Jan Petrik

Polychlorinated biphenyls and their hydroxylated metabolites (OH-PCBS) in pregnant women from eastern Slovakia.

Objective Our aim in the present study was to characterize and quantify the levels of polychlorinated biphenyls (PCBs) and specific polychlorobiphenylol (OH-PCB) metabolites in maternal sera from women delivering in eastern Slovakia. Design During 2002–2004, blood samples were collected from women delivering in two Slovak locations: Michalovce district, where PCBs were formerly manufactured, and Svidnik and Stropkov districts, about 70 km north. Participants A total of 762 and 341 pregnant women were sampled from Michalovce and Svidnik/Stropkov, respectively, and OH-PCBs were measured in 131 and 31. Evaluation/Measurements We analyzed PCBs using gas chromatography (GC)/electron capture detection. OH-PCBs and pentachlorophenol (PCP) were determined as methyl derivatives using GC-electron capture negative ionization/mass spectrometry. We characterized distributions in the full cohort using inverse sampling weights. Results The concentrations of both PCBs and OH-PCB metabolites of Michalovce mothers were about two times higher than those of the Svidnik/Stropkov mothers (p < 0.001). The median weighted maternal serum levels of the sum of PCBs (∑PCBs) were 5.73 ng/g wet weight (Michalovce) and 2.82 ng/g wet weight (Svidnik/Stropkov). The median sum of OH-PCBs (∑OH-PCBs) was 0.55 ng/g wet weight in Michalovce mothers and 0.32 ng/g wet weight in Svidnik/Stropkov mothers. 4-OH-2,2′ ,3,4′ ,5,5′ ,6-Heptachlorobiphenyl (4-OH-CB187) was a primary metabolite, followed by 4-OH-2,2′ ,3,4′ ,5,5′ -hexachlorobiphenyl (4-OH-CB146). Only four PCB congeners—CBs 153, 138, 180, and 170—had higher concentrations than 4-OH-CB187 and 4-OH-CB146 (p < 0.001). The median ratio of the ∑OH-PCBs to the ∑PCBs was 0.10. Conclusions Mothers residing in eastern Slovakia are still highly exposed to PCBs, and their body burdens of these pollutants and OH-PCB metabolites may pose a risk for adverse effects on health for themselves and their children.

Environmental contamination with polychlorinated biphenyls in the area of their former manufacture in Slovakia.

Evidently increased environmental pollution as a consequence of the 25-year manufacture of polychlorinated biphenyls (PCBs) in eastern Slovakia was observed. PCB levels determined in ambient air, soil, surface water, bottom sediment, wildlife (fish and game) samples collected in a potentially contaminated area of about 250 km2 (a part of the Michalovce district) were compared with those determined in a control area (Stropkov district). Up to 1700 ng/m3 were found in ambient air in a village close to a manufacturers dumping site and a highly contaminated manufacturers effluent canal whereas PCB concentrations in ambient air samples taken in villages in the control area were about 80 ng/m3 only. While soil samples taken from the agricultural fields of the polluted area contained PCBs at levels comparable with soil samples from the control area (about 0.008 mg/kg) much higher values (from 0.4 to 53,000 mg/kg) were determined in soil taken in the vicinity of manufacturers landfill and storage sites and especially plants preparing asphalted gravel using formerly PCBs in their heat-exchanging systems. The contamination of the Laborec river and large Zemplinska Sirava reservoir is caused by the manufacturers effluent canal since PCB levels in the canal sediment are still to be found about 3000 mg/kg. While PCB levels in sediment samples from Michalovce watercourses ranged between 1.7 and 6 mg/kg, sediment samples from the control Stropkov district ranged between 0.007 and 0.052 mg/kg only. Fish living in contaminated Michalovce waters contained about hundred times higher PCB levels than those caught in Stropkov ones. Similarly, game animals shot in Michalovce forests contained several times higher levels than those shot in Stropkov ones.

Impact of Polychlorinated Biphenyls Contamination on Estrogenic Activity in Human Male Serum

Polychlorinated biphenyls (PCBs) are thought to cause numerous adverse health effects, but their impact on estrogen signaling is still not fully understood. In the present study, we used the ER-CALUX bioassay to determine estrogenic/antiestrogenic activities of the prevalent PCB congeners and PCB mixtures isolated from human male serum. The samples were collected from residents of an area with an extensive environmental contamination from a former PCB production site as well as from a neighboring background region in eastern Slovakia. We found that the lower-chlorinated PCBs were estrogenic, whereas the prevalent higher-chlorinated PCB congeners 138, 153, 170, 180, 187, 194, 199, and 203, as well as major PCB metabolites, behaved as anti-estrogens. Coplanar PCBs had no direct effect on estrogen receptor (ER) activation in this in vitro model. In human male serum samples, high levels of PCBs were associated with a decreased ER-mediated activity and an increased dioxin-like activity, as determined by the DR-CALUX assay. 17β-Estradiol (E2) was responsible for a major part of estrogenic activity identified in total serum extracts. Significant negative correlations were found between dioxin-like activity, as well as mRNA levels of cytochromes P450 1A1 and 1B1 in lymphocytes, and total estrogenic activity. For sample fractions containing only persistent organic pollutants (POPs), the increased frequency of anti-estrogenic samples was associated with a higher sum of PCBs. This suggests that the prevalent non-dioxin-like PCBs were responsible for the weak antiestrogenic activity of some POPs fractions. Our data also suggest that it might be important to pay attention to direct effects of PCBs on steroid hormone levels in heavily exposed subjects.

Prenatal PCB exposure and thymus size at birth in neonates in Eastern Slovakia.

Background Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxicants, for which animal studies demonstrate immunotoxic effects, including thymic atrophy and suppressed immune responses; human investigations of similar end points are sparse. The thymus is essential for the differentiation and maturation of T-cell lymphocytes. Objectives The objective of this study was to examine the association between prenatal PCB exposures and estimated thymus volume in infants from eastern Slovakia, a region where PCBs were produced until 1984. Methods Mothers were enrolled at delivery, and maternal blood samples were collected for analysis of 15 PCB congeners, p,p′-DDT [1,1,1-trichloro-2,2′-bis(p-chlorophenyl)ethane], and p,p′-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene]. Each mother was interviewed to obtain information on sociodemographic characteristics, past pregnancies, occupational history, medication history, and living environment. Neonatal thymus volume was estimated using ultrasound measurements on the third or fourth day after birth. Thymic index was calculated on 982 newborns from mothers with PCB measurements. We developed a predictive model of the natural log of the thymic index using multiple linear regression with covariates selected from the bivariate analyses. Results Prenatal PCB exposure was associated with a smaller thymic index at birth [β= −36 (natural log-transformed; nanograms per gram lipids); p = 0.047]. District of residence and delivery also predicted thymic index. Male sex, later gestational age, larger birth weight z-score, and Roma ethnicity were associated with a larger thymic index, whereas respiratory illness was associated with a lower thymic index. Conclusions This study provides the first evidence to date that PCB exposure in neonates is associated with a smaller thymic volume, suggesting possible impaired immunologic development.

Prenatal polychlorinated biphenyl exposures in eastern Slovakia modify effects of social factors on birthweight

Polychlorinated biphenyls (PCB) were widely used for industrial purposes and consumer products, but because of their toxicity, production was banned by most industrialised countries in the late 1970s. In eastern Slovakia, they were produced until 1985. During 2002-04, a birth cohort of mothers (n = 1057) residing in two Slovak districts was enrolled at delivery, and their specimens and information were collected after birth. Congeners of PCBs were measured in maternal serum by high-resolution gas chromatography with electron capture detection. In this study, we used multiple linear regression to examine the effects of prenatal PCB exposure on birthweight adjusted for gestational age, controlling for inter-pregnancy interval, and maternal smoking, age, education, ethnicity, pre-pregnancy body mass index and height. The association between total maternal serum PCB levels and birthweight was not statistically significant. However, an interaction model indicated that maternal PCB concentrations were associated with lower birthweight in Romani boys. Based on the fitted regression model, the predicted birthweight of Romani boys at the 90th percentile of maternal PCBs (12.8 ng/mL) was 133 g lower than the predicted birthweight at the 10th percentile of maternal PCBs (1.6 ng/mL). This is a similar magnitude of effect to that observed for maternal smoking and birthweight. These results suggest that higher levels of PCBs in maternal blood sera may inhibit growth in boys, particularly in those already affected by social factors related to ethnicity. This study is consistent with previous findings that boys are more susceptible than girls to growth restriction induced by in utero organochlorine exposures, and further indicates that high PCBs may magnify the influence of social disadvantage in this vulnerable group of boys.

Case–control study of PCBs, other organochlorines and breast cancer in Eastern Slovakia

This case–control study was designed to investigate association between polychlorinated biphenyls (PCBs) and risk of breast cancer in an area of high environmental exposure in the Michalovce district of eastern Slovakia. Incident breast cancer cases from the Michalovce district diagnosed between May 1997 and May 1999 were recruited through the Oncology Department of the District Hospital. A total of 15 individual PCB congeners, 2,2′-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE), 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (DDT), and hexachlorobenzene (HCB) were measured in the serum of 24 breast cancer patients and 88 population controls in 1998–1999. The median levels of total PCBs were similar in cases (2586 ng/g of lipid) and controls (2682 ng/g of lipid). Higher serum levels (highest vs. lowest tertile) of total PCBs (odds ratio (OR)=0.42, 95% CI 0.10–1.82, p-for trend=0.31), group 1 congeners (OR=0.37, 95% CI 0.10–1.43, P-for trend=0.02), group 2 congeners (OR=0.32, 95% CI 0.07–1.56, P-for trend=0.60), and group 3 congeners (OR=0.49, 95% CI 0.12–2.04, P-for trend=0.51) were inversely associated with risk of breast cancer. Higher serum levels of DDE (OR=3.04, 95% CI 0.65–14.3, P-for trend=0.10) were positively associated with risk of breast cancer, while there was no association for DDT (OR=1.19, 95% CI 0.27–5.23, P-for trend=0.68), and an inverse association for HCB (OR=0.45, 95% CI 0.06–3.19, P-for trend=0.67). While generally not statistically significant, PCB and HCB levels were inversely associated with risk of breast cancer in this highly exposed population. DDE, but not DDT, was positively associated with risk.

High Prevalence of Anti-Glutamic Acid Decarboxylase (Anti-GAD) Antibodies in Employees at a Polychlorinated Biphenyl Production Factory

Abstract An increased prevalence of thyroid antibodies was seen in employees of a factory that formerly produced polychlorinated biphenyls (PCBs). In this study, the authors expand the evaluation of possible long-term PCB effects by comparing the prevalence of glutamic acid decarboxylase (anti-GAD) antibodies with the development of diabetes mellitus. The sera of 240 factory employees and 704 control subjects were analyzed. Anti-GAD antibody values exceeded 1.20 U/ml in all employees (40.4%), was 4 times higher (p < .001) than in all controls (10.5%), and were 5 times higher in employees aged 51-60 yr (53.2%) than in age-matched controls (10.5%) (p < .001). Although the prevalence of diabetes could not be determined from this retrospective study, this is the first report of a possible relationship between xenobiotics and the prevalence of anti-GAD antibodies, and it supports the concept of an immunomodulatory effect of PCBs. However, such antibodies may be present decades before the development of clinical diabetes, and not all anti-GAD antibody-positive individuals become diabetic. Presently, it is unknown whether there is an increased prevalence of diabetes among the former factory employees.

Atmospheric mercury levels in the Slovak Republic

Total mercury concentrations (as a sum of vapor and particulate mercury) were measured in 24-h samples of ambient air in 20 different localities of the Slovak Republic eight times during the period 1996-1997. Vapor mercury was analyzed on site by atomic fluorescence with amalgamation technique. Particulate mercury was determined by vapor hydride atomic absorption spectrometry after wet digestion of filters with particulate air samples. The results showed that 34% of the 160 individual total mercury concentrations exceeded 5 ng/m3--the ambient air quality guideline value recommended by the WHO. The range of total mercury concentrations in the ambient air of Slovakia was: 1.13-3.98 ng/m3 (geom. mean 2.63) in the background area; 2.25-5.27 ng/m3 (geom. mean 3.64) in the agricultural areas; 1.73-20.53 ng/m3 (geom. mean 4.57) in the urban areas; and 1.53-39.85 ng/m3 (geom. mean 5.28) in the industrial areas. The highest mercury levels occurred in areas with metallurgical industry and coal combustion. The predominant form of mercury present in air was vapor mercury. The particulate fraction of mercury in ambient air (as a percentage of total mercury) varied widely from 0.4% to 42.1% (geom. mean = 4.4%). This fraction was lower in agricultural areas (2.3%) than in urban areas (5.3%). Although the atmospheric vapor mercury concentrations were slightly higher in summer than in winter, a direct correlation of vapor mercury concentrations and ambient air temperature was not found. Furthermore, the particulate mercury concentrations did not correlate with total particulate levels.

Method for the group separation of non-ortho-, mono-ortho- and multi-ortho-substituted polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans using activated carbon chromatography

Abstract A cheap, efficient and reliable method for the separation of mono-ortho-/non-ortho-substituted polychlorinated biphenyls (PCBs), multi-ortho-PCBs and polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) from one another and from other interferents was developed. A mixture of activated carbon AX-21 (50 mg and Celite 545 as a carbon support (1:19) packed in a diposable tube was used. The compounds were gradually eluted with cyclohexane-dichloromethane-methanol (2:2:1) and toluene (a coplanar PCB fraction). PCDDs and PCDFs were regained by extraction of the inverted AX-21-Celite column with a small volume of toluene in a special miniaturized extraction apparatus. Recoveries from the column for PCBs and PCDDs/PCDFs varied from 63% to 100%. The method was used successfully for the fractionation of PCB technical formulations (Delor 103 and 105), municipal waste incinerator fly ash and biological samples (human adipose tissue, butter, egg and fish samples). The method is suitable for both mass spectrometric and electron-capture detection.

Project tocoen ‐ the fate of selected organic pollutants in the environment part XXI. ‐ The contents of PAHs, PCBs, PCDDs/Fs in sediments from Danube river catchment area

As a part of cooperation between Chemical Time Bombs Program and Project TOCOEN, the contamination of sediments in Moravian and Slovakian part of Danube river catchment area by PAHs, PCBs, PCDDs/Fs was determined. The total contents of PAHs ranged between 25.5 and 4,690.3 ng•g‐1, PCBs between 4.9 and 232 ng•g‐1 and PCDDs/Fs were detected at one site in concentration 0.0005 pg•g‐1 TEQ.