Search PubMed⌕ Search

Biomedical subjects

S Tola

Publications and source records attributed to S Tola.

At least 55 records · Page 3Linked to original sources
PubMed1980

Application of mathematical modelling for assessing the biological half-times of chromium and nickel in field studies.

The biological half-times of urinary chromium and nickel excretion and plasma nickel concentration were calculated for four welders and four electroplaters. A linear one-compartment kinetic model gave estimates of the half-times ranging from 15 to 41 hours for chromium in urine, from 17 to 39 hours for nickel in urine, and from 20 to 34 hours for nickel in plasma. The model allows a precise description to be made of a worker's state of exposure as affected by a varying concentration of the metals in the air.

Adult↗
PubMed1980

A cohort study on workers exposed to trichloroethylene.

The mortality of 2,117 workers exposed to trichloroethylene sometime between 1963 and 1976 was studied. Their names were collected from the files of one biochemical laboratory performing urinary trichloroacetic acid determinations and from the Occupational Disease Register of Finland. Both the total mortality (SMR 69) and the cancer mortality (SMR 77) were lower than expected. Because of the young age structure and the brief follow-up time the results should be interpreted with caution. They suggest, however, that given as short a latency period as 6 to 13 years, trichloroethylene is not a strong human carcinogen. The present material provides a cohort with defined exposure for further follow-up.

Adolescent↗
PubMed1979

Lung cancer mortality among iron foundry workers.

The present study was designed to test earlier findings of increased risk of lung cancer among iron foundry workers and to define the cause of the risk. The subjects were 3,425 workers with at least one year's employment in an iron foundry sometime between 1918 and December 31, 1972. The number (51) of cases of lung cancer which occurred prior to December 31, 1976 was statistically significantly higher than that expected, i.e., 35.3 based on proportional mortality. Molders and casters were determined to have the highest excess risk in a case-control study among the cohort. The worker groups with high exposure to polycyclic aromatic hydrocarbons (PAH) experienced a lung cancer risk higher than that of other groups, but the difference was not statistically significant.

Finland↗
PubMed1979

The battle against occupational lead poisoning in Finland. Experiences during the 15-year period 1964--1978.

Occupational lead poisoning has been greatly reduced as a problem in Finland during the 1970s. Case-finding efforts and increased awareness of plant physicians first caused an increase of the incidence with a peak of 89 reported cases in 1974. A sharp decline followed, and, although about 30 mild cases are still reported annually, classical clinical poisoning hardly exists anymore. An extensive regular monitoring program covering 8,000--10,000 blood lead (PbB) analyses a year also shows that exposure levels have been reduced. In 1977 only 70 PbB values, or 1%, were in excess of 70 micrograms/100 ml, and 243 values (4%) exceeded 60 micrograms/100 ml. All such values came from workers employed by less than 30 workplaces, and several of them belonged to workers monitored more than once a year. It is proposed that the general development of occupational health in Finland is to a great extent reflected in this favorable development; however, since special research, educational and informative efforts have been devoted to the lead problem, it may well be that these measures have also influenced the outcome. The results show that, on a nationwide scale, the lead problem can be coped with much more effectively than one has been apt to think. Hence the nonfeasibility of lowering maximum permissible exposure levels has been put in serious doubt. There is no reason to allow unnecessarily high exposure in the vast majority of workplaces only because a small minority has technical difficulties.

Environmental Exposure↗
PubMed1979

Urinary and plasma concentrations of nickel as indicators of exposure to nickel in an electroplating shop.

The relationship between atmospheric exposure to nickel and urine and plasma nickel concentrations was studied by following four workers from an electroplating shop for one work week by daily measurements of the nickel concentration in workroom air with personal samplers and nickel concentrations in blood and urine samples collected before and after the work shift. The workroom air concentrations ranged from 0.03 to 0.16 mg/m3. The urinary and plasma nickel concentrations were higher in the samples taken after than before the work shift and a close positive correlation was found between the air nickel concentrations and the urine and plasma nickel concentrations, respectively. There was also a close correlation between urinary and plasma nickel concentrations. A slight accumulation of nickel occurred as judged from the increasing concentrations of nickel in the urine and plasma morning samples during the study week. This study indicates that both plasma and urine nickel concentrations may be used as biological indicators of exposure to soluble nickel compounds.

Adult↗
PubMed1977

Urinary chromium as an indicator of the exposure of welders to chromium.

Five welders working with high alloy Cr-Ni steel and one working with mild steel were followed during one work week. The chromium concentration in air was measured concomitantly with urinary chromium determinations. The water-soluble chromium concentrations in air exceeded 0.05 mg/m3 during welding with coated electrodes, but metal inert-gas (MIG) welding produced much lower concentrations. The proportion of water-soluble hexavalent chromium in the air was usually more than 50% of the total chromium concentration during welding with coated electrodes, whereas less than 10% of the chromium produced during MIG welding was in a water-soluble. Since water-soluble chromium (hexavalent) is the more important biologically, the determination of both water-soluble and water-insoluble chromium concentrations is emphasized instead of the measurement of the total concentration. The urinary chromium concentration proved to be a good indicator of short-term exposure to water-soluble chromium when exposure was above the current threshold limit value of 0.05 mg/m3, concentrations of more than 30 microgram/g of creatinine representing an exposure level higher than the threshold limit value.

Adult↗
PubMed1976

Occupational lead exposure in Finland. VI. Final report.

Between 1970 and 1973, 2,209 workers representing 30 different types of work were studied in Finland for lead exposure. The indicator of lead exposure was the blood lead concentrations (Pb-B) of the workers. The highest recommended value for Pb-B in Finland, 70 mug/100 ml of blood, was exceeded in the following types of work: PVC plastic manufacturing, storage tank manufacturing and repairing, machine shop work, treating metal surfaces, paint manufacturing, car radiator repairing, spray painting, machine shop work (railway), and storage battery repair. The types of work with the highest average exposure were lead scrap smelting (Pb-B median 79 mug/100 ml, range 35--118), storage battery manufacturing (Pb-B median 66 mug/100 ml, range 19--101), metal founding, (Pb-B median 53 mug/100 ml, range 6--108) shipbreaking (Pb-B median 49 mug/100 ml, range 26--106) crystal glass manufacturing (Pb-B median 41 mug/100 ml, range 12--82), car radiator repairing (Pb-B median 38 mug/100 ml, range 17--83), and PVC plastic manufacturing (Pb-B median 37 mug/100 ml, range 10--126). During the past 5 years cases of clincial lead poisoning have occurred in all of these types of work, and the patients received workmen's compensation. The usefulness of the national poisoning register in predicting the relative hazard of lead exposure in the types of work studied was evaluated with the aid of rank order correlation statistics. The analysis showed that the poisoning register is a useful indicator of lead exposure in the most exposed types of work. However, the present survey also revealed work in which the hazard had escaped recognition in this country: metal founding, car repairing, and car radiator repairing, for example. Although it seems possible to predict the most heavily exposed work types from national poisoning registers only, the detection of workers with less severe manifestations of toxic effects, or somtimes even poisoning, in other types of work first requires a systematic survey of all types of work with possible lead exposure, and then regular monitoring of all exposed workers.

Automobiles↗
PubMed1976

Occupational lead exposure in Finland. V. Shipyards and shipbreaking.

Three Finnish shipyards and two shipbreaking enterprises were studied for lead exposure. Blood lead (Pb-B) concentration was measured for 568 workers in the shipyards and 13 workers in the shipbreaking enterprises. Erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity was determined for 139 workers in one shipyard and 7 workers in one shipbreaking enterprise. Hemoglobin level was determined for 545 workers in the three shipyards and 7 workers in one shipbreaking enterprise. Lead exposure in the shipyards was relatively low. No Pb-B value exceeded 70mug/100 ml. The most exposed occupations were welders, plumbers, painters, repairmen, and sheet metal workers. The mean Pb-B did not exceed 40 mug/100 ml in any of these groups. In both shipbreaking enterprises one Pb-B value exceeded 70 mug/100 ml, the mean Pb-B values of all the workers in the two enterprises being 51 and 46 mug/100 ml. respectively. ALAD values corresponded well with the respective Pb-B values. All the hemoglobin mean values were normal, and there were no statistically significant differences between the hemoglobin values of different groups.

5-Aminolevulinate Synthetase↗
PubMed1975

Subclinical neuropathy at "safe" levels of lead exposure.

Electrophysiological methods revealed subclinical neuropathy in 26 workers, exposed from 1 to 17 years to lead and whose blood lead (PbB) values had never exceeded 70mu/100ml, as ascertained by checking the monitor reports of the factory and by careful exposure history. The PbB determinations had been tested repeatedly and had been found valid. The main findings were slowing of the maximal motor conduction velocities of the median and ulnar nerves and particularly the conduction velocity of the slower fibers of the ulnar nerve. Electromyographical abnormalities comprised fibrillations, diminution of the number of motor units on maximal contraction, and an abnormally long duration of the units. Earlier similar measurements from heavily exposed workers had been even more abnormal. Thus, a dose-response relationship exists on a group basis. Since the regular monitoring of PbBs in most workers during their entire period of exposure excludes the possibility of a body burden out of proportion to the PbB slight neurological damage is produced at exposures hitherto regarded as quite safe.

Adult↗
PubMed1975

Occupational lead exposure in Finland. IV. The polyvinyl chloride plastic industry.

One hundred and fifty-two workers from ten polyvinyl chloride (PVC) plastic factories were studied for lead exposure. Blood lead (Pb-B) concentration was measured for all the workers, urinary delta-aminolevulinic acid (ala) for 130 workers, erythrocyte alpha-aminolevulinic acid dehydratase (ala-d) activity for 59 workers, and blood hemoglobin concentration or 93 workers. The median Pb-B for all the workers was 37 mug/100 ml, and the highest median found for one factory was 63 mug/100 ml. The highest single Pb-B value found was 126 mug/100 ml. The jobs with the heaviest lead exposure were those of mixing and weighing lead stearate powder. It is assumed that replacing the powder with a granule form of lead stearate will diminish the hazard of lead exposure in the future. Urinary ALA concentrations and erythrocyte ALA-D activities corresponded well with the Pb-B concentration, but the hemoglobin values did not show any relation to lead exposure. It is concluded that in the PVC plastic industry of Finland the risk of exposure to lead is high and regular health examinations should be performed.

Aminolevulinic Acid↗