Correlates of COVID-19 Information Overload and Information Seeking: Evidence from a Community Survey

PURPOSE

To examine the relationships among health literacy, risk perceptions, COVID-19 information overload, health information seeking, and race/ethnicity.

DESIGN

A cross-sectional non-probability community survey conducted between December 2020 and January 2021. A questionnaire was developed in collaboration with a local minority health task force.

SETTING

Albany, New York, USA.

SAMPLE

331 adults residing in Albany, NY and neighboring areas (80.3% completion rate).

MEASURES

Multi-item scales were used to measure health literacy, perceived severity, perceived susceptibility, information overload, and health information seeking frequency and types.

ANALYSIS

We conducted multivariate regression analysis.

RESULTS

Health literacy (standardized β = -.33, P < .001) and perceived severity (β = -.23, P < .001) were negatively associated with information overload. Information overload was negatively associated with health information seeking frequency (β = -.16, P < .05) and types (β = -.19, P < .01). A further analysis shows several factors, including information overload and race (African Americans), were negatively related to seeking specific types of information.

CONCLUSION

We find that low health literacy and perceived severity contribute to information overload and that information overload adversely affects health information seeking. Black individuals are less likely to search for certain types of information. The cross-sectional study design limits our ability to determine causality. Future research should employ panel data to determine the directionality of the observed relationships.

Exposure of Akwesasne Mohawk women to polychlorinated biphenyls and hexachlorobenzene is associated with increased serum levels of thyroid peroxidase autoantibodies

Persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (p,p'-DDT) were reported to influence immunological activity. As endocrine-disrupting chemicals (EDC), these pollutants may disrupt normal thyroid function and act as catalysts for development of autoimmune thyroid disease by directly and indirectly affecting levels of thyroid peroxidase antibodies (TPOAbs). Native American communities are disproportionately exposed to harmful toxicants and are at an increased risk of developing an autoimmune disease. The aim of this study was to determine the association between POPs and TPOAbs in serum obtained from Native American women. This assessment was used to measure whether increased risk of autoimmune thyroid disease occurred as a result of exposure to POPs. Data were collected from 183 Akwesasne Mohawk women, 21-38 years of age, between 2009 and 2013. Multivariate analyses were conducted to determine the association between toxicant exposure and levels of TPOAbs. In multiple logistic regression analyses, exposure to PCB congener 33 was related to elevated risk of individuals possessing above normal levels of TPOAbs. Further, HCB was associated with more than 2-fold higher risk of possessing above normal levels of TPOAbs compared to women with normal levels of TPOAbs. p,p'-DDE was not associated with TPOAb levels within this study. Exposure to PCB congener 33 and HCB was correlated with above normal levels of TPOAbs, a marker of autoimmune thyroid disease. Additional investigations are needed to establish the causes and factors surrounding autoimmune thyroid disease which are multiple and complex.

Levels of per- and polyfluoroalkyl substances (PFAS) in Norwegian children stratified by age and sex - Data from the Bergen Growth Study 2

BACKGROUND AND AIM

Due to the persistence, bioaccumulation and potential adverse health effects, there have been restrictions and phase out in the production of certain per- and polyfluoroalkyl substances (PFAS) since the early 2000s. Published serum levels of PFAS during childhood are variable and may reflect the impact of age, sex, sampling year and exposure history. Surveying the concentrations of PFAS in children is vital to provide information regarding exposure during this critical time of development. The aim of the current study was therefore to evaluate serum concentrations of PFAS in Norwegian schoolchildren according to age and sex.

MATERIAL AND METHODS

Serum samples from 1094 children (645 girls and 449 boys) aged 6-16 years, attending schools in Bergen, Norway, were analyzed for 19 PFAS. The samples were collected in 2016 as part of the Bergen Growth Study 2. Statistical analyses included Student t-test, one-way ANOVA and Spearman's correlation analysis of log-transformed data.

RESULTS

Of the 19 PFAS examined, 11 were detected in the serum samples. Perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS) and perfluorononaoic acid (PFNA) were present in all samples with geometric means of 2.67, 1.35, 0.47 and 0.68 ng/mL, respectively. In total, 203 children (19%) had PFAS levels above the safety limits set by the German Human Biomonitoring Commission. Significantly higher serum concentrations were found in boys compared to girls for PFOS, PFNA, PFHxS and perfluoroheptanesulfonic acid (PFHpS). Furthermore, serum concentrations of PFOS, PFOA, PFHxS and PFHpS were significantly higher in children under the age of 12 years than in older children.

CONCLUSIONS

PFAS exposure was widespread in the sample population of Norwegian children analyzed in this study. Approximately one out of five children had PFAS levels above safety limits, indicating a potential risk of negative health effects. The majority of the analyzed PFAS showed higher levels in boys than in girls and decreased serum concentrations with age, which may be explained by changes related to growth and maturation.

Maternal-infant interaction quality is associated with child NR3C1 CpG site methylation at 7 years of age

OBJECTIVE

Infancy is both a critical window for hypothalamic-pituitary-adrenal (HPA) axis development, and a sensitive period for social-emotional influences. We hypothesized that the social-emotional quality of maternal-infant interactions are associated with methylation of HPA-axis gene NR3C1 later in childhood.

METHODS

Using a subsample of 114 mother-infant pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC), linear regression models were created to predict variance in methylation of seven selected CpG sites from NR3C1 in whole blood at age 7 years, including the main predictor variable of the first principal component score of observed maternal-infant interaction quality (derived from the Thorpe Interaction Measure at 12 months of age) and covariates of cell-type proportion, maternal financial difficulties and marital status at 8 months postnatal, child birthweight, and sex.

RESULTS

CpG site cg27122725 methylation was negatively associated with warmer, more positive maternal interaction with her infant (β = 0.19, p = .02, q = 0.13). In sensitivity analyses, the second highest quartile of maternal behavior (neutral, hesitant behavior) was positively associated with cg12466613 methylation. The other five CpG sites were not significantly associated with maternal-infant interaction quality.

CONCLUSIONS

Narrow individual variation of maternal interaction with her infant is associated with childhood methylation of two CpG sites on NR3C1 that may be particularly sensitive to environmental influences. Infancy may be a sensitive period for even small influences from the social-emotional environment on the epigenetic determinants of HPA-axis function.

Linking infant size and early growth with maternal lifestyle and breastfeeding - the first year of life in the CRIBS cohort

BACKGROUND

Every third child in Croatia is classed as overweight or obese. Infant growth can represent early warning signs for obesity.

AIM

To detect early risk factors for obesity by investigating infant size and early growth trajectories and their association with maternal lifestyle and breastfeeding.

SUBJECTS AND METHODS

Ninety-eight mother-child pairs from the Croatian Islands' Birth Cohort Study (CRIBS) cohort were included in the study. Data were collected from questionnaires and medical records. Growth data were converted to Z-scores using World Health Organisation (WHO) standards and used as the primary outcome.

RESULTS

Z-score trajectories in the first year of life were in line with WHO standards. A direct link between infant size and maternal socioeconomic status (SES) or breastfeeding was not detected. However, child weight gain in the first 6 months was associated with maternal body mass index (BMI) before pregnancy (p < 0.01). A positive association was also established between breastfeeding and maternal SES and mothers that report an unhealthy diet have heavier children (p < 0.05, respectively).

CONCLUSION

Infant size and early growth in Croatia is in line with WHO standards and risk factors for obesity development were detectable in the first year of life, but not highly pronounced. However, more effective BMI monitoring and promotion of a healthy diet and lifestyle of women before and during pregnancy is needed.

Age at menarche and chemical exposure: per- and polyfluoroalkyl substances (PFAS), dichloro-diphenyl-trichloroethane (DDT), dichloro-diphenyl-dichloroethylene (DDE), and polychlorinated biphenyls (PCBs)

CONTEXT

Humans are now exposed to a multitude of chemicals throughout the life course, some of which may affect growth and development owing to their endocrine-like activity.

OBJECTIVE

To assess the relationship of suspect toxicants to maturation, specifically to age at menarche.

METHODS

We conducted two systematic reviews of age at menarche and PFOA, PFOS, PCBs and DDE/DDT based on publications indexed by pubmed.

RESULTS

16 unique reports were identified. Most studies of PFOA and PFOS reported either no association or delays in the age at menarche; only one reported an earlier age. Studies of DDT and DDE were more mixed. Reports on PCBs varied by PCB congener group with an equal number of them reporting delays and no association but one an acceleration. Sources of variation in results include the timing of exposure assessment (prenatal vs. postnatal), level of the toxicant, and sample size. No obvious pattern to the variation in results could be tied to those sources of variation.

CONCLUSION

The absence of consistent evidence from multiple reports of earlier age at menarche suggests that these toxicants may not be responsible for accelerated sexual maturation in girls. However, human populations naturally vary in the variety and levels of exposure, making the comparison of studies difficult. Further, studies vary in methodology, complicating aggregation of results and generalisations.

Deep phenotyping of pubertal development in Norwegian children: the Bergen Growth Study 2

BACKGROUND

The Bergen Growth Study 2 (BGS2) aims to characterise somatic and endocrine changes in healthy Norwegian children using a novel methodology.

SUBJECTS AND METHODS

A cross-sectional sample of 1285 children aged 6-16 years was examined in 2016 using novel objective ultrasound assessments of breast developmental stages and testicular volume in addition to the traditional Tanner pubertal stages. Blood samples allowed for measurements of pubertal hormones, endocrine disruptive chemicals, and genetic analyses.

RESULTS

Ultrasound staging of breast development in girls showed a high degree of agreement within and between observers, and ultrasound measurement of testicular volume in boys also showed small intra- and interobserver differences. The median age was 10.4 years for Tanner B2 (pubertal onset) and 12.7 years for menarche. Norwegian boys reached a pubertal testicular volume at a mean age of 11.7 years. Continuous reference curves for testicular volume and sex hormones were constructed using the LMS method.

CONCLUSIONS

Ultrasound-based assessments of puberty provided novel references for breast developmental stages and enabled the measurement of testicular volume on a continuous scale. Endocrine z-scores allowed for an intuitive interpretation of changing hormonal levels during puberty on a quantitative scale, which, in turn, provides opportunities for further analysis of pubertal development using machine-learning approaches.

Associations between autoimmune dysfunction and pollutants in Akwesasne Mohawk women: Dichlorodiphenyltrichloroethane and polychlorinated biphenyl exposure

BACKGROUND

Pollutant exposures, including polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT), have been found to disrupt normal immune function. Native American communities are disproportionately affected by autoimmune dysfunction and are more likely to be exposed to harmful pollutants than the general population.

OBJECTIVE

To determine the association between autoimmune dysfunction and pollutant exposure levels, this study evaluates the statistical relationship between the presence of autoimmune dysfunction and pollutant exposure.

METHODS

Information was collected from Akwesasne Mohawk women (n = 182), 21-39 years of age, between 2009 and 2013. Data collection included anthropometric measurements, medical diagnoses of autoimmune disease and symptoms of autoimmune dysfunction in the medical record, and blood draws for measurement of pollutants. Multivariate analyses determined the association between toxicant exposure and autoimmune dysfunction.

RESULTS

Toxicant p,p'-DDE was positively associated with an almost two-fold risk of autoimmune dysfunction. p,p'-DDE and PCB congeners 32, 136, and 138 were positively associated in a multivariate analysis with an autoimmune diagnosis.

CONCLUSIONS

Pollutant exposures, specifically to p,p'-DDE and some PCB congeners, are common exposures that are associated with autoimmune dysfunction and autoimmune disease, although there are other factors and causes related to autoimmune dysfunction incidence.

Testing the Institute of Medicine (IOM) recommendations on maternal reproductive health and associated neonatal characteristics in a transitional, Mediterranean population

BACKGROUND

High pre-pregnancy body mass index (BMI) and excessive gestational weight gain (GWG) are significant risk factors for maternal and neonatal health.

AIM

To assess pre-pregnancy BMI and GWG during pregnancy and their association with different maternal and neonatal characteristics in the transitional Mediterranean population from the Eastern Adriatic islands.

SUBJECTS AND METHODS

262 mother-child dyads from the CRoatian Islands' Birth Cohort Study (CRIBS) were included in the study. Chi-square test, ANOVA and regression analysis were used to test the association between selected characteristics.

RESULTS

22% of women entered pregnancy with overweight/obesity and 46.6% had excessive GWG. Pre-pregnancy overweight and obesity were significantly associated with elevated triglycerides uric acid levels, and decreased HDL cholesterol in pregnancy. Excessive GWG was associated with elevated fibrinogen and lipoprotein A levels. Women with high pre-pregnancy BMI and GWG values were more likely to give birth to babies that were large for gestational age (LGA), additionally confirmed in the multiple logistic regression model.

CONCLUSION

High maternal pre-pregnancy BMI and excessive GWG were both significantly associated with deviated biochemical parameters and neonatal size. More careful monitoring of maternal nutritional status can lead to better pre- and perinatal maternal health care.

Sex differences in the association of measures of sexual maturation to common toxicants: Lead, dichloro-diphenyl-trichloroethane (DDT), dichloro-diphenyl-dichloroethylene (DDE), and polychlorinated biphenyls (PCBs)

Many studies of human toxicant exposure examine the hypothesis that human sexual maturation can be affected through endocrine disruption. Within this body of literature there is significant variation in the findings. Variation may be related to the differential effects by toxicants between males and females as well as variation in sample size, toxicant levels, and the timing of exposure. We review sexual maturation outcomes between males and females when exposed to lead, dichlorodiphenyldichloroethylene (DDE), dichloro-diphenyl-trichloroethane (DDT), and polychlorinated biphenyls (PCBs) using a systematic process to gather peer-reviewed studies published from January 1994 through December 2019 on the NCBI website's PubMed search engine. The review includes 34 studies, some comprised of multiple analyses, to compare effects on sexual maturation by sex. The analysis shows that both boys and girls have delayed sexual maturation in relation to lead exposure. There are differences in the direction of effects associated with DDE/DDT and PCB exposure in boys and girls. PCBs exist as congeners of many structural forms, and that variation is considered in this review. Dioxin-like and non-dioxin-like PCBs exposure directionality differed between boys and girls as well. Future investigations into the basis of sex variation in DDE/DDT and PCB relationships to sexual maturation are warranted.

Prenatal Exposure to Favorable Social and Environmental Neighborhood Conditions Is Associated with Healthy Pregnancy and Infant Outcomes

Neighborhood and individual level risks commonly co-occur for pregnant women and may cumulatively contribute to birth outcomes. Moreover, the relationship between favorable social and environmental neighborhood conditions and perinatal outcomes has been understudied. This study considered the accumulated impact of prenatal exposure to positive neighborhood social, environmental, and educational conditions in relation to maternal health during pregnancy and birth size outcomes. In a prospective study of a multi-ethnic and socioeconomically diverse cohort (n = 239) of pregnant women and their infants, neighborhoods were characterized by the Child Opportunity Index (COI), a census-tract composite indicator representing favorable social, environmental, and educational community conditions. Adjusted generalized estimating equations showed that favorable neighborhood conditions promoted the growth of longer and heavier infant bodies, and reduced the risk of intrauterine growth restriction. The associations were stronger for female versus male infants, though not significantly different. Moreover, COI was associated with better maternal mental health and diet during pregnancy; diet significantly mediated the association between COI and birth size outcomes. This study underscores the importance of considering the accumulated benefit of neighborhood assets for maternal and infant health. Interventions that capitalizes on the full range of contextual assets in which mothers live may promote pregnancy health and fetal growth.

Doing biocultural anthropology: Continuity and change

Biocultural anthropology has long represented an important approach in the study of human biology. However, despite demonstrated utility, its somewhat amorphous identity leaves some scholars questioning just what it means to be biocultural. In this article, rather than providing proscriptive doctrine, we contribute to these conversations about the nature of biocultural anthropology by considering what biocultural research does. We begin with a consideration of some of the foundational themes of biocultural work including recognition of the dialectical nature of sociocultural and biological forces, interest in inequality, and incorporation of both evolutionary and political economic perspectives. To emphasize the consistency of biocultural work over time, we also trace these themes from originating work to their appearance in current research. We then identify some of the key actions of the biocultural approach, noting that biocultural work can execute any number though rarely all of these actions simultaneously. We then offer brief introductions to the articles that make up this special issue, highlighting the ways in which each piece undertakes key biocultural actions. Following these introductions, we provide a discussion of some of the types of biocultural work that are not present in this special issue, recognizing the breadth of biocultural research across multiple subfields of anthropology. Finally, we point to some potentially fruitful directions for future biocultural research. In the end, we conclude that while biocultural anthropology may not have a cohesive or set agenda, it does have a clear and recognizable form of content and methodology illuminated by its actions.

Modern water: A biocultural approach to water pollution at the Akwesasne Mohawk Nation

OBJECTIVES

The goal of this article is to review a body of research around water contamination conducted in the Akwesasne Mohawk Nation between 1995 and 2016, place these findings in a biocultural context, and consider implications for a human biology of water.

METHODS

This review draws on research projects conducted in partnership with the Akwesasne Mohawk Nation living along the St. Lawrence River as well as published research by others on water contamination at Akwesasne. Quantitative and qualitative methods including toxicological and epidemiological methods, surveys, and ethnographic studies are included.

RESULTS

Pollution of a river with polychlorinated biphenyls (PCBs) contaminated local fish, a major, traditional, food source. Following health advisories to avoid consuming local fish, consumption and PCB levels decreased. PCB levels were negatively associated with health outcomes. In adolescents, higher PCB levels were associated with advanced sexual maturation in females, reduced testosterone in males and reduced thyroxine levels in young adults. Avoiding fish consumption altered traditional dietary patterns and social interactions, generational transmission of knowledge, and relations between generations, all of which impacted cultural forms and may have added to the perceived injustices in this Native American community. Items substituted for fish may have contributed to increasing rates of obesity as well.

CONCLUSIONS

Water pollution has immediate direct health consequences as well as cultural impacts related to changed food consumption and altered patterns of social interaction.

Social Support During Pregnancy Modifies the Association Between Maternal Adverse Childhood Experiences and Infant Birth Size

Introduction Adverse childhood experiences (ACEs) can deleteriously affect health, including pregnancy and birth outcomes occurring later in life. Identification of modifiable factors during pregnancy that buffer the ill effects of adversity is warranted. Social support during pregnancy can promote better birth outcomes, yet it is unknown whether it could also mitigate perinatal risks stemming from ACEs. Thus, this study considers multiple forms of social support in pregnancy as modifiers of an ACEs and fetal growth association. Methods Data were collected from mother and infant pairs from an ongoing prospective birth cohort. Women enrolled around 27 weeks gestation and completed gold-standard assessments of ACEs and social support. Infant cephalization index scores [(head circumference /birthweight) × 100; a marker of asymmetric fetal growth] were derived. Multivariable regression models tested main effects and interaction between ACEs and social support in relation to infant cephalization. Results Higher levels of ACEs were associated with higher cephalization scores (β = 0.01, SE = 0.01, p < 0.05) whereas higher social support was associated with lower cephalization scores (β = - 0.03, SE = 0.01, p < 0.05). A significant interaction was observed showing a protective effect of social support among those with low (0 events) and moderate (1-3 events) ACEs but not among those with high ACEs (4 + events; p < 0.05). Tangible and emotional support, but not information support, contributed to the associations. Discussion Maternal ACEs can deleteriously affect birth size, yet social support during pregnancy provides some buffer from its enduring effects. Interventions designed to enhance pregnancy social support may not only improve maternal wellbeing, but may also safeguard infant health.

Patterns of PCB exposure among Akwesasne adolescents: The role of dietary and inhalation pathways

AIM

The objective of this study is to determine if consumption of fish and other dietary elements are related to the serum PCB levels of a group of adolescents. A dietary pattern approach is used to provide a more complete dietary exposure profile rather than a single food/group approach. Additionally, dietary patterns are examined in relation to traditional PCB groupings as well as derived PCB congener profiles.

PARTICIPANTS/SETTING AND METHODS

The sample is comprised of 246 Mohawk adolescents between the ages of 10-16.9 years of age residing at the Akwesasne Mohawk Nation. Food frequency data was collected and serum PCB levels were (101 congeners) quantitated during a cross-sectional study investigating adolescent exposure to environmental pollutants.

RESULTS

Principal component analysis identified four dietary patterns: "well-rounded" "snacks and sweets" "fruits and vegetables" "fish and dairy" and four PCB congener profiles: "1248-like", Persistent/"1260-like", "mono-ortho", and "1254-like". In a multiple regression models, the "fish and dairy" dietary or traditional PCB determinants (age, sex, prior breastfeeding, BMI, pattern) were each predictors of one or more of three of the identified PCB congener profiles. However, the "1248-like" pattern was not related to either dietary pattern or any of the typical PCB determinants, suggesting an alternative source/exposure pathway for this congener profile.

CONCLUSION

Even relatively low levels of fish consumption within the composite dietary matrix of adolescents at Akwesasne remains a pathway of exposure to postnatally acquired PCBs. In addition, there is evidence of an unidentified, perhaps airborne, exposure pathway that warrants further attention as this congener profile accounted for 50% of the total variance within the adolescents' serum PCB levels.

Persistent organic pollutants as predictors of increased FSH:LH ratio in naturally cycling, reproductive age women

Although several recent studies suggest endocrine disrupting compounds, such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p', DDE), and hexachlorobenzene (HCB), target different organs and systems in the body, their impact on female reproductive function in humans is not well characterized. We seek to determine the relationship between several known endocrine disrupting compounds and a marker of ovarian responsivity, the FSH:LH ratio (higher ratio indicates less ovarian responsivity). For this analysis, 169 naturally cycling women between 21 and 38 years of age completed interviews and had their blood drawn on day 3 of their menstrual cycle for analyses of toxicants, gonadal sex hormones (E₂ and P₄), and gonadotropins (FSH and LH). PCB congeners were classified into five groups based on their environmental persistence, distribution in human tissue, and toxicological action, reflecting the structure, mechanism, and known biological activity of individual PCB congeners. For every unit (ppb) increase in the level of the estrogenic PCB group, there was a 5-fold greater risk of a FSH:LH ratio ≥ 2, controlling for individual differences in age, percent body fat, cycle day 3 estradiol levels, parity, alcohol use and cigarette smoking in the past year (exp[ß] = 5; p = ≤0.01). PCB congeners identified as estrogenic were analyzed individually, and, of the 19 potentially estrogenic congeners, five were significantly, and positively related to an increased FSH:LH ratio. Four of these congeners are non-persistent, easily volatilize in the environment, and are easily metabolized, and hence, are indicative of very recent or current exposure. p,p'-DDE and HCB were not associated with FSH:LH ratio. We find a clinical indicator of ovarian responsivity, FSH:LH ratio, is associated with a specific group of estrogenic PCBs. These congeners may become airborne when they volatilize from dredged PCB-contaminated soil or from indoor PCB-containing window caulk and sealants in older buildings leading to inhalation exposure. PCB exposure, particularly to non-persistent, estrogenic congeners, may pose an unrecognized threat to female fecundity within the general population.

PCBs and measures of attention and impulsivity on a continuous performance task of young adults

The present study examines the relationship between current body burden of persistent PCBs and attention and impulsivity in 140 Akwesasne Mohawk young adults aged 17 to 21 whose environment has been contaminated by industrial effluent. Attention and impulsivity were measured by errors of omission, errors of commission, and patterns of reaction time responses on the Conners Continuous Performance Test. The PCB measure was the sum of those persistent PCB congeners detected in 50% of the participants. After adjusting for multiple covariates, regression analyses showed a significant positive relationship between PCB levels and omission scores, but only for males.

Maternal-infant interaction as an influence on infant adiposity

OBJECTIVES

The aim of this research is to identify whether specific aspects of the early life psychosocial environment such as quality of home and maternal-infant interaction are associated with increased infant adiposity, in a disadvantaged population in the United States.

METHODS

Data on 121 mother-infant pairs from the Albany Pregnancy and Infancy Lead Study were analyzed using three multiple linear regression models with subscapular skinfold thickness (SST), triceps skinfold thickness (TST), and weight z-scores at 12 months of age as outcome variables. Maternal-infant interaction was indexed by the Nursing Child Assessment Teaching Scales (NCATS) and home environment quality was indexed by the Home Observation for Measurement of the Environment (HOME).

RESULTS

In models including infant birth weight, cigarette use in second trimester, infant caloric intake at 9-12 months, size at birth for gestational age, infant sex, and mother's prepregnancy BMI, specific subscales of NCATs predicted infant adiposity z-scores. Poorer mother's response to infant distress was associated with greater SST ( β = -0.20, P = .02), TST ( β = -0.19, P = .04), and weight ( β = -0.14, P = .05). Better maternal sensitivity to infant cues was associated with larger SST ( β = 0.25, P < .01), while mother's poorer social-emotional growth fostering predicted greater SST ( β = -0.23, P < .01) and weight ( β = -0.16, P = .03). Better scores on HOME Organization of the Environment were associated with greater SST ( β = 0.34, P = .02) and TST ( β = 0.33, P = .04).

CONCLUSIONS

Emotionally relevant aspects of the maternal-infant interaction predicted infant adiposity, though in different directions. This indicates that the psychosocial environment, through maternal behavior, may influence infant adiposity. However, the general home environment was not consistently related to infant adiposity.

Endocrine disrupting chemicals and ovulation: Is there a relationship?

Although the potential for endocrine disrupting chemicals (EDCs) to disrupt female fecundity is great, few studies have assessed the threat to human reproduction. This study investigates levels of organochlorines in relation to their impact on women's menstrual cycles and ovulatory status. To address concerns of the Akwesasne Mohawk community in upstate New York regarding well-established exposure to EDCs, women's fertility and reproductive health endpoints, we recruited 215 women between the ages of 21 and 38 years to measure menstrual cycle characteristics and levels of local pollutants. Of these, 155 women collected saliva over the course of their menstrual cycle allowing for analysis of estradiol and progesterone levels and the determination of ovulatory status in relationship to their serum pollutant levels. A subset of participants (15) who did not commence cycling within a month of their enrollment were not included in the analysis, hence reducing the sample size to 140 participants. Additionally, a lipid panel, estradiol and progesterone were assessed in serum on Day 3 of the menstrual cycle. Median cycle length for women in the sample was 29 days. After aligning the cycles, 110 women were considered ovulatory and 45 (29%) anovulatory. Concentrations of groups of more persistent PCBs congeners, HCB, and p,p'-DDE did not differ significantly with ovulatory status. However, a sub-group of low-chlorinated PCB congeners, considered to be estrogenic were significantly higher among anovulatory women. These findings suggest that certain EDC's, ubiquitous in our environment, may adversely affect menstrual cycles and thus have the capacity to impair reproductive function, including likelihood of conception.

Power and pollutant exposure in the context of American Indian health and survival

BACKGROUND

American Indians and Alaskan Natives (AI/AN) are a highly diverse group in terms of culture and language, but share a history of oppression and attempted extermination that has left many with a legacy of poverty and poor health. Cultural and biological survival are important issues for many AI/AN groups.

METHODS

Using US criteria, AI/AN groups are more likely to be poor. The US National Center for Health Statistics reports that US AI/ANs have higher mortality and morbidity rates than the US population. While all groups racially defined by the US National Center for Health Statistics have been experiencing a decline in fertility since 1983, AI/ANs seem to be suffering a substantially greater and earlier decline in fertility. Given the importance of fertility in the survival of AI/AN communities, it is important to identify the source of this decline.

RESULTS

A recent study of one AI/AN group living along the St. Lawrence River found that obesity and exposure to a particular group of polychlorinated biphenyls were the factors most highly associated with indicators of impaired fertility. Economic factors are often cited as reasons for fertility declines, however in this situation these other factors may have either primary or contributing roles.

CONCLUSIONS

If the associations with obesity and toxicant exposure are confirmed, intervening on these factors might be important steps in stemming continued declines in fertility.

Religious-Commitment Signaling and Impression Management amongst Pentecostals: Relationships to Salivary Cortisol and Alpha-Amylase

Religious-commitment signaling is thought to indicate willingness to cooperate with a religious group. It follows that a desire to signal affiliation and reap concomitant benefits would lend itself to acting in socially desirable ways. Success or failure in such areas, especially where there is conscious intent, should correspond to proximal indicators of well-being, such as psychosocial or biological stress. To test this model, we assessed religious-commitment signaling and socially desirable responding among a sample of Pentecostals with respect to salivary biomarkers of stress and arousal. Results indicate that cortisol levels on worship and non-worship days were significantly influenced by religious-commitment signaling when moderated by impression management, a conscious form of socially desirable responding. No significant influences on salivary alpha-amylase were detected. These findings are important for understanding how religious-commitment signaling mechanisms may influence stress response when moderated by socially desirable responding and the role of communal orientation to psychosocial health.

Changes in persistent organic pollutant levels from adolescence to young adulthood

Elimination rates and their corresponding half-lives are conceptually important and intuitively accessible pharmacokinetic measures of toxicant elimination, but regression-based estimates are biased proportional to the degree of continuing (background) exposure. We propose an alternative estimator, the censored normal regression model, which uses all observations, but treats individuals whose initial level failed to exceed their follow-up level as censored observations to weight the regression estimates from those that declined between blood draws. In this manner, we derive the intrinsic elimination rate, the elimination rate free from ongoing exposure, as a parameter in a regression with an unobserved, latent dependent variable. We utilize sequential measurements of persistent organic pollutants (POPs) levels from adolescence to adulthood, a period of intense change in size and body composition, to quantify individual-level change within a community exposed to significant quantities of contaminants over an extended period of time. Although much research has been conducted on effects of POPs, far less attention has been given to vectors of intake and changes in toxicant levels during the life course. We apply exploratory factor analysis (EFA) to types and timing of consumption, along with physical behavioral characteristics, to identify a structure of seven underlying factors. Although several variables show factorial complexity, the latent constructs included an age/maturation and period-related factor, a nutritional composite, consumption prior to pregnancy, fish and fowl consumed during pregnancy, factors distinguishing body mass and weight from height, and bottom-feeding fish consumption. Unadjusted and adjusted half-lives using the censored normal regression estimator, as well as estimated half-lives from conventional log concentration regressions, are reported for PCB groupings, specific congeners, p,p'-DDE, and HCB.

Applying the community partnership approach to human biology research

Contemporary human biology research employs a unique skillset for biocultural analysis. This skillset is highly appropriate for the study of health disparities because disparities result from the interaction of social and biological factors over one or more generations. Health disparities research almost always involves disadvantaged communities owing to the relationship between social position and health in stratified societies. Successful research with disadvantaged communities involves a specific approach, the community partnership model, which creates a relationship beneficial for researcher and community. Paramount is the need for trust between partners. With trust established, partners share research goals, agree on research methods and produce results of interest and importance to all partners. Results are shared with the community as they are developed; community partners also provide input on analyses and interpretation of findings. This article describes a partnership-based, 20 year relationship between community members of the Akwesasne Mohawk Nation and researchers at the University at Albany. As with many communities facing health disparity issues, research with Native Americans and indigenous peoples generally is inherently politicized. For Akwesasne, the contamination of their lands and waters is an environmental justice issue in which the community has faced unequal exposure to, and harm by environmental toxicants. As human biologists engage in more partnership-type research, it is important to understand the long term goals of the community and what is at stake so the research circle can be closed and 'helicopter' style research avoided.

Culture, Urbanism and Changing Human Biology

Anthropologists have long known that human activity driven by culture changes the environment. This is apparent in the archaeological record and through the study of the modern environment. Perhaps the largest change since the paleolithic era is the organization of human populations in cities. New environments can reshape human biology through evolution as shown by the evolution of the hominid lineage. Evolution is not the only process capable of reshaping our biology. Some changes in our human biology are adaptive and evolutionary while others are pathological. What changes in human biology may be wrought by the modern urban environment? One significant new change in the environment is the introduction of pollutants largely through urbanization. Pollutants can affect human biology in myriad ways. Evidence shows that human growth, reproduction, and cognitive functioning can be altered by some pollutants, and altered in different ways depending on the pollutant. Thus, pollutants have significance for human biologists and anthropologists generally. Further, they illustrate the bio-cultural interaction characterizing human change. Humans adapt by changing the environment, a cultural process, and then change biologically to adjust to that new environment. This ongoing, interactive process is a fundamental characteristic of human change over the millennia.

Relationships of polychlorinated biphenyls and dichlorodiphenyldichloroethylene (p,p'-DDE) with testosterone levels in adolescent males

BACKGROUND

Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized.

OBJECTIVES

In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p´-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 to < 17 years of age with documented toxicant exposures.

METHODS

Data were collected between February 1996 and January 2000. Fasting blood specimens were collected before breakfast by trained Akwesasne Mohawk staff. Multivariable regression models were used to estimates associations between toxicants and serum testosterone, adjusted for other toxicants, Tanner stage, and potential confounders.

RESULTS

The sum of 16 PCB congeners (Σ16PCBs) that were detected in ≥ 50% of the population was significantly and negatively associated with serum testosterone levels, such that a 10% change in exposure was associated with a 5.6% decrease in testosterone (95% CI: -10.8, -0.5%). Of the 16 congeners, the more persistent ones (Σ8PerPCBs) were related to testosterone, whereas the less persistent ones, possibly reflecting more recent exposure, were not. When PCB congeners were subgrouped, the association was significant for the sum of eight more persistent PCBs (5.7% decrease; 95% CI: -11, -0.4%), and stronger than the sum of six less persistent congeners (3.1% decrease; 95% CI: -7.2, 0.9%). p,p´-DDE was positively but not significantly associated with serum testosterone (5.2% increase with a 10% increase in exposure; 95% CI: -0.5, 10.9%). Neither lead nor HCB was significantly associated with testosterone levels.

CONCLUSIONS

Exposure to PCBs, particularly the more highly persistent congeners, may negatively influence testosterone levels among adolescent males. The positive relationship between p,p´-DDE and testosterone indicates that not all POPs act similarly.

CITATION

Schell LM, Gallo MV, Deane GD, Nelder KR, DeCaprio AP, Jacobs A; Akwesasne Task Force on the Environment. 2014. Relationships of polychlorinated biphenyls and dichlorodiphenyldichloroethylene (p,p´-DDE) with testosterone levels in adolescent males. Environ Health Perspect 122:304-309; http://dx.doi.org/10.1289/ehp.1205984.

PCBs and ADHD in Mohawk adolescents

The present study examines the relationship between the levels of persistent polychlorinated biphenyls (PCBs) in adolescents' blood serum and concurrent measures of their ADHD-like behavior derived from ratings provided by parents and teachers. Two measures with demonstrated diagnostic validity, the Conners and ADDES scales, are used. The study was conducted in partnership with the Mohawk Nation at Akwesasne where the St. Lawrence River and surrounding waterways have been contaminated with PCBs that have entered the food chain. This study examines a subset of the data derived from the Mohawk Adolescent Well-Being Study (MAWBS), which was designed to investigate psychosocial and health related outcomes of 271 adolescents aged 10 years to 17 years and whose mothers were likely to have consumed PCB-contaminated fish and wild game before and during their pregnancy. No evidence of negative effects of adolescent blood PCB levels on ADHD-like behavior was found, and indeed occasional findings were in the unexpected direction. The possibility of negative confounding by SES and breastfeeding history was examined but dismissed.

Dietary patterns of Akwesasne Mohawk adolescents

BACKGROUND

Native American youth have greater rates of overweight/obesity than same-aged youth from the general population. Even though dietary shifts are suspected, surprisingly little information exists concerning the dietary patterns of contemporary Native American adolescents.

AIM

This study examines the dietary composition of Native American adolescents residing in upstate New York at the Akwesasne Mohawk Nation. The goal of this investigation is to assess the food patterns of Akwesasne adolescents via a total diet approach. PARTICIPANTS/SETTING AND METHODS: The sample is comprised of 246 Mohawk adolescents between the ages of 10-16.9 years of age residing at the Akwesasne Mohawk Nation. Food frequency data was collected from adolescents via interview during a cross-sectional study investigating their exposure to environmental pollutants.

RESULTS AND CONCLUSION

Nutrient-dilute but energy-dense foods characterize most of the top 10 dietary sources of energy, carbohydrates, and fat. Although micronutrient intakes are by and large adequate in the sample, micronutrients are most often derived from highly fortified food sources. Adolescent diets contain few naturally-occurring sources of many micronutrients, especially folate and iron. A narrow variety of foods dominate the top dietary sources across both macronutrient and micronutrients, strongly suggesting the need for increased dietary diversity within this age group.

Transitioning from traditional: pollution, diet and the development of children

Indigenous people in virtually all parts of the world have transitioned from a traditional way of life to incorporate western culture to some degree. The forces driving these transitions are varied although there are some common features. Today, some traditional communities are exposed to pollution from nearby industries that have been located in undeveloped areas to take advantage of natural resources, inexpensive labor, lax regulations, or other features. Avoiding sources of pollution can safeguard health, but may have untoward consequences. When exposure to pollutants is through components of the traditional diet, people must alter their diet to avoid the pollutants, and in so doing, they transition away from traditional culture. Further, avoiding local, contaminated food involves eating commercial, mass produced foods that can contribute to obesity which is a growing problem worldwide. The choice between eating uncontaminated food from stores or maintaining traditional ways including a traditional diet, is a stressful one adding to the overwhelming stress of acculturation.

Growth as a mirror: is endocrine disruption challenging Tanner's concept?

BACKGROUND

James Tanner coined the expression 'Growth as a Mirror' and summarized in four words the results of more than a century of research on growth. Nineteenth century social reformers saw poor child growth as a reflection of terrible environmental conditions of the working class. Later investigators in anthropology and other fields clarified the connections between poor nutrition, disease, psychosocial stress and poor growth.

AIM

To evaluate the growth as a mirror concept in light of recent studies of endocrine disruption. PAPERS AND IMPLICATIONS: Pollution is recognized as a prominent component of the modern environment. From studies of many pollutants it is clear that some pollutants depress growth while others speed sexual maturation and increase growth, primarily in weight and fatness. While such unwelcome environmental features do not always suppress growth, growth still mirrors the environment in all its complexity and this relationship is key to understanding growth patterns today. For example, Akwesasne Mohawk adolescents are characterized by high rates of obesity and overweight. Their growth reflects the multiple intersecting influences of psychosocial stress, several pollutant exposures and limited dietary choices.

CONCLUSION

Although Tanner did not anticipate the myriad influences of pollutants, the growth as a mirror concept continues to have great validity and utility.

Overweight and obesity among North American Indian infants, children, and youth

The frequency of overweight and obesity among North American Indian children and youth exceeds that of other ethnic groups in the United States. This observation is based on studies using body mass index as the primary measure of overweight and obesity. In the mid-20th century, there were regional differences among North American Indian groups in sub-adults' size and shape and only a few Southwestern groups were characterized by high rates of overweight and obesity. In most populations, the high prevalence of overweight and obesity developed in the last decades of the 20th century. Childhood obesity may begin early in life as many studies report higher birth weights and greater weight-for-height in the preschool years. Contributing factors include higher maternal weights, a nutritional transition from locally caught or raised foods to store bought items, psychosocial stress associated with threats to cultural identity and national sovereignty, and exposure to obesogenic pollutants, all associated to some degree with poverty. Obesity is part of the profile of poor health among Native Americans in the US and Canada, and contributes to woefully high rates of diabetes, cardiovascular disease, and early mortality. Interventions that are culturally appropriate are needed to reduce weights at all points in the lifespan.

What's NOT to eat--food adulteration in the context of human biology

Food has nutritional and non-nutritional components. The latter are not well-studied despite the fact that food adulteration has been common. Food adulteration may have reached its peak in cities of Western Europe and the US in the 18th and 19th centuries when foods were often purposely contaminated with additives to increase bulk, attractiveness, disguise spoilage, and increase profit. Effective regulation of food began in the late 19th and 20th centuries. Nevertheless, today food recalls for bacterial contamination are common, while pesticides and compounds from manufacturing are detected in many foods. Foods with strong reputations for healthiness, such as salmon, may have sizable contaminant contents. The contaminant content of many foods varies by origin and season. Nearly all commercially raised salmon has higher contaminant levels than wild caught salmon. Opting out of the commercial food distribution system is an option, but the value depends on the habitat in which the food is obtained. Traditionally, the Akwesasne Mohawk Nation has depended on local fish and wildlife for their diet. Now pollution of local waterways has led to the contamination of many local foods, and levels of the contaminant polychlorinated biphenyls in the Akwesasne Mohawk people reflect current or past dietary patterns. Many other communities in nonurban settings are exposed to contaminants through long-trail distribution of contaminants in food, air, and/or water. Human biologists considering nutrition, disease, growth, reproduction, aging, to name a few areas, may consider the non-nutritional components of food as many have the ability to alter physiological functioning.

Levels of persistent organic pollutant and their predictors among young adults

Exposure to persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethane (p,p'-DDE), and hexachlorobenzene (HCB) continues to be of concern due to their ubiquitous distribution and high persistence. Current toxicant body burden is still a primary concern within the Akwesasne Mohawk Nation since other studies conducted within the community have shown relationships between these POPs and endocrine disruption. In this article we describe the levels of these toxicants in young adults of the Akwesasne Mohawk Nation between the ages of 17 and 21 years of age (mean age 18.1 years), and investigate potential influences of their current body burden. Seventeen congeners in fourteen chromatographic peaks were detected in 50% or more of the individuals sampled (geometric mean [GM] of the sum of these congeners=0.43 ppb). Congeners 118, 138[+163+164] and 153 had the highest rate of detection (≥98%) within the Akwesasne young adults. Of the other organochlorines, HCB (GM=0.04 ppb) and p,p'-DDE (GM=0.38 ppb) were found in 100% and 99% of the sample respectively. Significantly higher levels of PCBs were found among individuals who were breastfed as infants, were first born, or had consumed local fish within the past year. When compared to levels of p,p'-DDE, HCB, and 13 specific congeners reported by the CDC for youth between the ages of 12 and 19 years, the geometric means of several congeners (CBs 99, 105, 110, and 118) among the Akwesasne were higher than the reported CDC 90th percentile. In contrast, levels of CB 28 in Akwesasne young adults were ~50% or less than those of the CDC cohort. p,p'-DDE and HCB levels were generally higher in the CDC cohort (GM of 0.516 and 0.065 ppb, respectively for Mohawks vs. 2.51 and 0.123, respectively, for CDC). Concentrations of non-persistent PCBs among this sample of Akwesasne young adults were higher than those reported by the CDC suggesting continued exposure, but lower than those associated with severe contamination. Additional research into the concentration trends of individual PCB congeners within Akwesasne youth and young adults is warranted to further improve our insight into the determinants and influences of organochlorine concentrations within members of the Akwesasne community.

Salivary alpha-amylase and cortisol among pentecostals on a worship and nonworship day

OBJECTIVES

This investigation used a biomarker of sympathetic nervous system activity novel to biocultural research to test the hypothesis that engaging in religious worship activities would reduce baseline stress levels on a non-worship day among Pentecostals.

METHODS

As detailed in Lynn et al. (submitted for publication), stress was measured via salivary cortisol and α-amylase among 52 Apostolic Pentecostals in New York's mid-Hudson Valley. Saliva samples were collected at four predetermined times on consecutive Sundays and Mondays to establish diurnal profiles and compare days of worship and non-worship. These data were reanalyzed using separate analyses of covariance on α-amylase and cortisol to control for individual variation in Pentecostal behavior, effects of Sunday biomarkers on Monday, and other covariates.

RESULTS

There was a significant decrease in cortisol and an increase in α-amylase on a non-worship day compared with a service day. Models including engagement in Pentecostal worship behavior explained 62% of the change in non-service day cortisol and 73% of the change in non-service day α-amylase.

CONCLUSIONS

Engagement in Pentecostal worship may be associated with reductions in circulatory cortisol and enhancements in α-amylase activity.

A study of the distribution of aluminium in human placental tissues based on alkaline solubilization with determination by electrothermal atomic absorption spectrometry

Aluminium (Al) is a nonessential element known to induce neurotoxic effects, such as dialysis dementia, in patients on hemodialysis, with compromised kidney function. The role of Al in the progression of some neurodegenerative diseases, such as Alzheimer's disease (AD), is controversial, and remains unclear. The effects of Al on other vulnerable populations, such as fetuses and infants, have been infrequently studied. In the present study, Al has been measured in human placenta samples, comprising ∼160 each of placenta bodies, placenta membranes, and umbilical cords, using electrothermal atomic absorption spectrometry (ETAAS) after atmospheric pressure digestion with tetramethylammonium hydroxide (TMAH) and ethylenediaminetetraacidic acid (EDTA). The sensitivity, or characteristic mass (m(0)), for Al at the 309.3-nm line was found to be 30 ± 4 pg. The instrumental detection limit (IDL) (3s) for Al in solution was calculated as 0.72 μg L(-1) while the method detection limit (MDL) (3s) was 0.25 μg g(-1). Accuracy was assessed through analysis of quality control (QC) materials, including certified reference materials (CRMs), in-house reference materials (RMs), and spike recovery experiments, of varying matrices. Placental tissue analyses revealed geometric mean concentrations of approximately 0.5 μg g(-1) Al in placenta bodies (n = 165) and membranes (n = 155), while Al concentrations in umbilical cords (n = 154) were about 0.3 μg g(-1). Al was detected in 95% of placenta bodies, and 81% of placenta membranes, but only in 46% of umbilical cords.

Environmental influences on human growth and development: historical review and case study of contemporary influences

Over the past 100 years, the study of environmental influences on human physical growth and development has focused on the influences of social and economic factors; family and household characteristics; urbanization/modernization; nutrition; and features of the physical environment such as altitude, temperature and climate. Continuing in this tradition are current investigations into the roles of pollutants and other aspects of the human-made environment in affecting patterns of human growth and development, specifically the timing of sexual maturation and the development of obesity. Some of the methodological problems in conducting such studies are presented, as are results from an ongoing investigation among one Native American community that show relationships of pollutants to sexual maturation, overweight/obesity and thyroid system function which can impact growth and maturation.

Relationships of putative endocrine disruptors to human sexual maturation and thyroid activity in youth

Endocrine disruption has become a significant human health concern, but is difficult to study outside of the laboratory for several reasons including the multiplicity of exposures, the difficulty in assessing each exposure, and the variety of possible outcomes among human populations. This review summarizes our studies of the relationships of measured persistent organic pollutants (PCBs, p,p'-DDE, HCB and mirex), and heavy metals (lead and mercury), to outcomes directly related to thyroid function and sexual maturation. These studies were conducted in a sample of Native American youth from the Akwesasne Mohawk community. The participants were first studied during puberty (10-16.9 years of age) and then at approximately 18 years of age. Results from these studies show that PCB levels are positively related to TSH and negatively to free T4. Further, these effects are conditioned by breastfeeding history. Anti-thyroid peroxidase antibody levels also are related to PCB levels suggesting elevated risk of autoimmune disease among the exposed. Earlier age at menarche is associated with higher PCB levels while risk of delay is associated with higher lead levels. Some evidence that the timing of exposure produces different effects is presented, and the level of exposure in the participants suggests that effects observed may be relevant to a considerable proportion of the US population. Further investigations are warranted to determine effect thresholds and mechanisms.

Growth of infants' length, weight, head and arm circumferences in relation to low levels of blood lead measured serially

To determine whether levels of blood lead during gestation and infancy that are below the CDC action level of 10 microg/dl affect infant growth, we studied 211 disadvantaged mother-infant pairs from Albany, NY. Mothers' lead levels were low (second trimester chi = 2.8 microg/dl) as were infants' (chi = 3.3 microg/dl at 6 months; 6.4 microg/dl at 12 months). Multiple linear regression analyses showed that second trimester lead levels were related to reduced head circumference at 6 and 12 months. Infants of mothers with second trimester lead at or above the median (>or=3 microg/dl) exhibited negative associations between blood lead and head circumference at 6 and 12 months, and with weight-for-age, weight-for-length, and upper arm circumference at 6 months, but those below the median did not. Infants' 6-month lead level was related to head circumference at 12 months in the total sample, and in the subsample of infants whose blood lead was above the infants' 6-month blood lead median. Infants were also grouped by changes in their relative blood lead status, that is, above vs. below the median, from second trimester to 12 months of age. Infants whose lead levels changed from above to below the median were larger than infants whose lead levels went from below to above the median. The results suggest that lead may affect some dimensions of infant growth at levels below 10 microg/dl, but effects of lead levels less than 3 microg/dl are not evident in this sample.

Analysis of PCB congeners related to cognitive functioning in adolescents

To investigate the characteristics of PCBs that are linked to cognitive functioning, those congeners that were concurrently found in 271 Mohawk adolescents were grouped according to structure (dioxin-like or non-dioxin-like) and persistence (persistent or low-persistent). After the effects of the congener groups were orthogonalized, regression analyses (controlling for a number of variables found to be related to the cognitive outcomes) examined the relationship of each congener group to scores on three cognitive tests (the non-verbal Ravens Progressive Matrices, the Test of Memory and Learning, and the Woodcock Johnson-Revised). Five subtests from these cognitive tests were found to be associated with one or more PCB congener groups, most often at a moderate level. Two measures of long-term memory (Delayed Recall and Long Term Retrieval) were associated with all four congener groups. Nevertheless, examination of the role of individual congeners in the significantly related congener groups revealed that almost all congeners associated with cognitive outcomes were non-dioxin-like and ortho-substituted. A notable exception was the Ravens test where scores were associated only with dioxin-like congeners. This finding adds to the limited evidence of neurotoxic effects of dioxin-like congeners. Auditory Processing was related only to the persistent congener group. The association of the non-persistent congener group with three cognitive test scores (Delayed Recall, Long Term Retrieval and Comprehension-Knowledge) suggests that the Mohawk adolescents have experienced continuing or recent environmental exposure to PCBs that is sufficient to result in detectable cognitive decrements. Comparison of our findings with those of other human studies was limited by the relative lack of specificity of both PCB measures and cognitive outcome measures in much previous work.

Persistent organic pollutants and anti-thyroid peroxidase levels in Akwesasne Mohawk young adults

Persistent organic pollutants, such as polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and p,p'-dichlorophenyldichloroethylene (DDE), have been found to elicit a broad spectrum of biologic, metabolic, and immunologic responses. The potential of these pollutants to impair immune responses and trigger autoimmune disease is of growing concern, given their structural similarity to thyroid hormones and their potential to modulate the mechanisms and interfere with the binding of these hormones. We examine the relationship of different groupings of PCBs, according to chlorination and structure, and of p,p'-DDE and HCB to anti-thyroid peroxidase antibody, a useful tool in the evaluation of thyroid dysfunction, among 115 young adults of the Akwesasne Mohawk Nation. Overall, 18 participants (15.4%) had anti-thyroid peroxidase antibodies (TPOAb) levels above the normal laboratory reference range (23% of females, 9% of males). Among participants who were breast fed (n=47), those with an elevated TPOAb level had significantly higher levels of all PCB groupings, with the exception of levels of non-persistent PCBs which did not differ significantly. Levels of p,p'-DDE were also significantly elevated, while HCB and mirex were not higher among those with elevated TPOAb. Also, after stratifying by breast-feeding status, participants who were breast fed showed significant, positive relationships between TPOAb levels and all PCB groupings, except groups comprised of non-persistent PCBs, and with p,p'-DDE, HCB, and mirex. No effects were evident among non-breast-fed young adults. Further studies are necessary to elucidate the site and mechanism of action of these persistent organic pollutants (POPs) and to establish thresholds for these effects, especially among populations with background levels of toxicant exposure.

Relationship of thyroid hormone levels to levels of polychlorinated biphenyls, lead, p,p'- DDE, and other toxicants in Akwesasne Mohawk youth

BACKGROUND

It is well documented that acute exposure to high levels of persistent organic pollutants, such as polychlorinated biphenyls (PCBs), p,p'-dichlorophenyldichloroethylene (p,p'-DDE), and hexachlorobenzene (HCB), can affect human health including thyroid function. Chronic exposure to multiple toxicants is common but difficult to analyze, and most prior studies have focused on adults or newborns, creating a gap in our understanding of multitoxicant effects among adolescents.

OBJECTIVE

We investigated whether levels of PCBs, p,p'-DDE, HCB, mirex, lead, and mercury reflecting past chronic exposure are associated with alterations in levels of thyroid-stimulating hormone (TSH), triiodothyronine (T(3)), total thyroxine (TT(4)), and free thyroxine (FT(4)) among older children and adolescents.

METHODS

The sample consists of youth from the Akwesasne Mohawk Nation (n=232) who reside in proximity to several industries that have contaminated the local environment. We used multiple regression analysis to examine the effect of PCB groupings, p,p'-DDE, HCB, lead, and mercury on thyroid hormones after adjusting for sociodemographic covariates and controlling for all other toxicants.

RESULTS

Exposure to PCBs affects the thyroid hormone profile in adolescents. The group of persistent PCBs was positively associated with TSH but inversely related to FT(4). Nonpersistent PCBs were significantly and negatively related to FT(4) only. HCB was negatively associated with T(4), and lead was positively associated with T(3). Breast-fed adolescents had higher levels of persistent PCBs and p,p'-DDE but not of nonpersistent PCBs or any other toxicant when compared with non-breast-fed adolescents. Though having lower levels of persistent PCBs and p,p'-DDE, non-breast-fed adolescents exhibited significant relationships between persistent PCBs and TSH and FT(4), but breast-fed adolescents did not. It appears that PCBs from breast milk obscure the relationship between prenatal PCB exposure and thyroid function by adding random variation in PCB levels.

CONCLUSION

Our results demonstrate a reduction in thyroid function in adolescents in relation to their current serum levels of PCBs. These observations are consistent with the hypothesis that pre-natal exposure to PCBs alters thyroid function in a long-lasting manner but does not exclude the possibility that postnatal exposure is influential also.

Is there an elephant in the room? Addressing rival approaches to the interpretation of growth perturbations and small size

Two interpretations of growth perturbation and small size are commonly applied in human biology: an adaptationist approach in which small size is considered to be an a relatively beneficial adjustment to environmental stressors, and a biomedical approach in which small size is considered nonadaptive, a sign of dysfunction or pathology. These two interpretations conflict, but are used without acknowledging or addressing the conflict. This article reviews the strengths and weaknesses of the two. This exercise does not prove the indisputable superiority of either approach. Considerations of epistemology show that biologists will never be faced with a decisive test of either, much as they might like such clear cut evidence. Nevertheless, it is possible that a gradual decrease in the productivity of one approach will become a sufficient reason to abandon it. Alternatively, if specific areas of application can be distinguished, each approach might continue to be productive in its own domain.

Advancing biocultural models by working with communities: a partnership approach

Culture and human behavior are recognized today as major forces acting on human biological variation around the world. Studies of the relationships between biology and processes, such as modernization, urbanization, and social stratification, are prominent in our journals and meetings. An ongoing study of the interrelationships between toxicant exposure (organochlorines, lead, and mercury), health, and culture among youth of the Mohawk Nation at Akwesasne is located within this context and is used to analyze the strengths and challenges of a partnership approach to biocultural research. To assist in modeling the complex relationships between health, behavior, and culture, we have employed concepts from contemporary social theory, integrated qualitative and quantitative research, and implemented community-based research principles to develop a partnership approach to research in human biology. The community is directly involved in identifying research goals, developing research protocols appropriate for local cultural sensitivities and complexities, implementing the protocols in the field, and collaborating in the analysis and publication of results. We show the utility of this approach for understanding the relationships of toxicants to behavior and biological outcomes (adolescent growth, sexual maturation, and endocrine system alteration); as well as how it facilitates the agency of participants and communities involved in research, and brings greater social engagement to the development of the new human biology.

Selected anthropometric measurements of Akwesasne Mohawk youth: Skinfolds, circumferences, and breadths

Nationally, Native American youth have been shown to be at risk for overweight, and an increased prevalence of obesity among Native American children has been consistently reported. We describe skinfolds, circumferences, and body breadths to assess body size and shape of Akwesasne Mohawk youth (n = 271) between the ages of 10.0 and 16.99. Akwesasne is a sovereign nation with territory in New York state and Canada. Sex- and age-specific comparisons were made to reference values published from the Advance Data from Vital and Health Statistics and from the Third National Health and Examination Survey (NHANES III). Akwesasne youth have thicker skinfolds and larger circumferences than youth in the national surveys. Additionally, these cross-sectional data indicate that body fat is more centrally distributed in Akwesasne Mohawk boys and girls. Given the numerous studies emphasizing the importance of body fat distribution as a risk factor for chronic, obesity-related diseases prevalent within Native American communities, and the high level of fatness presented in this study, more concerted efforts need to be applied to help reduce the development of overweight in children from an early age.

PCBs and cognitive functioning of Mohawk adolescents

This paper reports on the relationships between the cognitive functioning and PCB current body burdens of adolescents in the Mohawk Nation of Akwesasne where there is concern about industrial pollution of the environment. Three cognitive tests (Woodcock Johnson-Revised, Test of Memory and Learning, and Ravens Progressive Matrices) provide 13 subtests that allow a variety of cognitive outcomes to be assessed. A summary measure of PCB level was created from the congeners detected in at least 50% of the participants. The most notable finding was the significant negative relationship between PCB levels and two separate measures of long term memory. There was also a negative relationship with a measure of comprehension and knowledge. Significant relationships were not large, but provide evidence of subtle negative effects of PCB exposure.

Effects of Pollution on Human Growth and Development: An Introduction

Pollution is a worldwide problem and its potential to influence the physiology of human populations is great. Studies of human growth and development in relation to pollution have increased in number and quality since the mid-twentieth century. Many studies have found that some pollutants have detrimental effects on human growth, particularly prenatal growth. The heavy metal, lead, is commonly found in human populations and is related to smaller size at birth and studies have reported decrements that range up to about 200 grams. Noise stress from transportation sources also is related to reduced prenatal growth with somewhat smaller decrements reported. Studies of humans exposed to polychlorinated biphenyls, one of the persistent organic pollutants, have reduced size at birth, advanced sexual maturation and altered hormone levels related to thyroid regulation. Thus different pollutants exert effects through different physiological pathways. However, some studies have not observed these effects, which indicates that the situation is complex and requires further study with better study designs. Determining the effects of pollutants on human physiology and growth is difficult as it requires fairly large numbers of subjects who are not purposely exposed but for whom exposure can be measured. These effects of pollutants and the mechanisms of effect require further study to understand and, it is hoped, to blunt or block any detrimental effects on human health and well-being.