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Gump BB, Hill DT, Robinson M, Kannan K, Heffernan K, Atallah-Yunes NH, Brann L, Parsons PJ, Palmer CD, MacKenzie JA, Goodrich JM, Bendinskas K. Perfluoroalkyl substances (PFAS) and lead (Pb) as "cardiovascular disruptors" in 9-11-year-old children living in Syracuse, New York, United States. ENVIRONMENTAL RESEARCH 2023; 236:116758. [PMID: 37532213 DOI: 10.1016/j.envres.2023.116758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 08/04/2023]
Abstract
OBJECTIVE Per- and polyfluoro-alkyl substances (PFAS) and lead (Pb) are ubiquitous environmental toxicants with apparent impact on cardiovascular disease (CVD) risk. As one possible mechanism for this increased risk, we have previously demonstrated an association between Pb exposure and heightened cardiovascular reactivity to acute psychological stress, a CVD risk factor. The present study expands this approach and considers both PFAS and Pb exposures (and the possible interaction). METHODS We assessed 14 serum PFAS and whole blood Pb concentrations in a sample of 9-11 year-old children (N = 291; 43.2% White, 56.8% Black; 53.5% female). We measured cardiovascular functioning at rest and during psychological stress as well as multiple indicators of subclinical CVD including resting blood pressure (BP), carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT), and left ventricular mass (LVM). Data analysis included general linear modeling as well as a non-parametric approach to study metal mixtures, specifically Bayesian Kernel Machine Regression (BKMR). RESULTS Significant interactions between different PFAS and with Pb suggest the importance of considering toxicant mixtures when assessing potential disruption of the cardiovascular system. The pattern of findings suggests that greater "vascular reactivity" (elevated BP and vascular resistance during acute psychological stress) was associated with higher concentrations of perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and Pb, but only when perfluorooctanoic acid (PFOA) was concurrently elevated. With respect to subclinical outcomes, increasing perfluorodecanoic acid (PFDA) was associated with greater cIMT (β = 0.21, p = 0.010). CONCLUSION To our knowledge this is the first study to consider how PFAS exposures might affect cardiovascular functioning and subclinical disease. Although a complex pattern of associations emerged, it does appear that PFAS and Pb can be classified as "cardiovascular disruptors" in children. Further research is needed to replicate these novel findings and determine whether these disruptions produce future cardiovascular disease.
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Affiliation(s)
- Brooks B Gump
- Department of Public Health, Syracuse University, United States.
| | - Dustin T Hill
- Department of Public Health, Syracuse University, United States
| | - Morgan Robinson
- Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | | | - Kevin Heffernan
- Department of Exercise Science, Syracuse University, United States
| | | | - Lynn Brann
- Department of Nutrition and Food Studies, Syracuse University, United States
| | - Patrick J Parsons
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, United States; Department of Environmental Health Sciences, School of Public Health, The University at Albany, United States
| | - Christopher D Palmer
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, United States; Department of Environmental Health Sciences, School of Public Health, The University at Albany, United States
| | - James A MacKenzie
- Department of Biological Sciences, State University of New York College at Oswego, United States
| | - Jackie M Goodrich
- Department of Environmental Health Sciences, University of Michigan, United States
| | - Kestutis Bendinskas
- Department of Chemistry, State University of New York College at Oswego, United States
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Stewart PW, Reihman J, Lonky E, Pagano J. Issues in the interpretation of associations of PCBs and IQ. Neurotoxicol Teratol 2012; 34:96-107. [DOI: 10.1016/j.ntt.2011.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 11/18/2011] [Accepted: 11/18/2011] [Indexed: 10/14/2022]
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Tian YH, Hwan Kim S, Lee SY, Jang CG. Lactational and postnatal exposure to polychlorinated biphenyls induces sex-specific anxiolytic behavior and cognitive deficit in mice offspring. Synapse 2011; 65:1032-41. [PMID: 21425352 DOI: 10.1002/syn.20934] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 03/12/2011] [Accepted: 03/14/2011] [Indexed: 01/22/2023]
Abstract
The central nervous system is affected by polychlorinated biphenyls (PCBs). Previous studies have indicated that developmental exposure to PCBs impairs behavioral performance and alters cognitive abilities. This study assessed the effects of lactational and postnatal exposure to a commercial PCBs mixture, Aroclor 1254 (A1254), on mice performing several neurobehavioral tasks including the open field test, novel object test, elevated plus maze test, Y-maze test, and tail suspension test. In the open field test, PCBs treatment (6 and 18 mg/kg/day) was associated with increased movement, time duration, and frequency in the central zone in female but not male mice. PCBs-treated female mice (6 and 18 mg/kg/day) also showed decreased novel object recognition, indicating impairment in recognition memory. Finally, we performed autoradiographic receptor binding assays for dopamine (DA) D₁ and D₂ receptors, dopamine transporter (DAT), and the N-methyl-D-aspartic acid (NMDA) receptor after behavioral tests to examine whether alterations occurred in the dopaminergic and NMDAergic systems of the brain. Our results showed that PCBs treatment did not change D₁ and D₂ receptors or DAT binding in the dorsal striatum of female mice. However, PCBs treatment significantly decreased NMDA receptor binding in the dorsal striatum, frontal cortex, cingulate cortex, and motor cortex, and CA3 and dentate gyrus (DG) of the hippocampus in female mice. Collectively, our results suggest that long-term PCBs exposure can induce anxiolytic behavior, cognitive deficits, and changes of NMDA receptors.
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Affiliation(s)
- Yu-Hua Tian
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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McGraw JE, Waller DP. Fish ingestion and congener specific polychlorinated biphenyl and p,p'-dichlorodiphenyldichloroethylene serum concentrations in a great lakes cohort of pregnant African American women. ENVIRONMENT INTERNATIONAL 2009; 35:557-65. [PMID: 19046769 DOI: 10.1016/j.envint.2008.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 10/02/2008] [Accepted: 10/10/2008] [Indexed: 05/23/2023]
Abstract
A cohort of low income, city dwelling, pregnant African American Women (delivered from 1994-1999) was assembled to identify factors related to organochlorine exposure through consumption of Great Lakes resources. The cohort is known as the Great Lakes Cohort of Pregnant African American Women (GLCPAAW). Pregnant women from metropolitan Chicago, IL area clinics were administered a questionnaire on diet, demographics, and health history. Weight, height, and serum lipids were measured at delivery along with serum organochlorines such as PCBs and DDE. Congener specific concentrations of PCBs and p,p'-DDE found in the maternal serum are reported. Dominant PCB congeners found in the serum of the pregnant women at delivery included PCB 101, 118, 138, 153, and 180. The high prevalence and magnitude of PCB 101 (greater than the limit of detection in >80% of the women in the cohort) are unique characteristics of this cohort. Great Lakes fish has been identified as a source of exposure to organochlorines in several studies. Spearman correlations and robust regression models were utilized to identify the impact of Great Lakes fish ingestion on cohort serum organochlorine concentrations. Several potential confounders of the relationship between serum organochlorines and Great Lakes fish consumption were identified. Covariates related to organochlorines in correlations as well as regression models included age, body surface area, fish ingestion, lipids, parity, race and smoking. Lower chlorinated PCB congeners do not follow the same trends as the higher chlorinated congeners and DDE. The higher chlorinated PCB congeners (PCB 138, 153, and 180) and DDE were correlated with age while the lower chlorinated congeners were not. PCB 153 and 180 regression models included age as a significant covariate. None of the higher chlorinated congeners correlated to race, while both lower chlorinated congeners were correlated to race. Race was also significant in both lower chlorinated congeners' regression models. PCB 101, a lower chlorinated congener seldom found in human serum, is readily found in the cohort. Airborne PCB exposure as well as diminished metabolism of PCB 101 in African Americans may explain the increased presence of PCB 101 and it's correlation with race. High end sport fish consumers (> or =1 meal per week) carried elevated levels of DDE and higher chlorinated PCB congeners (138, 153, and 180) compared to non-sport fish eaters. Unexpectedly, DDE was correlated more consistently with fish ingestion and age (a marker of bioaccumulation) in comparison to PCBs. Small correlations were found between serum PCBs and fish ingestion (Spearman correlation=0.19 for total PCBs and fish meals per year). Additionally, Serum PCBs in low end Great Lakes sport fish consumers were not higher than non-consumers. These findings suggest the women of the cohort are being exposed to PCBs through other routes in addition to Great lakes sport fish. One major route of exposure may be Chicago air. The observed trends amongst individual PCB congeners has important ramifications because lower chlorinated congeners or their metabolites may be mediators of toxicity. Organochlorine exposure through Great Lakes fish ingestion was clearly identified in high end fish consumers while associations with race, metabolism, and possible airborne exposures pose new questions.
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Affiliation(s)
- Joseph E McGraw
- University of Illinois at Chicago, College of Pharmacy, Department of Biopharmaceutical Sciences, Chicago, Illinois 60621-7231, USA.
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Stewart PW, Lonky E, Reihman J, Pagano J, Gump BB, Darvill T. The relationship between prenatal PCB exposure and intelligence (IQ) in 9-year-old children. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:1416-22. [PMID: 18941588 PMCID: PMC2569105 DOI: 10.1289/ehp.11058] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2007] [Accepted: 05/28/2008] [Indexed: 05/02/2023]
Abstract
BACKGROUND Several epidemiologic studies have demonstrated relationships between prenatal exposure to polychlorinated biphenyls (PCBs) and modest cognitive impairments in infancy and early childhood. However, few studies have followed cohorts of exposed children long enough to examine the possible impact of prenatal PCB exposure on psychometric intelligence in later childhood. Of the few studies that have done so, one in the Great Lakes region of the United States reported impaired IQ in children prenatally exposed to PCBs, whereas another found no association. OBJECTIVES This study was designed to determine whether environmental exposure to PCBs predicts lower IQ in school-age children in the Great Lakes region of the northeastern United States. METHODS We measured prenatal exposure to PCBs and IQ at 9 years of age in 156 subjects from Oswego, New York. We also measured > 50 potential predictors of intelligence in children, including repeated measures of the home environment [Home Observation for Measurement of the Environment (HOME)], socioeconomic status (SES), parental IQ, alcohol/cigarette use, neonatal risk factors, and nutrition. RESULTS For each 1-ng/g (wet weight) increase in PCBs in placental tissue, Full Scale IQ dropped by three points (p = 0.02), and Verbal IQ dropped by four points (p = 0.003). The median PCB level was 1.50 ng/g, with a lower quartile of 1.00 ng/g and an upper quartile of 2.06 ng/g. Moreover, this association was significant after controlling for many potential confounders, including prenatal exposure to methylmercury, dichlorodiphenyldichloroethylene, hexachlorobenzene, and lead. CONCLUSIONS These results, in combination with similar results obtained from a similar study in the Great Lakes conducted 10 years earlier, indicate that prenatal PCB exposure in the Great Lakes region is associated with lower IQ in children.
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Affiliation(s)
- Paul W Stewart
- Center for Neurobehavioral Effects of Environmental Toxics, State University of New York at Oswego, Oswego, New York 13126, USA.
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Somers CM, Valdes EV, Kjoss VA, Vaillancourt AL, Quinn JS. Influence of a contaminated fish diet on germline expanded-simple-tandem-repeat mutation frequency in mice. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2008; 49:238-248. [PMID: 18288721 DOI: 10.1002/em.20380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Herring gulls (Larus argentatus) in polluted areas on the North American Great Lakes were previously shown to have elevated germline mutation frequencies at minisatellite DNA loci. Airborne or dietary contaminants likely caused induced mutations, but the importance of each exposure type was unknown. Follow-up experiments with lab mice determined that air pollution significantly induced germline mutations; however, an evaluation of mutations induced by the diet of herring gulls has not yet been conducted. To address this issue, we fed mice a high-fish diet (58% wet mass) of the most common prey species for herring gulls nesting in Hamilton Harbour, a polluted industrial area on Lake Ontario. We bred the mice and screened pedigrees for germline mutations at expanded-simple-tandem-repeat (ESTR) DNA loci. Mutation frequencies were compared to those in a reference group that was fed fish from Atlantic Canada, and a control group that was fed commercial chow. Germline mutation frequencies were highest in mice fed contaminated fish, but were only marginally or not significantly affected by diet treatment. Statistical power to detect differences among treatment groups was low, and the effect of diet may have more clearly emerged if larger sample sizes were available. Levels of organic pollutants in the fish from Hamilton Harbour were higher than those from Atlantic Canada, but their ability to induce ESTR mutations is unknown. Our findings suggest that a contaminated fish diet may contribute to the elevated germline mutation frequencies observed previously in gulls at this site, but air pollution is likely a more important route of exposure.
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Gump BB, Stewart P, Reihman J, Lonky E, Darvill T, Parsons PJ, Granger DA. Low-level prenatal and postnatal blood lead exposure and adrenocortical responses to acute stress in children. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:249-55. [PMID: 18288326 PMCID: PMC2235205 DOI: 10.1289/ehp.10391] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 11/15/2007] [Indexed: 05/03/2023]
Abstract
BACKGROUND A few recent studies have demonstrated heightened hypothalamic-pituitary-adrenal (HPA) axis reactivity to acute stress in animals exposed to heavy metal contaminants, particularly lead. However, Pb-induced dysregulation of the HPA axis has not yet been studied in humans. OBJECTIVE In this study, we examined children's cortisol response to acute stress (the glucocorticoid product of HPA activation) in relation to low-level prenatal and postnatal Pb exposure. METHODS Children's prenatal blood Pb levels were determined from cord blood specimens, and postnatal lead levels were abstracted from pediatrician and state records. Children's adrenocortical responses to an acute stressor were measured using assays of salivary cortisol before and after administration of a standard cold pressor task. RESULTS Pb exposure was not associated with initial salivary cortisol levels. After an acute stressor, however, increasing prenatal and postnatal blood Pb levels were independently associated with significantly heightened salivary cortisol responses. CONCLUSIONS Our results suggest that relatively low prenatal and postnatal blood lead levels--notably those below the 10 microg/dL blood lead level identified by the Centers for Disease Control and Prevention for public health purposes--can alter children's adrenocortical responses to acute stress. The behavioral and health consequences of this Pb-induced HPA dysregulation in children have yet to be determined.
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Affiliation(s)
- Brooks B Gump
- Department of Psychology, State University of New York College at Oswego, Oswego, NY 13126, USA.
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Basu N, Scheuhammer AM, O'Brien M. Polychlorinated biphenyls, organochlorinated pesticides, and polybrominated diphenyl ethers in the cerebral cortex of wild river otters (Lontra canadensis). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2007; 149:25-30. [PMID: 17321655 DOI: 10.1016/j.envpol.2006.12.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 12/14/2006] [Accepted: 12/18/2006] [Indexed: 05/14/2023]
Abstract
We measured the levels of ortho-substituted polychlorinated biphenyls (PCB), organochlorinated pesticides (OCP), and polybrominated diphenyl ethers (PBDE) in the cerebral cortex of river otters (Lontra canadensis) trapped from Ontario and Nova Scotia between 2002 and 2004. The mean concentration of total PCBs was 70.9+/-12.1 ng/g l.w., and congeners 153, 180 and 138 accounted for nearly 60% of the sum. The mean concentration of total OCPs was 21.2+/-3.7 ng/g l.w., and hexachlorobenzene (32.6% of total) and DDE (28.1%) accounted for the majority. The mean concentration of total PBDEs was 3.2+/-0.6 ng/g l.w., and congeners 99 (44.9%), 153 (30.5%), and 100 (24.7%) were measured at the indicated percentages. There was no relationship between these residue data and concentrations of brain mercury or neurochemical receptors and enzymes as determined in earlier studies on these same animals.
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Affiliation(s)
- Niladri Basu
- National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3, Canada.
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9
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Stewart PW, Sargent DM, Reihman J, Gump BB, Lonky E, Darvill T, Hicks H, Pagano J. Response inhibition during Differential Reinforcement of Low Rates (DRL) schedules may be sensitive to low-level polychlorinated biphenyl, methylmercury, and lead exposure in children. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:1923-9. [PMID: 17185286 PMCID: PMC1764150 DOI: 10.1289/ehp.9216] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND Animal studies have shown that exposure to common, low-level environmental contaminants [e.g., polychlorinated biphenyls (PCBs), lead] causes excessive and inappropriate responding on intermittent reinforcement schedules. The Differential Reinforcement of Low Rates task (DRL) has been shown to be especially sensitive to low-level PCB exposure in monkeys. OBJECTIVES We investigated the relationships between prenatal PCB and postnatal Pb exposure performance on a DRL schedule in children. We predicted that a) prenatal PCB exposure would reduce interresponse times (IRTs) and reinforcements earned, and b) postnatal Pb exposure would reduce IRTs and reinforcements earned. METHODS We tested 167 children on a DRL20 (20 sec) reinforcement schedule, and recorded IRTs and the number of reinforced responses across the session. We measured prenatal PCB exposure (cord blood), methylmercury (MeHg) (maternal hair), and postnatal Pb exposure (venous blood), and > 50 potentially confounding variables. RESULTS Results indicated impaired performance in children exposed to PCBs, MeHg, and Pb. Children prenatally exposed to PCBs responded excessively, with significantly lower IRTs and fewer reinforcers earned across the session. In addition, exposure to either MeHg or Pb predicted statistically significant impairments of a similar magnitude to those for PCBs, and the associated impairments of all three contaminants (PCB, MeHg, and Pb) were statistically independent of one another. CONCLUSIONS These results, taken with animal literature, argue the high sensitivity of DRL performance to low-level PCB, MeHg, and Pb exposure. Future research should employ behavioral tasks in children, such as DRL, that have been demonstrably sensitive to low-level PCB, MeHg, and Pb exposure in animals.
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Affiliation(s)
- Paul W Stewart
- Department of Psychology, State University of New York at Oswego, Oswego, New York 13126, USA.
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Mariussen E, Fonnum F. Neurochemical targets and behavioral effects of organohalogen compounds: an update. Crit Rev Toxicol 2006; 36:253-89. [PMID: 16686424 DOI: 10.1080/10408440500534164] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Organohalogen compounds (OHCs) have been used and still are used extensively as pesticides, flame retardants, hydraulic fluids, and in other industrial applications. These compounds are stable, most often lipophilic, and may therefore easily biomagnify. Today these compounds are found distributed both in human tissue, including breast milk, and in wildlife animals. In the late 1960s and early 1970s, high levels of the polychlorinated biphenyls (PCBs) and the pesticide dichlorodiphenyl trichloroethane (DDT) were detected in the environment. In the 1970s it was discovered that PCBs and some chlorinated pesticides, such as lindane, have neurotoxic potentials after both acute and chronic exposure. Although the use of PCBs, DDT, and other halogenated pesticides has been reduced, and environmental levels of these compounds are slowly diminishing, other halogenated compounds with potential of toxic effects are being found in the environment. These include the brominated flame retardants, chlorinated paraffins (PCAs), and perfluorinated compounds, whose levels are increasing. It is now established that several OHCs have neurobehavioral effects, indicating adverse effects on the central nervous system (CNS). For instance, several reports have shown that OHCs alter neurotransmitter functions in CNS and Ca2+ homeostatic processes, induce protein kinase C (PKC) and phospholipase A2 (PLA2) mobilization, and induce oxidative stress. In this review we summarize the findings of the neurobehavioral and neurochemical effects of some of the major OHCs with our main focus on the PCBs. Further, we try to elucidate, on the basis of available literature, the possible implications of these findings on human health.
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Affiliation(s)
- E Mariussen
- Norwegian Institute for Air Research, Kjeller, Norway.
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Somers CM, Valdes EV, Quinn JS. An approach to feeding high-percentage fish diets to mice for human and wildlife toxicology studies. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2006; 63:481-7. [PMID: 16406584 DOI: 10.1016/j.ecoenv.2005.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Revised: 03/04/2005] [Indexed: 05/06/2023]
Abstract
Experimental feeding of sport fish to rodents has been an important tool for the study of biological effects induced by a contaminated fish diet. Most rodent feeding studies have used low-to-moderate levels of tissue from large fish species incorporated into diets fed to rats and have given little consideration to issues of diet palatability or nutrition. There are currently no rodent diet models suitable for assessing the risk to human populations of diets very high in daily fish content or to wildlife species consuming high percentages of whole, small-bodied fish. In this study, we describe an approach to feeding mice high percentages (up to 50%) of homogenized, whole fish using Atlantic herring (Clupea harengus) as a test species. We created a novel gel diet medium for mice that contains a variety of nutritional supplements and is flexible in terms of the fish percentage that can be incorporated. In choice trials, mice preferred 30 and 35% fish gels to their regular commercial dry chow, indicating that the gel diet medium was palatable. In a longer feeding trial, mice ate 35% fish gel for 12 days and 50% fish gel for 12 days (total of 24 consecutive days) and did not differ in body mass compared to age- and sex-matched controls. We conclude that our fish-based gel diet is suitable for rodent feeding trials in toxicology studies that examine dose responses to fish consumption and risk in human and wildlife populations among which daily fish intake is very high. Our general approach may also be applicable for feeding mice materials other than fish.
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Affiliation(s)
- Christopher M Somers
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, Ont., Canada L8S 4K1
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Stewart P, Reihman J, Gump B, Lonky E, Darvill T, Pagano J. Response inhibition at 8 and 9 1/2 years of age in children prenatally exposed to PCBs. Neurotoxicol Teratol 2005; 27:771-80. [PMID: 16198536 DOI: 10.1016/j.ntt.2005.07.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Revised: 02/01/2005] [Accepted: 07/09/2005] [Indexed: 10/25/2022]
Abstract
We previously reported a relationship between prenatal PCB exposure and impulsive (excessive) responding on a continuous performance task in children at 4 1/2 years of age [P.W. Stewart, S. Fitzgerald, J. Reihman, B. Gump, E. Lonky, T. Darvill, J. Pagano, P. Hauser, Prenatal PCB exposure, the corpus callosum, and response inhibition, Environmental Health Perspectives 111 (13) (2003b) 1670-1677.]. The current study investigated the stability of this effect at 8 and 9 1/2 years of age. We tested the hypothesis that PCB-related impulsive responding might be a function of impaired response inhibition. Children (n=202) enrolled in the Oswego Children's Study were tested at 8 years of age using the NES2 Continuous Performance Test (CPT). This was followed by a series of Extended Continuous Performance Tests (E-CPT) at 9 1/2 years of age, designed to dissociate response inhibition from sustained attention. After taking into account more than 50 measured covariables, including maternal IQ, maternal sustained attention and maternal response inhibition, results revealed PCB-related associations with impulsive responding at both testing ages. At 8 years of age, prenatal PCB exposure was associated with increased impulsive responding on the CPT. At 9 1/2 years of age, E-CPT testing clearly indicated that the PCB-related impulsive responding was due to impaired response inhibition and not impaired sustained attention. These results were significant after extensive and rigorous control for multiple potential confounders, including several non-PCB contaminants (prenatal MeHg, DDE, HCB, and pre- and postnatal Pb). These data are consistent with, and in fact predicted by, several studies in PCB-exposed animals.
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Affiliation(s)
- Paul Stewart
- 304 Mahar Hall, State University of New York at Oswego, Oswego, NY 13126, USA.
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Sugawara N, Nakai K, Nakamura T, Ohba T, Suzuki K, Kameo S, Satoh C, Satoh H. Developmental and neurobehavioral effects of perinatal exposure to polychlorinated biphenyls in mice. Arch Toxicol 2005; 80:286-92. [PMID: 16244857 DOI: 10.1007/s00204-005-0042-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Accepted: 09/28/2005] [Indexed: 10/25/2022]
Abstract
Because behavioral deficits associated with gestational exposure to polychlorinated biphenyls (PCBs) have been a concern, we studied the developmental and neurobehavioral effects of perinatal exposure to Aroclor 1254 (A1254), a commercial mixture of PCBs, in mice. The PCB mixture (A1254; 0, 6, 18, and 54 mg/kg body weight) was administered to pregnant mice (C57BL/6Cr) every 3 days by gavage from gestational day (GD) 6 to postnatal day (PND) 20. Compared with the control, treatment with A1254 did not alter the maternal body weight during the gestation and lactation periods. The body weight of the offspring did not differ among treatments. To assess the effects on offspring following such exposure, physical and neurobehavioral development (i.e., pinna detachment, hair growth, eye opening, incisor eruption, grasp reflex, righting reflex, walking, negative geotaxis, and cliff avoidance) was observed before weaning. At PND 7, poor adult-like responses in negative geotaxis were observed in all exposed groups. When the offspring were at 8-week old, the PCB-treated (18 mg/kg body weight) mice showed a decreased walking speed in the open-field test, and a prolonged time to reach the platform in the water maze test. Spontaneous locomotion activity was not affected by PCB exposure at 9 weeks . These results showed that perinatal exposure to PCBs produces several behavioral alterations in mice. Although dose-dependent changes were not observed, the neurobehavioral effects such as a decreased walking speed in the open-field test and a prolonged time to reach the platform in the water maze test remained in adulthood after the seeming recovery from the transient delay in development before weaning.
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Affiliation(s)
- Norio Sugawara
- Department of Environmental Health Sciences, Tohoku University Graduate School of Medicine, 2-1 Seiryomachi, Aoba-ku, Sendai, 980-8575, Japan.
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Jelaso AM, DeLong C, Means J, Ide CF. Dietary exposure to Aroclor 1254 alters gene expression in Xenopus laevis frogs. ENVIRONMENTAL RESEARCH 2005; 98:64-72. [PMID: 15721885 DOI: 10.1016/j.envres.2004.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Revised: 05/19/2004] [Accepted: 05/21/2004] [Indexed: 05/24/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that contribute to worldwide health problems. Despite data associating PCBs with adverse health effects, decisions to clean up contaminated sites remain controversial. Cleanup decisions are typically based on risk assessment methods that are not sensitive enough to detect subtle changes in health. We have recently shown that gene expression signatures can serve as sensitive molecular biomarkers of exposure and related health effects. Our initial studies were carried out with developing Xenopus laevis tadpoles that were exposed to the PCB mixture Aroclor 1254 (A1254) for 2 days. A1254 was dissolved in dimethyl sulfoxide and added to the aquarium water for rapid loading of PCBs into the tadpole tissue. These studies showed that increases in the expression of specific genes occurred independent of adverse health effects, and decreases in specific genes correlated with the appearance of observable health effects, including decreased survival and gross morphological and behavioral abnormalities. In this report, we extend our previous work to test the use of gene expression signatures as biomarkers in frogs exposed to PCBs through the diet from early tadpole stages through metamorphosis. This work showed that chronic low-dose exposure to A1254 (24 ppm) in food produced tissue levels of 17 ppm and increased gene expression of nerve growth factor and proopiomelanocortin independent of adverse health effects. Exposure to higher doses of A1254 (200 ppm) produced tissue levels of 80 ppm and increased expression of p450 1A1, also, independent of adverse health effects. This work provides further evidence for the use of gene expression changes as biomarkers of exposure to PCBs.
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Affiliation(s)
- Anna M Jelaso
- Environmental Institute and the Great Lakes Center for Environmental and Molecular Sciences, Western Michigan University, Room 3924 Wood Hall, Kalamazoo, MI 49008, USA.
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Colborn T. Neurodevelopment and endocrine disruption. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:944-9. [PMID: 15198913 PMCID: PMC1247186 DOI: 10.1289/ehp.6601] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2003] [Accepted: 11/17/2003] [Indexed: 05/20/2023]
Abstract
In this article I explore the possibility that contaminants contribute to the increasing prevalence of attention deficit hyperactivity disorder, autism, and associated neurodevelopmental and behavioral problems in developed countries. I discuss the exquisite sensitivity of the embryo and fetus to thyroid disturbance and provide evidence of human in utero exposure to contaminants that can interfere with the thyroid. Because it may never be possible to link prenatal exposure to a specific chemical with neurodevelopmental damage in humans, I also present alternate models where associations have been made between exposure to specific chemicals or chemical classes and developmental difficulties in laboratory animals, wildlife, and humans.
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Affiliation(s)
- Theo Colborn
- Department of Zoology, University of Florida, Gainesville, Florida, USA.
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Stewart P, Reihman J, Lonky E, Darvill T, Pagano J. Prenatal PCB exposure and neurobehavioral development in infants and children: Can the Oswego study inform the current debate? PSYCHOLOGY IN THE SCHOOLS 2004. [DOI: 10.1002/pits.20003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Pohl HR, Roney N, Wilbur S, Hansen H, De Rosa CT. Six interaction profiles for simple mixtures. CHEMOSPHERE 2003; 53:183-197. [PMID: 12892681 DOI: 10.1016/s0045-6535(03)00436-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Agency for Toxic Substances and Disease Registry (ATSDR) has a program for chemical mixtures that encompasses research on chemical mixtures toxicity, health risk assessment, and development of innovative computational methods. ATSDR prepared a guidance document that instructs users on how to conduct health risk assessment on chemical mixtures (Guidance Manual for the Assessment of Joint Toxic Action of Chemical Mixtures). ATSDR also developed six interaction profiles for chemical mixtures. Two profiles were developed for persistent environmental chemicals that are often found in contaminated fish and also can be detected in human breast milk. The mixture included chlorinated dibenzo-p-dioxins, hexachlorobenzene, dichlorodiphenyl dichloroethane, methyl mercury, and polychlorinated biphenyls. Two profiles each were developed for mixtures of metals and mixtures of volatile organic chemicals (VOCs) that are frequently found at hazardous waste sites. The two metal profiles dealt with (a) lead, manganese, zinc, and copper; and (b) arsenic, cadmium, chromium, and lead; the two VOCs mixtures dealt with (a) 1,1,1-trichloroethane, 1,1-dichloroethane, trichloroethylene, and tetrachloroethylene; and (b) benzene, ethylbenzene, toluene, and xylenes (BTEX). Weight-of-evidence methodology was used to assess the joint toxic action for most of the mixtures. Physiologically based pharmacokinetic modeling was used for BTEX. In most cases, a target-organ toxicity dose modification of the hazard index approach is recommended for conducting exposure-based assessments of noncancer health hazards.
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Affiliation(s)
- Hana R Pohl
- Agency for Toxic Substances and Disease Registry, US Department of Health and Human Services, 1600 Clifton Road, Atlanta, Georgia 30333, USA.
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Stewart PW, Reihman J, Lonky EI, Darvill TJ, Pagano J. Cognitive development in preschool children prenatally exposed to PCBs and MeHg. Neurotoxicol Teratol 2003; 25:11-22. [PMID: 12633733 DOI: 10.1016/s0892-0362(02)00320-3] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A number of epidemiological studies have shown predictive relationships between prenatal exposure to polychlorinated biphenyls (PCBs) and subtle deficits in cognitive development in infancy through the preschool years [Child Dev. 56 (1985) 853; J. Pediatr. 116 (1990) 38; J. Pediatr. 134 (1999) 33; Toxicol. Lett. 102-103 (1998) 423; Neurotox. 21 (6) (2000) 1029-1038]. However, since not all studies have demonstrated these relationships (J. Pediatr. 119 (1991) 58-63), debate regarding the role of prenatal PCB exposure in cognitive development continues. The current study was designed to provide additional data to assist in resolving this question. Two hundred twelve children enrolled in the Oswego Newborn and Infant Development Project were assessed using the McCarthy Scales of Children's Abilities at 38 months of age, followed by a reassessment at 54 months of age. The relationship between prenatal exposure to PCBs (cord blood PCBs) and McCarthy performance was assessed at both ages after first controlling for a wide range of important predictors of cognitive development, including socioeconomic status (SES), maternal IQ, maternal education, home environment, cigarette smoking, and many others. Cord blood PCBs were statistically significant predictors of small but measurable deficits in McCarthy performance at 38 months of age. Moreover, a significant interaction between cord blood PCBs and maternal hair mercury (MeHg) was found, such that negative associations between prenatal MeHg exposure and McCarthy performance were found in subjects with higher levels of prenatal PCB exposure. No relationship between PCBs and/or MeHg and McCarthy performance was observed when the children were reassessed almost 1.5 years later (54 months of age). Inspection of the age-related trajectory of McCarthy performance revealed that the more highly exposed children caught up with the least exposed children by 54 months. Although the current data partially replicate the findings of Jacobson et al., Patandin et al., and Walkowiak et al. [J. Pediatr. 116 (1990) 38; J. Pediatr. 134 (1999) 33; Lancet 358 (2001) 1602], results reported here suggest that functional recovery may occur. Moreover, the interaction between PCB and MeHg cannot be considered conclusive until it has been replicated in subsequent investigations.
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Affiliation(s)
- Paul W Stewart
- Department of Psychology, State University of New York at Oswego, Oswego, NY 13126, USA.
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Jelaso AM, Lehigh-Shirey E, Means J, Ide CF. Gene expression patterns predict exposure to PCBs in developing Xenopus laevis tadpoles. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2003; 42:1-10. [PMID: 12874807 DOI: 10.1002/em.10173] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that pose global ecological and human health problems. Although it is well established that PCBs are associated with a variety of adverse health effects in wildlife and in humans, it is often difficult to determine direct cause-and-effect relationships between exposure and specific health outcomes. In this study, gene expression signatures were used to relate exposure to PCBs with altered physiological responses and/or specific health effects. Real-time PCR was used to measure gene expression levels for 10 genes in Xenopus laevis tadpoles (18 days postfertilization, PF) after acute exposure (2 days) to the PCB mixture Aroclor 1254. Specific gene expression signatures correlated with exposure and were predictive of adverse health effects. Exposure to low levels of Aroclor 1254 (5-50 ppb) significantly increased expression of six genes, independent of any health effects; exposure to midlevel concentrations (300-400 ppb) significantly decreased expression levels of two genes, NGF and beta-actin, prior to the onset of observable health effects; exposure to higher doses (500-700 ppb) significantly decreased NGF and beta-actin expression concomitant with the appearance of gross morphological abnormalities, behavioral deficits, and a statistically significant decrease in survival. This study expands upon our previous work that demonstrated an age-dependent susceptibility to Aroclor 1254 in Xenopus laevis tadpoles and that defined specific gene expression signatures as useful bioindicators of exposure and as predictors of overt or impending health effects.
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Affiliation(s)
- Anna M Jelaso
- Environmental Institute, Western Michigan University, Kalamazoo, Michigan, USA.
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Jelaso AM, Lehigh-Shirey E, Predenkiewicz A, Means J, Ide CF. Aroclor 1254 alters morphology, survival, and gene expression in Xenopus laevis tadpoles. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2002; 40:24-35. [PMID: 12211073 DOI: 10.1002/em.10089] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
PCBs are persistent environmental contaminants that cause a variety of adverse health effects in wildlife and humans. This article describes the use of signature gene expression patterns that link increased PCB exposure with progressive, adverse biological effects. Developing Xenopus laevis tadpoles of two age classes were exposed to the PCB mixture Aroclor 1254 for 2 days. Real-time PCR was used to quantitate mRNA expression for 11 physiologically relevant, potential bioindicator genes. Younger tadpoles (5 days postfertilization) were resistant to Aroclor 1254 and showed few changes in gross morphology, swimming behavior, survival, or gene expression. Older tadpoles (11 days postfertilization) were more susceptible to Aroclor 1254. Exposure to 25 and 50 ppm Aroclor 1254 caused alterations in gross morphology and swimming behavior and statistically significant decreases in survival. These tadpoles showed statistically significant decreases in gene expression for 9 out of the 11 genes measured. Tadpoles exposed to 10 ppm showed incipient health changes but had gene expression profiles similar to the tadpoles treated with higher doses of Aroclor 1254. Tadpoles exposed to 1 ppm did not exhibit any observable adverse health effects, yet statistically significant decreases in gene expression occurred in these tadpoles (4 out of 11 genes). After prolonged exposure, tadpoles exposed to 1 and 10 ppm Aroclor 1254 exhibited health effects similar to those exposed to higher concentrations. Therefore, changes in expression of specific genes may serve not only as molecular bioindicators of Aroclor 1254 exposure but also as predictors of impending adverse health effects.
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Affiliation(s)
- Anna M Jelaso
- Environmental Institute, Western Michigan University, Kalamazoo 49008, USA.
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Miao XS, Balazs GH, Murakawa SK, Li QX. Congener-specific profile and toxicity assessment of PCBs in green turtles (Chelonia mydas) from the Hawaiian Islands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2001; 281:247-253. [PMID: 11778957 DOI: 10.1016/s0048-9697(01)00835-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Chemical pollution may play a role in the etiology of fibropapillomatosis in green turtles (Chelonia mydas). In this preliminary study, polychlorinated biphenyls (PCBs) were measured in the livers and adipose fats of green turtles collected after they were stranded on Oahu Island, Hawaii in 1992-1993. Average concentrations of total PCBs were 45-58 ng/g dry weight and 73-665 ng/g in the liver and adipose tissues, respectively. Hexachlorobiphenyls were predominant homologues, PCBs 153 and 138 were dominant congeners in all the turtle tissues. Among the most toxic coplanar congeners, in the order of abundance, were PCB 77 > 126 > 169. Estimated toxic equivalents (TEQs) of PCBs to 2,3,7,8-tetrachlorodibenzo-p-dioxin were 8-15 pg/g in the livers and 13-48 pg/g in the adipose tissues. PCB 126 contributed 85-91% of the total TEQs.
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Affiliation(s)
- X S Miao
- Department of Molecular Biosciences and Biosystems Engineering, University of Hawaii, Honolulu 96822, USA
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Abstract
The neurological effects of polychlorinated biphenyls (PCBs) have been extensively investigated in humans and in animals. The main focus in human studies has been on the effects in neonates and young children, although studies of adults have also been conducted. A great deal of concern exists that even low levels of PCBs transferred to the fetus across the placenta may induce long-lasting neurological damage. Because PCBs are lipophilic substances, there is also concem that significant amounts might be transferred to nursing infants via breast milk. Studies in humans who consumed large amounts of Great Lakes fish contaminated with environmentally persistent chemicals, including PCBs. have provided evidence that PCBs are important contributors to subtle neurobehavioral alterations observed in newborn children and that some of these alterations persist during childhood. Some consistent observations at birth have been motor immaturity and hyporeflexia and lower psychomotor scores between 6 months and 2 years old. There is preliminary evidence that highly chlorinated PCB congeners, which accumulate in certain fish, are associated with neurobehavioral alterations seen in some newbom children. Subtle neurobehavioral alterations have also been observed in children bom to mothers in the general population with the highest PCB body burdens. Because of the limitations of epidemiological studies, these effects cannot be attributed entirely to PCB exposure. In one general population study, there was strong evidence that dioxins, as well as PCBs, were contributors to the neurobehavioral effects seen in exposed children. Children born to women who accidentally consumed rice oil contaminated with relatively high amounts of PCBs and chlorinated dibenzofurans (CDFs) during pregnancy also had neurodevelopmental changes. Studies in animals support the human data. Neurobehavioral alterations have been also observed in rats and monkeys following prenatal and/or postnatal exposure to commercial Aroclor mixtures, defined experimental congener mixtures, single PCB congeners, and Great Lakes contaminated fish. In addition, monkeys exposed postnatally to PCB mixtures of congeneric composition and concentration similar to that found in human breast milk showed learning deficits long after exposure had ceased. A few other generalizations can be made from the data in animals. It appears that ortho-substituted PCB congeners are more active than coplanar PCBs in modifying cognitive processes. In addition, one effect observed in both rats and monkeys--deficits on delayed spatial alternation--has been known to be induced by exposure to ortho-substituted PCBs, defined experimental mixtures, and commercial Aroclors. Both dioxin-like and non-dioxin-like PCB congeners have been shown to induce neurobehavioral alterations in animals. Changes in levels of neurotransmitters in various brain areas have also been observed in monkeys, rats, and mice. Of all the observed changes, the most consistent has been a decrease in dopamine content in basal ganglia and prefrontal cortex, but further research is needed before specific neurobehavioral deficits can be correlated with PCB-induced changes in specific neurotransmitters in specific brain areas.
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Affiliation(s)
- O Faroon
- Agency for Toxic Substances and Disease Registry (ATSDR) US Department of Health and Human Services, Atlanta, Georgia 30333, USA.
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