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Biomedical subjects

S Hernberg

Publications and source records attributed to S Hernberg.

At least 55 records · Page 3Linked to original sources
PubMed1983

Screening for occupational exposures and congenital malformations.

Since 1976 the Finnish matched-pair Register of Congenital Malformations has been linked to a special project which screens for associations between selected congenital malformations and chemical and physical exposures during early pregnancy. Case mothers and their referents are personally interviewed. Exposure data are quantitated blindly by a team of industrial hygienists and occupational health experts. An analysis of data from 1,047 pairs is now underway. The pairs consist of 289 defects of the central nervous system, 421 orofacial clefts, 200 selected structural malformations of the skeleton, and 137 selected cardiovascular defects. Exposure to organic solvents was associated with defects of the central nervous system in the initial two-year material. However this association was no longer detectable during the following three-year period. More pairs must be gathered before a reasonable judgment regarding the teratogenic potential of solvents becomes possible.

Abnormalities, Drug-Induced↗
PubMed1983

Nasal cancer and occupational exposures. Preliminary report of a joint Nordic case-referent study.

Nasal and sinus paranasal cancers have been associated with several occupational exposures, for example, dust from hardwood, nickel and unspecific agents occurring in the boot and shoe industry. A joint Danish-Finnish-Swedish case-referent investigation was initiated in 1977 to study further the connection between nasal and sinus paranasal cancers and various occupational exposures. All new cases of these cancers were collected from the national cancer registers (Finland & Sweden) or from hospitals (Denmark). Those still alive who agreed to the interview (N = 167) were individually matched for age and sex with patients with colonic or rectal cancer. A detailed telephone interview was performed according to a standardized procedure. Both the cases and referents thought that their condition was the one under study. The exposures were coded blindly by an experienced industrial hygienist. The results showed associations between nasal or sinus paranasal cancer and exposure to hardwood or mixed wood dust (discordant pairs 14/2); softwood dust alone (13/4); chromium 16/6); nickel (12/5, not significant); welding, flamecutting, and soldering (17/16); and lacquers and paints (12/0). Hardwood dust exposure showed a connection with adenocarcinoma. Softwood dust exposure alone was associated with epidermoid and anaplastic carcinomas. No associations were found for a number of exposures, including agricultural chemicals, textile dust, asbestos, quartz dust, organic solvents, and leather work. Possible exposure to formaldehyde was evenly distributed between the cases and referents.

Adult↗
PubMed1983

Early neurotoxic effects of occupational lead exposure: a prospective study.

A prospective follow-up study focusing on workers who entered a battery factory was started in 1975. Out of an initial number of 89 workers, 23 were available for the 1-yr, 15 for the 2-yr and 10 for the 4-yr re-examination. From an initially larger non-exposed reference group (N = 34), 23 were matched with respect to age, sex, and initial nerve conduction velocities and similarly followed. In the exposed group especially the sensory conduction velocities of the median nerve decreased during the 2-yr follow-up. Some increase in the motor distal latency of the median nerve was also noted. When the lead workers were divided into two groups according to the median Pb-B value (30 micrograms/100 ml), several motor and sensory conduction velocities were significantly slower in the lead group with the higher Pb-B levels in the 1- and 2-yr follow-up examinations as compared with those with the lower levels. Those workers whose Pb-B level hd quickly risen to over 30 micrograms/100 ml quit after one or two years. Those who continued in the battery plant for up to four years had a slower initial rise in their Pb-B levels, which rarely exceeded 30 micrograms/100 ml; this group showed no significant differences in their conduction velocities in the 4-yr re-examination in comparison with the reference group.

Adult↗
PubMed1982

Oral clefts and organic solvent exposure during pregnancy.

A cumulative case-referent study concerning selected exposures during pregnancy among mothers to children born with oral clefts has been in progress in Finland since December 1, 1977. The present study covering the initial 3.5 years' material can be regarded as a specific, more detailed extension of earlier retrospective studies concerning environmental factors in the causation of oral clefts, using material accumulated from the Finnish Register of Congenital Malformations. Information on exposures was gained by personal interviews with all the mothers. The analysis of different exposures and the classification of the material were performed blindly. Significantly more case-mothers than referent-mothers had been exposed to organic solvents during the first trimester of pregnancy (P less than 0.05).

Abnormalities, Drug-Induced↗
PubMed1982

Quantitated effects of carbon disulfide exposure, elevated blood pressure and aging on coronary mortality.

Risk function analysis was performed in order to clarify the relationship between coronary heart disease death rate and occupational carbon disulfide exposure along with two other important risk factors, elevated diastolic blood pressure and older age, in a data set obtained from a 10-year prospective follow-up of coronary mortality in two cohorts of over 340 male industrial workers in Finland. The sole effect of carbon disulfide on the coronary mortality was statistically significant (relative risk = 2.3), and it was largely independent of the level of the other two risk factors. Log-linear models were fitted to predict coronary heart disease deaths. The analysis identified the dual role of raised blood pressure in the potential mechanism of coronary death. Relative risks ranging up to 48 were obtained for the joint non-synergistic effect of these three factors in the exposed group compared to a subgroup of nonexposed, 40-year-old normotensive men. The effect of carbon disulfide exposure on the risk of coronary death, while clearly distinguishable from the effect of hypertension and aging, stayed subordinate to them, but nevertheless remained an important risk element in the work environment.

Adult↗
PubMed1982

Mortality of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid herbicide applicators in Finland: first report of an ongoing prospective cohort study.

Some recent epidemiologic studies have suggested that chlorinated phenoxy acid herbicides are human carcinogens. The mortality experience in a cohort of 1,926 men who had sprayed 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) during 1955-1971 has been followed prospectively from 1972 to 1980. The total phenoxy acid exposure was generally rather low because the duration of work had mostly been less than two months. In 1972-1976 mortality from all natural causes in the cohort was only 54% of the expected value (based on age-specific rates for the general population), and in the succeeding 4-a period 81% of the expected value. In the assessment of cancer, mortality allowance was made for 10- and 15-a periods of latency between the first exposure and the start of the recording of vital status during the follow-up. No increase in cancer mortality was detected, and the distribution of cancer types was unremarkable. No cases of death from lymphomas or soft tissue sarcomas were found. The study results must, however, be viewed with great caution owing to the small size of the cohort, the low past exposure, and the brief follow-up period.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1981

Blood lead levels in Finnish preschool children.

The blood lead (Pb-B), hemoglobin and hematocrit were measured in 286 Finnish children living in the three largest cities of Finland (n = 172), in rural areas (n = 54) and in a lead smelter area (n = 60). Pb-B was determinated using an atomic absorption spectrophotometric micro method. The precision of the method was good, as was the accuracy tested by an international interlaboratory comparison. The mean Pb-B in urban, rural and lead smelter areas varied between 6.0 - 6.7 microgram/100 ml** (range 3 - 17 microgram/100 ml) and there were no significant differences between the residential areas. The mean values of hemoglobin and hematocrit were in the normal range. The Pb - B values in Finnish children studied were low compared with many international studies but at a similar level as in some recent Scandinavian studies.

Age Factors↗
PubMed1981

"Negative" results in cohort studies--how to recognize fallacies.

Negative studies are important in occupational medicine because knowledge on noneffect levels for harmful exposures is pertinent. A truly negative study must (i) be large, (ii) be sensitive, and (iii) have well-documented exposure data. Small and/or insensitive so-called negative studies are uninformative, and negative results can only be related to the actual or lower exposure levels. Some of the causes for falsely negative results are inappropriate design (eg, cross-sectional instead of longitudinal), crude measuring methods, inappropriate type of examination, wrong categories of exposed workers, inclusion of workers with too short an exposure time and too low an exposure intensity in the exposed series, too short a follow-up for diseases with long latency times (eg, cancer), incomplete follow-up, wrong reference category (eg, the general population), poor precision of measuring methods, and insensitive or wrong statistical methods. Finally, the same data may be interpreted in different ways. Correct interpretation requires both knowledge of the subject and apprehension of the fact that errors in design and measurement often tend to mask existing differences. At the most, a small insensitive study may rule out very strong effects.

Epidemiologic Methods↗
PubMed1980

Subclinical lead neuropathy.

It had been shown that subclinical impairment of the peripheral nerves may occur in neurologically symptom-free lead workers. In a cross-sectional study, 78 workers from two storage battery plants and one engineering shop were studied; their lead exposure had been monitored with regular blood lead measurements (PbB). The reference group comprised 34 unexposed manual workers. An exposure-effect relationship between occupational lead exposure and nerve functions emerged, as nerve conduction velocities decreased with increasing PbBs. The strongest correlations were found between PbB measures and sensory and motor conduction velocities of the median nerve. An exposure-response relationship also emerged as the proportion of subjects with abnormal nerves increased with increasing exposure levels. In a prospective study 24 workers were followed-up from the commencement of their lead work for one year and 16 for two years. The lead exposed showed a tendency of decreasing conduction velocities of arm nerves, but as a group they did not differ statistically significantly from the control group. When the lead exposed were divided into two groups using the median PbBs as the splitting point, the ones with PbBs over 30 micrograms/100 ml showed slowing of serveral nerve conduction velocities, while in the lower exposure the conduction velocities remained at the initial level. Again the clearest difference was noted in conduction velocities of the median nerve. Nerve conduction velocities, especially in the arm nerves slow down in lead exposure and this impairment is caused by really low lead exposure as noted in the prospective follow-up study, which can be regarded as intervention study.

Cross-Sectional Studies↗
PubMed1980

Neurological picture of organic solvent poisoning in industry. A retrospective clinical study of 37 patients.

A retrospective evaluation of neurological, neuroradiological, neurophysiological, psychological, and laboratory findings on 37 patients, remitted to the Institute of Occupational Health, Helsinki because of suspected poisoning due to organic solvents, was performed. Patient selection was made on the basis of performed pneumoencephalography (PEG). Most of the patients had been exposed to a mixture of solvents (19 cases). Carbon disulphide exposure had occurred in six cases, trichloroethylene in five cases, and the rest of the patients had been exposed to styrene (one case), thinner (two cases), toluene (1 case), methanol (1 case), and carbon tetrachloride (two cases). Clinical neurological findings comprised slight psycho-organic alteration, cerebellar dysfunction, and peripheral neuropathy. The PEG showed changes suggesting brain atrophy in 63% of the patients. Slight asymmetric central atrophy and localized cortical atrophy were the most frequent findings. The main electroencephalographic finding was slight diffuse slow-wave. Electroneuromyography showed slight changes suggesting peripheral neuropathy in 23 of the 28 patients examined. Psychological alterations were seen in all patients: personality changes and psychomotor disturbances were the most common findings. Because individual constitutional differences existed, no clear-cut exposure-effect relationship could be established. Thus, neurological evaluation of all those exposed to neurotoxic agents who present symptoms, regardless of the degree of current exposure, is important.

Adult↗
PubMed1980

Exposure to industrial solvents and brain atrophy. A retrospective study of pneumoencephalographic findings among 37 patients with exposure to industrial solvents.

Pneumoencephalographic (PEG) findings of 37 patients referred to the Institute of Occupational Health, Helsinki, because of suspected chronic organic solvent intoxication showed changes suggesting brain atrophy in 64% of the patients. Slight asymmetric central and slight local cortical atrophy were the most common findings. There were no significant difference between those considered having heavy exposure and those with less significant exposure either in regards to PEG findings or other neurological findings. Thus, lack of dose-response relationship in this study suggests nonspecificity of the slight PEG findings and possibly also individual susceptibility to neurotoxic agents.

Atrophy↗
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↗