Krystyna Pawlas

Blood cadmium, mercury, and lead in children: an international comparison of cities in six European countries, and China, Ecuador, and Morocco.

Childrens blood-lead concentration (B-Pb) is well studied, but little is known about cadmium (B-Cd) and mercury (B-Hg), in particular for central Europe. Such information is necessary for risk assessment and management. Therefore, we here describe and compare B-Pb, B-Cd and B-Hg in children in six European, and three non-European cities, and identify determinants of these exposures. About 50 school children (7-14 years) from each city were recruited (totally 433) in 2007-2008. Interview and questionnaire data were obtained. A blood sample was analyzed: only two laboratories with strict quality control were used. The European cities showed only minor differences for B-Cd (geometric means 0.11-0.17 μg/L) and B-Pb (14-20 μg/L), but larger for B-Hg (0.12-0.94 μg/L). Corresponding means for the non-European countries were 0.21-0.26, 32-71, and 0.3-3.2 μg/L, respectively. For B-Cd in European samples, traffic intensity close to home was a statistically significant determinant, for B-Hg fish consumption and amalgam fillings, and for B-Pb sex (boys higher). This study shows that European city childrens B-Cd and B-Pb vary only little between countries; B-Hg differs considerably, due to varying tooth restoration practices and fish intake. Traffic intensity seemed to be a determinant for B-Cd. The metal concentrations were low from a risk perspective but the chosen non-European cities showed higher concentrations than the cities in Europe.

Modification by the genes ALAD and VDR of lead-induced cognitive effects in children.

Lead has negative effect on cognitive functions in children. However, individuals differ in susceptibility. One possible explanation is a genetic predisposition. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD) and the vitamin D receptor (VDR) genes may modify lead metabolism and neurotoxicity, but information regarding the central nervous system is very limited. The aim of the study was to determine whether ALAD and VDR polymorphisms modify blood lead (B-Pb), and the association between B-Pb and cognitive function (IQ) in children. In 2007-2010 a cohort of 175 children (age 6-10years, mean 7.8) was recruited in Southern Poland, tested for IQ (Wechsler intelligence scale) and analyzed for B-Pb (range 9.0-221; mean 46.6μg/L), ALAD (RsaI, MspI) and VDR (FokI, BsmI, TaqI) polymorphisms. ALAD or VDR genotypes were not associated with B-Pb. B-Pb was non-significantly negatively associated with full scale IQ (r(S)=-0.11; P=0.14), and significantly with performance subscale results (r(S)=-0.19; P=0.01). The ALAD RsaI polymorphism modified the relationship between full scale IQ and B-Pb: RsaI T carriers had a steeper slope compared to CC homozygote carriers (β coefficient -0.06 vs 0.32, respectively, P for interaction <0.001, adjusted for the childs age, mothers education and family income). This means that with increasing B-Pb with 1μg/L, T carriers demonstrate 0.06 score lower IQ. For the VDR BsmI, B carriers had a steeper slope than the bb homozygotes carriers (β coefficient -0.08 vs 0.16, respectively, P for interaction=0.001), and similar effect was found for TaqI t carriers vs TT homozygotes (P for interaction=0.02). For ALAD MspI and VDR FokI there was no significant modification. The ALAD RsaI, VDR BsmI and TaqI polymorphisms modified the relationship between IQ and B-Pb. Hence, there is a fraction of the population, which is particularly sensitive to lead neurotoxicity.

Cadmium, mercury and lead in the blood of urban women in Croatia, the Czech Republic, Poland, Slovakia, Slovenia, Sweden, China, Ecuador and Morocco

ObjectivesThe aim of the study was to make an international comparison of blood levels of cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) of women in seven European, and three non-European cities, and to identify determinants.Materials and MethodsAbout 50 women (age: 46–62) from each city were recruited (totally 480) in 2006–2009. Interview and questionnaire data were obtained. Blood samples were analysed in one laboratory to avoid interlaboratory variation.ResultsBetween the European cities, the B-Pb and B-Cd results vary little (range of geometric means: 13.5–27.0 μg/l and 0.25–0.65 μg/l, respectively); the variation of B-Hg was larger (0.40–1.38 μg/l). Between the non-European cities the results for B-Pb, B-Cd and B-Hg were 19.2–68.0, 0.39–0.99 and 1.01–2.73 μg/l, respectively. Smoking was a statistically significant determinant for B-Cd, while fish and shellfish intakes contributed to B-Hg and B-Pb, amalgam fillings also contributed to B-Hg.ConclusionsThe present results confirm the previous results from children; the exposure to lead and cadmium varies only little between different European cities suggesting that other factors than the living area are more important. The study also confirms the previous findings of higher cadmium and lead levels in some non-European cities. The geographical variation for mercury is significant.

A multicenter study on the audiometric findings of styrene-exposed workers

Abstract Objective: The objective of this study was to evaluate hearing loss among workers exposed to styrene, alone or with noise. Design: This cross-sectional study was conducted as part of NoiseChem, a European Commission 5th Framework Programme research project, by occupational health institutes in Finland, Sweden, and Poland. Study sample: Participants’ ages ranged from 18–72 years (n = 1620 workers). Participants exposed to styrene, alone or with noise, were from reinforced fiberglass products manufacturing plants (n = 862). Comparison groups were comprised of workers noise-exposed (n = 400) or controls (n = 358). Current styrene exposures ranged from 0 to 309 mg/m3, while mean current noise levels ranged from 70–84 dB(A). Hearing thresholds of styrene-exposed participants were compared with Annexes A and B from 2. Results: The audiometric thresholds of styrene exposed workers were significantly poorer than those in published standards. Age, gender, and styrene exposure met the significance level criterion in the multiple logistic regression for the binary outcome ‘hearing loss’ (P = 0.0000). Exposure to noise (<85 dBA p = 0.0001; ≥85 dB(A) p = 0.0192) interacted significantly with styrene exposure. Conclusions: Occupational exposure to styrene is a risk factor for hearing loss, and styrene-exposed workers should be included in hearing loss prevention programs. Sumario Objetivo: El objetivo de este estudio fue evaluar la pérdida auditiva en trabajadores expuestos a estireno, aisladamente o con ruido. Diseño: Se realizó este estudio transversal como parte del NoiseChem, Comisión Europea del 5°. Proyecto Marco de investigación, en institutos de salud ocupacional de Finlandia, Suecia y Polonia. Muestra de estudio: La edad de los participantes fue de 18–72 a os (N = 1,620 trabajadores). Los trabajadores (n = 862) estuvieron expuestos a estireno, solo o con ruido, en plantas de fabricación de productos de fibra de vidrio reforzada. Los grupos de comparación fueron trabajadores expuestos a ruido (n = 400) y los de un grupo control (n = 358). Las exposiciones reales a estireno variaron de 0 a 309 mg/m3, mientras que los niveles reales de ruido, variaron de 80–84 dB(A). Se compararon los niveles de audición de los participantes expuestos a estireno con los de los anexos A y B de 2. Resultados: Los umbrales audiométricos de los trabajadores expuestos a estireno, fueron significativamente más pobres que los que se han publicado como estándar. La edad, el género y la exposición a estireno, cubrieron los criterios de niveles de significatividad de la regresíón logística múltiple para los resultados binarios de la “perdida auditiva” (P = 0.0000). La exposición a ruido (<85 dB(A) p = 0.0001; ≥85 dB(A) p = 0.0192) interactu significativamente con la exposición a estireno. Conclusiones: La exposición ocupacional a estireno es un factor de riesgo de pérdida auditiva por lo que los trabajadores expuestos a estireno deben ser incluidos en programas de prevención de pérdidas auditivas.

Influence of selenium and/or magnesium on alleviation alcohol induced oxidative stress in rats, normalization function of liver and changes in serum lipid parameters.

The aim of this study was to evaluate the attenuating effect of given selenium and/or magnesium on ethanol-induced oxidative stress, disturbances of liver function and cholesterol metabolism. Forty male rats were divided into five groups: C – control, Et – intoxicated with alcohol (15% solution in drinking water), Et + Mg, Et + Se, Et + Mg + Se – intoxicated with alcohol and supplemented with selenium (0.4 mg Se/l water), magnesium (100 mg Mg/l water) and combination of Se and Mg, respectively. The experiment was carried out over the 3 months. The results show that the chronic ingestion of alcohol induces lipid peroxidation and histopathological changes in liver. Supplementation with magnesium only partially alleviates oxidative stress and damages in this tissue. The both selenium alone and combination of magnesium and selenium significantly elevated total antioxidant status (TAS) in serum, activity of glutathione peroxidase and ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) in liver and retarded oxidative stress and histopathological changes in this tissue. Chronic administration of ethanol (alone and with magnesium) resulted in significant decrease in the serum total cholesterol and retardation in the body weight gain in comparison with the control group. In the groups supplemented with selenium and selenium and magnesium simultaneously, concentration of total cholesterol in serum and body gains was similar to the control group. Supplementation of Se or selenium and magnesium simultaneously significantly enhances antioxidant defence and is more effective against alcohol-induced oxidative stress, disturbance of liver function and cholesterol metabolism than the separate use of magnesium.

Effects of chronic exposure to lead, cadmium, and manganese mixtures on oxidative stress in rat liver and heart

Abstract The aim of this study was to assess the effects of chronic combined exposure to low, environmental doses of Cd, Pb, and Mn on oxidative stress in the liver and heart of rats and on their liver function parameters. Male Wistar rats were divided randomly into eight groups. For nine months controls were receiving drinking water alone, whereas the exposed groups were receiving drinking water with Pb (0.2 mg L-1), Cd (1 mg L-1), and Mn (2 mg L-1) alone or in combinations. Malondialdehyde (MDA) significantly increased in both heart and liver of the animals after combined exposure to metals. Heart MDA correlated with blood Cd, Pb, and Mn and liver MDA with blood Cd. Aspartate aminotransferase (AST) activity and bilirubin concentration also increased significantly in the animal group exposed to all three metals and correlated positively with blood Cd, Pb, and Mn. Our study has confirmed the synergistic effect of the Cd, Mn, and Pb combination on the increase in heart MDA. A similar synergy was observed for Pb+Mn in the increase of serum alanine aminotransferase (ALT) activity as an indicator of liver function. Cilj je ovog istraživanja bio ocijeniti učinke kronične izloženosti kombinaciji Cd, Pb i Mn u niskim dozama kakve su u okolišu na oksidativni stres u jetrima i srcu štakora te na pokazatelje jetrene funkcije. U tu smo svrhu mužjake Wistar štakora nasumce podijelili u osam skupina, od kojih je kontrolna pila čistu vodu, a izložene skupine vodu pomiješanu s olovom (0,2 mg L-1), kadmijem (1 mg L-1) i manganom (2 mg L-1), zasebno ili u kombinacijama. Koncentracija malondialdehida (MDA) značajno se povećala u oba organa životinja izloženih kombinacijama metala. Srčani MDA korelirao je s razinama kadmija, olova i mangana u krvi, a jetreni MDA s razinom kadmija u krvi. Aktivnost aspartat aminotransferaza (AST) i koncentracije bilirubina također su bile značajno povišene u skupini izloženoj svim trima metalima te su korelirale s razinama kadmija, olova i mangana u krvi. Rezultati istraživanja potvrdili su da zajedno ova tri metala djeluju na povećanje MDA u srcu. Slična je sinergija zamijećena i između olova i mangana s obzirom na povećanje razine alanin aminotransferaze (ALT) u serumu, koji je pokazatelj jetrene funkcije.

Disturbance of posture in children with very low lead exposure, and modification by VDR FokI genotype

INTRODUCTION AND OBJECTIVE Lead has a negative effect on the central nervous system (CNS), inter alia indicated by disturbance of posture. However, knowledge of the CNS effects at low exposure is insufficient. Individuals differ in vulnerability, possibly because of genetic predisposition. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes may modify lead metabolism and neurotoxicity. The objective of the study was to determine whether very low lead exposure affects posture in children, and whether ALAD and VDR genotypes modify the effect. MATERIALS AND METHODS In 1996-2001, 108 (age 5-13, mean 6.9), and in 2008-2010 231 (age 5-11, mean 7.9) children from Poland were tested by posturography and blood-lead concentration (B-Pb; medians 50 and 36 µg/L, respectively). The children were genotyped for ALAD (RsaI, MspI) and VDR (FokI, BsmI, TaqI). RESULTS There were correlations between posture and B-Pb (sway area with closed eyes: rS=0.24, P<0.001; velocity: rS=0.21, P<0.001). Significant effects (adjusted for the potential confounders height and mother´s education) were present already at (ln-transformed) B-Pb<50 µg/L [β (regression coefficient) for sway area 0.025, p=0.001), and even stronger than at higher levels (β=0.006, p=0.06, respectively)]. The ff carriers in VDR FokI polymorphism were more susceptible to the effect of lead on the balance system, while other VDR or ALAD genotypes did not significantly modify the effect. CONCLUSIONS Effects on CNS, as reflected by disturbances of posture, were present at very low lead exposure (B-Pb<50 µg/L), and the effect was significantly greater at such low B-Pbs than at higher. VDR FokI significantly modified the effect.

Interaction between blood selenium concentration and a levels of oxidative stress and antioxidative capacity in healthy children

The study aimed at defining the relationship between blood selenium concentration (Se-B) and levels of oxidative stress and antioxidative capacity in healthy children. The studies were conducted on 337 children (mean age: 8.53±1.92 years). The groups of individuals with Se-B <1st quartile (group I, Se-B<70μg/L), with Se-B fitting the range of 1st quartile and median (group II, Se-B: 70-76.9μg/L), with Se-B between the median and 3rd quartile (group III, Se-B: 77-83.9μg/L) and those with Se-B above the 3rd quartile (group IV, Se-B≥84μg/L) were distinguished. Level of oxidative stress was defined using determination of urine malonyldialdehyde concentration (MDA) and urine 8-hydroxy-2-deoxyguanosine concentration (8-OHdg). Urine total antioxidant status (TAS) was determined. In group IV TAS was significantly higher than in groups I-III. A positive correlation was detected between Se-B and TAS. In healthy children an appropriately high Se-B seems to ensure higher total antioxidative status.

The influence of 9-day trekking in the Alps on the level of oxidative stress parameters and blood parameters in native lowlanders

BACKGROUND The stimuli acting on a person in a high mountain environment (such as hypobaric hypoxia with subsequent reoxygenation, physical exercise) can significantly increase oxidative stress, stimulate erythropoiesis, lead to changes in the blood count and participate in the development of altitude sickness. OBJECTIVE The aim was to investigate changes in haematological parameters, indicators of oxidative stress (malondialdehyde - MDA) and antioxidant defences: catalase (CAT), superoxide dismutase (SOD), and total antioxidant status (TAS) in the plasma of young, healthy people after a 9-day expedition in the Alps. MATERIALS AND METHOD A total of 5 patients (4 men and 1 woman), members of the Wrocław Mountaineering Club, aged 24-26 years. Collection of blood samples was carried out immediately before departure and 3 days after the end of exposure to high-altitude conditions. During the expedition, the subjects were exposed to heights: 2,050-4,165 m.a.s.l., and exercise associated with climbing. RESULTS Trekking in the Alps neither caused significant changes in the parameters of red blood cells nor increased the level of oxidative stress parameters in plasma. CAT activity increased, the ratio of SOD / CAT decreased. There was also a decrease in the total number of leukocytes, mainly monocytes and basophils. CONCLUSIONS 9-day exposure to high-altitude conditions is not a substantial burden for the organism of young, physically active people. The increase in antioxidant capacity is sufficient to stop oxidative processes, which are severe in these conditions, and to prevent the occurrence of significant oxidative stress. Discontinuation of exposure to allergens and dust pollution clears the airways, which is indicated by the reduction in the number of monocytes and basophils.

Blood selenium concentration in a selected population of children inhabiting industrial regions in Upper Silesia (Poland).

PURPOSE Present study aimed at determining blood selenium concentration (Se-B) in a selected population of children inhabiting industrial regions. METHODS The studies were conducted on a group of 267 children inhabiting industrial regions in Upper Silesia (Poland). Determination of Se-B was performed using hydride generation atomic absorption technique. RESULTS In the studied group of children mean Se-B amounted to 76.75±12.52μg/L. Only in 38.20% of studied children the estimated Se-B could be regarded as an optimal. Children with underweight (BMI<15th centile) manifested a significantly lower Se-B than children with BMI within the normal range (BMI 15-85th centile). In the entire study group of children a significant positive linear correlation was disclosed between BMI and Se-B (r=0.16, p<0.05). Regression analysis demonstrated that in the studied subgroup of children (with normal height, body mass and BMI) a higher BMI represented an independent factor of Se-B increase and a more pronounced age an independent factor of Se-B decrease. Moreover, maternal education represented an independent factor of Se-B increase in the studied group of children (with normal height, body mass and BMI). CONCLUSIONS Se-B in the studied group children from industrial area in Upper Silesia corresponded with the lower range of blood selenium concentrations noted in recent years in other populations. A negative relationship was documented between age and Se-B and a positive relationship between BMI of a child and maternal education on one hand and Se-B of a child on the other.