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Biomedical subjects

S Skerfving

Publications and source records attributed to S Skerfving.

At least 37 records · Page 2Linked to original sources
PubMed2000

Cadmium levels in kidney cortex in Swedish farmers.

The cadmium levels in kidney cortex (K-Cd) did not differ statistically between 10 nonsmoking farmers from the south of Sweden, who had a high intake of locally produced food and who were affected by acid precipitation (as indicated by low pH in the drinking water from their private wells) and 10 farmers less affected (medians: K-Cd, 18 vs. 14 microg/g; water pH, 5.2 vs. 7.8). Neither did 10 farmers selected because of "high" blood cadmium (B-Cd) differ from 10 with "low" [medians: K-Cd, 15 vs. 9 microg/g; B-Cd, 2.6 vs. 1.3 nmol/L (0.29 vs. 0.14 microg/L)]. In all 40 farmers, there was an increase of urinary cadmium levels (U-Cd) with decreasing drinking water pH (r(s) = -0.32, P = 0.045). Further, K-Cd increased with rising B-Cd (r(s) = 0.33, P = 0.037), and both B-Cd (r(s) = 0.73, P = 0.0005), and U-Cd (r(s) = 0.74, P = 0.0005) rose with increasing age. Further, there was an association between U-Cd and B-Cd (r(s) = 0.68, P = 0.0005). We could not demonstrate with certainty any effect of the acid precipitation on the cadmium retention in the farmers, although the association between U-Cd and drinking water pH deserves further study.

Adult↗
PubMed2000

Impact of physical exposure on neck and upper limb disorders in female workers.

Physical workload [muscular load of the trapezius and infraspinatus muscles using electromyography (EMG), wrist positions and movements by electrogoniometers] and neck and upper limb disorders (from, for example, a physical examination) were studied in women with repetitive industrial work (n = 95) and referents (n = 74). The repetitive work displayed higher ratings for wrist movements, but not for EMG. The prevalences of neck, shoulder and wrist/hand disorders were elevated for women with repetitive work [age-adjusted prevalence odds ratios (PORs) 2.0-7.5]. For the left hand, high frequency of wrist movements (mean power frequency 0.53 Hz) was associated with a high prevalence of disorders (56%), as compared to low (0.28 Hz and 26%; POR 3.5). We found no consistent and significant effect of muscular load, on either neck or shoulder disorders. However, selection and other bias may have diminished our possibility to observe such effects. Psychosocial work environment factors were not confounding the results. Measurements of wrist movements may be used for identification of high-risk work tasks.

Adult↗
PubMed2000

Assessment of environmental tobacco smoke exposure in children with asthmatic symptoms by questionnaire and cotinine concentrations in plasma, saliva, and urine.

To validate a detailed questionnaire for assessment of environmental tobacco smoke (ETS) exposure by the biomarker cotinine in various media, a population-based study in the urban area of Malmö, Sweden was performed in children aged 8-13 years with and without asthmatic symptoms. There were strong correlations between urinary and saliva cotinine concentrations and also, though to a lesser extent, between these media and plasma. Even a detailed questionnaire gave only a rough picture of the ETS exposure, as indicated by the biomarkers. In a multivariate model, the most significant questionnaire-derived predictor of the cotinine levels was the maternal smoking habits; other questionnaire variables gave only a minimal explained variance. Children with a history of asthmatic symptoms had statistically significantly lower median cotinine levels in urine and saliva compared to referent children, most likely because of the antismoking information to their parents. This should be considered in epidemiological studies of ETS risks.

Adolescent↗
PubMed2000

Sensitivity of trapezius electromyography to differences between work tasks - influence of gap definition and normalisation methods.

Surface electromyography (EMG) has been used extensively to estimate muscular load in studies of work related musculoskeletal disorders, especially for the trapezius muscle. The occurrences of periods of EMG silence (gaps), the time below a predetermined threshold level (muscular rest) and various percentiles of the amplitude distribution (APDF) are commonly used summary measures. However, the effects of the criteria used to calculate these measures (e.g., gap duration, threshold level, normalisation method) on the sensitivity of these measures to accurately differentiate work loads is not well known. Bilateral trapezius EMG was recorded, for a full workday, for 58 subjects following both maximal (MVE) and submaximal (RVE) reference contractions. Gap frequency, muscular rest, and percentiles were derived for eight fundamental work tasks. The calculations were performed using different gap duration criteria, threshold levels and normalisation methods.A gap duration of less than 1/2 s, and threshold level approximately 0.3% MVE for gap frequency, and approximately 0.5% MVE for muscular rest, were the criteria that optimised sensitivity to task differences. Minimal sensitivity to tasks and a high sensitivity to individuals was obtained using gap frequency with a threshold level of approximately 1% MVE. Normalisation to RVE, rather than MVE, improved sensitivity to differences between tasks, and reduced undesirable variability. Muscular rest was more sensitive to task differences than APDF percentiles.

Adult↗
PubMed2000

Muscular rest and gap frequency as EMG measures of physical exposure: the impact of work tasks and individual related factors.

Owing to an orderly recruitment of motor units, low threshold type I fibres are presumed to be vulnerable in contractions of long duration. To study load on these fibres muscular rest was registered as the time fraction of electromyographic (EMG) activity below a threshold. Moreover, the frequency of periods with muscular rest, EMG gaps, was derived, since a low gap frequency has been shown to be a risk factor for musculoskeletal disorders. Trapezius EMG was registered in 24 female hospital cleaners, 21 female office workers and 13 male office workers during one working day. Cleaners have a high risk of neck/shoulder pain and had much less muscular rest than office workers measured as a percentage of total registered time (median value = 1.5%, range = 0.2-13% vs. median value = 12%, range = 0.0-32%, respectively). Gap frequency showed no difference between the two occupational groups. Both measures displayed a wide inter-individual variation. For the cleaners, some of the variance was explained by body mass index (BMI) and age, with lower values of muscular rest for older subjects with a high BMI. Among the office workers, low values of muscular rest and a high gap frequency were registered in subjects with a low subjective muscular tension tendency. Gender, strength, smoking, job strain, employment time and musculoskeletal symptoms had no impact on either EMG measure.

Adult↗
PubMed2000

Exposure biomarkers and risk from gluing and heating of polyurethane: a cross sectional study of respiratory symptoms.

OBJECTIVES: To define the relation between exposure to polyurethane (PUR) glue, biomarkers of exposure and effect, and work related symptoms that occur at least once a week. METHODS: In a cross sectional study, 152 workers and 14 clerks in a factory with exposure to sprayed and heated PUR glue containing 4, 4'-diphenylmethane (MDI) or 1,6-hexamethylene (HDI) di-isocyanate were examined with gas chromatography-mass spectrometry (GC-MS) for metabolites of MDI in plasma (P-MDX) and urine (U-MDX), 2,4- and 2, 6-toluene di-isocyanate (TDI; P-TDX, U-TDX) and HDI in plasma and urine, specific serum IgG (S-IgG-MDI, S-IgG-HDI, and S-IgG-TDI, respectively) and IgE (S-IgE-MDI). Work related symptoms of the eyes and airways (nose or lower airways, or both), and lung function were also evaluated. RESULTS: P-MDX was detected in 65% of the workers, U-TDX in 47%, HDX in none. Three per cent were positive for S-IgE-MDI, 33% for S-IgG-MDI, 32% for S-IgG-TDI, and 12% for S-IgG-HDI. A few clerks had metabolites, and some had antibodies. Most metabolites and immunoglobulins were slightly correlated-for example, P-MDX v S-IgG-MDI: r(s)=0.21. Workers who heated glue had increased P-MDX (odds ratio (OR)=12 for a value above the median) and S-IgG-MDI (OR=3.7), sprayers P-2,4-TDX (OR=6.2) and P-2,6-TDX (OR=16). Twenty six per cent of the workers had work related symptoms of the airways, 21% from the nose, 11% from the lower airways. Spraying of glue increased the risk of work related symptoms and slightly decreased lung function. U-MDX was associated with work related symptoms from the airways (OR=3.7) and P-2,6-TDX with work related symptoms from the lower airways (OR=6.6). S-IgG-MDI was related to work related symptoms from the airways (OR=2.6). CONCLUSIONS: There were relations between exposures to sprayed and heated PUR glue based on MDI and HDI, concentrations of metabolites of MDI and TDI in plasma and urine, specific IgG serum antibodies against MDI, TDI, and HDI, and work related symptoms.

Adhesives↗
PubMed2000

Musculoskeletal symptoms among dental personnel; - lack of association with mercury and selenium status, overweight and smoking.

Our objective was to describe the occurrence of musculoskeletal symptoms and how they affect the daily life of three different occupational groups of dental personnel. A cross sectional-study was performed among 268 dental staff members and 111 referents. Female dental hygienists and female dentists showed, compared with their referents, higher prevalence of symptoms during the past 12 months from neck, shoulders and hands/wrists. Both dental groups also had higher frequencies of combined symptoms from these body regions, as well as longer duration of symptoms in neck and shoulders during the past 12-month period. Male dentists had higher frequencies of neck and shoulder symptoms compared with their referents. Female dental assistants did not deviate from their referents. The symptoms from each single body region, or the occurrence of symptoms from multiple regions in a subject, did not show any statistically significant association with mercury (whole blood and urinary levels) or selenium (plasma level) status, neither with smoking habits nor overweight (Body Mass Index). The high frequency of musculoskeletal disorders probably reflects the specific work load in dentistry, with high demands on vision and precision and fine manipulative hand movements and work with unsupported, elevated arms. The symptoms might impair work capacity and the future possibility to stay in the profession. Further studies are needed to verify this.

Adult↗
PubMed1999

Lead in plasma and whole blood from lead-exposed children.

In 31 children exposed to lead and 13 considerably less exposed children ("unexposed"), the plasma (Pb-P) concentrations ranged from 0.46 to 18.4 (median, 2.4) and from 0.14 to 0.38 (median, 0.21) microg/L, respectively. Corresponding whole-blood concentrations (Pb-B) were 99-920 (median, 370) and 39-120 (median, 66) microg/L, respectively. The relation between Pb-B and Pb-P was nonlinear; when Pb-P rose, the Pb-B increased relatively less. There was a close association between Pb-B and log Pb-P (r=0.95; P=0.0001). When these data were compared to previous data on adults, there was no major difference between children and adults in the Pb-B/Pb-P relation. Free erythrocyte protoporphyrins in blood were associated with Pb-P (r=0.75; P=0.0001) and Pb-B (r=0.90; P=0.0001). Also, there was an association between blood-hemoglobin concentration and Pb-P in both exposed (r=-0.67; P=0.0001) and unexposed (r=-0.67; P=0.01) children; the corresponding figures for Pb-B were r=-0.42; P=0.02, and r=-0.80; P=0.001, respectively. Thus, at least with regard to toxicity on hematopoiesis at high lead levels, Pb-P may be a more relevant indicator of exposure and risk than Pb-B. Because the curved Pb-B/Pb-P relation indicates a saturation of binding sites for lead in red cells, exposure and risk at high lead levels may easily be underestimated from Pb-B data.

Adolescent↗
PubMed1999

Chelated lead in relation to lead in bone and ALAD genotype.

In order to assess whether lead in bone is available for chelation by 2,3 meso-dimercaptosuccinic acid (DMSA), 21 workers (10 active and 11 retired) from a secondary lead smeltery were studied. A morning urine sample was obtained from all participants, followed by ingestion of 10 mg per kg body weight of the chelating agent DMSA. All urine produced during the following 24 h was collected in consecutive 6- and 18-h portions. Concentrations of lead in blood (B-Pb) and urine were determined by flameless atomic absorption spectrometry (AAS), in plasma (P-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), and in finger bone (Bone-Pb) by K X-ray fluorescence technique (XRF). DMSA-chelatable lead excreted in the 24-h portion correlated well with the excretion in the 6-h portion (U-Pb6h; rs=0.95; P<0.001). U-Pb6h showed a non-linear relationship to B-Pb (rs=0.84; P<0.001) and linear relationships to P-Pb (rs=0. 91; P<0.001) and lead in morning urine (rs=0.95; P<0.001). In active workers, but not in retired ones, P-Pb and U-Pb6h showed some relationship to Bone-Pb. In alternative multiple regression models B-Pb or P-Pb were both significant predictors of U-Pb6h, while Bone-Pb did not significantly improve the models. It can, thus, be concluded that DMSA-chelatable lead mainly reflects lead concentrations in blood, soft tissues, and possibly also trabecular bone. It is not a good index of total body burden and long-term exposure. For such estimations cortical Bone-Pb is more valid, as it contains the major fraction of long-term accumulated lead in the body. Further, the mobilization test did not give better information than measurements of lead levels in blood, plasma, or urine without chelation.

Age Factors↗
PubMed1999

Musculoskeletal disorders among female dental personnel--clinical examination and a 5-year follow-up study of symptoms.

OBJECTIVES: To explore the natural course of musculoskeletal disorders during a 5-year period among dental personnel, to survey findings and diagnoses according to a standardized protocol, and to compare and evaluate different methods for the detection of musculoskeletal disorders in a population. METHODS: In a 5-year follow-up study, dental personnel (n = 90) and referents (n = 30) were studied. The Nordic questionnaire (years 0 and 5), the present pain rating according to the Borg category ratio scale, and physical examination (year 5) were used. RESULTS: In year 0 the prevalence of symptoms in the shoulders, the wrists/hands, and, unexpectedly, the hips was higher in the dental personnel as compared with the referents. Furthermore, those (16%) who had left the dental profession during the observation period showed a higher prevalence of and, often, combined symptoms from several body regions in year 0 than did those who stayed. Dental personnel who remained in the profession tended to have an increased risk of developing more symptoms in the shoulders and the elbows/wrists/hands in year 5 as compared with year 0 and at year 5 were in more pain and had received more diagnoses for the neck/shoulder region relative to the referents. Furthermore, there was a considerable variation in symptoms during the follow-up period. The sensitivity of the pain rating and of the Nordic questionnaire in detecting musculoskeletal disorders was high for the neck and shoulders but was not as high for the elbow, wrists/hands, or hips. The association was better for diagnoses than for findings. The opposite patterns were observed for specificity. CONCLUSIONS: Dental personnel had an increased risk of developing musculoskeletal disorders as verified by symptoms and diagnoses and more painful or persistent conditions. This led to a selection out of work. The questionnaire and the present pain rating gave a relatively good picture of the prevalence of musculoskeletal disorders arising from the neck, shoulders, and hips and would be useful as screening tools. Their sensitivity in detecting disorders was higher for diagnoses than for findings. However, these methods were not as sensitive for disorders involving the elbows/wrists/hands. Physical examinations gave more detailed information.

Adult↗
PubMed1999

Efficacy of measures of hygiene in workers sensitised to acid anhydrides and the influence of selection bias on the results.

OBJECTIVES: Organic acid anhydrides are potential sensitisers and cause occupational airway diseases. In an intervention study the efficacy of measures of hygiene at the workplace and possible selection bias were investigated. METHODS: A first investigation with 110 workers exposed to hexahydrophthalic acid anhydride (HHPA) and methyltetrahydrophthalic acid anhydride (MTHPA) was carried out in July 1991. The results (skin prick test, specific serum IgE) showed that 20 people were sensitised, and in a challenge test the clinical relevance of the sensitisation was confirmed in six subjects. In December 1991, the hygiene conditions at the plant were improved. In November 1995 a second investigation of 84 people was performed (anamnesis, skin prick test, specific IgE, spirometry, and ambient and biological monitoring). The 27 people who had left the plant in the meantime were asked their reasons for leaving. RESULTS: The relative risk of people sensitised in 1991 of leaving the plant between 1991 and 1995 was 2.6 (95% confidence interval (95% CI) 1.4 to 4.9) compared with people without any sign of sensitisation. The percentage of people identified as sensitised in 1991, who were still working at the plant and came to the second investigation, was higher than for people without evidence of sensitisation (10/10 v 47/73; p < 0.05). In all the 10 sensitised people in 1991 the findings of the first investigation were confirmed in 1995. The rate of sensitisation in 1995 was 21%. None of the six people employed after 1991 showed evidence of sensitisation. Of the six people with clinically relevant sensitisation confirmed by a challenge test in 1991, five were still at their workplace. From 1991 they were only exposed to MTHPA at a reduced concentration (< 0.5-36 micrograms/m3 in 1995). All of them reported fewer symptoms than in 1991. No signs of bronchial obstruction were detected by spirometry at the workplace. CONCLUSIONS: In cross sectional studies there is a selection bias with a risk of underestimating the incidence of allergic diseases. The results further suggest that the improved hygiene conditions probably had a positive effect on the symptoms in sensitised people.

Adult↗
PubMed1999

Fish processing work: the impact of two sex dependent exposure profiles on musculoskeletal health.

OBJECTIVES: To evaluate the impact of work tasks, physical exposure, and psychosocial factors on the risk of musculoskeletal disorders in men and women, in a defined industrial setting. METHODS: 116 male and 206 female fish industry workers were compared with 129 men and 208 women with more varied work. Physical and psychosocial work load as well as musculoskeletal complaints were recorded by a questionnaire. A physical examination was performed and an observation method was used for work evaluation. 196 male and 322 female former fish processing workers received a postal questionnaire. RESULTS: The women workers in the fish industry had worse working conditions than the men for repetitiveness, constrained neck postures, and psychosocial work environment. They also had higher prevalences of complaints of the neck and shoulder (prevalence odds ratio (POR) 1.9; 95% confidence interval (95% CI) 1.1 to 3.2), neck and shoulder and elbow and hand complaints (POR 2.9; 95% CI 1.8 to 4.7 and POR 2.8; 95% CI 1.6 to 4.7, respectively). The women more often than the men left the industry because of neck and upper limb complaints. Also, women in other work had a higher prevalence of complaints of the neck and shoulder (POR 2.3; 95% CI 1.1 to 5.1) than the men. The men in the fish processing industry had a higher prevalence of complaints of the neck and shoulder than the men in other work (POR 3.6; 95% CI 1.6 to 8.0). This difference was not shown up by the questionnaire. CONCLUSIONS: Despite superficially similar work, there were clear sex differences in physical exposure and psychosocial work environment. Work in the fish processing industry was associated with a high risk of neck and upper limb disorders in women, which was probably mainly due to their extremely repetitive work tasks; the corresponding men had less repetitive work and less disorders. Also, a healthy worker effect on neck and upper limb disorders was found. The advantage of a physical examination compared with a questionnaire is clearly shown.

Adult↗
PubMed1999

Interindividual variation of physical load in a work task.

OBJECTIVES: This study analyzed the variation in physical work load among subjects performing an identical work task. METHODS: Electromyographs from the trapezius and infraspinatus muscles and wrist movements were recorded bilaterally from 49 women during a highly repetitive industrial work task. An interview and a physical examination were used to define 12 potential explanatory factors, namely, age, anthropometric measures, muscle strength, work stress, and musculoskeletal disorders. RESULTS: For the electromyographs, the means of the 10th percentiles were 2.2% and 2.8% of the maximal voluntary electrical activity (%MVE) for the trapezius and infraspinatus muscles, respectively. However, the interindividual variations were very large [coefficients of variation (CV) 0.75 and 0.62, respectively]. Most of the variance could not be explained; only height, strength, and coactivation of the 2 muscles contributed significantly (R2(adj)0.20-0.52). The variation was still large, though smaller (CV < or =0.63), for values normalized to relative voluntary electrical activity (RVE). For the wrist movements, the median velocity was 29 degrees per second, and the interindividual variations were small (CV < or =0.24). Six factors contributed to the explained variance (R2(adj)0.12-0.55). CONCLUSIONS: The interindividual variation is small for wrist movements when the same work tasks are performed. In contrast, the electromyographic variation is large, even though less after RVE normalization, which reduces the influence of strength, than when MVE is used. Because of these variations, several electromyographs are needed to characterize the exposure of a specific work task in terms of muscular load, and individual electromyographs are preferable when the worker' s risk of myalgia is being studied.

Adult↗
PubMed1999

Environmental health in the Baltic region--toxic metals.

Recent reports on concentrations of lead, cadmium, methylmercury, arsenic and nickel in some biological media in populations in the Baltic region are reviewed. In particular, children in parts of Poland, the Czech Republic, and Germany have uptakes of lead sufficient to cause adverse effects on the central nervous system and kidneys. Cadmium exposure is also high in Poland. Slight cadmium-induced effects on the kidneys have been reported from Germany and Sweden. Methylmercury uptake is dependent upon the intake of fish, in particular from contaminated lakes and rivers in Sweden and Finland, as well as the eastern coast of the Baltic Sea. There are some indications of immunotoxic effects associated with the intake of such fish. However, fish also contain other immunomodulating agents. Exposure to arsenic seems to be low everywhere in the Baltic region. There is high nickel exposure in northern Russia.

Adolescent↗
PubMed1998

Cancer predictive value of cytogenetic markers used in occupational health surveillance programs: a report from an ongoing study by the European Study Group on Cytogenetic Biomarkers and Health.

The cytogenetic endpoints in peripheral blood lymphocytes: chromosomal aberrations (CA), sister chromatid exchange (SCE) and micronuclei (MN) are established biomarkers of exposure for mutagens or carcinogens in the work environment. However, it is not clear whether these biomarkers also may serve as biomarkers for genotoxic effects which will result in an enhanced cancer risk. In order to assess this problem, Nordic and Italian cohorts were established, and preliminary results from these two studies indicated a predictive value of CA frequency for cancer risk, whereas no such associations were observed for SCE or MN. A collaborative study between the Nordic and Italian research groups, will enable a more thorough evaluation of the cancer predictivity of the cytogenetic endpoints. We here report on the establishment of a joint data base comprising 5271 subjects, examined 1965-1988 for at least one cytogenetic biomarker. Totally, 3540 subjects had been examined for CA, 2702 for SCE and 1496 for MN. These cohorts have been followed-up with respect to subsequent cancer mortality or cancer incidence, and the expected values have been calculated from rates derived from the general populations in each country. Stratified cohort analyses will be performed with respect to the levels of the cytogenetic biomarkers. The importance of potential effect modifiers such as gender, age at test, and time since test, will be evaluated using Poisson regression models. The remaining two potential effect modifiers, occupational exposures and smoking, will be assessed in a case-referent study within the study base.

Biomarkers, Tumor↗