Search NASA⌕ Search

SEARCH · Search NASA

Results for “Multivariate Analysis”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Solar plants, environmental degradation and local socioeconomic contexts: A case study in a Mediterranean country

Photovoltaic plants developed on rural land are becoming a common infrastructure in the Mediterranean region and may contribute, at least indirectly, to various forms of environmental degradation including landscape deterioration, land take, soil degradation and loss in traditional cropland and biodiversity. Our study illustrates a procedure estimating (i) the extension of ground-mounted photovoltaic fields at the municipal scale in Italy and (ii) inferring the socioeconomic profile of the Italian municipalities experiencing different expansion rates of ground-mounted photovoltaic fields over the last years (2007-2014). The procedure was based on diachronic information derived from official data sources integrated into a geographical decision support system. Our results indicate that the surface area of ground-mounted photovoltaic fields into rural land grew continuously in Italy between 2007 and 2014 with positive and increasing growth rates observed during 2007-2011 and positive but slightly decreasing growth rates over 2012-2014, as a result of market saturation and policies containing the diffusion of solar plants on greenfields. We found important differences in the density of ground-mounted solar plants between northern and southern Italian municipalities. We identified accessible rural municipalities in southern Italy with intermediate population density and large availability of non-urban land as the most exposed to the diffusion of solar plants on greenfields in the last decade. Our approach is a promising tool to estimate changes in the use of land driven by the expansion of photovoltaic fields into rural land.

14 SOLAR ENERGY↗
DOE OSTI2013

Placental concentrations of heavy metals in a mother-child cohort

Heavy metals are environmental contaminants with properties known to be toxic for wildlife and humans. Despite strong concerns about their harmful effects, little information is available on intrauterine exposure in humans. The aim of this study was to evaluate prenatal exposure to As, Cd, Cr, Hg, Mn, and Pb and its association with maternal factors in a population-based mother-child cohort in Southern Spain. Between 2000 and 2002, 700 pregnant women were recruited and 137 placentas from the cohort were randomly selected and analyzed for the selected metals by atomic absorption. Maternal sociodemographic and lifestyle factors were obtained by questionnaire after delivery. Bivariate analysis and multivariate linear regression were performed. Cd and Mn concentrations were detected in all placentas, while Cr, Pb, and Hg were found in 98.5%, 35.0%, and 30.7% of samples, respectively. The highest concentrations were observed for Pb (mean: 94.80 ng/g wet weight of placenta), followed by Mn (63.80 ng/g), Cr (63.70 ng/g), Cd (3.45 ng/g), and Hg (0.024 ng/g). Arsenic was not detected in any sample. Gestational age and smoking during pregnancy were associated with placental Cd concentrations, while no factor appeared to influence concentrations of Cr, Hg, Mn, or Pb. In comparison to results of European studies, these concentrations are in a low-intermediate position. Studies are required to investigate the factors contributing to early exposure to heavy metals and to determine how placental transfer of these toxic compounds may affect children's health.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Cadmium exposure induces hematuria in Korean adults

Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; P{sub trend}=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Exposure to mercury among Spanish preschool children: Trend from birth to age four

The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations. - Highlights: • The geometric mean of hair Hg concentrations was 1.10 µg/g. • 19% of children had Hg concentrations above the RfD proposed by the WHO. • Hair Hg concentrations in children increased as a function of total fish intake. • Swordfish, lean fish and canned fish were the most related to Hg concentrations. • There was a decrease in Hg concentrations from birth to age four.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Cadmium exposure and neuropsychological development in school children in southwestern Spain

This study assessed the association between cadmium exposure and neuropsychological development in children from a region with high industrial and mining activities in southwestern Spain. We conducted a cross-sectional study with 261 children aged 6–9 years between January and March 2012. Cadmium exposure was measured in urine and hair of children, and neuropsychological development was assessed with the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) and with three computerized tests from the Behavioral Assessment and Research System (BARS): Reaction Time Test (RTT), Continuous Performance Test (CPT) and Selective Attention Test (SAT). Multivariate linear regression models, adjusted for potential confounders, were used to estimate the association between neuropsychological development and cadmium exposure measured in urine and hair samples. Geometric means of urine and hair cadmium levels were 0.75 μg/g creatinine and 0.01 μg/g, respectively. We observed that doubling of levels of cadmium in urine was associated with a reduction of two points (95% CI: −3.8 to −0.4) in the Full-Scale intelligence quotient (IQ) in boys. By domains, association was statistically significant for Verbal Comprehension (β=−2.0; p=0.04) and close to the significance level for Perceptual Reasoning (β=−1.8; p=0.06). Among girls, only Verbal Comprehension showed suggestive associations with cadmium exposure (β=−1.7; p=0.06). Cadmium exposure is associated with cognitive delays in boys in our region. Our results provide additional evidence of the neurotoxic effect of low-level postnatal cadmium exposure among children, and support the hypothesis of differences between sexes in the neurotoxic effect of metals on children. - Highlights: • This study associates Cd exposure and neuropsychological development in children. • Cd exposure was associated with cognitive delay in boys, but not in girls. • Intellectual quotient of boys decreased two points for a doubling of urine Cd levels. • Verbal Comprehension and Perceptual Reasoning were the most affected domains in boys. • Results support the sex-related differences in the neurotoxicity of metals in children.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Modeling spatial effects of PM{sub 2.5} on term low birth weight in Los Angeles County

Air pollution epidemiological studies suggest that elevated exposure to fine particulate matter (PM{sub 2.5}) is associated with higher prevalence of term low birth weight (TLBW). Previous studies have generally assumed the exposure–response of PM{sub 2.5} on TLBW to be the same throughout a large geographical area. Health effects related to PM{sub 2.5} exposures, however, may not be uniformly distributed spatially, creating a need for studies that explicitly investigate the spatial distribution of the exposure–response relationship between individual-level exposure to PM{sub 2.5} and TLBW. Here, we examine the overall and spatially varying exposure–response relationship between PM{sub 2.5} and TLBW throughout urban Los Angeles (LA) County, California. We estimated PM{sub 2.5} from a combination of land use regression (LUR), aerosol optical depth from remote sensing, and atmospheric modeling techniques. Exposures were assigned to LA County individual pregnancies identified from electronic birth certificates between the years 1995-2006 (N=1,359,284) provided by the California Department of Public Health. We used a single pollutant multivariate logistic regression model, with multilevel spatially structured and unstructured random effects set in a Bayesian framework to estimate global and spatially varying pollutant effects on TLBW at the census tract level. Overall, increased PM{sub 2.5} level was associated with higher prevalence of TLBW county-wide. The spatial random effects model, however, demonstrated that the exposure–response for PM{sub 2.5} and TLBW was not uniform across urban LA County. Rather, the magnitude and certainty of the exposure–response estimates for PM{sub 2.5} on log odds of TLBW were greatest in the urban core of Central and Southern LA County census tracts. These results suggest that the effects may be spatially patterned, and that simply estimating global pollutant effects obscures disparities suggested by spatial patterns of effects. Studies that incorporate spatial multilevel modeling with random coefficients allow us to identify areas where air pollutant effects on adverse birth outcomes may be most severe and policies to further reduce air pollution might be most effective. - Highlights: • We model the spatial dependency of PM{sub 2.5} effects on term low birth weight (TLBW). • PM{sub 2.5} effects on TLBW are shown to vary spatially across urban LA County. • Modeling spatial dependency of PM{sub 2.5} health effects may identify effect 'hotspots'. • Birth outcomes studies should consider the spatial dependency of PM{sub 2.5} effects.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Prenatal exposure to polycyclic aromatic hydrocarbons/aromatics, BDNF and child development

Objectives: Within a New York City (NYC) birth cohort, we assessed the associations between polycyclic aromatic hydrocarbon (PAH) and other aromatic DNA adducts and brain derived neurotrophic factor (BDNF) concentrations in umbilical cord blood, and neurodevelopment at age 2 years and whether BDNF is a mediator of the associations between PAH/aromatic-DNA adducts and neurodevelopment. Methods: PAH/aromatic-DNA adduct concentrations in cord blood were measured in 505 children born to nonsmoking African-American and Dominican women residing in NYC, and a subset was assessed for neurodevelopment at 2 years using the Bayley Scales of Infant Development Mental Development Index (MDI). A spectrum of PAH/aromatic-DNA adducts was measured using the {sup 32}P-postlabeling assay; DNA adducts formed by benzo[a]pyrene (B[a]P), a representative PAH, were measured by High Performance Liquid Chromatography (HPLC)/fluorescence. BDNF mature protein in cord blood plasma was quantified by an ELISA. Multivariate regression analysis, adjusting for potential confounders, was conducted. Results: PAH/aromatic-DNA adduct concentration measured by postlabeling was inversely associated with BDNF concentration (p=0.02) and with MDI scores at 2 years (p=0.04). BDNF level was positively associated with MDI scores (p=0.003). Restricting to subjects having all three measures (PAH/aromatic-DNA adducts by postlabeling, MDI, and BDNF), results were similar but attenuated (p=0.13, p=0.05, p=0.01, respectively). Associations between B[a]P-DNA adducts and BDNF and B[a]P-DNA adducts and MDI at age 2 years were not significant. At age 3 years, the positive association of BDNF with MDI was not observed. Conclusions: The results at age 2 suggest that prenatal exposure to a spectrum of PAH/aromatic pollutants may adversely affect early neurodevelopment, in part by reducing BDNF levels during the fetal period. However, the same relationship was not seen at age 3. - Highlights: • Cord blood Polycyclic Aromatic Hydrocarbon (PAH)/aromatic-DNA adducts were assayed. • Brain Derived Neurotrophic Factor (BDNF) concentration was measured concurrently. • Associations between biomarkers and neurodevelopment at age 2 years were assessed. • Adduct level was inversely associated with BDNF concentration and neurodevelopment. • BDNF level was positively associated with neurodevelopment scores at age 2 years.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Circulating levels of perfluoroalkyl substances are associated with dietary patterns – A cross sectional study in elderly Swedish men and women

Background: In our daily life, we are exposed to perfluoroalkyl substances (PFAS) with possible health implications. The main exposure route for these substances is diet but comparative studies on how dietary habits influence exposure are lacking. Objectives: To examine the relations between blood levels of PFAS and adherence to three predefined dietary patterns (a WHO recommended diet, a Mediterranean-like diet, and a Low-Carbohydrate High-Protein (LCHP) diet) in an elderly Swedish population. Methods: Dietary data from 7-day food records and serum concentrations of PFAS were obtained from a 70-year-old Swedish population (n=844), the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. The Healthy Diet Indicator score (based on WHO recommendations), the Mediterranean Diet Score and LCHP score were used to assess adherence. Multivariate linear regression was used to assess the associations between eight major PFAS and adherence to each dietary pattern. Results: The WHO recommended diet was positively associated with perfluorohexane sulfonic acid (PFHxS). The LCHP diet was positively related to four out of eight PFAS; namely, perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA). The Mediterranean-like diet was positively associated with most PFAS; namely perfluorooctanoic acid (PFOA), perfluorooctane sulfonamide (PFOSA), PFHxS, PFNA, PFDA, and PFUnDA. Conclusions: All dietary patterns were positively associated with blood levels of PFAS. The highest body burden of PFAS was found in individuals with high adherence to a Mediterranean-like diet, whilst individuals who more closely followed the officially recommended diet displayed a lower body burden of these compounds. - Highlights: • Perfluoroalkyl substances (PFAS) quantified in blood of 70-y-old Swedish subjects. • Adherence to predefined dietary patterns was associated with circulating PFAS. • A Mediterranean-like diet was positively associated with most circulating PFAS. • A low-carbohydrate high-protein diet was positively related to some PFAS in blood. • A WHO-recommended diet was only related to higher circulating levels of PFHxS.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Environmental exposure to arsenic and chromium in children is associated with kidney injury molecule-1

Environmental hazards from natural or anthropological sources are widespread, especially in the north-central region of Mexico. Children represent a susceptible population due to their unique routes of exposure and special vulnerabilities. In this study we evaluated the association of exposure to environmental kidney toxicants with kidney injury biomarkers in children living in San Luis Potosi (SLP), Mexico. A cross-sectional study was conducted with 83 children (5–12 years of age) residents of Villa de Reyes, SLP. Exposure to arsenic, cadmium, chromium, fluoride and lead was assessed in urine, blood and drinking water samples. Almost all tap and well water samples had levels of arsenic (81.5%) and fluoride (100%) above the permissible levels recommended by the World Health Organization. Mean urine arsenic (45.6 ppb) and chromium (61.7 ppb) were higher than the biological exposure index, a reference value in occupational settings. Using multivariate adjusted models, we found a dose-dependent association between kidney injury molecule-1 (KIM-1) across chromium exposure tertiles [(T1: reference, T2: 467 pg/mL; T3: 615 pg/mL) (p-trend=0.001)]. Chromium upper tertile was also associated with higher urinary miR-200c (500 copies/μl) and miR-423 (189 copies/μL). Arsenic upper tertile was also associated with higher urinary KIM-1 (372 pg/mL). Other kidney injury/functional biomarkers such as serum creatinine, glomerular filtration rate, albuminuria, neutrophil gelatinase-associated lipocalin and miR-21 did not show any association with arsenic, chromium or any of the other toxicants evaluated. We conclude that KIM-1 might serve as a sensitive biomarker to screen children for kidney damage induced by environmental toxic agents. - Highlights: • Children living in Mexico had exceedingly high arsenic and chromium exposure. • Arsenic and chromium exposure was significantly associated with urinary KIM-1. • KIM-1 might serve as a sensitive biomarker to evaluate kidney injury in children.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Time-varying coefficient vector autoregressions model based on dynamic correlation with an application to crude oil and stock markets

This paper proposes a new time-varying coefficient vector autoregressions (VAR) model, in which the coefficient is a linear function of dynamic lagged correlation. The proposed model allows for flexibility in choices of dynamic correlation models (e.g. dynamic conditional correlation generalized autoregressive conditional heteroskedasticity (GARCH) models, Markov-switching GARCH models and multivariate stochastic volatility models), which indicates that it can describe many types of time-varying causal effects. Time-varying causal relations between West Texas Intermediate (WTI) crude oil and the US Standard and Poor’s 500 (S&P 500) stock markets are examined by the proposed model. The empirical results show that their causal relations evolve with time and display complex characters. Both positive and negative causal effects of the WTI on the S&P 500 in the subperiods have been found and confirmed by the traditional VAR models. Similar results have been obtained in the causal effects of S&P 500 on WTI. In addition, the proposed model outperforms the traditional VAR model.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Elemental content of the placenta: A comparison between two high-risk obstetrical populations, adult women carrying multiples and adolescents carrying singletons

Background: The placenta is responsible for the exchange of nutrients and for preventing harmful compounds from entering the fetal circulation. With increasing industrialization, exposures to commercial and toxic metals become a concern for both pregnant women and those planning a pregnancy. The understanding of transport mechanisms and pharmacokinetics for most inorganic elements is incomplete and limited to normal term deliveries. Objectives: To obtain novel data on 46 inorganic elements in placentae from two high-risk obstetric populations, women carrying multiples and adolescents carrying singletons, evaluating differences, if present, and identifying predictors of placental content. Methods: Placental tissue was collected from adolescents carrying singletons and adults carrying multiples. Elemental content was analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). Multivariate regression and factor analyses were used. Results: With the exception of Au and Pt, almost all placentae contained quantifiable concentrations of each element analyzed. All placentae contained the essential elements Ca, Fe, Mg, Se and Zn, which clustered together onto the same factor. Most elements were higher in placentae from women carrying multiples. Differences in placental content disappeared after adjusting for maternal age. Rare earth elements (REEs) clustered together and remained higher in the multiples even after adjusting for maternal age. Conclusion: Human placentae contain a wide range of elements, including REEs. Ranges differed considerably between cohorts. Elements with similar chemical properties, like REEs or nutritionally essential elements, clustered together. Maternal age, and therefore longer environmental exposure, was significantly associated with elevated element concentrations in the placenta. Placental concentrations of several metals that are known to be nutritionally essential (e.g., Fe, Ca, Mg, and Zn) did not differ significantly between cohorts, suggesting tight regulation, whereas concentrations of environmental contaminants differed significantly between groups, even after adjusting for maternal age. - Highlights: • Levels of 46 elements were measured in placentae from two high-risk cohorts. • Almost all placentae contained traces of the 46 elements, including REEs. • Maternal age was significantly associated with concentrations in the placenta. • Elements with similar properties and roles clustered together.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Use of electronic cigarettes in public and private settings in Barcelona (Spain)

Objectives: To describe the prevalence of e-cigarette users who use them in selected indoor public and workplaces, and private venues in Barcelona (Spain) in 2015. Methods: This is a cross-sectional study of a sample of e-cigarette users (≥ 18 years) from Barcelona (n = 600). We calculated the proportion of e-cigarette users who used the device in public and private settings (in the last 30 days). We fit multivariate logistic regression models adjusted for sex and age to calculate the odds ratios (OR) with their 95% confidence intervals (CI) of e-cigarette use by socio-demographic factors, dual use and nicotine-containing e-cigarettes. Results: The highest proportion of e-cigarette users who used them in public places was found at restaurants or bars (69.4%) and nightclubs or pubs (55.4%). Also being current conventional tobacco smokers (dual users) was significantly associated with lower use of e-cigarettes in workplaces (OR = 0.61, 95%CI:0.41–0.91), restaurants (OR = 0.66, 95%CI:0.45–0.97) and nightclubs (OR = 0.56, 95%CI:0.37–0.86). Moreover, being a nicotine-containing e-cigarette user was associated with higher odds of using the device in workplaces (OR = 2.01, 95%CI:1.34–3.01), and lower odds of using it in nightclubs (OR = 0.56, 95%CI:0.39–0.82). 96.8% of the included e-cigarette users declared to use the device at home. Being a current tobacco smoker was associated with increased odds of using e-cigarettes at home (OR = 3.17, 95%CI:1.22–8.22). Conclusions: E-cigarette use in private settings and in public settings where their use is not regulated by law is high. Therefore, the public health administration in Spain should consider expanding the prohibition of e-cigarette use to indoor public places and should take into account the possibility of exposure to aerosol from e-cigarettes. - Highlights: • Describe use e-cigarette in indoor public and workplaces. • Describe use e-cigarette in indoor private venues. • E-cigarette use in private settings is high. • Dual users declared a higher use of e-cigarettes. • Expanding the prohibition of e-cigarette use should be considered.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Geographic and social disparities in exposure to air neurotoxicants at U.S. public schools

Highlights: • Ambient neurotoxicants pose serious risks at US public schools. • There are social and spatial disparities in ambient neurotoxicant risks. • One-third of all schools in EPA Region 2 are at “high risk” for neurotoxicant exposure. • Schools with higher % of Hispanic, black, and Asian students face disparate risks. • Schools serving the youngest (vs. older) students face disparate risks. Children are especially vulnerable to the health and developmental impacts of environmental hazards and they spend significant portions of their days at school. Yet there are no national-level studies examining school-level environmental inequalities and few have examined disparate exposure to neurological air toxicants, even though chronic exposure to air pollution impacts children's brain functioning. We paired information about the geographic locations and demographics of each public school in the US with air neurotoxicant exposure estimates pertaining to 24 known neurotoxicants included in the US Environmental Protection Agency's National Air Toxics Assessment. Using bivariate and multivariate statistics, we tested for environmental injustices in air neurotoxicant exposure at 84,969 US public schools. Metropolitan New York City (EPA Region 2) is the geographic region most burdened by air neurotoxicant exposures at schools since one-third of all schools in that region are in the top 10% (at {sup h}igh risk{sup )} for ambient neurotoxicant exposure among all schools nationwide. Students attending “high risk” public schools nationwide are significantly more likely to be eligible for free/reduced price meals, and to be Hispanic, black, or Asian/Pacific Islander (API). They are significantly less likely to be white or of another race. In a multivariate generalized estimating equation controlling for school district effects, schools with greater proportions of Hispanic, black, and API students, schools with higher enrollment, and schools located in more urban (vs. rural) counties face greater risks. Schools serving the youngest students (e.g., pre-kindergarten) have greater levels of risk than schools serving older students. Across all analyses, this study shows that racial/ethnic minority children are bearing the brunt of air neurotoxicant exposures at school, which may be unequally impacting their school performance and future potential.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Neurocognitive and physical functioning in the Seveso Women's Health Study

Highlights: • Little research exists on the neurotoxic effects of dioxins in older women. • TCDD was associated with grip strength but not other measures of physical function. • TCDD exposure was not adversely associated with working memory. • This relationship was not modified by menopause nor timing of TCDD exposure around menarche. • TCDD susceptibility may increase as the women age, warranting further research. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is neurotoxic in animals but few studies have investigated its effects on the human brain. Related dioxin-like compounds have been linked to poorer cognitive and motor function in older adults, with effects more pronounced in women, perhaps due to the loss of neuro-protective estrogen in menopause. On 10 July 1976, a chemical explosion in Seveso, Italy, resulted in one of the highest known residential exposures to TCDD. In 1996, we initiated the Seveso Women's Health Study, a retrospective cohort study of the health of the women who were newborn to 40 years old in 1976. Here, we investigate whether TCDD exposure is associated with physical functioning and working memory more than 20 years later. Individual TCDD concentration (ppt) was measured in archived serum collected soon after the explosion. In 1996 and 2008, we measured physical functioning (n=154) and working memory (n=459), respectively. We examined associations between serum TCDD and motor and cognitive outcomes with multivariate linear regression and semi-parametric estimators. A 10-fold increase in serum TCDD was not associated with walking speed (adjusted β=0.0006 ft/s, 95% Confidence Interval (CI): −0.13, 0.13), upper body mobility (adjusted β=−0.06, 95% CI: −0.36, 0.23), or manual dexterity (adjusted β=0.34, 95% CI: −0.65, 1.33). We observed an inverted U-shaped association in grip strength, with poorer strength in the lowest and highest TCDD exposure levels. There was no association between TCDD and the Wechsler digit and spatial span tests. Neither menopause status at assessment nor developmental timing of exposure modified associations between TCDD and working memory. Our findings, in one of the only studies of TCDD's effects on neuropsychological and physical functioning in women, do not indicate an adverse effect on these domains, with the exception of a U-shaped relationship with grip strength. Given the limited assessment and relative youth of the women at this follow-up, future work examining additional neuropsychological outcomes is warranted.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Relationship between serum trimethylamine N-oxide and exposure to dioxin-like pollutants

Highlights: • TMAO has been linked to cardiovascular disease risk in human studies and animal models. • TMAO was positively associated with 22 indexes of dioxin-like pollutant exposures in ACHS-II. • Associations with TMAO were significant among females (except at high BMIs) but not among males. • The dioxin TEQ: TMAO association was unaltered by adjustment for independent covariates of TMAO. Trimethylamine N-oxide (TMAO) is a diet and gut microbiota-derived metabolite that has been linked to cardiovascular disease risk in human studies and animal models. TMAO levels show wide inter and intra individual variability in humans that can likely be accounted for by multiple factors including diet, the gut microbiota, levels of the TMAO generating liver enzyme Flavin-containing monooxygenase 3 (FMO3) and kidney function. We recently found that dioxin-like (DL) environmental pollutants increased FMO3 expression to elevate circulating diet-derived TMAO in mice, suggesting that exposure to this class of pollutants might also contribute to inter-individual variability in circulating TMAO levels in humans. To begin to explore this possibility we examined the relationship between body burden of DL pollutants (reported by serum lipid concentrations) and serum TMAO levels (n = 340) in the Anniston, AL cohort, which was highly exposed to polychlorinated biphenyls (PCBs). TMAO concentrations in archived serum samples from the Anniston Community Health Survey (ACHS-II) were measured, and associations of TMAO with 28 indices of pollutant body burden, including total dioxins toxic equivalent (TEQ), were quantified. Twenty-three (22 after adjustment for multiple comparisons) of the 28 indices were significantly positively associated with TMAO. Although the design of ACHS-II does not enable quantitative assessment of the contributions of previously known determinants of TMAO variability to this relationship, limited multivariate modeling revealed that total dioxins TEQ was significantly associated with TMAO among females (except at high BMIs) but not among males. Our results from this cross-sectional study indicate that exposure to DL pollutants may contribute to elevated serum TMAO levels. Prospective longitudinal studies will be required to assess the joint relationship between DL pollutant exposures, other determinants of TMAO, and health outcomes.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Adipose tissue levels of polybrominated diphenyl ethers and breast cancer risk in Chinese women: A case–control study

Highlights: • Associations between adipose tissue PBDE levels and breast cancer risk were assessed. • Levels of most individual PBDE congeners were higher in breast-cancer cases than controls. • Breast-cancer risk was increased with both 2nd and 3rd tertiles of BDE-47 and BDE-209 levels with a trend. • Breast-cancer risk was also increased with the 3rd tertile of BDE-28, 99, 100, 138, 153, 154, and ∑PBDE levels. • PBDE concentrations are associated with breast-cancer risk in women in Chaoshan, China. Polybrominated diphenyl ethers (PBDEs) are suspected to be associated with breast cancer risk because of their estrogenic potencies. Epidemiological studies of PBDEs and breast cancer are scarce. Our study aimed to estimate the association between adipose-tissue PBDE concentrations and breast cancer risk. A total of 209 breast cancer cases and 165 controls were recruited from hospitals between January 2014 and May 2016 in Shantou, Chaoshan area, China. Concentrations of 14 PBDE congeners were measured in adipose tissues obtained from the breast for cases and the abdomen/breast for controls during surgery. Demographic and clinicopathologic characteristics were obtained from medical records. Breast cancer risk as well as clinicopathologic characteristics were evaluated by adipose-tissue PBDE level. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for breast cancer risk associated with levels of PBDE congeners were estimated from logistic regression models for all cases and stratified by estrogen receptor (ER) status. Level of total PBDEs (∑PBDE) and most individual PBDE congeners were higher in breast cancer cases than controls (median ∑PBDE, 94.99 vs 73.72 ng/g lipid). In the adjusted univariate model for all cases, breast cancer risk was increased with both 2nd and 3rd tertiles versus the 1st tertile of BDE-47 level (OR 2.05 [95% CI 1.08–3.92]; 5.47 [2.96–10.11]) and BDE-209 level (2.48 [1.30–4.73]; 4.72 [2.52–8.83]) with trend (both P < 0.001) and with the 3rd tertile of BDE-28 level (2.83 [1.63–4.92]), BDE-99 (3.22 [1.85–5.60]), BDE-100 (5.45 [2.90–10.23]), BDE-138 (2.40 [1.37–4.20]), BDE-153 (1.74 [1.02–2.97]), BDE-154 (1.84 [1.05–3.22]), and ∑PBDE levels (1.83 [1.07–3.14]) but decreased with the 3rd tertile of BDE-71 level (0.38 [0.22–0.65]) with trend (all P < 0.01). After stratifying by ER-positive or -negative status, the adjusted results were similar for ER-positive patients except for BDE-153 and BDE-154, with no statistical significance. In the multivariate model for all cases, age, menarche age, BDE-47, 71, 99, 100, 183 and 209 were independent factors associated with breast-cancer risk. ∑PBDE and most individual PBDE congeners investigated were positively associated with breast cancer risk in women from the Chaoshan area, China. PBDE may play a role in the occurrence and development of breast cancer.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Comparative estrogenicity of endogenous, environmental and dietary estrogens in pregnant women I: Serum levels, variability and the basis for urinary biomonitoring of serum estrogenicity

Biomonitoring of human exposure to estrogens most frequently focuses on environmental and dietary estrogens, and infrequently includes measures of exposure to potent endogenous estrogens present in serum. Pregnancy is a developmentally sensitive period during which “added” serum estrogenicity exceeding normal intra-individual daily variability may be of particular relevance. Here, we made repeated measurements of serum concentrations of estrone (E1), estradiol (E2), estriol (E3), estetrol (E4), daidzein (DDZ), genistein (GEN) and bisphenol A (BPA) in thirty pregnant women using ultra-performance liquid chromatography coupled with tandem mass spectrometry detection (UPLC-MS/MS) and electrospray ionization (ESI). Serum E1, E2, and E3 concentrations varied significantly (coefficients of variation 9–10%) with broad ranges across the cohort: 1.61–85.1 nM, 9.09–69.7 nM, and 1.5–36.3 nM respectively. BPA (undetected, estimated from total exposure), DDZ and GEN concentrations were 1-5 orders of magnitude lower. The 24-h urinary elimination profiles of endogenous estrogens were each strongly correlated with their corresponding serum concentrations (Pearson's Correlation Coefficients of 0.83 (E1), 0.84 (E2) and 0.94 (E3)). Lastly, a multivariate regression analysis produced equations for estimating serum concentrations of E1, E2, E3, E4, GEN and DDZ from urinary elimination rates and gestation period, an important step towards non-invasive biomonitoring for assessment of “added” estrogenicity during pregnancy.

59 BASIC BIOLOGICAL SCIENCES↗