and exposure, whereas case-referent (case-control) studies utilize a sample from the base, the referents, for information about the exposed and non-exposed domains of the base, and the referents are a sort of relative denominators for the cases. An association in the base between the exposure and another determinant of the disease means confounding and can be fully accounted for in the cohort approach, but not in the case-referent study as relying on a sample of the base. The reason is that the occurrence of the confounder among the referents is influenced by random variation in the sampling procedure and the referents may therefore not always reflect the true situation with regard to confounding in the base. Computer simulations of the acquisition process of referents illustrate that neither a confounded nor a non-confounded base might always be properly reflected in case-referent data. However, the variation of the confounding rate ratio (the crude rate ratio/SMR) might not be expected to vary by more than about a factor of two. Particularly in nested case-referent studies, a relatively large number of referents helps stabilize the random variation, but only the cohort approach provides full control of confounding, a fact, that becomes the more important, the smaller the effect under study.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers↗
PubMed1983

Solvents and the liver.

Explore the source record for details and available documents.

Chemical and Drug Induced Liver Injury↗
PubMed1983

Quantitative aspects of radon daughter exposure and lung cancer in underground miners.

Epidemiological studies have shown an excessive incidence of lung cancer in miners with exposure to radon daughters. The various risk estimates have ranged from six to 47 excess cases per 10(6) person years and working level month, but the effect of smoking has not been fully evaluated. The present study, among a group of iron ore miners, is an attempt to obtain quantitative information about the risk of lung cancer due to radon and its daughters among smoking and non-smoking miners. The results show a considerable risk for miners to develop lung cancer; even non-smoking miners seem to be at a rather high risk. An additive effect of smoking and exposure to radon daughters is indicated and an estimate of about 30-40 excess cases per 10(6) person years and working level month seems to apply on a life time basis to both smoking and non-smoking miners aged over 50.

Aged↗
PubMed1983

Elucidation of some epidemiologic principles.

This review is an attempt to elucidate some fundamental epidemiologic concepts, particularly various aspects of the case-referent design and its relations to the cohort type of study. Some of these aspects also have direct implications for judgements about the comparability of differently exposed population groups, eg, with regard to confounding.

Epidemiologic Methods↗
PubMed1983

Experiences and concerns on lung cancer and radon daughter exposure in mines and dwellings in Sweden.

A high mortality from lung cancer among miners was reported from Central Europe already in the 19th century. In the 60s and 70s several reports have indicated an increased lung cancer mortality among uranium miners and other metal-miners, e.g. in the US, UK, France and Sweden, but also among fluorspar miners in Canada. The cause is supposed to be the decay products of radon as emanating from the rocks, i.e. the alpha-radiation from short-lived radon daughters. Radon and radon daughter exposure in dwellings have more recently attracted interest as a potential hazard to the general population, especially since radon daughter concentrations seem to have increased due to more effective insulation for energy saving. In many Swedish houses the radon daughter exposures amount to levels similar to that of mines. Some epidemiological evaluations of the relationship between lung cancer and exposure to radon daughters, i.e. residency in stone houses versus wooden houses (with and without consideration of the contribution of radon from the ground underneath the houses), seem to indicate a risk also to the general population and, moreover, the risk of smoking seems to be several times greater in stone houses than in wooden houses, the latter usually having less radon daughters on the average.

Adult↗
PubMed1983

Assessment of methods and results of reproductive occupational epidemiology: spontaneous abortions and malformations in the offspring of working women.

Epidemiological studies relating occupational exposures of working women to spontaneous abortions and malformation are reviewed and some methodological considerations are presented. The reproductive epidemiology is less developed than epidemiology in general and seems to involve some specific problems. The ascertainment of exposure and of outcome may be problematic. The exposures may be reported differently by the women depending on the outcome of the pregnancy; thus confirmation of exposure from an independent data source would be an asset. The recognition of spontaneous abortions by women is variable and this should be considered in the study design. An access to medical records could provide objective data on the outcome, but it may introduce other types of asymmetries. The types of occupational exposures of the women, suggested to carry a risk of spontaneous abortions, include anesthetic agents, laboratory work, copper smelting, soldering, and chemical sterilization using ethylene oxide and glutaraldehyde. Maternal employment in laboratories and exposure to solvents has been linked to a risk of congenital malformations in the offspring in five studies. Data on the teratogenic effects of anesthetic gases has been conflicting. In one study, employment in copper smelting was associated with malformations in the offspring.

Abnormalities, Drug-Induced↗
PubMed1983

Pregnancy outcome among women in a Swedish rubber plant.

Suspicions of reproductive disturbances among women in a tirebuilding department was the reason for this study, encompassing 42 women, 30 of whom provided a total of 84 pregnancies out of which 21 were exposed to the tirebuilding process. Nine of the 21 exposed pregnancies had an unfavorable outcome (threatening abortion, spontaneous abortion or malformation) versus only seven of the remaining 63 nonexposed pregnancies, a difference which remained significant also when various risk indicators like age, smoking, pregnancy order, and calendar year were taken into account. In contrast to earlier observations, there was no difference in thioether excretion in the urine (as potentially indicative of the skin absorption of rubber chemicals) between women working in the tirebuilding department and a reference group. It remains unclear however whether the observed cluster was causally related to occupational exposures or not, but, together with other observations, this report may contribute to the elucidation of possible reproductive disturbances in the rubber industry.

Abnormalities, Drug-Induced↗
PubMed1982

Epidemiological study of nasal and nasopharyngeal cancer and their relation to phenoxy acid or chlorophenol exposure.

Soft tissue sarcoma and malignant lymphoma have been related to exposure to chlorinated phenoxy acids or chlorophenols as well as exposure to organic solvents and malignant lymphoma. However, colon cancer studied by the same case-referent design did not show any such associations, which helps to rule out alleged systematical bias of the study approach. Further considerations about exposure routes for phenoxy acids and chlorophenols suggested that nasal and nasopharyngeal cancers should be studied. Forty-four cases with nasal cancer and 27 cases with nasopharyngeal cancer were eligible for study during 1970-1979 together with 541 referents, as utilized also in the aforementioned studies. Exposure to phenoxy acids gave formally a doubled but insignificant risk for the studied cancer types. Exposure to chlorophenols, as present particularly in woodwork, was related to an about sevenfold and significant increase in the risk for both cancer types. In woodworkers without exposure to chlorophenols there was an approximate normal risk, but cabinet makers, even without exposure to chlorophenols, had nearly doubled (but insignificant) risk of nasal cancer.

Adenocarcinoma↗