Biomedical subjects

Lars Gerhardsson

Publications and source records attributed to Lars Gerhardsson.

12 recordsLinked to original sources

PubMed2006

Plasma-lead concentration: investigations into its usefulness for biological monitoring of occupational lead exposure.

BACKGROUND: The lead concentration in plasma is correlated to that in whole blood with a two to fourfold variation. It has never been investigated if this variation is inter-individual. METHODS: Lead and hemoglobin were determined in blood and plasma from 13 lead workers with a history of relatively high blood-lead concentrations, sampled three times during 1 day. The variation in the distribution of lead between cells and plasma was studied, but not the variation in the lead concentrations as such. RESULTS: Blood hemoglobin decreased with rising plasma lead (0.9-3.0 microg/L). Regarding the distribution of lead, no effect of current exposure during the day or of recent meals appeared. As much as 84% of the overall variance of the distribution of lead between cells and plasma could be attributed to individual factors. After adjustment for erythrocyte volume fraction this decreased to 67%. Plasma samples with elevated hemoglobin concentrations (due to in vitro hemolysis) had somewhat elevated lead concentrations. CONCLUSIONS: Plasma lead is not significantly altered by variation in a single day's exposure and, therefore, the choice of time of the day is not critical for sampling. However, plasma lead is negatively correlated to blood hemoglobin and mild hemolysis (not visible by the eye) in a sample may increase plasma lead with up to 30%. Finally, plasma provides lead exposure information that differs from whole blood, but it is not clear which one of these is the biomarker with the closest relation to exposure and/or effects.

Adult↗

PubMed2006

Lung cancer development in primary smelter workers: a nested case-referent study.

OBJECTIVE: The objective of this study was to study the impact of work-related exposure to mainly arsenic and lead versus smoking in primary smelter workers developing lung cancer. METHODS: In a cohort of 3979 primary smelter workers, 46 subjects had contracted respiratory malignancies. They were compared with 141 age-matched male referents by conditional logistic regression analysis. RESULTS: Cases showed a significantly higher smoking rate as compared with referents: odds ratio (OR) = 4.0; 95% confidence interval (CI) = 1.6-10.1; P = 0.003. When restricted to smokers (33 cases, 63 referents), the cumulative air arsenic exposure index, but not the lead exposure indices, was significantly higher among the cases: OR = 1.07; 95% CI = 1.02-1.11; P = 0.005. CONCLUSIONS: Cumulative arsenic exposure and smoking were identified as risk factors for the development of lung cancer; lead exposure, however, was not.

Arsenic Poisoning↗

PubMed2005

Lead concentrations in cortical and trabecular bones in deceased smelter workers.

The aim of the study was to compare bone lead concentrations in cortical and trabecular bones in long-term exposed primary copper and lead smelter workers, and to relate the measured concentrations to the previous lead exposure of the workers. Lead concentrations in seven bones (trabecular: sternum, vertebrae, iliac crest, rib; cortical: femur, left forefinger, and temporal bone) were determined by electrothermal atomic absorption spectrometry in 32 male, long-term exposed copper and lead smelter workers, and compared with levels in 10 male occupationally unexposed reference persons. A time-integrated blood lead index (cumulative blood lead index, CBLI) was calculated for each worker. The lead levels in the seven studied bones were all significantly higher in active and retired lead workers as compared with the reference group (p<or=0.003). The highest lead concentrations among the workers were observed in finger bone (median 106 microg/g), followed in order by vertebrae, iliac crest and sternum. The highest quotients between median bone lead concentrations of workers vs. reference group were observed for trabecular bones (sternum 12.3, iliac crest 11.8, rib 8.8 and vertebrae 8.5). In retired workers, strong positive correlations were noted between lead levels in sternum and iliac crest (rs=0.91; p<0.001) and femur and temporal bone (rs=0.88, p<0.001). Neither CBLI nor exposure-time was related to the bone lead concentrations in any of the studied groups. The findings indicate similarities in the metabolism for bones with the same basic structure. The highest lead concentrations were found in finger bone, which can be used for retrospective exposure evaluations in lead exposed populations, e.g. through XRF-measurements.

Age Factors↗

PubMed2005

Environmental tobacco smoke (ETS) exposure in children with asthma-relation between lead and cadmium, and cotinine concentrations in urine.

Exposure to heavy metals from environmental tobacco smoke (ETS) was investigated in 23 children with asthma (8.4+/-3.7 yr). ETS exposure was assessed by an inquiry data-based exposure index, the urinary concentration of cotinine (U-cotinine; a major nicotine metabolite) and the house dust (fine and coarse fractions) concentrations of nicotine at home. The corresponding concentrations of the heavy metals cadmium and lead in dust and urine (U-Cd; U-Pb) were determined in the same samples. There were strong associations between the ETS exposure index and U-cotinine (r(s)=0.62; P<0.002) and nicotine in house dust (r(s)=0.77; P<0.001). There was a strong positive correlation between lead and cadmium concentrations in both fine (r(s)=0.86; P<0.001) and coarse dust (r(s)=0.57; P=0.02). Although, there was a tendency for a relation between nicotine and lead concentrations in fine dust (r(s)=0.52; P=0.06), no other significant associations were found between house dust metals and nicotine concentrations. U-Cd correlated well with U-cotinine (r(s)=0.50; P=0.02). Further, U-Pb were associated with U-cotinine, however not statistically significant (r(s)=0.41; P=0.06). A probable explanation is a direct inhalation of side-stream smoke containing heavy metals and/ or an increased pulmonary uptake, due to a small airways disease in children with asthma.

Air Pollution, Indoor↗

PubMed2005

Lead in finger bone, whole blood, plasma and urine in lead-smelter workers: extended exposure range.

OBJECTIVES: To assess the historical exposure and to study the relationships between lead concentrations in whole blood (B-Pb), plasma (P-Pb), urine (U-Pb), finger bone (Bone-Pb) and duration of employment in workers at a secondary lead smelter and to compare the relationships between B-Pb and P-Pb with results from previous studies of populations with a wide range of lead exposure. METHODS: In 39 lead workers (29 active, ten retired), recruited from those with the highest exposure at a German secondary lead smelter, levels of B-Pb, P-Pb and U-Pb were determined by inductively coupled plasma mass spectrometry (ICP-MS). Bone-Pb was determined by in vivo X-ray fluorescence (XRF). Results were compared with data from a previous study on 90 workers (71 active, 19 retired) with lower exposure, from a Swedish secondary lead smelter, as well as with previously collected data from 42 active Russian lead workers and 34 Ecuadorian lead-exposed subjects. RESULTS: The median values in the active/retired German lead workers were: age 44/59 years, duration of employment 20/38 years, Bone-Pb 71/150 microg/g, B-Pb 500/330 microg/l, P-Pb 2.7/1.1 microg/l, and U-Pb 25/13 micromol/mol creatinine. Bone-Pb increased with duration of employment by 4.2 microg/g per year and 1.6 microg/g per year in German and Swedish workers, respectively. The median Bone-Pb was three times higher in both active and retired German workers than in Swedish smelter workers with essentially the same age distribution and duration of employment. The linear regression equation between B-Pb and log P-Pb in the combined group of Ecuadorian, German, Russian and Swedish lead-exposed subjects (n=176) was B-Pb=545 x log[P-Pb] + 258 (r(s)=0.94; P<0.001). CONCLUSIONS: The high Bone-Pb values recorded for the German smelters implied a historical lead exposure of considerable magnitude. The long-term high lead exposure also showed up in the B-Pb levels for both active and retired workers, leading to the implementation of necessary industrial safety measures in order to respond to biological threshold limits. The suggested equation describing the relationship between B-Pb and P-Pb in the combined group of subjects with a wide range of lead exposure can be useful in future cross-sectional and longitudinal studies of lead-exposed populations, relating, e.g., lead exposure to adverse health outcomes.

Adult↗

PubMed2005

Intoxication from an accidentally ingested lead shot retained in the gastrointestinal tract.

A 45-year-old woman was referred to the Department of Occupational and Environmental Health in January 2002 because of increased blood lead concentrations of unknown origin. She suffered from malaise, fatigue, and diffuse gastrointestinal symptoms. She had a blood lead level of 550 microg/L (normal range < 40 microg/L). The patient had not been occupationally exposed to lead, and no potential lead sources, such as food products or lead-glazed pottery, could be identified. Her food habits were normal, but she did consume game occasionally. Clinical examination, including standard neurologic examination, was normal. No anemia was present. Laboratory tests showed an increased excretion of lead in the urine, but there were no signs of microproteinuria. An abdominal X ray in October 2002 revealed a 6-mm rounded metal object in the colon ascendens. Before the object could be further localized, the patient contracted winter vomiting disease (gastroenteritis) and the metal object was spontaneously released from the colon during a diarrhea attack. The object was a lead shot pellet, possibly but not normally used in Sweden for hunting wild boar or roe deer. Blood lead levels slowly decreased. Nine months later the patient's blood lead levels were almost normal (approximately 70 microg/L) and her symptoms had almost completely disappeared. In this case, a rare source of lead exposure was found. In investigations of blood lead elevations of unknown origin, we recommend abdominal X ray in parallel with repeated blood lead determinations.

Adult↗

PubMed2004

Vascular and nerve damage in workers exposed to vibrating tools. The importance of objective measurements of exposure time.

The aim of the present study was to compare the development of vibration white fingers (VWF) in workers in relation to different ways of exposure estimation, and their relationship to the standard ISO 5349, annex A. Nineteen vibration exposed (grinding machines) male workers completed a questionnaire followed by a structured interview including questions regarding their estimated hand-held vibration exposure. Neurophysiological tests such as fractionated nerve conduction velocity in hands and arms, vibrotactile perception thresholds and temperature thresholds were determined. The subjective estimation of the mean daily exposure-time to vibrating tools was 192 min (range 18-480 min) among the workers. The estimated mean exposure time calculated from the consumption of grinding wheels was 42 min (range 18-60 min), approximately a four-fold overestimation (Wilcoxon's signed ranks test, p<0.001). Thus, objective measurements of the exposure time, related to the standard ISO 5349, which in this case were based on the consumption of grinding wheels, will in most cases give a better basis for adequate risk assessment than self-exposure assessment.

Acceleration↗

PubMed2003

Hair element concentrations in females in one acid and one alkaline area in southern Sweden.

Concentrations of 34 trace elements in hair have been determined in 47 females from an acid region in southern Sweden, who were compared with 43 females from an alkaline area. The concentrations of these elements in hair and drinking water were determined by inductively coupled plasma optical emission spectroscopy and inductively coupled plasma mass spectrometry. The hair concentrations of boron and barium were significantly higher (p < 0.001) in hair samples from the acid region, the hair levels of calcium, strontium, molybdenum, iron, and selenium were significantly higher (p < 0.001) in the alkaline region. For some metals, e.g. calcium, lead, molybdenum, and strontium, there were positive correlations between the concentrations in hair and water (rs = 0.34-0.57; p < or = 0.001), indicating the importance of intake from minerals in water. The increased ratio of selenium/mercury concentrations in hair samples obtained in the alkaline district (p < 0.001) indicates that these subjects may have better protection against the toxic effects of mercury.

Adult↗

PubMed2002

Copper allergy from dental copper amalgam?

A 65-year-old female was investigated due to a gradually increasing greenish colour change of her plastic dental splint, which she used to prevent teeth grinding when sleeping. Furthermore, she had noted a greenish/bluish colour change on the back of her black gloves, which she used to wipe her tears away while walking outdoors. The investigation revealed that the patient had a contact allergy to copper, which is very rare. She had, however, had no occupational exposure to copper. The contact allergy may be caused by long-term exposure of the oral mucosa to copper from copper-rich amalgam fillings, which were frequently used in childhood dentistry up to the 1960s in Sweden. The deposition of a copper-containing coating on the dental splint may be caused by a raised copper intake from drinking water, increasing the copper excretion in saliva, in combination with release of copper due to electrochemical corrosion of dental amalgam. The greenish colour change of the surface of the splint is probably caused by deposition of a mixture of copper compounds, e.g. copper carbonates. Analysis by the X-ray diffraction technique indicates that the dominant component is copper oxide (Cu2O and CuO). The corresponding greenish/bluish discoloration observed on the back of the patient's gloves may be caused by increased copper excretion in tears.

Copper↗

PubMed2002

Cadmium, copper and zinc in tissues of deceased copper smelter workers.

Workers at a copper and lead smelter in northern Sweden have a multifactorial exposure to a number of heavy metals. The concentrations of cadmium, copper and zinc in liver, lung, kidney and brain tissues have been determined by atomic absorption spectrometry in 32 deceased long-term exposed male lead smelter workers, and compared with those of 10 male controls. Furthermore, copper and zinc levels in hair and nails were determined by energy-dispersive X-ray fluorescence. The highest cadmium concentrations among both workers and controls were observed in kidney, followed in order by liver, lung and brain. The levels in kidney, liver and lung were all significantly higher in the workers than in the controls (p < 0.03). Among the workers relatively strong positive correlations (p < 0.03) were observed between cadmium concentrations in liver and lung, liver and kidney, liver and brain, and lung and brain. In the exposed workers a positive correlation was observed between cadmium and zinc concentrations in the kidney (rs = 0.38; p = 0.034). This is probably mainly due to the protein metallothionein, which is stored in the kidney, binding equimolar amounts of these two metals. The highest concentrations of copper were found in hair and nails among both workers and controls, followed in order by liver, brain, kidney and lung. The tissue concentrations of copper in brain, lung and kidney were all significantly higher among the smelter workers than in the controls (p < 0.036). Copper levels in lung and age at time of death were positively correlated among the exposed workers (rs = 0.39; p = 0.029). In the same group, positive correlations between copper and zinc concentrations in kidney (rs = 0.45; p = 0.009) and nails (rs = 0.68; p < 0.001) were also observed, reflecting possible biological interactions between these two metals. Among both workers and controls, the highest zinc concentrations were found in hair, followed in order by nails, liver, kidney, brain and lung. Significantly higher tissue concentrations among the workers as compared with the reference group were noted in kidney, liver and brain (p < 0.033). Neither copper nor zinc concentrations in hair and nails seemed to provide a useful measure of the trace element status of the smelter workers.

Body Burden↗

PubMed2002

Blood lead concentration after a shotgun accident.

In an accidental shooting, a man in his late forties was hit in his left shoulder region by about 60 lead pellets from a shotgun. He had injuries to the vessels, the clavicle, muscles, and nerves, with total paralysis of the left arm due to axonal injury. After several surgical revisions and temporary cover with split skin, reconstructive surgery was carried out 54 days after the accident. The brachial plexus was swollen, but the continuity of the nerve trunks was not broken (no neuroma present). We determined the blood lead (BPb) concentration during a follow-up period of 12 months. The BPb concentration increased considerably during the first months. Although 30 lead pellets were removed during the reconstructive surgery, the BPb concentration continued to rise, and reached a peak of 62 microg/dL (3.0 micromol/L) on day 81. Thereafter it started to decline. Twelve months after the accident, BPb had leveled off at about 30 microg/dL. At that time, muscle and sensory functions had partially recovered. The BPb concentration exceeded 30 microg/dL for 9 months, which may have influenced the recovery rate of nerve function. Subjects with a large number of lead pellets or fragments embedded in the body after shooting accidents should be followed for many years by regular determinations of BPb. To obtain a more stable basis for risk assessment, the BPb concentrations should be corrected for variations in the subject's hemoglobin concentration or erythrocyte volume fraction.

Foreign Bodies↗

PubMedDate not supplied

Genetic influences on the retention of inorganic mercury.

Mercury is eliminated as glutathione (GSH) conjugates. GSH production is mediated by glutamyl-cysteine ligase (GCL), and conjugation by glutathione S-transferases (GST). This study tested if polymorphisms in GCL and GST genes modify mercury retention in humans exposed to elemental mercury vapor. Total mercury concentrations in whole blood, plasma and urine, and genotypes for GCLC, GCLM, GSTA1, GSTM1, GSTP1, and GSTT1 were determined in 309 gold miners, gold buyers and controls. The presence of the GCLM-588T allele was associated with increased blood, plasma and urine mercury levels. These results indicate that genotypes with decreased GSH availability for mercury conjugation affect the metabolism of inorganic mercury.

Adolescent↗