Platinum levels in nasal lavage fluid as a biomarker for traffic-related exposure and inflammation in children.

Platinum (Pt) is a well-known constituent of particles emitted by catalytic converters during car operation. To evaluate Pt as a potential marker for traffic related particle exposure, we investigated Pt content along with metals vanadium (V) and chromium (Cr) in coarse and fine particulate matter (PM), sampled in four areas with different traffic density, as well as in the nasal lavage (NAL) of 67 children (average age: 6 years) living in these areas. The different sites were characterised by significant differences in air pollutants including PM, NO, NO(2), CO and Cr, but differences in V or Pt were absent. No significant differences in neutrophil and epithelial cell counts or concentrations of the neutrophil chemoattractant interleukin-8 (IL-8) were found in the NAL of children living in the different areas. In addition, the concentrations of V, Cr and Pt, which were detectable in 64%, 73% and 93% of the individuals, respectively, did not differ between the different locations. However, in the NAL of the children, a significant correlation between Pt and the number of neutrophils/ml (r=0.40, p<0.001) as well as of epithelial cells/ml (r=0.41, p<0.001) was found. No relation was present between nasal inflammation and nasal Cr levels, whereas a relatively weak association was observed between V and epithelial cells counts (r=0.30, p=0.018). In conclusion, our data suggests a role for nasal lavage Pt as a candidate biomarker for traffic-related PM, which is able to induce inflammation in the upper respiratory tract.

Cognitive and sensorimotor functions in 6-year-old children in relation to lead and mercury levels: adjustment for intelligence and contrast sensitivity in computerized testing.

Within a larger environmental health screening program neurobehavioral measures were taken in 384 6-year-old children (mean age 74 months) in the cities of Leipzig, Gardelegen, and Duisburg. Lead concentrations in venous blood samples (PbB) and urinary mercury excretion in 24-h samples (HgU) were measured as markers of environmental exposure by electrothermal AAS. Dependent variables included two subtests from the WISC [vocabulary (V) and block design (BD)] as well as five tests from the NES2 [pattern comparison, pattern memory, tapping, simple reaction time, and the continuous performance test (CPT; child version)]. In addition, visual functions [visual acuity (TITMUS-test) and contrast sensitivity (FACT)] were tested as covariates. The overall average PbB (geometric mean) was 42.5 microg/l (upper 95% value = 89 microg/l). The overall average mercury excretion (HgU) was 0.16 microg/24 h. Whereas no significant or borderline associations between HgU and any of the target variables was found, significant negative associations were observed between PbB and verbal intelligence (WISC vocabulary but not WISC Block Design) and false-positive responses (false alarms), as well as false-negative responses (miss) in the CPT. Whereas parental education was the most important confounder for WISC performance, visual contrast sensitivity and computer familiarity also proved predictive for performance in several computer-based NES subtests. It is concluded that non-IQ measures, namely measures of sustained attention, are negatively affected in children with 95% of blood-lead levels below 90 microg/l, even after adjustment for intelligence and contrast sensitivity, whereas the causative role of lead in altering IQ functions remains somewhat equivocal, because important covariates could not be controlled for.

Visual functions in 6-year-old children in relation to lead and mercury levels.

Within a larger comparative environmental health screening program in East and West Germany we investigated functions of the developing visual system in field experiments in a total of 384 children living in three different areas. Visual functions were assessed neurophysiologically by visual-evoked potentials (VEPs) and psychophysically by measuring the contrast sensitivity (CS). Blood lead concentrations and urinary mercury levels were used as markers of environmental and/or amalgam-derived exposure, respectively. The relationships among lead and mercury concentrations and the neurophysiological and psychophysical outcomes were investigated by means of linear regression analysis. After adjusting for confounding effects, statistically significant lead-related changes were found only for some of the VEP interpeak latencies, while some of the CS values were significantly reduced with increasing mercury concentrations. All other outcome variables were not significantly related to lead or mercury levels. It is concluded that even at blood lead levels in the range of 14 to 174 micrograms/l and at very low urinary mercury levels subtle changes in visual system functions can be measured.

Strain differences in tissue concentrations of mercury in inbred mice treated with mercuric chloride.

Tissue concentrations of mercury were determined by cold vapor atomic absorption spectrometry in different inbred mouse strains after continuous treatment with HgCl2 (3 weekly sc injections of 0.5 mg/kg bw) for up to 12 weeks. Except for the thymus, in which steadily increasing mercury concentrations were found, in steady state levels of mercury were reached in blood and liver after 4 weeks and in spleen and kidney after 8 weeks. In the closely related strains C57BL/6, B10.D2, and B10.S, which differ only or primarily at the major histocompatibility complex, mercury concentrations in blood and liver were about twofold lower and renal concentrations were about three- to fivefold lower than those detected in strains A.SW and DBA/2. Another strain difference was observed in the spleen: after 8 and 12 weeks of continuous HgCl2 treatment, mercury concentrations in the spleen of strains A.SW, C57BL/6, and B10.S were significantly higher than those in strains DBA/2 and B10.D2. The strain difference in the spleen, an organ of the immune system, correlates with the susceptibility to the HgCl2-induced systemic autoimmune syndrome in mice in that the strains showing a higher mercury accumulation in the spleen are susceptible to this form of chemically induced autoimmunity, whereas the strains with lower mercury concentrations in the spleen are resistant.

[Lead and cadmium content in deciduous teeth of children of Stolberg and other cities of North-Rhine-Westphalia: a chronological trend 1968-1993]. / Blei- und Cadmiumgehalte in Milchschneidezähnen von Kindern aus Stolberg und anderen Städten Nordrhein-Westfalens: Entwicklungstrend 1968-1993.

The levels of lead and cadmium were determined in deciduous teeth (incisors only) of children living in Stolberg and some other cities located in North-Rhine-Westfalia, Germany. The Stolberg children were born in 1968-1973 (group 1; n = 103) and 1982/1983 (group 2; n = 103). The other children (n = 109) were born between 1979 and 1986. All teeth were analysed within the same analytical series by atomic absorption spectrometry (AAS). The results show that the average levels of lead and cadmium in milk teeth have decreased significantly in the time period from 1970 to 1990. Considering the Stolberg children the fall of tooth lead was about 50% and the fall of tooth cadmium was about 60%. Children from other cities show a comparable decrease of tooth lead and tooth cadmium. The results indicate that a significant decrease of the lead body burden and cadmium body burden of children and probably also of the general population of Germany has occurred during the last years.

Persistent increases in scotopic B-wave amplitudes after lead exposure in monkeys.

The electroretinogram (ERG) of rhesus monkeys was re-examined more than 2 years after termination of lead exposure when mean blood lead levels had declined to values below 10 micrograms dl-1. Amplitude of the b-wave was increased by lead exposure at scotopic conditions, while there were no changes in photopic signals. The lead-induced effects were similar to alterations detected during the treatment phase and, thus, are not dependent on current exposure. Taking into account, that dopamine antagonists cause similar changes in the ERG, it is suggested that the observed effects may be mediated by a permanent change of dopaminergic processes since immunoreactivity also revealed adverse effects on the dopaminergic system in the retinae of these monkeys.

Internal lead and cadmium exposure in 6-year-old children from western and eastern Germany.

Lead and cadmium levels in blood and deciduous teeth (shed incisors only) of 6-year-old German children were determined in 1991 in a large epidemiological study carried out in rural and urban areas of western Germany (Duisburg, Essen, Gelsenkirchen, Dortmund, Borken) and eastern Germany (Leipzig, Halle, Magdeburg, Osterburg, Gardelelegen, Salzwedel). In total, blood lead and cadmium levels of 2311 German children and tooth lead and cadmium levels of 790 German children were analyzed. Blood lead levels were generally low in all study areas with geometric means between 39.3 micrograms/l and 50.8 micrograms/l in the western German and between 42.3 micrograms/l and 68.1 micrograms/l in the eastern German study areas. The mean blood lead level of Turkish children (n = 213) living in the western German study areas was 50.1 micrograms/l and thus 5.6 micrograms/l higher than the overall geometric mean of the western German children. The higher exposure may be explained by a higher oral uptake from food and different living conditions. These children were excluded from multiple regression analysis because they were all living in the western study areas. The mean tooth lead levels ranged between 1.50 and 1.74 micrograms/g in the western and between 1.51 micrograms/g and 2.72 micrograms/g in the eastern study areas. Thus, they show a distribution pattern similar to blood. Blood and tooth lead levels were higher in urban than in rural areas and higher in the eastern German than in the western German study areas. With regard to the blood and tooth cadmium concentrations, no significant differences between the study areas could be found.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurobehavioral and neurophysiological observations in six year old children with low lead levels in East and West Germany.

Within a larger comparative environmental health screening program in East and West Germany neurobehavioral and neurophysiological measures were taken in 367 six year old children in Leipzig (N = 179), Gardelegen (N = 68), and Duisburg (N = 120). Lead concentrations from venous blood samples (PbB) and from deciduous teeth (PbT) were measured as markers of environmental lead exposure by electrothermal AAS. Dependent variables included four subtests from NES1 (tapping, reaction time, pattern comparison, and Benton visual retention), as well as VEP-latencies (N2, P100, N3) evoked by checkerboard patterns of different size and contrast. The overall median blood lead-concentration was 5 micrograms/dl (range: 1.3-19.0 micrograms/dl), and the corresponding tooth lead-concentration was 2 micrograms/g (0.2-14 micrograms/g). The 95-percentile of the overall frequency distribution for PbB was below 10 micrograms/dl. Associations between markers of lead-exposure and neurobehavioral or neurophysiological outcome were assessed by means of multiple linear or logistic regression analyses. After adjusting for relevant confounders/covariates significant (p < 0.05) Pb-related deficit was found for tapping and pattern recognition with respect to PbB but not PbT. No such associations could be established for VEP-latencies. These results are compatible with the hypothesis that subtle neurobehavioral dysfunction in children may be associated with very low PbB.

[Heavy metal pollution of soil and garden products of Stolberg home gardens and lead and cadmium pollution of small farms in Stolberg]. / Untersuchungen zur Schwermetallbelastung von Böden und Gartenprodukten aus Stolberger Hausgärten und zur Blei- und Cadmiumbelastung von Kleingärtnern aus Stolberg.

Cadmium, lead and zinc were determined in garden soils and vegetable products from private gardens located in a lead/zinc smelter area (Stolberg, Germany). At the same time lead and cadmium were measured in blood and urine samples collected from 90 garden owners. Inspite of extraordinary high levels of cadmium and lead in garden soils and vegetables, blood lead, blood cadmium and urine cadmium levels were not or only slightly elevated in the gardeners when compared to a reference group of subjects from the same area who did not consume home-grown vegetables and fruits. The results show that high levels of pollutants in soil and vegetables are not necessarily associated with an increased burden of pollutants in the human body, and that the transfer of pollutants from soil to humans might have been overestimated in some cases. Moreover, the results underline the preventive character of the guideline values presently applied with respect to the evaluation of soil contaminants.

[Lead and cadmium burden of children in Stolberg]. / Untersuchungen zur Blei- und Cadmiumbelastung von Kindern aus Stolberg.

In 1989, blood lead and blood cadmium levels were determined in 229 children (age 6-7 years) living at Stolberg (West Germany). The area of Stolberg is heavily polluted by lead and other toxic metals due to emissions from a large primary lead smelter. The mean blood lead level was 6.3 micrograms/dl (range 2.6-15.5 micrograms/dl) and the mean blood cadmium level was 0.14 microgram/l (range less than 0.1-0.5 microgram/l). The blood lead levels were affected by the following factors: living in the central urban area with high lead levels in dust fall-out; living in a family of foreigners; involuntary inhalation of smoke at home; living in a family with a family member employed in the lead industry. Children from foreign families also had higher blood cadmium levels than children from German families. However, inhalation of tobacco smoke did not affect the blood cadmium levels. In total, there has been a significant decline of blood lead and blood cadmium levels among children from the Stolberg area since 1982.

[Blood lead and blood cadmium concentrations in 55-66-year-old women fron different areas of Nordrhein-Westfalen--chronological trends during 1982-1988]. / Blutblei- und Blutcadmiumkonzentrationen bei 55-66jährigen Frauen aus verschiedenen Gebieten Nordrhein-Westfalens--Entwicklungstrends 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.

[Lead and cadmium content in deciduous incisors of children from Duisburg and Gummersbach--developing trend 1976-1988]. / Blei- und Cadmiumgehalte in Milchschneidezähnen von Kindern aus Duisburg und Gummersbach--Entwicklungstrend 1976-1988.

Shed deciduous teeth (incisors only) were collected from children (n = 199) living in Duisburg and Gummersbach (F.R.G.) in 1976 and 1988. The teeth were analysed for lead and cadmium. Considering all teeth, there was a significant of tooth lead and tooth cadmium from 1976 to 1988. The reduction was between -40 and -50% for tooth lead and -45% for tooth cadmium. Regarding tooth lead, the reduction was more pronounced in children from Duisburg, an area heavily polluted by lead and other heavy metals due to the presence of large iron and steel plants and a large lead-/zinc smelter. Teeth from the upper jaw were found to have higher lead and calcium concentrations than teeth from the lower jaw. Moreover, it was found that central incisors had higher lead and cadmium concentrations than lateral incisors. Even after the effects of jaw and tooth type had been allowed for, the reduction of tooth lead and tooth cadmium could be demonstrated. Children living in pre-war houses were found to have higher tooth lead and tooth cadmium levels than children living in post-war houses. The higher lead and cadmium burden of children living in old houses seems to be related to a higher degree of exposure to lead and cadmium via drinking water resulting from the release of these metals from old zinc-plated steel water pipes. In total, our results indicate that there has been a significant decrease of lead and cadmium exposure in West-German children since the mid-70s. The reduction of tooth lead levels parallels the decrease of blood and bone lead levels, which has been observed in previous studies.

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.