PubMed HealthSearch

Biomedical subjects

R Alexandersson

Publications and source records attributed to R Alexandersson.

At least 19 recordsLinked to original sources

Small airways function in aluminium and stainless steel welders.

The effect of welding fumes on small airways was studied in 25 male subjects who welded in aluminium (Al) and to some extent also in stainless steel (SS). Despite a low exposure to welding fumes as compared to the permissible exposure limits, excretion of Al in urine was found to be increased in all subjects (median value: 0.29 mmol/mol creatinine on Friday afternoon, as compared to an upper reference level of 0.10 mmol/mol creatinine). In addition, the welders displayed increased prevalences of work-related eye and airways (pharyngitis and non-specific bronchial hyperreactivity) symptoms, as compared to 25 matched controls. Short-term welders (< or = 2.5 years) had more symptoms related to the upper airways than did long-term welders, which may indicate a selection. Spirometry, closing volume and volume of trapped gas (VTG) did not deviate. However, after methacholine inhalation, the long-term welders had a significantly steeper slope of the alveolar plateau on the single-breath nitrogen wash-out test, and a slight increase in VTG, as compared to the short-term welders and the controls. These findings may indicate a welding fume-induced increase in the reactivity of the small airways. Because Al welding was far more frequent than SS welding, an association with the former seems likely.

Adult

Lung function and precipitating antibodies in low exposed wood trimmers in Sweden.

Wood trimmers are exposed to molds that periodically grow on timber that may induce alveolitis and obstructive lung disease. We have evaluated respiratory symptoms, bronchial reactivity, and lung function in 28 wood trimmers at a Swedish sawmill and in 19 unexposed office workers. Eleven (sero-positive) of the wood trimmers had precipitating antibodies in peripheral blood against one or several molds. The exposure to dust (median 0.26 mg/m3), viable mold spores (median 2950 cfu/m3), viable bacteria (median 370 cfu/m3), airborne endotoxins (range 0.0015-0.0025 microgram/m3), and terpenes (range 0.4-23 mg/m3) was lower than levels that earlier have been reported to affect lung function. The wood trimmers reported an increased prevalence of cough and breathlessness. They also showed signs of a mild obstructive impairment with a tendency to increase bronchial sensitivity to metacholine and decreased FEV1 after 2 days free from exposure. FEV1 decreased more during the working week in the sero-positive workers than among the sero-negative workers, and for the whole group the decrease in FEV1 and MEF25 was correlated to the degree of mold exposure.

Adult

Lung function and exposure to asbestos among vehicle mechanics.

Vehicle mechanics (n = 99) exposed to asbestos (annual median value 0.08 f/ml), and local controls (n = 83) not occupationally exposed to asbestos were studied with regard to symptoms and pulmonary function. The inclusion criteria to participate in this study was an age of at least 40 years with no known exposure to lung irritating agents, and for the exposed subjects, more than 15 years occupational exposure to asbestos with at least 20 years from the first exposure. The subjects were studied during identical conditions by means of dynamic and static spirometry, single breath wash-out with nitrogen (N2) and carbon monoxide (CO). The median for cumulative exposure of asbestos during the entire work life among the studied mechanics was 2.3 f*y/ml. The mechanics had reduced transfer factor (TLCO), after adjustment for age, height, and smoking category. A significant dose-response relationship was noted between the cumulative exposure of asbestos and CV%. The findings suggest a slight influence of small airways and alveoli. The evaluation of the prognostic significance of this requires a longitudinal study.

Adult

Signs of alveolar inflammation in non-smoking Swedish wood trimmers.

Wood trimmers are periodically exposed to mould and may develop extrinsic allergic alveolitis (EAA). To investigate if there were any signs of EAA in wood trimmers with low exposure, 19 non-smoking wood trimmers underwent bronchoalveolar lavage (BAL), spirometry, and measurement of diffusion capacity (TLCO). The group was subdivided into those with (n = 9) and without serological antibodies against mould. In 14 workers the TLCO was measured both at the beginning and at the end of a week at work. Twenty five healthy non-smokers served as BAL controls and 19 healthy non-smokers as lung function controls. The median exposure of total dust was well below the Swedish threshold value, and the exposure of mould and bacteria was also low. The cell concentrations and the proportions of the various alveolar cells did not differ between the groups. The concentrations of the soluble components albumin, fibronectin, and hyaluronan were, however, significantly increased (p less than 0.001 for all) in the workers. No difference was found in lung function between the workers and the controls, and the TLCO was not impaired during a week at work. The groups of seropositive and seronegative workers did not differ in any of these parameters. The results are interpreted as a low intensity alveolar inflammation. The presence of precipitating antibodies against mould did not predict any greater risk of developing a more intense inflammation. Analysis of soluble non-cellular BAL components seems to reflect a discrete ongoing alveolar inflammation better than cell counts only.

Adult

Temporary health effects from exposure to water-borne paints.

Temporary health effects of exposure to experimental paints were studied. Ten painters feeling nuisance from water-borne paints and eight painters not feeling such nuisance applied eight experimental water-borne paints according to normal work routines. The effects were a decrease in forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow, an increase in urine excretion, and a decrease in urine density. A small, but statistically highly significant, increase in the mean volume of erythrocytes was observed. The effects were similar in the two groups, but the "nuisance group" reacted with a larger urine excretion and a larger increase in the mean volume of erythrocytes. The effects did not influence physical work capacity. The effects on the lungs and urinary excretion were probably not associated with the organic solvents or ammonia in the paints. Instead, they were probably due to derivatives of isothiazolinone. This assumption needs verification.

Adult

Pulmonary function in workers exposed to diesel exhausts: the effect of control measures.

To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were measured for each subject during entire work shifts. The effect of the exposure on the lung function variables was measured by dynamic spirometry, carbon monoxide single breath technique, and nitrogen single breath wash-out. The exhaust pipe filtering had a protective effect, directly discernible in the drivers on vital capacity and FEV1.0 and for the whole group on FEV% and TLco. The dust respirators had no effect, probably because of the difficulties in correctly using personal protection under the circumstances in the tunnel. In the absence of a true exposure assessment, control measures for diesel exhausts can be tested by medical effect studies. Catalytic particle filters of diesel exhausts are one method of rendering the emissions less irritant, although they will not remove irritant gases. An indicator of diesel exhaust exposure should include the particle fraction of the diesel exhausts, but a discrimination between different sources of organic dust must be possible.

Adult

Impeded lung function in moulders and coremakers handling furan resin sand.

A total of 39 moulders and coremakers exposed to furan resin sand and 27 unexposed local controls were examined by lung-function tests before and after a work shift. In all, 28 of the subjects exposed to furan resin sand and the control group were evaluated by dynamic spirometry and nitrogen washout. The remaining 11 subjects exposed to furan resin sand were studied using both static and dynamic spirometry and the CO single-breath technique. The time-weighted average exposure to furfuryl alcohol was about 7 mg/m3, with peak values exceeding the present Swedish short-term exposure limit (40 mg/m3). The exposure to respirable dust and formaldehyde as time-weighted over the shift was less than 2 mg/m3 and 0.4 mg/m3, respectively, in all groups. During the work shift studied, the 28 exposed subjects had more complaints of airway symptoms than did the controls, showing an average decrease of 0.21 in forced vital capacity but no fall in any other lung-function variable. The remaining 11 exposed subjects demonstrated a post-shift decrease in total lung capacity. The results indicate an acute restrictiveness induced by exposure to furan resin sand, but the underlying mechanism is unclear. Chronic impairment of lung function was not observed.

Adult

Serum IgE and lung function in workers exposed to phthalic anhydride.

A total of 23 phthalic anhydride (PA)-exposed workers (air levels up to 17 mg/m3) showed significantly (P less than 0.01) more workrelated symptoms in their eyes (48% vs 6%) and nose (39% vs 0) than did 18 unexposed control subjects. Two of the exposed workers had PA-associated asthma. Surprisingly, the control group exhibited significantly (P less than 0.05) more symptoms of nonspecific bronchial hyperreactivity (44% vs 13%). The exposed workers showed significantly higher levels of total serum IgE (medians, 32 vs 15 kIU/l, P less than 0.05), although values for specific IgE against PA did not differ. This may indicate that such exposure can facilitate the entry of common allergens. There was a significant difference in PA-specific IgG [enzyme-linked immunosorbent assay (ELISA) ratios 0.21 vs 0.12; P less than 0.01]. There were no differences in lung function with regard to vital capacity (VC) and forced expiratory volume (FEV1), closing volume expressed as a percentage of VC (CV%), volume of trapped gas (VTG) before and after inhalation of metacholine, or carbon monoxide transfer factor (TLCO), whereas exposed workers displayed significantly higher late expiratory flow rates (MEF50 and MEF25). In a [99mTc]-diethylenetriamine penta-acetate (DTPA) clearance test, there was no difference between exposed subjects and controls. In summary, exposure to PA did not cause subclinical effects of the lungs. Subjects with lower-airway symptoms showed lower FEV1, MEF50, and MEF25 values and higher VTG (after metacholine) than did those without symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Pulmonary reactions caused by welding-induced decomposed trichloroethylene.

This is the report of a welder who performed argon-shielded electric arc welding in an atmosphere containing trichloroethylene. He developed immediate respiratory symptoms, pulmonary edema 12 hours after exposure, and recurring dyspnea ten days after exposure. These pulmonary reactions might be explained by inhalation of decomposition products of trichloroethylene such as dichloroacetyl chloride and phosgene.

Dyspnea

Decreased lung function and exposure to diisocyanates (HDI and HDI-BT) in car repair painters: observations on re-examination 6 years after initial study.

Thirty-six car painters and 115 control persons participated in a follow-up investigation 6 years after the initial study, including measurement of lung function (dynamic spirometry and nitrogen washout test) and estimation of exposure to diisocyanates based on individual working routines, use of respiratory protection equipment, and measurements. The mean exposure for the car painters was 0.0015 mg/m3 hexamethylenediisocyanate (HDI) and 0.09 mg/m3 hexamethylenediisocyanate-biurettrimer (HDI-BT), but frequently there were peak exposures exceeding 2.0 mg/m3 HDI-BT for at least 30 sec. Compared with smoking controls, the smoking car painters had greater yearly reduction in FVC (95 versus 38 ml), FEV1 (61 versus 28 ml), and VC (77 versus 30 ml). The nonsmoking car painters showed no differences in lung volumes compared with their nonsmoking controls. The impairment correlated well with the frequency of high peak exposures to HDI-BT, but not with the mean exposure to diisocyanates.

Adult

Reduction in adverse effect on pulmonary function after exposure to filtered diesel exhaust.

A statistically significant temporary reduction on pulmonary function was measured with spirometry in stevedores on a roll-on-roll-off ro-ro ship who were exposed to diesel exhausts from trucks during a work shift. When all trucks were equipped with specially designed microfilters mounted on the exhaust pipes, this impairment in pulmonary function was reduced. Removal of the particulate fraction of the exhausts by filtering is an important factor in reducing the adverse effect of diesel exhaust on pulmonary function. The particle fraction should be considered when designing an indicator of the biological effects of diesel exhausts.

Adult

Long-term follow up of workers exposed to solvents.

Long term occupational exposure to organic solvents may cause adverse effects to the central nervous system. This collaborative study between six Swedish departments of occupational medicine examines the overall prognosis in terms of working capacity, symptoms, and psychometric test performance for individuals occupationally exposed to organic solvents. After re-analyses of the data from an initial clinical investigation of 111 men, the subjects were divided into two subgroups: one group of 65 with symptoms but no impairment on the tests and one group of 46 with toxic encephalopathy (symptoms and test impairment). At least five years after the initial examination the subjects were asked to attend a re-examination that included a structured medical interview and a psychometric investigation. The results indicate that effects on the central nervous system persist even when exposure has ceased. In the group of 46 more men had stopped working and were receiving sickness or early retirement pensions. This group also had reduced activity levels with regard to everyday life, leisure activities, and education or training and more neuropsychiatric symptoms. There was no support for the view that a solvent induced toxic encephalopathy is a progressive disease comparable with presenile dementia such as Alzheimer's disease or Pick's disease. If a worker was removed from exposure when he presented symptoms without signs of impairment in intellectual function recovery was seen in most cases.

Aged

Single and multiple breath nitrogen wash-out--closing volume and volume of trapped gas for detection of early airway obstruction.

Thirty-eight patients with varying degrees of peripheral airway involvement were studied by flow-volume curves and two nitrogen wash-out techniques in an on-site study. Closing capacity (CC), closing volume in percentage of vital capacity (CV%), slope of the alveolar plateau (phase III), volume of trapped gas (VTG), and maximum expiratory flow at 50 and 75% of vital capacity (MEF50, MEF25) were determined and correlation analyses were performed. A biphasic or exponential correlation was noted between the degree of airway closure and VTG with rapidly increasing VTG at high CC. Although there were correlations between spirometry and the two nitrogen wash-out techniques, a large scatter precluded the use of the flow-volume variables to predict CC, CV% and VTG. The coefficient of variation was lower for the measurements of CV% than for the recording of VTG. Since the single breath nitrogen wash-out technique is also technically simpler it is recommended prior to the multiple breath technique.

Adult