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Biomedical subjects

A Brockhaus

Publications and source records attributed to A Brockhaus.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Blood lead and blood cadmium concentrations in 55-66-year-old women fron different areas of Nordrhein-Westfalen--chronological trends during 1982-1988].

Blood lead levels were determined in 3098 55-66 year-old women living in different areas of Northrhine-Westphalia (F.R.G.). Blood cadmium levels were determined in a subgroup of 2538 women. The studies were performed between 1982 and 1988. The results show that there has been a further fall of blood lead levels in the general population of West-Germany since the CEC blood lead surveys of 1979 and 1981. A comparable reduction of blood cadmium was not noted. Residents of large urban agglomerations had, on average, slightly higher blood lead levels than residents of small cities located in rural areas (+0.2-0.5 microgram/dl). With regard to blood cadmium, no differences were seen. Smokers were found to have, on average, 3-4 times higher blood cadmium levels than non-smokers. Blood lead was also elevated in smokers when compared to non-smokers. The highest blood lead levels recorded were in the range of 15-30 micrograms/dl. The data further suggest that lead mobilization during conditions of bone demineralization, e.g. in cases of osteoporosis, does not result in toxic blood lead levels in postmenopausal women.

Aged↗
PubMed1989

Levels of benzene and other volatile aromatic compounds in the blood of non-smokers and smokers.

The concentrations of benzene, toluene, ethylbenzene, and o-, m-and p-xylene were measured in venous blood samples collected from 13 non-smokers and 14 cigarette smokers. The blood samples were analysed by a purge and trap technique followed by gas chromatography/mass spectrometry/computer analysis. The above-mentioned volatile organic compounds (VOC) could be detected in measurable amounts in all blood samples. This finding seems to reflect the ubiquitous exposure of humans to these agents in the urban environment, in non-smokers as well as in smokers. Smokers were found to have significantly higher blood concentrations of benzene (median 547 ng/l) and toluene (median 2201 ng/l) than non-smokers (median 190 ng/l and 1141 ng/l, respectively). The concentrations of ethylbenzene and xylenes also tended to be higher in smokers when compared to non-smokers. The different concentrations of these compounds in the blood of non-smokers appear to reflect the common concentration pattern found in outdoor urban air as well as in indoor air and also seem to be influenced by the different blood/air partition coefficients of these compounds. The results indicate that smoking is associated with a significant additional exposure to VOC, in particular to benzene and toluene.

Benzene Derivatives↗
PubMed1989

Exposure to lead and cadmium of children living near a lead smelter at Lavrion, Greece.

Exposure of children of the Greek town of Lavrion to lead and cadmium has been evaluated by determination of the levels of lead (PbB) and cadmium (CdB) in the blood of 514 children living in the town. The Lavrion area is heavily polluted by lead owing to the presence of a large lead-zinc mining and smelting industrial complex. The industrial PbB level (geometric mean) was 21.7 micrograms dl-1 (range 7.4-79.8 micrograms dl-1). The CdB levels were, on average, 0.36 micrograms l-1 (range 0.1-3.1 micrograms l-1). The results were evaluated with respect to a number of constitutional, social and environmental variables, such as age, gender, distance of the school from the lead-zinc mining and smelting complex, and occupation and education of the father.

Age Factors↗
PubMed1989

[Exposure of children to benzene and other motor vehicle emissions].

The concentrations of benzene, toluene, and lead and the percentage of carboxyhemoglobin (COHb) were measured in the venous blood of 48 children living in a central urban area with high traffic density (Cologne, FRG). The same parameters were also evaluated in a reference group of children (n = 72) living in a small city located in a rural area of West-Germany (Borken, Münsterland). The above named parameters could be quantitated in all blood samples. The children living in the central urban area had, on average, significantly higher concentrations of benzene, toluene, lead, and COHb in blood than the children of the reference group. The blood benzene concentrations were, on average, 71% and the toluene concentrations 56% higher in the urban children when compared to the reference group. The median values of the urban group/reference group were: benzene, 115/70 ng/l; toluene, 545/370 ng/l; lead, 5.2/4.7 micrograms/dl; COHb, 0.9/0.6%. It is concluded that the higher levels of benzene, toluene, lead, and COHb found in the blood of the urban children result from the higher atmospheric concentrations of these pollutants generally found in central urban areas with high traffic density.

Air Pollution↗
PubMed1988

Exposure to lead and cadmium of children living in different areas of north-west Germany: results of biological monitoring studies 1982-1986.

Between 1982 and 1986 several surveys were carried out to determine the levels of lead and cadmium in blood, urine, and shed deciduous teeth (incisors only) of children living in rural, suburban, urban, and industrial areas of North-West Germany. Blood lead (PbB) and blood cadmium (CdB) were measured in about 4000 children. In rural, suburban and urban areas the median PbB levels vary between 5.5 and 7 micrograms/dl, with 98th percentiles varying between 10 and 13 micrograms/dl. The median CdB levels are between 0.1 and 0.2 microgram/dl, with 95th percentiles between 0.3 and 0.4 microgram/l. Children from urban areas have significantly higher PbB levels than children from rural and suburban areas. Regarding CdB no differences could be detected. Children living in areas around lead and zinc smelters, particularly those living very close to the smelters, have substantially increased PbB and CdB levels. Children from lead worker families also have substantially increased PbB and CdB levels. The lead levels in shed milk teeth (PbT) were determined in about 3000 children. In rural, suburban and urban areas the median PbT levels are between 2 and 3 micrograms/g, with 95th percentiles between 4 and 7 micrograms/g. Children from urban areas have significantly higher PbT levels than children from rural and suburban areas. The highest PbT levels (on a group basis) are in children from nonferrous smelter areas. The median levels of lead in urine (PbU) are between 6 and 10 micrograms/g creatinine, with 95th percentiles between 20 and 30 micrograms/g creatinine. Children from polluted areas have higher PbU levels than children from less polluted areas. The median levels of cadmium in urine (CdU) are in the order of 0.1 microgram/g creatinine, with 95th percentiles being in the range of 0.5 and 1.0 microgram/g creatinine. Girls have higher CdU levels than boys. There are no differences between groups of children from different areas. Children from lead worker families have higher PbU and CdU levels than otherwise comparable children. The results of the present studies indicate a further decrease of PbB in children from North-West Germany since the CEC blood lead campaigns carried out in 1979 and 1981. The decrease of lead exposure also seems to be reflected by a decrease of tooth lead levels.

Adolescent↗
PubMed1987

Cadmium in kidney cortex of inhabitants of North-West Germany: its relationship to age, sex, smoking and environmental pollution by cadmium.

The cadmium concentration in kidney cortex (CdKc) was determined in 388 deceased persons, who at the time of death had lived in the cities of Düsseldorf and Duisburg, Federal Republic of Germany (FRG), and surrounding areas. The average CdKc concentration was found to be 17.1 micrograms/g wet weight. Individual values range from less than 0.4 to 94.3 micrograms/g wet weight. The CdKc levels rapidly increase during the first decades of life. At the age of about 40 years, a plateau phase is reached. At high ages (greater than 70 years), the CdKc levels tend to decrease. Cigarette smokers have significantly higher CdKc concentrations than non-smokers. The increase of CdKc depends on the number of cigarettes smoked. Cigar and pipe smokers have slightly increased CdKc levels compared to non-smokers. Non-smokers who had spent the major part of their life in the area of Duisburg, a cadmium-polluted area, have, on the average, significantly higher CdKc levels than non-smokers from the less-polluted surrounding areas. In smokers the residential factor is masked by the effect of cigarette smoking.

Adult↗
PubMed1986

Human exposure to volatile halogenated hydrocarbons from the general environment.

The objective of this study was to assess individual human exposure to volatile halogenated hydrocarbons (VHH) under normal environmental conditions by means of biological monitoring, i.e. by the measurement of these compounds or their metabolites in body fluids, such as blood, serum, and urine. Blood samples of 39 normal subjects without known occupational exposure to these agents were examined for the occurrence of VHH. The following compounds were present in quantifiable concentrations in 60 to 95% of the blood samples examined: chloroform (median 0.2 microgram/l; range less than 0.1-1.7 microgram/l), 1,1,1-trichloroethane (median 0.2 microgram/l; range less than 0.1-3.4 micrograms/l), tetrachloroethylene (median 0.4 microgram/l; range less than 0.1-3.7 micrograms/l). Trichloroethylene could be detected in 31% of all blood samples (median less than 0.1 microgram/l; range less than 0.1-1.3 microgram/l). In addition, the levels of trichloroacetic acid (TCA) were determined in serum and 24-h urine samples of 43 and 94, respectively, normal subjects. TCA was present in measurable concentrations in all serum and urine samples examined. The median of the TCA levels in serum was 21.4 micrograms/l (range 4.8-221.2 micrograms/l) and in urine 6.0 micrograms/24 h (range 0.6-261.4 micrograms/24 h). The results are discussed in relation to data from the literature on human exposure to VHH from the general environment, i.e. via air, food, and water. The upper normal limits calculated from the results of this investigation can be used to detect even minor excessive exposures to VHH.

Adult↗
PubMed1985

Environmental exposure to cadmium and renal function of elderly women living in cadmium-polluted areas of the Federal Republic of Germany.

An epidemiological study was performed to assess whether environmental pollution by cadmium as found in cadmium-polluted areas of the Federal Republic of Germany is associated with an increased prevalence of biological signs of kidney dysfunction in population groups non-occupationally exposed to heavy metals. The study was run in two industrial areas known to be highly contaminated by cadmium, lead and other heavy metals, viz. Stolberg and Duisburg. Düsseldorf was selected as a reference area. As a study population we selected 65- and 66-year-old women (n = 286) who had spent the major part of their lives in one of these areas. The average cadmium levels in blood (CdB) and urine (CdU) revealed significant differences in exposure to cadmium in the order Stolberg greater than Duisburg greater than Düsseldorf. Serum creatinine levels were, on average, significantly higher in the Stolberg group than in the Duisburg and Düsseldorf groups. However, with respect to the urinary excretion of low molecular weight proteins (beta 2-microglobulin, retinol-binding protein), albuminuria, total proteinuria, aminoaciduria, phosphaturia and some other biological findings, no significant differences between the study populations were noted. Similarly, the prevalence of clinically-confirmed hypertension as well as the relative frequency of hypertensive subjects (systolic greater than or equal to 160 and/or diastolic greater than or equal to 95 mm Hg) did not differ significantly among the three study groups. There was no exposure-response relationship between CdU and tubular proteinuria in the range of the CdU-levels found (0.1 to 5.2 micrograms/g creatinine). However, albuminuria tended to be increased at CdU levels greater than 2 micrograms/g creatinine.

Aged↗
PubMed1983

Neuropsychological studies in children with elevated tooth-lead concentrations. II. Extended study.

Results from neuropsychological tests, collected under double-blind-precautions, were evaluated for 115 schoolage children (mean age: 9.4 years) living in a lead smelter area (Stolberg, FRG). Tooth-lead concentrations (PbT) from shed incisor teeth as measures of longtime lead-exposure were available for these children (mean = 6.16 ppm; range: 1.9-38.5 ppm), and for 83 of them blood-lead concentrations (PbB) were available as well (mean = 14.3 micrograms/dl; range: 6.8-33.8 micrograms/dl). The following functional capacities were tested: intelligence (German WISC), perceptual-motor integration (Göttinger Formreproduktionstest = GFT, Diagnosticum for Cerebralschädigung = DCS), reaction performance (Wiener Determinationsgerät), finger-wrist tapping-speed, and repetitive cancellation-performance (Differentieller Leistungstest). In addition standardized behavior ratings were obtained by the examiners, the mothers, and the teachers. Multiple stepwise regression-analysis (forced solution) was calculated for outcome-variables and Pb-tooth, including age, sex, duration of labor, and socio-hereditary background as covariates. Significant (P less than 0.05) or near-significant (P less than 0.1) association was established between Pb-tooth and GFT-performance (errors), reaction-performance (false reactions), and four behavioral dimensions as rated by the mothers, namely distractability, restlessness, lack of information, and wasting of time; the proportion of explained variance never exceeded 6%, however. No significant association was found between PbT and WISC verbal-IQ after the effects of "socio-hereditary background" had been eliminated, although there was still a tendency for high level-children (PbT greater than 10 ppm) to be inferior to low level-children (PbT less than or equal to 4 ppm) by 4.6 IQ-points after correction for confounding. There was a near-significant, inverse relationship between finger-wrist tapping-speed and Pb-blood. The results are discussed within the framework of attention-deficit disorder, and compared to neurobehavioral Pb-effects from animal-experiments, which provide suggestive evidence for a causal relationship between developmental lead-exposure and certain neurobehavioral deficits.

Child↗
PubMed1983

Repeated surveillance of exposure to thallium in a population living in the vicinity of a cement plant emitting dust containing thallium.

From 1979 to 1981, several medical surveys were carried out among a population living in the vicinity of a cement plant that emitted dust containing thallium until August, 1979. Air, soil, plants, and domestic animals in the area were contaminated by thallium and this led to an increased intake of thallium in the population, mainly due to the consumption of home-grown vegetables and fruit. In order to assess the degree of the individuals' exposure to thallium, thallium levels in 24-h urine samples (TlU) were determined. Three surveys were carried out from September to December, 1979 to assess the degree of thallium exposure of different parts of the general population. Subjects with relatively high exposure, as indicated by the results of the above mentioned population surveys, or those suffering from health disorders that might be related to an increased intake of thallium, were reexamined several times from 1979-1981. Special attention was also given to children attending a kindergarten situated about 0.5 km from the cement plant. As compared to an "unexposed" reference population (mean TlU: 0.3 microgram/l), the majority of the population living in the cement plant area had significantly elevated urinary thallium levels (range: less than 0.1-76.5 micrograms/l) indicating a substantially increased environmental exposure. A reduction of the intake of thallium was mainly achieved by the fact that the population, as advised by the authorities, largely avoided the consumption of home-grown, potentially contaminated foodstuffs. Reports on the teratogenicity of thallium in certain animal species caused great concern that thallium might have exerted teratogenic effects on the newborn of women exposed to thallium during pregnancy. Therefore, an investigation of children born between January, 1978 and August, 1979 (n = 297) was carried out. Although the number of congenital malformations was greater than expected, we conclude, considering carefully all data available, that there is likely no causal relationship between thallium and the occurrence of congenital malformations in the children investigated.

Abnormalities, Drug-Induced↗
PubMed1983

Levels of cadmium and lead in blood in relation to smoking, sex, occupation, and other factors in an adult population of the FRG.

Levels of cadmium (CdB) and lead (PbB) were determined in the blood of 579 60-65 year-old residents of Cologne and two small cities near Cologne. CdB-levels in cigarette smokers are on the average 3-4 times higher than in non-smokers (geometric means: non-smokers, 0.44 micrograms/l; less than or equal to 10 cigarettes/d, 1.16 micrograms/l; greater than 10 cigarettes/d, 1.85 micrograms/l). The results indicate that, with regard to the internal dose, cadmium exposure via smoking may contribute even more than does exposure via food. PbB-levels (geometric mean: 8.49 micrograms/100 ml; range: 2.9-30.3 micrograms/100 ml) are in the acceptable range as defined by the CEC reference values. Male smokers have on the average slightly higher PbB-levels than male non-smokers. In women PbB-levels are on the average lower than in men.

Aged↗
PubMed1982

Lead in deciduous teeth of children living in a non-ferrous smelter area and a rural area of the FRG.

Lead concentrations were measured in the deciduous teeth (incisors) of 302 children living in a lead-smelter area in the FRG (Stolberg, Rheinland) and of 86 children living in a nonpolluted rural area (Gummersbach, Bergisches Land). Blood lead levels were determined in 83 of the children living in the lead-smelter area. On average, tooth lead levels of children living in the smelter area (mean: 6.0 microgram/g; range: 1.49-38.5 microgram/g) were significantly higher than those of children living in the rural area (mean: 3.9 microgram/g; range: 1.6-9.4 microgram/g). Blood lead levels were 6.8-33.8 microgram/100 ml (mean: 14.3 microgram/100 ml). Children of lead-workers had on average higher tooth lead and blood lead levels than children of people who were not lead-workers. Tooth lead levels increased with increasing duration of residence in the lead-smelter area and with the degree of local environmental pollution by lead, as indicated by the lead content of the atmospheric dust fall-out around the children's homes. The correlation coefficient of tooth lead vs blood lead was 0.47. The intra-individual variability of tooth lead levels was low (r = 0.86), and tooth lead levels of brothers and sisters were similar (r = 0.75), suggesting that tooth lead may be used as a representative and reliable indicator of long-term lead exposure.

Child↗
PubMed1982

Neuropsychological studies in children with elevated tooth-lead concentrations. I. Pilot study.

In contrast to blood-lead (PbB), tooth-lead concentrations (PbT) provide retrospective information about longterm, cumulative childhood lead-intake. From a basic sample of 458 school age children from the city of Duisburg (FRG), whose lead-concentrations in shed incisor teeth had been measured (means = 4.6 ppm; range: 1.4-12.7 ppm), two extreme-groups of 26 children each (mean age: 8.5 years) with low (means = 2.4 ppm) and elevated (means = 9.2 ppm) PbT were selected. After pair-matching both groups for age, sex, and father's occupational status, these children were tested under double-blind precautions for intellectual performance (German WISC), for perceptual-motor integration (Göttinger Formreproduktionstest = GFT, Diagnostikum für Cerebralschädigung = DCS, Benton-Test), and for gross motor-coordination (Körper-Koordinationstest für Kinder = KTK). Significant (P less than 0.05) inferiority of the lead-children was found in two tests of perceptual-motor integration (increased GFT-errors; lower success rate for DCS). In addition a near significant (P less than 0.1) reduction of 5-7 IQ-points was determined in these children. Although this pilot study has provided some evidence for an association between childhood lead-exposure and neuropsychological impairment, this association cannot yet be considered proven, because the observed effects were discrete and statistically confirmed only in part, and because there was a slight prevalence of perinatal risk factors in the lead group. Further research to clarify the issue is necessary.

Behavior↗
PubMed1982

Membrane-associated nucleotide pyrophosphatase activity on leucocytes from different compartments.

The distribution of membrane-associated nucleotide pyrophosphatase activity has been investigated on mouse leucocytes of different origin. It is shown that enzyme-specific activity is higher on bone-marrow cells than on cells derived from peripheral organs. Since thymus lymphocytes show the lowest activity, it is obvious that the thymus environment can influence the enzyme activity on bone-marrow stem cells which have entered this organ. Spleen cells from thymus-deficient nude mice displayed more enzyme activity than spleen cells from normal mice, although the percentage of lymphocytes was similar in both donor-cell populations.

Animals↗