| 1. |
- Bergdahl, Ingvar A., et al.
(author)
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Lead binding to delta-aminolevulinic acid dehydratase (ALAD) in human erythrocytes
- 1997
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In: Basic and Clinical Pharmacology and Toxicology. - : Wiley. - 0901-9928. ; 81:4, s. 153-158
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Journal article (peer-reviewed)abstract
- Over 99% of the lead present in blood is usually found in erythrocytes. To investigate the nature of this selective accumulation of lead in erythrocytes, the specific binding of lead to proteins in human erythrocytes was studied using liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS). The principal lead-binding protein had a mass of approximately 240 kDa, and adsorption to specific antibodies showed that protein was delta-aminolevulinic acid dehydratase (ALAD). Thus, the previous notion that lead in erythrocytes was bound primarily to haemoglobin has to be revised. Furthermore, in lead-exposed workers, the percentage of lead bound to ALAD was influenced by a common polymorphism in the ALAD gene. Specifically, in seven carriers of the ALAD2 allele, 84% of the protein-bound lead recovered was bound to ALAD compared to 81% in seven homozygotes for the ALAD1 allele whose erythrocytes were matched for blood-lead concentration. The small difference was statistically significant in Wilcoxon matched-pairs signed-rank test (P = 0.03). No ALAD allele-specific difference in ALAD-bound lead was found among 20 unexposed controls. Perhaps the difference in ALAD-bound lead can provide an explanation for the previously reported finding of higher blood-lead levels among carriers of the ALAD2 allele than among ALAD1 homozygotes in lead-exposed populations.
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| 2. |
- Engström, Tomas, 1950, et al.
(author)
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Några reflektioner om tvär- respektive mångvetenskap”. Arbete människa miljö
- 1999
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In: Arbete människa miljö & Nordisk Ergonomi. ; :1, s. 4 - 13
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Journal article (other academic/artistic)abstract
- This publication summarises some important aspects of science that still are valid. Especially so for broad or rather broad applied science disciplines. The content discussed are based on all of the different the authors’ experiences of the cross and multi-disciplinary research approaches. To some extent will it explain Engström’s standpoints with regard to explain which and how his publications are registered in Chalmers Public Library (CPL). This very publication was actually written during a period of time when we were engaged in an extensive research programme financed by the National Institute for Working Life in Solna (Cooperative for Optimisation of industrial production systems regarding Productivity and Ergonomics COPE). The advancements, as well as the organisational strains and scientific clashes, more or less forced us to clear out some particular aspects. This publication relay ought to be translated into English since it gives food for thoughts for both practitioners and scientists (see some of the other publications registered in CPL).
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| 3. |
- Jakobsson, Kristina, et al.
(author)
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Deaths and tumours in workers grinding stainless steel - a follow-up study
- 1997
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In: Occup Environ Med. - : BMJ. ; 54:11, s. 9-825
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To study cause specific mortality and cancer morbidity in workers exposed to the dust of grinding materials, grinding agents, and stainless steel, especially with regard to a possibly increased risk of respiratory, stomach, and colorectal cancer. METHODS: Retrospective cohort study, using reference cohorts of blue collar workers and population rates for comparison. The exposed cohort comprises workers with at least 12 months employment time at two plants, producing stainless steel sinks and saucepans (n = 727). Also, reference cohorts of other industrial workers (n = 3965) and fishermen (n = 8092) were analysed. The observation period began 15 years after the start of employment. Standardised mortality or incidence ratios (SMRs, SIRs; county reference rates) were calculated for cause-specific mortality between 1952 and 1993, and for cancer morbidity between 1958 and 1992. RESULTS: In the exposed cohort, overall mortality, cardiovascular mortality, and all malignant mortality and morbidity were slightly lower than expected. Also, the risk estimates for cancer in the upper and lower respiratory tracts and for stomach cancer were lower than expected. There was an increase in morbidity from colon cancer, which was explained by an excess of tumours in the sigmoid part only. Here, the risk estimates were higher in workers with long employment time (1-14 years: four observed cases, SIR 1.7, 95% confidence interval (95% CI) 0.4 to 4.5; > or = 15 years: three observed cases, SIR 4.3, 95% CI 0.9 to 13) and the increased risk was especially pronounced among those first employed before 1942. A slight nominal excess of rectal cancers (nine observed cases, SIR 1.4, 95% CI 0.6 to 2.6), and a significant excess of prostate cancer morbidity (36 observed cases, SIR 1.7, 95% CI 1.2 to 2.4) were found. These risk estimates did not, however, increase with employment time. CONCLUSIONS: The finding of an increased risk of cancer in the sigmoid part of the colon, which was not found in the reference cohorts, and with indication of a relation between duration of employment and response, is consistent with a causal relation. The limited size of the exposed cohort makes a detailed exposure-response analysis unstable, and the confidence limits are wide. Albeit slightly raised, the risk estimate for rectal cancer in the exposed cohort was not different from the estimate among the other industrial workers.
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| 4. |
- Nordander, Catarina, et al.
(author)
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Fish processing work: the impact of two sex dependent exposure profiles on musculoskeletal health
- 1999
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In: Occupational and Environmental Medicine. - 1470-7926. ; 56:4, s. 256-264
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Journal article (peer-reviewed)abstract
- 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.
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| 5. |
- Willers, Stefan, et al.
(author)
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Urinary cotinine in children and adults during and after semiexperimental exposure to environmental tobacco smoke
- 1995
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In: Archives of Environmental Health. - 0003-9896. ; 50:2, s. 130-138
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Journal article (peer-reviewed)abstract
- Urinary cotinine (U-cotinine) as a biomarker of environmental tobacco smoke exposure was evaluated in 14 children (age 4-11 y) and in 7 adults who were exposed to environmental tobacco smoke at an air nicotine level of 110 mg/m3 for 2 h in a bus. Nicotine in air and U-cotinine were measured by gas chromatography/mass spectrometry before, during, and after the experiment. U-cotinine rose rapidly to a maximum after a median of 6 h following the end of exposure; remained at an apparent plateau for half a day; and then decreased exponentially, with a mean half-time of 19 h (95% confidence interval 18-20 h; no significant difference between children and adults). The maximum U-cotinine was higher in the children (mean = 22 mg/l) than in the adults (13 mg/l; p = .005); decreased with age among the children (r = -.74; p = .002); and increased as the estimated inhaled nicotine dose increased. Therefore, the findings of the present study showed that young children had higher U-cotinine than adults at the same experimental environmental tobacco smoke exposure, probably because they had a higher relative nicotine dose because of a higher relative ventilation rate, and possibly also because of metabolic differences; the elimination rate did not differ. The long half-time makes U-cotinine a good biomarker of environmental tobacco smoke exposure; the time of sampling is not very critical. Dilution-adjusted concentrations should be employed, and in children, preferably by density correction. A certain urinary cotinine level indicates a lower environmental tobacco smoke exposure in a small child than in an adult.
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| 8. |
- Zhang, X D, et al.
(author)
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Antibody responses of rats after immunization with organic acid anhydrides as a model of predictive testing
- 1998
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In: Scandinavian Journal of Work, Environment and Health. - 0355-3140. ; 24:3, s. 220-227
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Journal article (peer-reviewed)abstract
- OBJECTIVES: The sensitizing properties of organic acid anhydrides (OAA) were evaluated in a rat model. METHODS: The development of specific immunoglobulin (Ig)E and Ig G in serum was investigated after immunization with 14 OAA and 3 OAA conjugates. Brown Norway rats were injected intradermally with 0.1 ml of 0.2 M OAA in liquid paraffin or 1.4 mg of rat serum albumin conjugate in saline. Serum samples were collected after 4 weeks. Antibodies were analyzed with enzyme-linked immunosorbent assay. RESULTS: The serum titers of specific Ig E after immunization with the different free OAA varied from <50 to 6400. The rats immunized with 4-methylphthalic anhydride exhibited the highest titers. The specificity of Ig E was demonstrated by enzyme-linked immunosorbent assay inhibition tests. A good correlation was observed between the Ig E and Ig G titers. Immunization with OAA conjugates showed results parallel to the findings for the free compounds. Importantly, the Ig E titers for the OAA agreed well with findings from guinea pigs and with literature data from epidemiologic studies of exposed workers. CONCLUSIONS: The present animal model may be a valuable tool for predicting the sensitizing potential of OAA and possibly the sensitizing potential of low-molecular-weight compounds in general. Furthermore, the antibody specificity of the haptens and the variations in the magnitude of the antibody titers indicate a valuable approach for studies of quantitative structure-activity relationships.
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| 9. |
- Åkesson, Ingrid, et al.
(author)
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Neuropathy in female dental personnel exposed to high frequency vibrations
- 1995
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In: Occupational and Environmental Medicine. - 1470-7926. ; 52:2, s. 116-123
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Journal article (peer-reviewed)abstract
- Objective-To evaluate early neuropathy in dental personnel exposed to high frequency vibrations. Methods-30 dentists and 30 dental hygienists who used low and high speed hand pieces and ultrasonic scalers were studied, and 30 dental assistants and 30 medical nurses not exposed to vibration (all women). Vibrotactile sensibility, strength, motor performance, sensorineural symptoms and signs, and vascular symptoms in the hands, as well as mercury concentrations in biological samples and cervicobrachial symptoms, were studied. Results-The two groups exposed to vibration had significant impairments of vibrotactile sensibility, strength, and motor performance, as well as more frequent sensorineural symptoms. In the dentists there were significant associations between the vibrotactile sensibility and strength, motor performance, superficial sensibility, and sensorineural symptoms. There were no associations between these findings and cervicobrachial symptoms, mercury concentrations, or smoking. There was no increase of vascular symptoms of the hands in the groups exposed to vibration. Conclusion-Dental hygienists and dentists had a slight neuropathy, which may be associated with their exposure to high frequency vibrations, and which may be detrimental to their work performance. Thus, development of safer equipment is urgent.
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| 10. |
- Österberg, Kai, et al.
(author)
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A neurobehavioural study of long-term occupational inorganic lead exposure
- 1997
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In: Science of the Total Environment. - 0048-9697. ; 201:1, s. 39-51
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Journal article (peer-reviewed)abstract
- A group of 38 male workers at a secondary smelter (period of employment 2-35 years; median 10 years) was divided into two subgroups depending on bone-lead concentration, arranged as 19 matched pairs according to age, education and job level. The median concentrations for finger-bone lead (Bone-Pb) were 16 vs. 32 μg/g; for current blood-lead (B-Pb), 1.6 vs. 1.8 μmol/l; for retrospective peak blood-lead (Peak-Pb), 2.7 vs. 3.0 μmol/l; and for a retrospective cumulative blood lead index (CBLI), 143 vs. 233 μmol/l x months. Nineteen unexposed male workers from a nearby mechanical plant served as controls, using the same matching algorithm. The triplets were examined with a standardised neuropsychological test battery, and four questionnaires for self-rating of symptoms and activity/stress level related to work environment. No sign of behavioural deterioration was observed in the exposed groups, either in objective cognitive tests or in subjective symptom/mood self-rating scales. Despite the limited sample size, the statistical power was sufficient to conclude that a concealed lead-associated effect was unlikely. Covariations between behavioural measures and lead exposure indices were generally low and non-significant, as a whole not exceeding a random level. No confounding or effect-modifying factor was detected that could explain the results as a type II error. To conclude, a current B-Pb of 1.8 μmol/l was not associated with adverse behavioural effects, and a long-term lead exposure around 2.0 μmol/l for 13 years (mean values) was not associated with permanent brain dysfunction.
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