Sol-gel-derived iron oxide thin films on silicon: surface properties and interfacial chemistry.

Uniform high-quality iron oxide thin films can be formed from the spin coating of iron oxide/hydroxide sol-gels on a silicon substrate. Thermal processing of the films at temperatures of approximately 300 degrees C results in the transformation of films into a ternary layered structure with iron oxide, Fe(2)O(3), at the surface, characterized by Mossbauer spectroscopy, and reduced, metallic iron characterized by depth profiling of the surface by X-ray photoelectron spectroscopy as a function of Ar(+) etching. Imaging of the etched surface by scanning electron microscopy reveals two distinct regions at the interface, nanoparticles that are very iron-rich separated by an unstructured region that is somewhat less iron-rich. The results demonstrate a synthetic protocol for the spontaneous formaton of a ternary layered structure from a simple one-step preparation.

Lead and cadmium in the hair and blood of children from a highly industrial area in Poland.

The study covered the children living in Miasteczko Slaskie, near the largest Zn plant in Poland. This is one of the areas highly contaminated with heavy metals. The subjects were 158 children aged from 8 to 15 (98 boys and 60 girls). The average Pb and Cd levels in the hair of the entire children population was 8.21 +/- 5.59 microg/g, and 0.91 +/- 0.61 microg/g, and the average Pb and Cd levels in their blood were 14.32 +/- 3.98 and 0.52 +/- 0.24 microg/dL(-1), respectively. The children population under investigation was divided according to their sex. The hair of the girls contained, on the average, 5.06 +/- 2.81 microg/g of Pb and 0.74 +/- 0.48 microg/g of Cd and the hair of the boys 10.14 +/- 6.0 microg/g of Pb and 1.01 +/- 0.65 microg/g of Cd. The blood of the girls contained, on the average, 13.23 +/- 4.23 microg/dL of Pb and 0.48 +/- 0.21 microg/dL of Cd, and the blood of the boys 14.99 +/- 3.68 microg/dL of Pb and 0.55 +/- 0.24 microg/dL of Cd. Thus, both the hair and blood of the boys accumulated more Pb and Cd than those of the girls. A correlation between the concentrations of these metals was confirmed.

Blood lead levels in industrial workers in Poland.

Occupational exposure to lead occurs in about 1,300 enterprises in Poland. According to the 1994 data, based on the reports of the State Sanitary Inspectorate, 1,970 persons were employed at that time under conditions of exposure exceeding the Polish MAC level of 0.050 mg/m3. The measurements of workers' blood lead concentrations (Pb-B) were carried out only in 90 factories. In 1996, the Minister of Health and Social Welfare issued a directive stating that the Pb-B determinations in employees occupationally exposed to lead are compulsory. The aim of the present study was to assess lead exposure of workers employed in different branches of the Polish economy, based on Pb-B determinations. The measurements were performed on 2,324 male and 165 female workers of 13 different types of industry, including manufacture of crystal glass, battery industry, copper and zinc smelters, welding in a repair shipyard and some other workposts under conditions of lead exposure. The results of the determinations indicate that exposure to lead continues to be a serious problem in Polish industry. Pb-B concentrations exceeded the newly introduced Polish biological exposure index (BEI) value of 500 micrograms/l for men workers in about 30% of workers examined in 1996. In about 65% of females under 45 years of age the Pb-B concentrations were higher than 300 micrograms/l recommended as BEI for this age group. Considering the WHO-recommended health-based maximum individual biological action level of 400 micrograms/l, the percentage of the employees for whom higher values were found amounted to about 45% for men workers. The results point to the necessity of enforcing the implementation of Pb-B determinations according to the ministerial ordinance as well as of removing from exposure the workers with Pb-B levels exceeding the present BEI values. The improvement of working conditions and the implementation of health education for workers are also the actions to be promptly undertaken. In order to achieve these goals a close cooperation is required between the State Sanitary Inspectorate, the institutes of occupational health as well as the employers and trade unions.

Ethanol inhibits cadmium accumulation in brains of offspring of pregnant rats that consume cadmium.

The present study was designed to test the effect of ethanol on cadmium accumulation in tissues of pregnant rats and their offspring. Starting 10 days before mating and continuing until parturition, ethanol (10% v/v) was present in the drinking water of half the rats. Cadmium chloride (CdCl2; 50 ppm) was present in the water of half the rats (+/- ethanol) from the fist day after mating until parturition. On the day of parturition cadmium accumulated to a moderate level in bone (7.3 micrograms/g tissue, wet weight; this and other values, P < 0.05 vs. control), liver (12.9 micrograms/g) and kidney (13.0 micrograms/g) of dams, while the brain had only a low level of cadmium (0.45 microgram/g). In offspring at 6 weeks cadmium accumulated in high amounts in the brain (34.0 micrograms/g), bone (15.9 micrograms), kidney (78.2 micrograms/g) and particularly the liver (227.3 micrograms/g). Ethanol, given simultaneously with cadmium, inhibited cadmium accumulation in brain (1.8 micrograms/g), bone (3.28 micrograms/g) and kidney (61.3 micrograms/g), but enhanced cadmium accumulation in liver (408.7 micrograms/g). At 12 weeks there were only residual levels of cadmium in all tissues of offspring. These findings demonstrate an interaction between 2 known teratogenic agents, with ethanol conferring protection of the brain from cadmium accumulation. The nature of this interaction is not known, but is likely to be related to ethanol induction of metallothionein in the liver and placenta.

[Exposure to lead in the Silesian region]. / Narazenie na olów w przemysle Slaskim.

The work is based on the determination of blood lead levels performed by the Central Laboratory of Toxicology of Heavy Metals in workers employed in various plants in the Katowice voivodship. The method of atomic absorption (ASA) was used for the determination. The Laboratory has participated successfully in the inter-laboratory programme of quality assurance. The study revealed that the highest exposure to lead occurs in overhaul and dismantle plants (group II) which work for large industrial establishments of non-ferrous metals (group I). Among establishments of group I higher exposure was found in raw material departments. Workers of certain professions such as fitters, refiners, smelters are particularly exposed regardless of the production profile of plants. The blood lead level is an important marks of occupational exposure to lead. Examinations should be performed only by laboratories involved in the programme of quality assurance of laboratory measurements.

[Thyroxine (T4) levels in workers exposed to lead]. / Stezenie tyroksyny (T4) u ludzi pracujacych w stycznosci z olowiem.

Thirty men occupationally exposed to lead have been examined. The selection of subjects was based on increased lead poisoning indices as well as on the data proving there had been no thyroid disease incidence noted prior to the lead poisoning. Each of the subjects underwent determination of T4 concentration simultaneously with the measurement of three basic indicators of lead poisoning: ALA in urine and ZPP and Pb in blood. Three T4 concentration ranges have been obtained therefore all the cases have been divided into three groups: I increased T4 concentration: II normal T4 concentration; III decreased T4 concentration. In each group T4 concentrations have been compared with the poisoning indicators. The highest poisoning indicators have been found in group II exhibiting normal T4 concentrations (43.33% of cases). It differed significantly from group III (50.0% of cases) exhibiting decreased T4 concentrations. The determination values in group I (increased T4 concentrations) have been excluded from statistical calculations, as there were too few cases (6.67%). The discrepancy of T4 results, their pathological picture at lower values of poisoning indices evidence that the establishment of Pb effects upon thyroid function would call for the determination of a number of additional factors possibly affecting the mechanism handling this phenomenon.

Granulocyte viability test in children from an environment with heavy metal pollution.

In a group of 43 school-children living near a zinc plant, the test of granulocyte viability by the method of Cocchi et al, the lead level by flame atomic absorptiometry, and the level of erythrocyte zinc-protoporphyrin by the fluorimetric method were determined in peripheral blood. The mean result of the granulocyte viability test was 6.49%. In 18 children, the proportion of abnormal granulocytes was raised abnormally above 6.0%. The lead level was in the range from 14.1 to 53 micrograms/dl, and the level of erythrocyte ZPP was from 0.3 to 2.1 micrograms/g Hb. No correlation was found between the results of the granulocyte viability test and the blood lead level. The result of a comparison with the ZPP value was of borderline significance (p = 0.05).

[Erythrocyte zinc protoporphyrin concentration in occupational exposure to lead]. / Stezenie cynkowej protoporfiryny w krwinkach czerwonych w zawodowym narazeniu na olów.

The paper is aimed at analysing the correlation between zinc protoporphyrin and hemoglobin concentrations and lead level in blood and the correlation between hemoglobin concentration and zinc protoporphyrin content in erythrocytes. The studies covered 73 men aged 19-58, exposed for 1-15 years. The control group was composed of 20 healthy men, age interval 17-66, with no occupational exposure to lead. A statistically significant difference for zinc protoporphyrin was demonstrated between the control and examined groups. No significant difference was found in hemoglobin concentration between those groups. On the other hand, a highly statistically significant increase with time was found in zinc protoporphyrin in erythrocytes. The dependence of zinc protoporphyrin concentration on lead concentration increases with employment length, reaching the correlation coefficient 0.6 after more than 9 years. No correlation was found between hemoglobin and lead concentrations in blood. Neither was it found between hemoglobin and zinc protoporphyrin concentrations.