Obesogenic and diabetogenic impact of high organochlorine levels (HCB, p,p'-DDE, PCBs) on inhabitants in the highly polluted Eastern Slovakia.

OBJECTIVE: This study was aimed to evaluate possible obesogenic and diabetogenic impact of highly increased serum level of persistent organochlorinated pollutants POPs, such as polychlorinated biphenyls (PCBs), dichlorodiethyl-dichloroethylene (p,p'-DDE), and hexachlorobenzene (HCB), on the level of obesity markers (cholesterol and triglyceride level in serum, and body mass index [BMI]) and diabetes markers (fasting glucose and fasting insulin in serum) in inhabitants of Eastern Slovakia. METHODS: In young (21-40 years) males (n=248) and females (n=330) as well as in old (41-75 years) males (n=586) and females (n=889), the serum levels of 15 polychlorinated biphenyl congeners (Σ15PCBs), p,p'-DDE and HCB, and serum insulin, testosterone, total cholesterol, triglycerides and glucose levels have been estimated by high resolution gas chromatography/mass spectrometry and by the appropriate electrochemiluminiscent immunoassay or chemical methods, respectively. RESULTS: In both age groups of males and females, the levels of Σ15PCBs, p,p'-DDE, and HCB were very high and their mutual interrelations were highly significant (p<0.01). However, it should be noted that no significant changes were found in individual variables related to very high level of Σ15PCBs, except of increased BMI (p>0.05) in females.In all ages and gender groups, defined above general as related to increasing level of individual OCPs in individual age and gender groups, significant increase in cholesterol and triglyceride levels as well as BMI values, supported their obesogenic effect, while significant increase in fasting glucose and insulin in serum, supported their diabetogenic effect. Finally, highly significant decrease in testosterone level, as found in both young and old males, supported the antiandrogenic effect, namely of HCB. However, somewhat less of p,p'-DDE, while PCBs did not show any such effect in spite of their very high level. CONCLUSIONS: Highly increased blood levels of diabetes (fasting glucose and insulin) and obesity markers (cholesterol, triglyceride and BMI) were found in large groups of males and females in highly polluted area of Slovakia. Significant decrease in testosterone level was also observed in males.

[Possible influence of genetic polymorphism in the area of GSTs genes on the serum PCB level]. / Mozný vplyv génového polymorfizmu v oblasti GSTs génov na sérovú hladinu polychlorovaných bifenylov (PCB).

OBJECTIVE: To find out whether the serum PCB level depends on genetic polymorphism in the area of GSTs genes. MATERIAL AND METHODS: In the group of 147 men (112 with an average age of 59.1 ± 10.1 and serum PCB level > 1,000 ng/ g lipid -  PCB1, and 35 with an average age of 56.2 ± 12.9 and serum PCB level < 700 ng/ g lipid -  PCB2), the PCR RLFP analysis of DNA was used to determine the genetic polymorphism in the area of GSTs genes. RESULTS: As regards PCB, an association was found between serum PCB concentrations and the null genotype of GSTT1 gene. Men above the median PCB levels displayed, with significantly greater frequency, the null genotype GSTT1 compared to men below the median PCB levels, both in the PCB1 set and in the PCB2 set. In the PCB1 set, the presence of the null genotype GSTT1 increased the risk of high PCB levels 11- fold, in the PCB2 set 4- fold (p < 0.001). In the PCB2 set, an association was also discovered between GSTP1 Val/ Val genotype and higher PCB levels. The risk of high PCB levels in the individuals with the Val/ Val genotype was 5- fold higher than in the carriers of the Ile allele (p < 0.001). In neither set was the GSTM1 genotype associated with serum PCB concentrations. CONCLUSION: The association between high PCB levels and the GSTT1 null and GSTP1 Val/ Val suggests that harmful effects depend not only on the intake amounts of PCB but also on the ability of the organism to detoxify these substances. Individuals living in the same environment are therefore at different risks of developing a disease when exposed to PCB. Polymorphism in the area of GSTTl gene (GSTT1 null) could be a potential genetic risk marker.

Thyroid volume, iodine intake, autoimmune thyroid disorders, inborn factors, and endocrine disruptors: twenty-year studies of multiple effects puzzle in Slovakia.

OBJECTIVE: The aim of this study was to evaluate multiple interrelations between several endogenous and exogenous effects and the thyroid volume and function in large groups of children, adolescents, and adults with a sufficient whole life intake of the iodine. SUBJECTS AND METHODS: The data were obtained either by cross sectioned or longitudinal studies in a total of 4998 children and adolescents (aged 7 to 17 years) and 2501 adults (1071 males and 1430 females aged 20-75 years). Thyroid volume (ThV) was measured by ultrasound, antibodies, and hormones by electrochemiluminiscent immunoassay, and endocrine disruptors (EDs, polychlorinated biphenyls-PCB, dichlorodiethyl-ichloroethylene-DDE, and hexachlorobenzene-HCB) by high resolution gas chromatography/mass spectrometry. RESULTS: 1. In large groups of boys and girls of age 7, 10, 13 or 17 years, the ThV was significantly higher in the 10th decile than in pooled nine lower deciles. Moreover, in 17-year old subjects significantly higher prevalence of hypoechogenicity by ultrasound, positive thyroperoxidase antibodies (TPOab), and increased thyrotropin (TSH) levels were found in the 10th decile. 2. In a small group of children, some individuals revealed consistently higher ThV during the whole 7-year follow-up period irrespective of supplementation with iodine. 3. In 325 sibling pairs of age 10-19 years, born within three years, three groups with different ThV/m2 of body surface were distinguished: Group A (183 pairs having both ThVs small), Group B (103 pairs having both ThVs large); Group C (33 pairs having one ThV small and the other one large). Similar aggregation of ThVs in three groups was observed in 13 pairs of discordant twins and 19 sibling triads in which all the siblings were born within four years. 4. In 42 concordant twins, several pairs had ThV nearly twice as high (in terms of both plain ThV or ThV/m2 of the body surface) as several other pairs of the same age which is assumed to be a result of a genetic background. 5. In large cohorts of males and females, a highly significant positive correlation was found between the ThV and high level of TPOab on one side and EDs on the other side. However, in nearly the same numbers of subjects with low TPOab, negative correlation was seen between ThV and disruptors. These observations may apparently support the synergic effect of the autoimmunity and EDs on the thyroid function. CONCLUSIONS: Several cases of an excessive thyroid growth in the iodine replenished children, adolescents, and adults may apparently result from the autoimmune thyroiditis, probably induced by immunogenic action of iodine in presumably disposed individuals. However, in some cases even simultaneous participation of EDs can not be excluded. Some observations have also suggested that excessive thyroid growth in the iodine replenished adolescent and adult population which was equally exposed to disruptors may also result from other reasons as the unfavorable hereditary background.

Blood testosterone in middle aged males heavily exposed to endocrine disruptors is decreasing more with HCB and p,p'-DDE related to BMI and lipids, but not with Σ15PCBs.

OBJECTIVE: This work was aimed to evaluate the fundamental relations between the blood levels of testosterone (TEST) and persistent organochlorinated pollutants (POPs) related to body mass index (BMI) and blood lipids in a cohort of heavily exposed males from Eastern Slovakia. METHODS: In 429 middle aged (41-55 years) males heavily exposed to POPs the levels of 15 polychlorinated biphenyl congeners (Σ15PCBs), hexachlorobenzene (HCB), and dichlorodiethyl-dichloroethylene (p,p'-DDE) were measured by gas chromatography/mass spectrometry and the total testosterone (TEST) by electrochemiluminiscent immunoassay. RESULTS: After classifying the values of BMI, TEST, HCB, p,p'-DDE, and Σ15PCBs in quintiles and evaluating mutual interrelations of individual quintile counts in pairs of variables with chi-square, statistically significant interrelation was found for BMI/TEST (<0.0001) and HCB/TEST (p<0.001), but not for p,p'-DDE/TEST (p<0.6036) and Σ15PCBs/TEST (p<0.3246). Moreover, highly significant negative correlation was found between HCB and TEST by means of both Pearson (p<0.01) and Spearman rank correlations (p<0.0001). However, similar correlations performed between p,p'-DDE and Σ15PCBs did not reveal statistical significance. Finally, highly significant positive correlations were found between HCB and BMI, age, total lipids, and triglycerides. However, these correlations were less significant for p,p'-DDE and not significant or even negligibly negative for Σ15PCBs. In contrast, correlations of TEST with BMI and lipid fractions were significantly negative. CONCLUSION: It appears that HCB might play a role in a decrease of TEST in males with relatively narrow age range of males highly exposed to POPs. Highly significant positive correlation of HCB with BMI and blood lipids points out the role of BMI as an imaginary compartment closely related to the total body fat mass and representing a depot of POPs which is closely related to the level of POPs and lipids in blood. However, the differences in the affinity of individual POPs to BMI and blood lipids as well as the mechanism of their different relation to blood TEST levels remain to be still explained.

Alpha-fetoprotein, carcinoembryonic antigen and beta2-microglobulin in adult population highly exposed to organochlorinated pollutants (PCB, DDE and HCB).

OBJECTIVE: It is aimed to obtain some general information about the prevalence of certain biomarkers in highly exposed population and on the interrelations between their serum level as related to that of some major organochlorines (OCs). METHODS: The level of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and beta2-microglobulin (beta2-MG) as well as that of polychlorinated biphenyls (Σ15PCBs), dichlorodiphenyl-dichloroethylene (DDE) and hexachlorobenzene (HCB) was estimated in 2046 adults (834 males and 1212 females) from highly polluted Eastern Slovakia. RESULTS: Great majority of blood levels was lower than two specific units used for individual markers, while the prevalence of values higher than two specific units of appropriate markers. At the same time, the prevalence of all markers level higher than 2 specific units was highly significantly increasing with of stratified PCBs level quintiles which were also positively related to these of DDE and HCB. Some significant correlations between biomarkers level and age were also observed. CONCLUSIONS: Although from the data obtained within this multipurpose field survey any notable interrelations between AFP, CEA and beta2-MG and some specific diseases and/or malignant processes could not be retrospectively specified, from the data obtained it appears that some of such interrelations cannot be definitely excluded.

Polychlorinated biphenyls and testosterone: age and congener related correlation approach in heavily exposed males.

OBJECTIVE: It was aimed to evaluate some fundamental correlations of 15 individual PCB congeners and their sum with serum testosterone level in highly and long-term exposed males with special respect to minimize the interfering effect of age. METHODS: A total of 834 males from eastern Slovakia (age range of 21-78 years; median, 75th and 90th percentile of 48, 54 and 58 years, respectively) were examined consisting of 432 males from highly polluted area and 402 males from the area of background pollution. In all of them the serum level of 15 polychlorinated biphenyl congeners (PCBs), hexachlorobenzene (HCB) and dichlorodiethyl-dichloroethylene (DDE) was measured by gas chomatography/mass spectrometry and total testosterone in serum was measured with the aid of electrochemiluminiscent immunoassay. Pearson's correlation coefficients for each individual PCB congener as well as for Sigma15PCBs with testosterone were assessed in the cohort of all 834 males and also in the cohort of 444 males with age range of 41-55 years in which any significant negative influence of age on testosterone level has not been found and thus the interfering effect of aging on that level was apparently minimized. RESULTS: In the cohort of 834 males with high level of Sigma15PCBs (median = 885; range = 211-77,084; 5% - 95% = 377 - 4051 ng/g lipid) and highly significant negative correlation with age (r= 0.303; p<0.000) a significant negative correlation (p<0.05) with testosterone has been observed only for two mono-ortho-congeners (CB-105 and -118). However, in the cohort of 444 males aged 41-55 years any significant correlation for individual PCB congeners and for Sigma15PCBs with testosterone did not appear. CONCLUSION: In a large cohort of highly exposed males with minimized interfering effect of age any significant correlations between 15 PCB congeners analyzed and total testosterone were not found.

High prevalence of prediabetes and diabetes in a population exposed to high levels of an organochlorine cocktail.

AIMS/HYPOTHESIS: A heavily polluted area of Eastern Slovakia was targeted by the PCBRISK cross-sectional survey to search for possible links between environmental pollution and both prediabetes and diabetes. METHODS: Associations of serum levels of five persistent organic pollutants (POPs), namely polychlorinated biphenyls (PCBs), 2,2'-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE), 2,2'-bis(4-chlorophenyl)-1,1,1-trichloro-ethane (p,p'-DDT), hexachlorobenzene (HCB) and beta-hexachlorocyclohexane (beta-HCH), with prediabetes and diabetes were investigated in 2,047 adults. Diabetes and prediabetes were diagnosed by fasting plasma glucose in all participants and by OGTT in 1,220 compliant participants. RESULTS: Our population was stratified in terms of individual POPs quintiles and associations between environmental pollution, prediabetes and diabetes were investigated. Prevalence of prediabetes and diabetes increased in a dose-dependent manner, with individuals in upper quintiles of individual POPs showing striking increases in prevalence of prediabetes as shown by OR and 95% CI for PCBs (2.74; 1.92-3.90), DDE (1.86; 1.17-2.95), DDT (2.48; 1.77-3.48), HCB (1.86; 1.7-2.95) and beta-HCH (1.97; 1.28-3.04). Interestingly, unlike PCBs, DDT and DDE, increased levels of HCB and beta-HCH seemed not to be associated with increased prevalence of diabetes. Nevertheless, individuals in the 5th quintile of the variable expressing the cumulative effect of all five POPs (sum of orders) had a more than tripled prevalence of prediabetes and more than six times higher prevalence of diabetes when compared with the 1st referent quintile. CONCLUSIONS/INTERPRETATION: Increasing serum concentrations of individual POPs considerably increased prevalence of prediabetes and diabetes in a dose-dependent manner. Interaction of industrial and agricultural pollutants in increasing prevalence of prediabetes or diabetes is likely.

Multiple organochlorine pollution and the thyroid.

OBJECTIVE: Although the biological effects of major persistent organochlorinated pollutants (POPs) appear to be essentially similar, some effects which would be specific for certain substance cannot be excluded. We attempted to study the thyroid volume and thyrotropin level in the population living in the area with multiple pollution by polychlorinated biphenyls (PCBs) and pesticides (DDE and hexachlorobenzene - HCB). METHODS: A total of 454 adults was examined within the pilot field survey in 1998. Among them were 237 males (age range 19-78 years, median 47) and 227 females (age range 19-78 years, median 48). Fifteen environmentally prevalent congeners of polychlorinated biphenyls and also p,p-DDE (2,2-bis(4-chlorophenyl)-1,1-dichloroethylene), p,p-DDT (2,2-bis(4-chlorophenyl)- 1,1,1-trichloro-ethane), hexachlorobenzene (HCB) as well as alpha-, beta- and gamma-hexachlorocyclohexane (HCH) were determined in serum by high resolution gas chromatography using microelectron capture detector and microcapillary column. Thyroid volume (ThV) was measured by real time sonography using the ellipsoid method with the aid of sonographic instrument Sonoline SI-400 (Siemens, Germany). The level of TSH was estimated by supersensitive immunoradiometric method using commercial kits by Immunotech (Marseille, France). Pearsons correlation coefficients after logarithmic transformation of values and Spearmans correlation coefficients were used for statistical evaluation. RESULTS: Significant positive association (p<0.01) was found between DDE and PCB, DDE and HCB, while that between PCB and HCB was not significant. Similar positive association (p<0.01) was also found between each individual organochlorine and their sum. Significant negative association (p<0.01) was found between ThV and TSH. When using categorical PCB values either >2000 (N=208) or >3000 (N=127) ng/g lipid, significant positive association (p<0.05 and p<0.01, respectively) was found between the sum of all organochlorines (PCB+DDE+HCB) and ThV, while that between PCB and ThV (p<0.01) was found only at the PCB levels >3000 ng/g lipid. When using Spearmans correlation coefficients, significant negative association appeared between PCB and TSH (p<0.05), sum of organochlorines and TSH (p<0.05) and ThV and TSH (p<0.01). CONCLUSIONS: Although several significant positive and negative associations were found, this study, like several others, could not exactly define the participation level of individual POPs in their common toxic effects, but possibly contributed to the recognition and elucidation of some problems related to this task.

Human thyroid in the population exposed to high environmental pollution by organochlorinated pollutants for several decades.

OBJECTIVE: To study possible effects of long-time exposure of chemical factory employees and population of surrounding polluted area to polychlorinated biphenyls and pesticides on the thyroid volume and function as compared to the population from the area of background pollution. METHODS: A total of 461 adults consisting of 239 men and 222 women was examined and divided into four groups according to their permanent domicile as related to the level of environmental pollution, e.g. SR (area of background pollution, n = 207), SI (slightly polluted area, n = 59), MI (polluted city of Michalovce, n = 94) and CH (employees of chemical factory subjected to high PCB exposure, n = 101), combined first three groups being also called LPA (less polluted areas, n = 360). Thyroid volume (ThV) and echogenicity were measured by real time sonography. The level of polychlorinated biphenyls (PCB) and pesticides (hexachlorbenzene--HCB, DDE (2,2'-2-bis(4-chlorobiphenyl)- 1,1-dichloroethylene), p,p'-DDT (2,2'-bis(4-chlorophenyl)- 1,1,1-trichloroethane) and alpha-, beta- and gamma-hexachlorcyclohexane--HCH) was estimated by congener specific analysis using HP 5890 gas chromatograph with a 63Ni electron capture detector. Serum levels of thyrotropin (TSH) and thyroid peroxidase antibodies (anti-TPO) were measured by specific sensitive immunoassays. RESULTS: The association of very high PCB level (e.g. 7300 +/- 871 ng/g lipid; mean +/- S.E.) with increased ThV (e.g. 16.3 +/- 0.73 ml) in CH has been found, the values being significantly higher than these of 360 subjects in LPA (e.g. 2045 +/- 147 ng/g, p < 0.001 for PCB and 14.0 +/- 0.32 ml, p < 0.001 for ThV). In 23 subjects from CH with PCB level > 10000 ng/g the ThV was 18.7 +/- 2.32 ml, while that in 251 subjects from LPA with PCB level of < 2000 ng/g was 13.8 +/- 0.35 ml (p < 0.05). In addition, ThV as well as PCB levels were strikingly increasing with age. In parallel with PCB levels, also the levels of other organochlorines estimated (namely these of DDE) were increasing. Although the participation of these substances in the development of adverse effects cannot yet be defined, it cannot be excluded. The association of increased levels of episodic congener PCB 101 with increased ThV appeared to be more pronounced than that of stable congeners PCB 153 and 180. Finally, significant increase in the frequency of thyroid hypoechogenicity by ultrasound, ThV > 20.0 ml and thyroperoxidase antibodies in CH area was observed as compared to LPA. CONCLUSIONS: Several associations of high PCB and pesticides level with characteristics of thyroid disorders (e.g. increased thyroid volume, frequency of hypoechogenicity and frequency of positive thyroperoxidase antibodies level in blood) were observed in the area with heavy industrial pollution by PCB.

Simple solid-phase extraction method for determination of polychlorinated biphenyls and selected organochlorine pesticides in human serum.

A simple off-line solid-phase extraction (SPE) method for isolation of polychlorinated biphenyls (PCBs) and selected organochlorine pesticides (OCPs) from human serum has been developed. The procedure includes denaturation of serum proteins by a mixture of water-1-propanol, application of the sample by aspiration twice repeatedly through the SPE column and elution with a mixture of n-hexane-dichlormethane. After final clean-up the compounds of interest were analysed by gas chromatography with micro-electron capture detection (GC-microECD). The recoveries achieved for PCB congeners using spiked porcine serum samples were 99-120% and for OCPs 88-115%. Relative standard deviations (RSD) ranged from 3 to 7%. The method was applied to real human serum samples and the recoveries of analytes in the serum were proportionally recalculated considering the recovery of the internal standard PCB-174. PCB-103 served as a syringe standard to correct volume of samples analysed. The aim of this study was to develop an effective off-line SPE procedure by optimization of existing SPE methods to supply laborious, solvent- and time-consuming liquid-liquid extraction (LLE) in routine analytical process.

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 manufacturer's dumping site and a highly contaminated manufacturer's 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 manufacturer's 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 manufacturer's 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.

TOCOEN project.

The basic goals of the TOCOEN project (Toxic Organic COmpounds in the ENvironment) are to detect and understand the fate of selected organic pollutants (PAHs, PCBs and PCDDs/Fs mainly) in the environment. The TOCOEN project was established in 1988 as a free association of Czech and Slovak environmental chemists, ecototoxicologists and other environmentalists.

Levels of PCBs and some organochlorine pesticides in the human population of selected areas of the Slovak Republic. I. Blood.

Fifty samples of human blood collected in 1992 from the general human population living in five selected areas of the Slovak Republic (the Michalovce, Velký Krtís and Nitra District, Myjava area and Bratislava) were analysed for polychlorinated biphenyls (IUPAC Nos. 28, 52, 77, 101, 105, 114, 118, 123, 126, 138 (+163), 153, 156, 157, 167, 169, 180 and 189) and some organochlorine pesticides (HCB, gamma-HCH, p,p'-DDE and p,p'-DDT). PCB levels (the sum of the congeners analysed) in serum lipids averaged for all the samples analysed were 1.79 micrograms.g-1 (range: 0.53-9.20 micrograms.g-1, median: 1.33 micrograms.g-1), HCB 5.38 micrograms.g-1 (0.16-23.20 micrograms.g-1, 4.27 micrograms.g-1), gamma-HCH 0.012 microgram.g-1 (< 0.01-0.18 microgram.g-1), p,p'-DDE 6.05 micrograms.g-1 (1.30-34.80 micrograms.g-1, 4.39 micrograms.g-1) and p,p'-DDT 0.27 microgram.g-1 (< 0.01-0.79 microgram.g-1, 0.23 microgram.g-1). About three times higher levels of PCBs were found in the samples from the district where PCB formulations had been produced (the Michalovce District).