Biomedical subjects

S Skerfving

Publications and source records attributed to S Skerfving.

At least 19 recordsLinked to original sources

PubMed1992

Fish as a source of exposure to mercury and selenium.

In a total of 395 subjects with varying fish consumption habits, mercury levels in whole blood (B-Hg), and selenium levels in plasma (P-Se) were studied. Also, in subcohorts, mercury levels in blood cells (Ery-Hg; n = 79), plasma (P-Hg; n = 158) and urine (U-Hg; n = 125) were analysed. There were statistically significant associations between fish intake on the one hand, and B-Hg, Ery-Hg and P-Hg, on the other, but not so with U-Hg. In subjects who never had fish, the average B-Hg was 1.8 ng/g, in subjects who had at least two fish meals each week, 6.7 ng/g. Ery-Hg, and to a less extent P-Hg, were associated with levels of marine n-3 polyunsaturated fatty acids (PUFA) in serum phosphatidylcholine. P-Hg and U-Hg were associated with numbers of teeth with amalgam fillings. P-Se also correlated with fish intake. In subjects who never had fish, P-Se averaged 80 micrograms/l, in subjects who had at least two fish meals per week, 91 micrograms/l. There was an association between PUFA and P-Se. Further, there were statistically significant associations between P-Se on the one hand, and B-Hg, Ery-Hg and P-Hg on the other. The data clearly demonstrate the importance of fish for the exposure to methylmercury and selenium in the Swedish diet, and the impact of amalgam as a source of exposure to inorganic mercury.

Adult↗

PubMed1992

Hormone status in occupational toluene exposure.

Twenty toluene-exposed rotogravure printers, without signs of solvent-induced toxic encephalopathy, had lower median plasma levels of follicle stimulating hormone (FSH) (3.2 vs. 4.9 IU/L; p = .02) and luteinizing hormone (LH) (6.4 vs. 7.2 IU/L; p = .05) and also lower serum levels of free testosterone (7.8 vs. 86.8 pmol/L; p = .05), respectively, than 44 unexposed referents. The individual time-weighted toluene levels in air were 36 (median; range 8-111) ppm. The printers' median toluene levels in blood were 1.7 (1.0-6.6) mumol/l, and in subcutaneous adipose tissue 5.7 (2.5-21) mg/kg fat. There was a negative association between blood toluene and plasma levels of prolactin. In eight printers, the levels of FSH and LH increased during a 4 week vacation, while the levels of thyroid stimulating hormone, free triiodothyronine, and free thyroxine decreased during the same period. The results indicate a slight, reversible effect of toluene on the cortical level or on the hypothalamic-pituitary axis at exposures well below the permissible levels, possibly mediated through an effect on catecholamine neurotransmission.

Adipose Tissue↗

PubMed1992

Lead exposure in indoor firing ranges.

Higher air lead levels (time-weighted average 660, range 112-2238 micrograms/m3) were measured in firing ranges where powder charges were employed than in ranges where air guns were used (4.6, range 1.8-7.2 micrograms/m3); levels in the latter were in turn higher than those in ranges used for archery (0.11, range 0.10-0.13 micrograms/m3). Twenty-two marksmen who used powder charges had significantly increased blood lead levels during the indoor shooting season (before: median 106, range 32-176 micrograms/l; after: 138; range 69-288 micrograms/l; P = 0.0001), while 21 subjects who mainly used air guns displayed no significant increase (before: median 91, range 47-179 micrograms/l; after: 84; range 20-222 micrograms/l). Thirteen archers had significantly lower levels than the pistol shooters before the season (P = 0.006), and showed a significant decrease during the season (before: median 61, range 27-92 micrograms/l; after: 56; range 31-87 micrograms/l; P = 0.04). At the end of the indoor season, there was a significant association between weekly pistol shooting time and blood lead levels.

Adolescent↗

PubMed1992

Assessment of accumulated body burden of metals.

Knowledge of the body burden of a metal is important for evaluation of exposure and risk. Traditionally, the burden has been estimated through levels in blood, urine, hair, or shed teeth, or by mobilization tests. However, all these methods have limitations. In vivo methods for determination of cadmium in kidney by neutron activation analysis or X-ray fluorescence (XRF) reflect the burden, long-term exposure, and risk of toxic effect. In vivo determination by XRF of lead in fingerbone, tibia, or calcaneus reflect the long-term exposure, and should become a valuable tool in epidemiological studies, especially of chronic effects.

Body Burden↗

PubMed1992

Allergy to methyltetrahydrophthalic anhydride in epoxy resin workers.

One hundred and forty four current and 26 former workers in a plant producing barrels for rocket guns from an epoxy resin containing methyltetrahydrophthalic anhydride (MTHPA; time weighted average air concentration up to 150 micrograms/m3) were studied. They showed higher frequencies of work related symptoms from the eyes (31 v 0%; p < 0.001), nose (53 v 9%; p < 0.001), pharynx (26 v 6%; p < 0.01), and asthma (11 v 0%; p < 0.05) than 33 controls. Also they had higher rates of positive skin prick test to a conjugate of MTHPA and human serum albumin (16 v 0%; p < 0.01), and more had specific IgE and IgG serum antibodies (18 v 0%; p < 0.01 and 12 v 0%; p < 0.05 respectively). There were statistically significant exposure-response relations between exposure and symptoms from eyes and upper airways, dry cough, positive skin prick test, and specific IgE and IgG antibodies. There was a non-significant difference in reaction to metacholine between exposed workers and non-smoking controls. In workers with and without specific IgE antibodies, differences existed in frequency of nasal secretion (54 v 23%; p < 0.05) and dry cough (38 v 12%; p < 0.05). Workers with specific IgG had more dry cough (38 v 12%; p < 0.05), but less symptoms of non-specific bronchial hyperreactivity (0 v 26%; p < 0.05). Atopic workers sneezed more than non-atopic workers (65 v 30%; p < 0.01). In a prospective study five sensitised workers who left the factory became less reactive to metacholine, and became symptom free. In 41 workers who stayed, there was no improvement, despite a 10-fold reduction in exposure. The results show the extreme sensitising properties of MTHPA.

Adolescent↗

PubMed1992

Chelated lead and bone lead.

In this study a close correlation [correlation coefficient (r) = 0.86, P less than 0.001] was found between the blood lead level of 20 lead workers and their urinary excretion of lead for 24 h after intravenous infusion with 1 g of the chelating agent calcium disodium edetate. In addition, there were significant associations between lead levels in different bones (tibia/calcaneus: r = 0.93, P less than 0.001; tibia/phalanx: r = 0.67, P less than 0.002; calcaneus/phalanx: r = 0.80, P less than 0.001), as measured by in vivo X-ray fluorescence. Chelation produced no significant change in the lead level in either tibia or calcaneus. There was a significant correlation between chelated lead and bone lead (eg, for calcaneus, r = 0.62) in currently exposed workers. However, there was no significant relationship when a retired worker and an inactive worker were included (r = 0.14). It was concluded that chelatable lead mainly reflects the blood and soft-tissue lead pool, which is only partly dependent upon the skeletal lead content that comprises the biggest share of the total body burden.

Adult↗

PubMed1991

Exposure to dioxins and dibenzofurans through the consumption of fish.

BACKGROUND: In some regions, including the Baltic Sea, fatty fish such as salmon and herring contain high levels of polychlorinated dibenzodioxins and dibenzofurans. We investigated human exposure to these potentially toxic substances in relation to the consumption of fish from the Baltic Sea. METHODS: Plasma levels of 10 different dibenzofurans and 7 dioxins were analyzed in three groups of Swedish men: one group with a high intake of fish (fish eaten almost daily; n = 11), one with a moderate intake of fish (about once per week; n = 9), and one with no consumption of fish (usually because of allergy; n = 9). RESULTS: Plasma levels of several of the compounds we measured were higher in the men with a high intake of fish than in those who consumed moderate amounts, and the levels were higher in those who ate moderate amounts of fish than in those who ate none. The median amounts of the most toxic dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) were 8.0 pg per gram of plasma lipid (range, 2.0 to 13) in the high-intake group, 2.6 pg per gram (range, 1.2 to 4.2) in the moderate-intake group, and 1.8 pg per gram (range, 1.0 to 2.5) in the nonconsumers (P = 0.001 and 0.02, respectively). There were consistent and statistically significant associations between the reported amount of fish eaten and the plasma levels of several of the dibenzofurans and dioxins. CONCLUSIONS: Contaminated fish such as those from the Baltic Sea are an important source of exposure to polychlorinated dibenzofurans and dibenzodioxins in persons who eat fish regularly. However, the clinical consequences of such exposure remain uncertain.

Adult↗

PubMed1991

Mobilized mercury in subjects with varying exposure to elemental mercury vapour.

In a mercury mobilization test, 0.3 g of the complexing agent sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) was given orally to 10 workers with moderate occupational exposure to elemental mercury vapour, to 8 dentists with slight exposure, to 18 matched controls, and to 5 referents without amalgam fillings. In the workers, DMPS caused an increase in 24-h urinary mercury excretion by a factor of 10; in the dentists, 5.9; in the controls, 5.3; and in the amalgam-free referents, 3.8. Of the mercury excreted during 24 h, 59% appeared during the first 6 h. Close, albeit non-linear, associations were found between mobilized mercury and the premobilization mercury levels in plasma and urine, but not with the duration of occupational exposure or the rough estimate of the integrated function of blood levels vs time. The present data indicate that mercury mobilized after a single DMPS dose in close connection with exposure is mainly an index of recent exposure and is not significantly affected by slow body pools or long-term exposure.

Adult↗

PubMed1991

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↗

PubMed1991

Cytogenetic effects in rotogravure printers exposed to toluene (and benzene).

Comparing 21 rotogravure printers exposed to toluene (medians: time-weighted air level 150 mg/m3, blood toluene 1.6 mumole/l) and 21 unexposed controls (median blood toluene less than or equal to 0.01 mumole/l) there was a significant increase in the frequency of micronuclei (MN) in pokeweed mitogen (PWM)-stimulated peripheral blood lymphocytes in the printers, as compared to the controls (2.8% vs. 1.5%; p = 0.03; all p adjusted for age and smoking). The frequency of small MN (size ratio MN/main nucleus less than or equal to 0.03) in PWM-stimulated lymphocytes was associated with the exposure (1% vs. 0.3%; p = 0.05). Furthermore, among the exposed subjects there was an association between blood toluene and small MN (0.17% per mumole/l; p = 0.0005). Small MN in phytohemagglutinin (PHA) cultures displayed no association with any exposure parameter. However, in the printers, an estimated cumulative exposure index was weakly correlated with the frequency of total MN in PHA-stimulated cells (0.00003% per mg/m3 x year; p = 0.07). Among the printers, chromosomal breaks in PHA-stimulated cells were associated with the duration of earlier benzene exposure (0.03% per year; p = 0.01). The results of this study strongly indicate that toluene causes a clastogenic effect on the B-cells even at low exposure levels. Further, earlier benzene exposure seems to have caused chromosomal breaks in T-cells.

Adult↗

PubMed1991

Kinetics of lead in bone and blood after end of occupational exposure.

In 14 retired lead workers, followed for over 18 years after end of exposure, repeated analyses of lead levels in finger bone by an in vivo X-ray fluorescence method revealed a decrease of lead concentration. The data were analysed using an exponential retention model. For the whole group the biological half-time was 16 (asymptotic 95% confidence interval, CI 12,23) years. The median of the estimated bone lead levels at the end of exposure was 85 micrograms.g-1 above the "background" (3 micrograms.g-1). A simultaneous follow-up of blood lead levels displayed a decrease, which could be described by a tri-exponential retention model with group half-times of 34 (CI 29,41) days, 1.2 (CI 0.9,1.8) years, and 13 (CI 10,18) years, respectively. The median of the estimated blood lead levels at the end of exposure for the three components were 0.49, 0.61, and 1.1 mumol.l-1 above the "background" (0.38-0.56 mumol.l-1), respectively. The well-documented decrease of lead exposure in the general population over the years, urged the use of a decreasing "background" of blood lead during the time of the study. The slowest of the three components represented the skeleton (probably mainly cortical bone), as did mainly probably also the intermediate one (trabecular bone). The data show the rather slow turnover of lead in the skeleton, the usefulnes of in vivo skeletal lead measurements as a long-term exposure index, and the importance of bone as a source of "endogenous" lead exposure.

Adult↗

PubMed1990

Effects of ethanol ingestion and urinary acidity on the metabolism of triethylamine in man.

In four volunteers exposed to triethylamine (TEA) by inhalation (20 mg/m3, 8 h), the nonrenal clearance of TEA into triethylamine-N-oxide (TEAO) was inhibited by 15 to 30% by intake of ethanol (blood serum level in average 25 mmol/l). Ethanol intake caused a decrease of plasma levels of TEA and TEAO, and of the fractional formation of TEAO. This may partly be due to a second effect of ethanol; it caused a slight decrease of urinary pH, which led to an increase of the urinary TEA excretion rate, with a possible withdrawal of TEA from oxygenation. Indeed, this effect was efficiently counteracted by intake of sodium bicarbonate, which caused a decrease of renal clearance of TEA, and increases of plasma levels of TEA and TEAO, and of the fractional formation of TEAO. A change of urinary pH by about two units caused a change of renal clearance of TEA by a factor of three and of the oxygenation by two. The renal clearance of TEAO was not affected by urinary pH.

Air Pollutants, Occupational↗

PubMed1990

Specific antibodies to methyltetrahydrophthalic anhydride in exposed workers.

A group of 145 workers exposed to methyltetrahydrophthalic anhydride (MTHPA) was investigated. They were working in a plant which, since 1983, handled an epoxy resin with MTHPA as a hardener. Specific IgE antibodies (RAST) to a conjugate between MTHPA and human serum albumin (HSA) were statistically significantly increased (P = 0.001; 26 subjects = 18% positive) in the exposed group, compared to a non-exposed control group (n = 33). One positive worker was only exposed for 2 months. Twenty-three exposed subjects were also skin-prick test positive to MTHPA-HSA. The exposed group was divided into three different exposure categories, according to their contact with the epoxy resin. The average exposure levels at the time of the investigation were, in zone I 0.085 mg/m3, in zone II 0.014 mg/m3, and in zone III 0.010 mg/m3, though the exposure probably had been higher earlier. There was an association between exposure intensity and RAST-positive persons (P = 0.0025, chi-square trend test). Forty-four persons (30%) were smokers, and 16 (11%) atopics. No association between sensitization and either atopy or smoking was found. There was an association between exposure intensity and specific IgG antibodies (P = 0.0003, chi-square trend test). Specific IgG4 antibodies were closely related to specific total IgG antibodies (P = 0.0001). These findings demonstrate that MTHPA is a sensitizing agent at low levels of exposure.

Antibody Specificity↗

PubMed1990

Deaths and tumours among rotogravure printers exposed to toluene.

A cohort of 1020 rotogravure printers exposed to toluene and employed for a minimum period of three months in eight plants during 1925-85 was studied. Air levels of toluene were available since 1943 in one plant and since 1969 in most. Based on these measurements and on present concentrations of toluene in blood and subcutaneous fat, the yearly average air levels in each plant were estimated. They reached a maximum of about 450 ppm in the 1940s and 1950s but were only about 30 ppm by the mid-1980s. Exposure to benzene had occurred up to the beginning of the 1960s. Compared with regional rates, total mortality did not increase during the observation period 1952-86 (129 observed deaths v 125 expected; SMR = 1.03). There was no increase in mortality from non-malignant diseases of the lungs, nervous system, or gastrointestinal and urinary tracts. There was no overall excess of tumours 1958-85 (68 v 54, SMR = 1.26; 95% confidence interval, CI = 0.95-1.7). Among the specific cancers, only those of the respiratory tract were significantly increased (16 v 9; SMR = 1.76, CI = 1.03-2.9). Statistical significance was not attained, however, when only subjects with an exposure period of at least five years and a latency period of at least 10 years were considered. Further, there were no dose response relations with cumulated toluene dose (ppm years). There were no significant increases of tumours at other sites, including leukaemias/lymphomas/myelomas.

Adult↗

PubMed1990

Normal pituitary hormone response to thyrotrophin and gonadotrophin releasing hormones in subjects exposed to elemental mercury vapour.

Exposure to elemental mercury (Hg) vapour results in an accumulation of Hg in the pituitary, the thyroid, and the testis. In this study, basal serum concentrations of pituitary hormones (thyrotrophin (TSH), prolactin (PRL), follicle stimulating hormone (FSH), and luteinising hormone (LH] or their response after administration of thyrotrophin and gonadotrophin releasing hormones did not differ between 11 male workers (mean urinary Hg (U Hg) concentration 26 nmol/mmol creatinine) and nine male dentists (U Hg concentration 1.3 nmol/mmol creatinine) exposed to elemental Hg vapour when compared with matched referent groups (U Hg concentration 0.6 and 0.4 nmol/mmol creatinine). Thus there was no evidence of an effect of Hg on the pituitary. Neither was there any association between exposure to Hg and serum concentrations of free thyroid hormones (S FT3, S FT4), testosterone, or cortisol. Increased plasma concentrations of selenium (Se) were associated with increased basal serum concentrations of TSH, decreased concentrations of basal serum cortisol, and decreased release of FSH.

Adult↗

PubMed1990

Mercury, selenium, and glutathione peroxidase before and after amalgam removal in man.

In 10 healthy persons all amalgam fillings were replaced with gold inlays. Blood and urinary levels were measured on 10 occasions during a 4-month period before and a 12-month period after amalgam removal. These variables were also measured three times in 10 healthy controls. A strong statistically significant relation was found between plasma mercury values and both the total number of amalgam surfaces (r = 0.71, p = 0.0006) and the total surface area of the fillings (r = 0.73, p = 0.0004). In the immediate postremoval phase plasma mercury rose three- to four-fold, whereas the urinary and erythrocyte mercury rose about 50%. These peak values declined to the preremoval level at about 1 month. Twelve months after the removal the plasma and urinary mercury levels were significantly reduced to 50% and 25%, respectively, of the initial values for the experimental group. Apart from the significantly lower plasma selenium values 5 and 10 days after removal no significant differences were found with regard to plasma selenium or erythrocyte glutathione peroxidase either within or between the experimental and the control groups. A large number of supplementary biochemical analyses did not show any influence on organ functions or any differences between the groups before or after the amalgam removal. Amalgam fillings considerably contributed to the plasma and urinary mercury levels.

Adult↗

PubMed1990

The influence of dental amalgam placement on mercury, selenium, and glutathione peroxidase in man.

Amalgam restorations were inserted in eight healthy persons, previously unprovided with dental restorations, who had several severe carious lesions. The mean number of surfaces restored were 16.1 (range, 11 to 22). The total mean calculated amount of mercury inserted was 2.9 g (range, 1.5 to 4.3 g). Blood and urinary levels were measured on seven occasions during a 4-month period before and a 3-month period after amalgam placement. One and 3 months after placement, the P-mercury mean values were almost equal to the preplacement values (3.3 nmol/l). After placement U-mercury increased continuously; 3 months after placement a statistically significantly higher (p less than 0.05) mean U-mercury value (0.58 nmol/mmol creatinine) was found compared with the mean preplacement value (0.34 nmol/mmol creatinine). No statistically significant correlation was found between the P- and U-mercury concentrations and the total number of amalgam surfaces. Selenium levels in plasma and urine and erythrocyte glutathione peroxidase showed no systematic change of pattern. The results show that the insertion of amalgam fillings contributed to the U-mercury concentration, but apparently even more extensive amalgam therapy and/or longer exposure periods are needed to affect the P-mercury concentration. No negative effects on the P- and U-selenium or the erythrocyte glutathione peroxidase levels could be found during the 3 months immediately after an extensive amalgam placement. The supplementary blood and urine analyses were not influenced by the insertion of amalgam fillings.

Adult↗

PubMed1989

Pharmacokinetics of triethylamine and triethylamine-N-oxide in man.

The pharmacokinetics of the industrially important compound triethylamine (TEA) and its metabolite triethylamine-N-oxide (TEAO) were studied in four volunteers after oral and intravenous administration. TEA was efficiently absorbed from the gastrointestinal (GI) tract, rapidly distributed, and in part metabolized into TEAO. There was no significant first pass metabolism. TEAO was also well absorbed from the GI tract. Within the GI tract, TEAO was reduced into TEA (19%) and dealkylated into diethylamine (DEA; 10%). The apparent volumes of distribution during the elimination phase were 192 liters for TEA and 103 liters for TEAO. Gastric intubation showed that there was a close association between levels of TEA in plasma and gastric juice, the latter levels being 30 times higher. The TEA and TEAO in plasma had half-lives of about 3 and 4 hr, respectively. Exhalation of TEA was minimal. More than 90% of the dose was recovered in the urine as TEA and TEAO. The urinary clearances of TEA and TEAO indicated that in addition to glomerular filtration, tubular secretion takes place. For TEAO at high levels, the secretion appears to be saturable. The present data, in combination with those of earlier studies, indicate that the sum of TEA and TEAO in urine may be used for biological monitoring of exposure to TEA.

Administration, Oral↗