Bedford Harbor Superfund Site Research Articles

Multiple prenatal exposures and acute-care clinical encounters for asthma among children born to mothers living near a Superfund site.

Prenatal exposures are associated with childhood asthma, and risk may increase with simultaneous exposures. Pregnant women living in lower-income communities tend to have elevated exposures to a range of potential asthma risk factors, which may interact in complex ways. We examined the association between prenatal exposures and the risk of childhood acute-care clinical encounters for asthma (hospitalizations, emergency department visits, observational stays) using conditional logistic regression with a multivariable smoothing term to model the interaction between continuous variables, adjusted for maternal characteristics and stratified by sex. All births near the New Bedford Harbor (NBH) Superfund site (2000-2006) in New Bedford, Massachusetts, were followed through 2011 using the Massachusetts Pregnancy to Early Life Longitudinal (PELL) Data System to identify children aged 5-11 years with acute-care clinical asthma encounters (265 cases among 7787 children with follow-up). Hazard ratios (HRs) were higher for children living closer to the NBH site with higher umbilical cord blood lead levels than in children living further away from the NBH site with lower lead levels (P<.001). HRs were higher for girls (HR=4.17; 95% CI, 3.60-4.82) than for boys (HR=1.72; 95% CI, 1.46-2.02). Our results suggest that prenatal lead exposure in combination with residential proximity to the NBH Superfund site is associated with childhood asthma acute-care clinical encounters. This article is part of a Special Collection on Environmental Epidemiology.

Differential DNA methylation and metabolite profiling of Atlantic killifish (Fundulus heteroclitus) from the New Bedford Harbor Superfund site

Atlantic killifish (Fundulus heteroclitus) is a valuable model in evolutionary toxicology to study how the interactions between genetic and environmental factors serve the adaptive ability of organisms to resist chemical pollution. Killifish populations inhabiting environmental toxicant-contaminated New Bedford Harbor (NBH) show phenotypes tolerant to polychlorinated biphenyls (PCBs) and differences at the transcriptional and genomic levels. However, limited research has explored epigenetic alterations and metabolic effects in NBH killifish. To identify the involvement of epigenetic and metabolic regulation in the adaptive response of killifish, we investigated tissue- and sex-specific differences in global DNA methylation and metabolomic profiles of NBH killifish populations, compared to sensitive populations from a non-polluted site, Scorton Creek (SC). The results revealed that liver-specific global DNA hypomethylation and differential metabolites were evident in fish from NBH compared with those from SC. The sex-specific differences were not greater than the tissue-specific differences. We demonstrated liver-specific enriched metabolic pathways (e.g., amino acid metabolic pathways converged into the urea cycle and glutathione metabolism), suggesting possible crosstalk between differential metabolites and DNA hypomethylation in the livers of NBH killifish. Additional investigation of methylated gene regions is necessary to understand the functional role of DNA hypomethylation in the regulation of enzyme-encoding genes associated with metabolic processes and physiological changes in NBH populations.

Adolescent endocrine disrupting chemical exposure and academic achievement

BackgroundEpidemiologic studies support associations of exposure to endocrine disrupting chemicals (EDCs), such as some phthalates, phenols, and parabens with a wide range of cognitive and behavioral traits. While many of these traits are associated with academic achievement, the relationship of EDC exposure specifically with academic achievement in adolescence has not yet been studied. ObjectiveWe assessed the association of urinary biomarker concentrations of EDCs with academic achievement in adolescents as well as the potential for psychosocial factors to modify associations. MethodsWe quantified urinary concentrations of select EDCs in 205 adolescent participants from the New Bedford Cohort (NBC), a prospective birth cohort of children born to mothers residing near the New Bedford Harbor Superfund site in Massachusetts, and estimated associations between EDCs and adolescent academic achievement assessed with the Wide Range Achievement Test (WRAT). Measures of socioeconomic status and the home environment were used to estimate psychosocial stress. ResultsUrinary concentrations of antiandrogenic phthalates were inversely associated with Math Computation scores. For example, each doubling of the concentration of antiandrogenic phthalate metabolites in urine was associated with a 1.94 point decrease (95% CI: 3.84, −0.05) in Math Computation scores, indicating poorer performance. For the most part, associations were stronger in adolescents with more, as compared to less, social disadvantage, but most of these differences did not achieve statistical significance. ConclusionOur findings support the potential for adolescents’ exposure to antiandrogenic phthalates to correlate with poorer academic achievement in math, particularly among participants with greater psychosocial stress.

Comparing Equilibrium Concentrations of Polychlorinated Biphenyls Based on Passive Sampling and Bioaccumulation in Water Column Deployments.

Biomonitoring at contaminated sites undergoing cleanup, including Superfund sites, often uses bioaccumulation of anthropogenic contaminants by field-deployed organisms as a metric of remedial effectiveness. Bioaccumulation studies are unable to assess the equilibrium status of the organisms relative to the contaminants to which they are exposed. Establishing equilibrium provides a reproducible benchmark on which scientific and management decisions can be based (e.g., comparison with human dietary consumption criteria). Unlike bioaccumulating organisms, passive samplers can be assessed for their equilibrium status. In our study, over a 3-year period, we compared the bioaccumulation of selected polychlorinated biphenyls (PCBs) by mussels in water column deployments at the New Bedford Harbor Superfund site (New Bedford, MA, USA) to codeployed passive samplers. Based on comparisons to the calculated passive sampler equilibrium concentrations, the mussels were not at equilibrium, and the subsequent analysis focused on evaluating approaches for estimating equilibrium bioaccumulation. In addition, a limited evaluation of metal bioaccumulation by the exposed mussels and a metal passive sampler was performed. In general, mussel and passive sampler accumulation of PCBs was significantly correlated; however, surprisingly, agreement on the magnitude of accumulation was optimal when bioaccumulation and passive sampler uptake were not corrected for nonequilibrium conditions. A subsequent comparison of four approaches for estimating equilibrium mussel bioaccumulation using octanol-water partition coefficients (KOW ), triolein-water partition coefficients (KTW ), and two types of polymer-lipid partition coefficients demonstrated that field-deployed mussels were not at equilibrium with many PCBs. A range of estimated equilibrium mussel bioaccumulation concentrations were calculated, with the magnitude of the KOW -based values being the smallest and the polymer-lipid partition coefficient-based values being the largest. These analyses are intended to assist environmental scientists and managers to interpret field deployment data when transitioning from biomonitoring to passive sampling. Environ Toxicol Chem 2023;42:317-332. Published 2022. This article is a U.S. Government work and is in the public domain in the USA.

Prenatal Exposure to Chemical Mixtures and Inhibition among Adolescents.

Inhibition, one of the building blocks of executive function, is the ability to focus one’s attention despite interference from external stimuli. It undergoes substantial development during adolescence and may be susceptible to adverse impacts of prenatal exposure to chemical mixtures, yet few studies have explored this association. The New Bedford Cohort (NBC) is a birth cohort of residents living near the New Bedford Harbor Superfund site in Massachusetts. Among adolescents from the NBC, we investigated the association of biomarkers of prenatal exposure to organochlorines (DDE, HCB, PCBs) and metals (Pb, Mn) with inhibition, assessed with the Delis–Kaplan Executive Function System Design Fluency (non-verbal task) and Color–Word Interference (verbal task) subtests. An exploratory mixtures analysis using Bayesian kernel machine regression (BKMR) informed a traditional multivariable regression approach. NBC adolescents are diverse with 29% non-white and 31% in a low-income household at birth. Cord serum organochlorine concentrations and cord blood metals concentrations were generally similar to other birth cohorts. In BKMR models, we observed a suggestive adverse association of the chemical mixture with Color–Word Interference but not Design Fluency. In covariate-adjusted linear regression models including all five chemical exposure measures, a doubling of cord blood Mn was associated with poorer Color–Word Interference completion time scaled scores (difference = −0.74; 95% CI: −1.34, −0.14). This study provided evidence of an adverse joint association between prenatal exposure to a five-chemical mixture and verbal inhibition in adolescence with exposure to Mn potentially driving this overall association.

Assessing the relation of chemical and non-chemical stressors with risk-taking related behavior and adaptive individual attributes among adolescents living near the New Bedford Harbor Superfund site

BackgroundEarly life exposure to neurotoxicants and non-chemical psychosocial stressors can impede development of prefrontal cortical functions that promote behavioral regulation and thereby may predispose to adolescent risk-taking related behaviors (e.g., substance use or high-risk sexual activity). This is particularly concerning for communities exposed to multiple stressors. MethodsThis study examined the relation of exposure to mixtures of chemical stressors, non-chemical psychosocial stressors, and other risk factors with neuropsychological correlates of risk-taking. Specifically, we assessed psychometric measures of both adverse behavioral regulation and adaptive attributes among adolescents (age ∼ 15 years) in the New Bedford Cohort (NBC), a sociodemographically diverse cohort of 788 children born 1993–1998 to mothers residing near the New Bedford Harbor Superfund site. The NBC includes biomarkers of prenatal exposure to organochlorines and metals; sociodemographic, parental and home characteristics; and periodic neurodevelopmental assessments. We modelled exposure mixtures using multi-dimensional smooths within generalized additive models. ResultsChildren of younger mothers with lower IQ who were exposed prenatally to higher polychlorinated biphenyls and lead had poorer anger control. This pattern was not apparent for children of older mothers with higher IQs. Direction of associations between increased hyperactivity and prenatal levels of organochlorine mixtures differed by maternal age and depression symptoms. Higher cord blood Pb levels, in conjunction with poorer HOME scores, were associated with poorer self-esteem when mothers had fewer depression symptoms. ConclusionsAnalyses suggest that prenatal chemical exposures and non-chemical factors interact to contribute to neuropsychological correlates of risk-taking behaviors in adolescence. By simultaneously considering multiple factors associated with adverse behavioral regulation, we identified potential high-risk combinations that reflect both chemical and psychosocial stressors amenable to intervention.

Prenatal chemical exposures associated with subsequent digital media use in adolescence

Background: Use of digital media (computer, smart phones, social media, gaming, etc.) has increased drastically in the past decade, with 97% of US teens reporting use. While digital media can be a valuable educational and social tool, excessive use has been associated with adverse health including maladaptive behavior. Despite established associations between environmental chemical exposure and adverse neurobehavioral development, there are limited data on the role of these exposures as predictors of maladaptive digital media use.Methods: Participants were a subset of the New Bedford Cohort (NBC), a birth cohort study of 788 children born 1993-1998 to mothers residing near the New Bedford Harbor Superfund site, Massachusetts Biomarkers of prenatal chemical exposure to metals and organochlorines were measured from samples collected at delivery (cord blood) or approximately 10 days post-partum (maternal hair/nails)children. Digital media use was assessed via questionnaire from 528 NBC participants as adolescents (age ~15 yrs). We used multivariable negative binomial models to assess the association between a 2-fold increase in chemical biomarker concentrations and risk of high (&gt;75th% of hrs/week) digital media use.Results: In this racially diverse (31% non-white or Hispanic) and socioeconomically disadvantaged population of adolescents (e.g., at birth, 38% lived in low income households, and 58% of mothers had ≤ high school education), each doubling of peripartum maternal toenail arsenic was associated with a 1.34 increase in relative risk of high digital media use (95% CI: 1.06, 1.70), while each doubling of toenail cadmium was associated with a 1.26 increase (95% CI:1.05, 1.50). We did not observe associations with organochlorines.Conclusion: Our findings suggest that prenatal exposure to some metals may be associated with excessive digital media use in adolescence. Understanding environmental risk factors for maladaptive use is key to strategies for remediating digital media’s potential adverse health impacts.[Funding: NIEHS/NIH P42ES005947, R01ES014864; T32ES007069].

Early infant behavioural correlates of social skills in adolescents.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder typically diagnosed after the second year of life; however, differences in brain structure and function associated with ASD have been ascertained in early infancy. Identifying behavioural markers of ASD risk in early infancy has the potential to facilitate early detection and intervention. We examined associations between infant behaviour and adolescent behaviours associated with ASD. Analyses leveraged data available on 370 participants from the New Bedford Cohort, a sociodemographically diverse prospective birth cohort of children born from 1993 to 1998 to mothers residing near the New Bedford Harbor Superfund site in Massachusetts. Longitudinal assessments were used to examine the associations between behaviours when children were approximately 2weeks old (measured by the Neonatal Behavioral Assessment Scale [NBAS]), and subsequent maladaptive behaviours associated with ASD at approximately 15years old [measured by the Behavior Assessment System for Children, 2nd Edition-Teacher Rating Scale (BASC-2 TRS) scores which are standardised to a mean (SD) of 50 (10)]. Poorer performance on select individual items and cluster scales of the NBAS was associated with an increase in behaviours associated with ASD in adolescents. Associations were strongest for neonatal measures of self-regulation, response to auditory input, and autonomic nervous system regulation. For example, in covariate-adjusted models, infants with Regulation of State NBAS cluster scores in the lowest tertile (poorest performance) compared to infants with scores in the higher two tertiles had adolescent BASC-2 TRS Developmental Social Disorders T-scores that were 2.9 points higher (95% CI: 0.8, 4.9), indicating more behaviours associated with ASD. The NBAS is an established and accessible instrument that assesses a broad range of behaviours in very young infants, and may be a useful tool for newborn assessments of developmental risk, including risk of ASD-associated behaviours.

Human health risks due to airborne polychlorinated biphenyls are highest in New Bedford Harbor communities living closest to the harbor

In response to concerns raised by communities surrounding the New Bedford Harbor Superfund site, we completed a field and modeling study that concluded the harbor is the primary source of polychlorinated biphenyls (PCBs) in air around the harbor. The follow-up question from residents was whether the PCBs measured in air pose a risk to their health. The US Environmental Protection Agency focuses their site-specific, risk-based decisions for site clean-up on cancers. We focused our assessment on the non-cancer effects on the thyroid based on the congener specific patterns and concentrations of PCBs measured in air near and distant to the harbor. Human and animal studies of PCB-induced effects on the thyroid provide evidence to support our analysis. Drawing from the published toxicological data, we used a Margin of Exposure (MOE) approach to derive a human-equivalent concentration in air associated with human health effects on the thyroid. Based on the MOEs calculated herein, evaluation of the MOE indicates that changes in thyroid hormone levels are possible among people living adjacent to the Harbor. Changes in thyroid hormone levels are more likely among people who live near the harbor compared to residents living in areas distant from the harbor. This risk assessment documents potential health risks associated with proximity to a marine Superfund Site using site-specific ambient air PCB congener data.

Exposure to endocrine disrupting chemicals and behaviors associated with ADHD in adolescents

TPS 731: Neurological effects in children, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: Phthalates and parabens are endocrine disrupting chemicals (EDCs) commonly found in personal care products. Studies suggest that exposure to EDCs may influence childhood behaviors associated with attention deficit/hyperactivity disorder (ADHD), but the relationship during adolescence has not been studied. Methods: Urinary biomarker concentrations of phthalates and parabens commonly found in personal care products were quantified in 152 adolescents (age ~15 yrs) in the New Bedford Cohort, a birth cohort study among residents near the New Bedford Harbor Superfund site, Massachusetts. ADHD-associated behavior was assessed with multiple indices from self, parent, and teacher completed behavioral checklists using the Conners’ Attention Deficit Scale and the Behavior Assessment System for Children, 2nd ed., where higher scores indicate more problem behaviors. We used a repeated measures analysis with negative binomial models to estimate the adjusted association of each analyte with these multiple measures of ADHD-related behavior. Results: In this racially diverse (38% non-white or Hispanic) and socioeconomically disadvantaged (31% in low income households, 43% had unmarried mothers, 59% had mothers with a high school education or less) population, a doubling in urinary concentration of the molar sum of paraben biomarkers was associated with an 2% increase in behavior score associated with ADHD in girls (95% CI: 1.01, 1.04), but not boys; this association appeared to be driven by propyl and methyl paraben. We also observed a 3% increase in the ADHD-related behavior score in both sexes with a doubling of the molar sum of urinary phthalate biomarkers commonly found in personal care products (95% CI: 1.01, 1.04); this association was predominantly driven by monobutyl phthalate (%diff: 1.04, 95% CI: 1.02, 1.07), although we observed a smaller significant association with mono-iso-butyl phthalate. Conclusion: Our findings suggest that exposure to some parabens and phthalates during adolescence may be associated with behaviors characteristic of ADHD.

Using Birth Cohort Data to Estimate Prenatal Chemical Exposures for All Births around the New Bedford Harbor Superfund Site in Massachusetts.

Background:Children born near New Bedford, Massachusetts, have been prenatally exposed to multiple environmental chemicals, in part due to an older housing stock, maternal diet, and proximity to the New Bedford Harbor (NBH) Superfund site. Chemical exposure measures are not available for all births, limiting epidemiologic investigations and potential interventions.Objective:We linked biomonitoring data from the New Bedford Cohort (NBC) and birth record data to predict prenatal exposures for all contemporaneous area births.Methods:We used prenatal exposure biomarker data from the NBC, a population-based cohort of 788 mother–infant pairs born during 1993–1998 to mothers living near the NBH, linked to their corresponding Massachusetts birth record data, to build predictive models for cord serum polychlorinated biphenyls (expressed as a sum, ), (DDE), hexachlorobenzene (HCB), cord blood lead (Pb), and maternal hair mercury (Hg). We applied the best fit models (highest pseudo ), with multivariable smooths of continuous variables, to predict exposure biomarkers for all 10,270 births during 1993–1998 around the NBH. We used 10-fold cross validation to validate the exposure models and the bootstrap method to characterize sampling variability in the exposure predictions.Results:The 10-fold cross-validated for the , DDE, HCB, Pb, and Hg exposure models were 0.54, 0.40, 0.34, 0.46, and 0.40, respectively. For each exposure model, multivariable smooths of continuous variables improved the fit compared with linear models. Other variables with significant effects on exposure estimates were paternal education, maternal race/ethnicity, and maternal ancestry. The resulting exposure predictions for all births had variability consistent with the NBC measured exposures.Conclusions:Predictive models using multivariable smoothing explained reasonable amounts of variance in prenatal exposure biomarkers. Our analyses suggest that prenatal chemical exposures can be predicted for all contemporaneous births in the same geographic area by modeling available biomarker data for a subset of that population. https://doi.org/10.1289/EHP4849

Endocrine disrupting chemical exposure and maladaptive behavior during adolescence

BackgroundStudies suggest that exposure to endocrine disrupting chemicals (EDCs), including phthalates, phenols, and parabens may influence childhood behavior, but the relationship during adolescence has not been assessed. ObjectiveWe investigated the association between urinary biomarker concentrations of potential EDCs, including some phthalate and bisphenol A replacement chemicals, and behavior in adolescents. MethodsParticipants were from the New Bedford Cohort (NBC), a prospective birth cohort of residents near the New Bedford Harbor Superfund site in Massachusetts. We measured urinary concentrations of 16 phthalate metabolites or replacements, 8 phenols, and 4 parabens in 205 NBC adolescents and estimated associations between select EDCs and adolescent behavior assessed with the Behavior Assessment System for Children, Second Edition -Teacher Rating Scale (BASC-2). Of note, up to 32 of the 205 in our assessment had missing outcome information imputed. ResultsIncreased urinary concentrations of the sum of 11 antiandrogenic phthalate metabolites were associated with an increase in maladaptive behaviors (Externalizing Behavior, Behavioral Symptoms Index, and Developmental Social Disorders or DSD), and a decrease in Adaptive Skills. For example, a doubling of urinary concentrations of antiandrogenic phthalate metabolites was associated with an increased risk of Externalizing Behavior (RR=1.04; 95% CI: 1.01–1.08). While associations were generally stronger in males, sex differences were not statistically significant. Urine concentrations of phenols and parabens were not associated with adverse behavior. ConclusionOur findings support the importance of exposure to antiandrogenic phthalates during adolescence as a potential correlate of maladaptive behaviors including Externalizing Behavior, DSD behaviors, and decrements in Adaptive Skills.

Using Birth Cohort Data to Estimate Prenatal Exposures for All Births around the New Bedford Harbor Superfund Site in Massachusetts

Introduction: Children born near New Bedford, Massachusetts, USA have been prenatally exposed to environmental chemicals, in part due to an older housing stock, high fish consumption rates, and proximity to the New Bedford Harbor (NBH) Superfund site. Chemical exposure measures are not available for the general population, limiting epidemiologic investigations and potential interventions. Our objective was to leverage available sociodemographic and biomonitoring data from the New Bedford Cohort (NBC) to retrospectively estimate prenatal exposures for all 10,273 births between 1993-1998 in the 4 towns neighboring the NBH Superfund site.Methods: The NBC, a population-based cohort of 788 mother-infant pairs born between 1993-1998 near the NBH, collected questionnaire data and prenatal exposure biomarkers including cord serum polychlorinated biphenyls (PCB), &amp;#961;,&amp;#961;&amp;#8242;-dichlorodiphenyl dichloroethylene (DDE), hexachlorobenzene (HCB), cord blood lead (Pb), and maternal hair mercury (Hg). We used bootstrapped samples of the NBC data to build prenatal exposure models, with multivariable smooths of birth location, birth year, maternal age at birth, and other NBC maternal sociodemographic characteristics as predictors.Results: Maternal country of birth was the strongest exposure predictor across all exposures with women from the Azores and Cape Verde having the highest levels. Maternal age, education, and marital status also were important predictors. The PCB, DDE, HCB, Pb, and Hg exposure models explained 55%, 53%, 41%, 43% and 38% of the variance, respectively.Conclusions: Our analyses suggest that multiple prenatal exposures can be estimated at the population level by modeling available data for a subset of the population. Predictive models using multivariable smoothing explained reasonable amounts of variance. Other exposure models with comparable performance have been used successfully in epidemiologic investigations to characterize exposure-outcome associations.

Assessing the Relation of Chemical and Non-Chemical Stressors with Risk-Taking Behavior among Adolescents Living near the New Bedford Harbor Superfund Site

Background: Adolescent risk-taking is multifactorial and influenced by sociodemographics and peer behavior. In addition, evidence suggests that early life exposure to neurotoxicants such as polychl...

Exposure to Endocrine Disrupting Chemicals and Maladaptive Behavior during Adolescence

Introduction: Experimental and epidemiologic studies suggest that exposure to endocrine disrupting chemicals (EDCs), including phthalates and phenols, may influence childhood behavior, but the relationship during adolescence has not been studied.Methods: We investigated the association of EDC exposures with maladaptive behavior in 205 adolescent (age 15 yrs) participants in the New Bedford Cohort, a birth cohort study of chemical exposure and neurodevelopment among residents near the New Bedford Harbor Superfund site, Massachusetts. Urine concentrations of biomarkers of phthalates, phenols and related replacement chemicals were quantified with mass spectrometry. Behavior was assessed with the Behavior Assessment System for Children, 2nd edition Teacher Rating Scale, including the Developmental Social Disorders (DSD) scale related to autistic behaviors. Associations were examined using linear (normally distributed outcomes) or negative binomial (over dispersed Poisson distributed outcomes) regression adjusted for multiple potential confounders.Results: 40% of the adolescents were non-white or Hispanic; at birth, 32% were in low income households and 42% had unmarried mothers. Increased urine concentrations of the molar sum of antiandrogen phthalate biomarkers were associated with an increase in Externalizing Behavior, Behavioral Symptoms Index, and DSD and a decrease in Adaptive Skills. E.g., a doubling of urine antiandrogen phthalate biomarkers was associated with increased Externalizing (RR&amp;#61;1.04; 95% CI: 1.01, 1.08) and DSD (&amp;#946;&amp;#61;1.4; 95% CI: 0.4, 2.5) behaviors. Associations were stronger in males, but not significantly so. Phenols, other phthalates, and replacement chemicals were not associated with adverse behavior.Conclusion: Our findings support that antiandrogen phthalate exposure during adolescence is a potential correlate of maladaptive behavior.

Spatial Variability in ADHD-Related Behaviors Among Children Born to Mothers Residing Near the New Bedford Harbor Superfund Site.

Attention-deficit/hyperactivity disorder (ADHD) has an uncertain etiology, with potential contributions from different risk factors such as prenatal environmental exposure to organochlorines and metals, social risk factors, and genetics. The degree to which geographic variability in ADHD is independent of, or explained by, risk factors may provide etiological insight. We investigated determinants of geographic variation in ADHD-related behaviors among children living near the polychlorinated biphenyl–contaminated New Bedford Harbor (NBH) Superfund site in Massachusetts. Participants were 573 children recruited at birth (1993–1998) who were born to mothers residing near the NBH site. We assessed ADHD-related behaviors at age 8 years using Conners’ Teacher Rating Scale–Revised: Long Version. Adjusted generalized additive models were used to smooth the association of pregnancy residence with ADHD-related behaviors and assess whether prenatal organochlorine or metal exposures, sociodemographic factors, or other factors explained spatial patterns. Models that adjusted for child's age and sex displayed significantly increased ADHD-related behavior among children whose mothers resided west of the NBH site during pregnancy. These spatial patterns persisted after adjusting for prenatal exposure to organochlorines and metals but were no longer significant after controlling for sociodemographic factors. The findings underscore the value of spatial analysis in identifying high-risk subpopulations and evaluating candidate risk factors.

Integrating Monitoring and Genetic Methods To Infer Historical Risks of PCBs and DDE to Common and Roseate Terns Nesting Near the New Bedford Harbor Superfund Site (Massachusetts, USA).

Common and roseate terns are migratory piscivorous seabirds with major breeding colonies within feeding range of the polychlorinated biphenyl (PCB)-contaminated New Bedford Harbor (NBH, MA, USA) Superfund site. Our longitudinal study shows that before PCB discharges into NBH ceased (late 1970s), tern eggs had very high but variable PCB concentrations. However, egg concentrations of PCBs as well as DDE (1,1-bis(p-chlorophenyl)-2,2-dichloroethene), the degradation product of the ubiquitous global contaminant DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane), have since declined. Rate constants for temporal decline of PCB congeners in tern eggs varied inversely with log10KOW (n-octanol-water partition coefficient), shifting egg congener patterns away from those characterizing NBH sediment. To estimate the toxic effects on tern eggs of PCB dioxin-like congener (DLC) exposures, we extrapolated published laboratory data on common terns to roseate terns by characterizing genetic and functional similarities in species aryl hydrocarbon receptors (AHRs), which mediate DLC sensitivity. Our assessment of contaminant risks suggests that terns breeding near NBH were exposed historically to toxic levels of PCBs and DDE; however, acute effects on tern egg development have become less likely since the 1970s. Our approach demonstrates how comparative genetics at target loci can effectively increase the range of inference for chemical risk assessments from tested to untested and untestable species.

Prenatal organochlorine and methylmercury exposure and memory and learning in school-age children in communities near the New Bedford Harbor Superfund site, Massachusetts.

Background: Polychlorinated biphenyls (PCBs), organochlorine pesticides, and methylmercury (MeHg) are environmentally persistent with adverse effects on neurodevelopment. However, especially among populations with commonly experienced low levels of exposure, research on neurodevelopmental effects of these toxicants has produced conflicting results.Objectives: We assessed the association of low-level prenatal exposure to these contaminants with memory and learning.Methods: We studied 393 children, born between 1993 and 1998 to mothers residing near a PCB-contaminated harbor in New Bedford, Massachusetts. Cord serum PCB, DDE (dichlorodiphenyldichloroethylene), and maternal peripartum hair mercury (Hg) levels were measured to estimate prenatal exposure. Memory and learning were assessed at 8 years of age (range, 7–11 years) using the Wide Range Assessment of Memory and Learning (WRAML), age-standardized to a mean ± SD of 100 ± 15. Associations with each WRAML index—Visual Memory, Verbal Memory, and Learning—were examined with multivariable linear regression, controlling for potential confounders.Results: Although cord serum PCB levels were low (sum of four PCBs: mean, 0.3 ng/g serum; range, 0.01–4.4), hair Hg levels were typical of the U.S. fish-eating population (mean, 0.6 μg/g; range, 0.3–5.1). In multivariable models, each microgram per gram increase in hair Hg was associated with, on average, decrements of –2.8 on Visual Memory (95% CI: –5.0, –0.6, p = 0.01), –2.2 on Learning (95% CI: –4.6, 0.2, p = 0.08), and –1.7 on Verbal Memory (95% CI: –3.9, 0.6, p = 0.14). There were no significant adverse associations of PCBs or DDE with WRAML indices.Conclusions: These results support an adverse relationship between low-level prenatal MeHg exposure and childhood memory and learning, particularly visual memory.Citation: Orenstein ST, Thurston SW, Bellinger DC, Schwartz JD, Amarasiriwardena CJ, Altshul LM, Korrick SA. 2014. Prenatal organochlorine and methylmercury exposure and memory and learning in school-age children in communities near the New Bedford Harbor Superfund Site, Massachusetts. Environ Health Perspect 122:1253–1259; http://dx.doi.org/10.1289/ehp.1307804

Bioaccumulation of polychlorinated biphenyls and organochlorine pesticides in young-of-the-year bluefish (Pomatomus saltatrix) in the vicinity of a Superfund Site in New Bedford Harbor, Massachusetts, and in the adjacent waters

Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides were examined in the young-of-the-year (YOY) bluefish (Pomatomus saltatrix) in the vicinity of a PCB Superfund Site in New Bedford Harbor, Massachusetts, and in the adjacent waters. PCB concentrations in bluefish varied between different locations, and also among fish from a given location. A generally decreasing gradient in PCB concentrations was evident as the bluefish were collected away from the Superfund Site. The average sum of PCB concentrations were highest for bluefish collected in the Upper Harbor between Interstate-195 Bridge and Coggeshall Street Bridge (Upper Harbor), followed by bluefish in Lower Harbor from north of Popes Island Bridge (Lower Harbor), and bluefish from Outer Harbor south of Hurricane Barrier (Outer Harbor). The levels of PCBs in bluefish from Clarks Cove and PCBs in bluefish from Buzzards Bay were similar and lowest among all bluefish specimens analyzed in the present study. Pesticide concentrations were about one order of magnitude or lower than the PCB concentrations, and the gradient of pesticide concentrations generally followed the gradient of PCB concentrations. Some of the commonly detected pesticides in the order of decreasing concentrations included DDTs and metabolites, heptachlor epoxide, endosulfan sulfate, and α-chlordane. Distribution of PCBs and organochlorine pesticides were examined in the tissues of YOY bluefish from Clarks Cove. PCBs and lipids in the brain samples of YOY bluefish were generally numerically greater than PCBs in the liver samples, but these differences were not statistically significant. PCBs and lipids in hypaxial muscle samples were numerically greater than PCBs in epaxial muscle samples, although these two groups of tissues were not statistically different. Despite the higher susceptibility of lighter PCB homologs to geophysical and biogeochemical weathering processes, the relative dominance of lighter homologs in the Upper Harbor and Lower Harbor samples suggested ongoing or recent sources of these lighter PCBs, particularly Aroclor 1242 and Aroclor 1016 in this area. The presence of heavier homologs in the Upper Harbor and Lower Harbor bluefish samples could be attributed to Aroclor 1252 and Aroclor 1254 that were being used in relatively smaller quantities in the manufacture of electrical components in addition to Aroclor 1242 and Aroclor 1016. The concentration of heavier PCB homologs appears to increase in YOY bluefish the further away from the PCB Superfund Site in the Acushnet Estuary the samples were collected. Principal component analyses of PCB 153 normalized concentrations of the individual PCB congeners resulted in two general groupings; a relatively tight group comprised of YOY bluefish from Upper Harbor, Lower Harbor, and Outer Harbor, and a rather loose and more dispersed group comprised of Buzzards Bay bluefish and the tissue samples of bluefish from Clarks Cove. Principal component analyses of major pesticides suggested close groupings of bluefish from Clarks Cove and bluefish from Buzzards Bay. Pesticides in bluefish from Upper Harbor, Lower Harbor, and Outer Harbor formed a loose group, with some bluefish from these locations populating close to Clarks Cove and Buzzards Bay bluefish. Although PCBs have been implicated in various behavioral and health effects in the experimental and field studies, the deleterious effects of chronic exposure to high concentrations of PCBs and the potential for recruitment of New Bedford Harbor YOY bluefish population to the adult stock remains obscure. Adaptive or evolutionary resistance to contaminants have been documented in resident species in some highly contaminated estuaries, however similar responses have not been investigated in the migratory species like bluefish. The results of the present study provide a reference baseline for YOY bluefish for “before-and-after” comparative studies and other toxicological studies for the New Bedford Harbor Superfund Site that is currently being remediated.

The New Bedford Harbor Superfund site long-term monitoring program (1993–2009)

New Bedford Harbor (NBH), located in southeastern Massachusetts, was designated as a marine Superfund site in 1983 due to sediment contamination by polychlorinated biphenyls (PCBs). Based on risks to human health and the environment, the first two phases of the site cleanup involved dredging PCB-contaminated sediments from the harbor. Therefore, a long-term monitoring program (LTM) was developed to measure spatial and temporal chemical and biological changes in sediment, water, and biota to assess the effects and effectiveness of the remedial activities. A systematic, probabilistic sampling design was used to select sediment sampling stations. This unbiased design allowed the three segments of the harbor to be compared spatially and temporally to quantify changes resulting from dredging the contaminated sediments. Sediment was collected at each station, and chemical (e.g., PCBs and metals), physical (e.g., grain size), and biological (e.g., benthic community) measurements were conducted on all samples. This paper describes the overall NBH-LTM approach and the results from the five rounds of sample collections. There is a decreasing spatial gradient in sediment PCB concentrations from the northern boundary (upper harbor) to the southern boundary (outer harbor) of the site. Along this same transect, there is an increase in biological condition (e.g., benthic community diversity). Temporally, the contaminant and biological gradients have been maintained since the 1993 baseline collection; however, since the onset of full-scale remediation, PCB concentrations have decreased throughout the site, and one of the benthic community indices has shown significant improvement in the lower and outer harbor areas.