Environment and health - Human biomonitoring

Title

Do toxic heavy metals affect antioxidant defense mechanisms in humans?

Reference

Ecotoxicology and Environmental Safety
Volume 78  April 2012 Pages 195-205

Author(s)

Study type

Peer Review Journal    

Abstract

The aim of this study was to prove whether anthropogenic pollution affects antioxidant defense mechanisms such as superoxide dismutase (SOD) and catalase (CAT) activity, ferritin (FRT) concentration and total antioxidant status (TAS) in human serum. The study area involves polluted and salted environment (Kujawy region; northern-middle Poland) and Tuchola Forestry (unpolluted control area). We investigated 79 blood samples of volunteers from polluted area and 82 from the control in 2008 and 2009. Lead, cadmium and iron concentrations were measured in whole blood by the ICP–MS method. SOD and CAT activities were measured in serum using SOD and CAT Assay Kits by the standardized colorimetric method. Serum TAS was measured spectrophotometrically by the modified Benzie and Strain (1996) method and FRT concentration—by the immunonefelometric method. Pb and Cd levels and SOD activity were higher in volunteers from polluted area as compared with those from the control (0.0236 mg l−1 vs. 0.014 mg l−1; 0.0008 mg l−1 vs. 0.0005 mg l−1; 0.137 U ml−1 vs. 0.055 U ml−1, respectively). Fe level, CAT activity and TAS were lower in serum of volunteers from polluted area (0.442 g l−1 vs. 0.476 g l−1; 3.336 nmol min−1 ml−1 vs. 6.017 nmol min −1 ml−1; 0.731 Trolox-equivalents vs. 0.936 Trolox-equivalents, respectively), whilst differences in FRT concentration were not significant (66.109 μg l−1 vs. 37.667 μg l−1, p=0.3972). Positive correlations between Pb (r=0.206), Cd (r=0.602) and SOD in the inhabitants of polluted area, and between Cd and SOD in the control (r=0.639) were shown. In volunteers from both studied environments TAS–FRT (polluted: r=0.625 vs. control: r=0.837) and Fe–FRT (polluted area: r=0.831 vs. control: r=0.407) correlations, and Pb–FRT (r=0.360) and Pb–TAS (r=0.283) in the control were stated.
The higher lead and cadmium concentrations in blood cause an increase of SOD activity. It suggests that this is one of the defense mechanisms of an organism against oxidative stress caused by environmental factors, whilst non-enzymatic mechanisms marked by TAS are the main antioxidant defense system in relation with Pb concentration in humans from unpolluted area. Simultaneously, the higher CAT activity and TAS can indicate that these mechanisms play a key role in the antioxidant protection in non-stressed environments.

Policy theme(s)

Air pollution >> Impact of emissions >> Health impacts
Chemicals >> Impacts >> Health impacts
Environment and health >> Health risks >> Human biomonitoring

Keywords

Entry Source:

Shortlisted for Science for Environment Policy News Alert

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http://www.sciencedirect.com/science/article/pii/S0147651311004155
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monicjus@wp.pl

Title

Analysis of the toxicogenomic effects of exposure to persistent organic pollutants (POPs) in Slovakian girls: Correlations between gene expression and disease risk

Reference

Environment International
Volume 39, Issue 1, February 2012, Pages 188–199

Author(s)

Irva Hertz-Picciotto, Tomas Trnovec, Lubica Palkovicova, Eva Sovcikova, Svetlana Ghimbovschi, Eric P. Hoffman, Sisir K. Dutta

Study type

Peer Review Journal    

Abstract

The chemical composition of persistent organic pollutants (POPs) in the environment is not uniform throughout the world, and these contaminants contain many structurally different lipophilic compounds. In a well-defined study cohort in the Slovak Republic, the POP chemicals present in the peripheral blood of exposed children were chemically analyzed. The chemical analysis data revealed that the relative concentration and profile of structurally different organic pollutants, including 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 β-hexachlorocyclohexane (β-HCH), may vary from individual to individual, even within the same exposure area. These chemicals can be broadly classified into two groups. The first group, the PCB congeners, primarily originated from industrial compounds and their byproducts. The second group of compounds originated from or was commonly used in the agricultural sector (e.g., DDT, HCB). The objective of this study was to examine the effects of the two POP exposure profiles on gene expression. For the study population, we selected pre-pubertal girls (mean age of 46.2 ± 1.4 months) with high POP concentrations in their blood (> 75% tile of total POP) and classified them in the high ‘PCB’ group when the total PCB concentration was significantly higher than the total concentration of other POP components and in the ‘Other Than PCB’ (OTP) group, when the total PCB concentration was significantly lower than the concentration of the other major POP constituents. A matched control group of girls (< 25% tile of total POP) was selected for comparison purpose (n = 5 per group). Our aims were to determine whether there were any common effects of high POP exposure at a toxicogenomic level and to investigate how exposure may affect physiological functions of the children in two different exposure scenarios. Global gene expression analysis using a microarray (Affymetrix Gene Chip Human genome U133 Plus 2.0 Array) platform was conducted on the total RNA of peripheral blood mononuclear cells from the girls. The results were analyzed by Partek GS, Louis, MI, which identified twelve genes (ATAD2B, BIVM, CD96, CXorf39, CYTH1 ETNK1, FAM13A, HIRA, INO80B, ODG1, RAD23B, and TSGA14) and two unidentified probe sets, as regulated differentially in both the PCB and OTP groups against the control group. The qRT-PCR method was used to validate the microarray results. The Ingenuity Pathway Analysis (IPA) software package identified the possible molecular impairments and disease risks associated with each gene set. Connective tissue disorders, genetic disorders, skeletal muscular disorders and neurological diseases were associated with the 12 common genes. The data therefore identified the potential molecular effects of POP exposure on a genomic level. This report underscores the importance of further study to validate the results in a random population and to evaluate the use of the identified genes as biomarkers for POP exposure.

Policy theme(s)

Air pollution >> Impact of emissions >> Health impacts
Chemicals >> Impacts >> Health impacts
Environment and health >> Health risks >> Human biomonitoring

Keywords

Persistent Organic Pollutant (POP); Gene environment interaction; Gene expression; Human PBMC; IPA analysis; Disease and disorders

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Shortlisted for Science for Environment Policy News Alert

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http://www.sciencedirect.com/science/article/pii/S0160412011002285
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sdutta@howard.edu

Title

Prenatal Exposure to Polychlorinated Biphenyls (PCB) and Dichlorodiphenyldichloroethylene (DDE) and Birth Weight: A Meta-analysis within 12 European Birth Cohorts

Reference

Author(s)

Eva Govarts, Mark Nieuwenhuijsen, Greet Schoeters, Ferran Ballester, Karolien Bloemen, Michiel de Boer, Cécile Chevrier, Merete Eggesbø, Monica Guxens, Ursula Krämer, Juliette Legler, David Martinez, Ľubica Palkovicová;, Evridiki Patelarou, Ulrich Ranft, Arja Rautio, Maria Skaalum Petersen, Rémy Slama, Hein Stigum, Gunnar Toft, Tomáš Trnovec, Stephanie Vandentorren, Pál Weihe, Nynke Weisglas Kuperus, Michael Wilhelm, Jurgen Wittsiepe, Jens Peter Bonde, on behalf of OBELIX/ENRIECO

Study type

Peer Review Journal

Abstract

Objectives: Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but the evidence at low exposure levels is limited. Large studies with substantial exposure contrasts and appropriate exposure assessment are warranted. Within the framework of the EU ENRIECO and EU OBELIX projects, we examined the hypothesis that polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) adversely affects birth weight.
Methods: We used maternal and cord blood and breast milk samples in 7,990 women enrolled in 15 study populations from 12 European birth cohorts from 1990-2008. Using identical variable definitions, we performed for each cohort linear regression of birth weight on estimates of cord serum concentration of PCB 153 and p,p’-DDE adjusted for gestational age and a priori selected covariates. We obtained summary estimates by meta-analysis and performed analyses of interactions.
Results: The median concentration of cord serum PCB 153 was 140 ng/L (range of cohort medians 20-484) and that of p,p’-DDE was 528 ng/L (range of cohort medians 50-1208). Birth weight decreased with increasing cord serum concentration of PCB 153 after adjustment for potential confounders in 12 of 15 study populations. The meta-analysis including all cohorts indicated a birth weight decline of 150 g (95% CI -250, -50) per 1-µg/L increase in PCB 153, an exposure contrast that is close to the range of exposuress across the cohorts. A 1-µg/L increase in p,p’-DDE was associated with a 7 g decrease in birth weight (95% CI -18, 4 g).
Conclusions: The findings suggest that low-level exposure to PCB (or correlated exposures) impairs fetal growth, while p,p’-DDE exposure does not. The study adds to mounting evidence that low-level exposure to PCBs is inversely associated with fetal growth.

Policy theme(s)

Chemicals >> Impacts >> Health impacts
Chemicals >> Pollutants/hazardous substances >> Pesticides
Environment and health >> Health risks >> Human biomonitoring

Keywords

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

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http://dx.doi.org/10.1289/ehp.1103767  
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jpb@bbh.regionh.dk

Title

Internal exposure to pollutants and sexual maturation in Flemish adolescents

Reference

Journal of Exposure Science and Environmental Epidemiology
(2011) 21, 224-233; doi:10.1038/jes.2010.2

Author(s)

Elly Den Hond, Willem Dhooge, Liesbeth Bruckers, Greet Schoeters, Vera Nelen, Els van de Mieroop, Gudrun Koppen, Maaike Bilau, Carmen Schroijen, Hans Keune, Willy Baeyens and Nicolas van Larebeke

Study type

Peer Review Journal

Abstract

Flanders is densely populated with much industry and intensive farming. Sexual maturation of adolescents (aged 14-15 years) was studied in relation to internal exposure to pollutants. Serum levels of pollutants and sex hormones were measured in 1679 participants selected as a random sample of the adolescents residing in the study areas. Data on sexual development were obtained from the medical school examination files. Self-assessment questionnaires provided information on health, use of medication and lifestyle factors. In boys, serum levels of hexachlorobenzene (HCB), p,p'-DDE and polychlorinated biphenyls (sum of marker PCB138, 153 and 180) were significantly and positively associated with pubertal staging (pubic hair and genital development). Higher levels of serum HCB and blood lead were associated with, respectively, a lower and a higher risk of gynecomastia. In girls, significant and negative associations were detected between blood lead and pubic hair development; higher exposure to PCBs was significantly associated with a delay in timing of menarche. Environmental exposures to pollutants at levels actually present in the Flemish population are associated with measurable effects on pubertal development. However, further understanding of toxic mode of action and sensitive windows of exposure is needed to explain the current findings.

Policy theme(s)

Environment and health >> Health risks >> Human biomonitoring
Air pollution >> Impact of emissions >> Health impacts

Keywords

Human biomonitoring, Adolescents, Hormone levels, Sexual maturation, Environment, Pollution

Entry Source:

Shortlisted for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://www.nature.com/jes/journal/v21/n3/full/jes20102a.html
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kim.croes@vub.ac.be

Title

Reference

Journal of Exposure Science and Environmental Epidemiology 21, 106113; doi:10.1038/jes.2009.63;

Author(s)

Willem Dhooge, Elly Den Hond, Gudrun Koppen, Liesbeth Bruckers, Vera Nelen, Els van de Mieroop, Maaike Bilau, Kim Croes, Willy Baeyens, Greet Schoeters and Nicolas van Larebeke

Study type

Peer Review Journal

Abstract

Flanders is densely populated with much industry and intensive farming. Hormonal status of 14- to 15-year-old male adolescents was studied in relation to internal exposure to pollutants. A total of 887 participants were selected as a random sample of the adolescents residing in the study areas. Confounding factors and significant covariates were taken into account. Serum levels of testosterone, free testosterone and estradiol, and the aromatase index showed significant positive associations with serum levels of marker polychlorobiphenyls (sum of PCBs 138, 153, and 180) and of hexachlorobenzene (HCB) and a negative association with urinary cadmium concentration. Serum levels of estradiol also showed a positive association with serum levels of dichlorodiphenyldichloroethylene (DDE). A doubling of serum concentrations of marker PCBs and HCB and of urinary concentration of cadmium were, respectively, associated with an increase of 16.4% (P<0.00001) and 16.6% (P<0.001) and a decrease of 9.6% (P<0.001) in serum testosterone concentration. Similar findings were made after additional adjustment for concurrent exposures. Associations between biological effects and internal exposures were, in terms of the regression coefficient, often stronger at exposures below the median. Environmental exposures to pollutants resulting in 'normal' levels of internal exposure were associated with quite substantial differences in hormone concentrations.

Policy theme(s)

Air pollution >> Impact of emissions >> Health impacts
Environment and health >> Health risks >> Air pollution
Environment and health >> Health risks >> Human biomonitoring

Keywords

Lead, Cadmium, Organochlorines, Polychlorobiphenyls, PCB 118, Dioxin-like activity, Hexachlorobenzene, p,p'-Dichlorodiphenyldichloroethylene, Body mass index, Height, Health effects, Low dose

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://www.nature.com/jes/journal/v21/n1/full/jes200963a.html
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nicolas.vanlarebeke@ugent.be

Title

Polychlorinated Biphenyls, Lead, and Mercury Are Associated with Liver Disease in American Adults: NHANES 2003-2004

Reference

Environ Health Perspect 118:1735-1742 doi:10.1289/ehp.1002720

Author(s)

Matt Cave , Savitri Appana, Mihir Patel, Keith Cameron Falkner, Craig J. McClain, Guy Brock

Study type

Peer Review Journal

Abstract

Background: High-level occupational exposures to some industrial chemicals have been associated with liver diseases, including nonalcoholic fatty liver disease (NAFLD). However, the potential role of low-level environmental pollution on liver disease in the general population has not been evaluated. Objective: We determined whether environmental pollutants are associated with an elevation in serum alanine aminotransferase (ALT) activity and suspected NAFLD in U.S. adults. Methods: This cross-sectional cohort study evaluated adult participants without viral hepatitis, hemochromatosis, or alcoholic liver disease from the National Health and Nutrition Examination Survey (NHANES) for 2003-2004. ALT elevation was defined in men as ≥ 37 IU/L (age18-20 years) and ≥ 48 IU/L (age ≥ 21 years) and in women as ≥ 30 IU/L (age 18-20 years) and ≥ 31 IU/L (age ≥ 21 years). Adjusted odds ratios (ORs) for ALT elevation were determined across exposure quartiles for 17 pollutant subclasses comprising 111 individual pollutants present with at least a 60% detection rate. Adjustments were made for age, race/ethnicity, sex, body mass index, poverty income ratio, and insulin resistance. Individual pollutants from subclasses associated with ALT elevation were subsequently analyzed. Results: The overall prevalence of ALT elevation was 10.6%. Heavy metals and polychlorinated biphenyls (PCBs) were associated with dose-dependent increased adjusted ORs for ALT elevation. Within these subclasses, increasing whole-blood levels of lead and mercury and increasing lipid-adjusted serum levels of 20 PCBs were individually associated with ALT elevation. Conclusions: PCB, lead, and mercury exposures were associated with unexplained ALT elevation, a proxy marker of NAFLD, in NHANES 2003-2004 adult participants.

Policy theme(s)

Chemicals >> Pollutants/hazardous substances >> Heavy metals
Environment and health >> Health risks >> Air pollution
Environment and health >> Health risks >> Human biomonitoring

Keywords

environmental liver disease, hepatotoxicity, lead, mercury, NAFLD, NASH, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, PCBs, polychlorinated biphenyls, TASH.

Entry Source:

Shortlisted for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.1002720 There is a fee to view this study in full

Contact the study author at:

craig.mcclain@louisville.edu