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Doctor of Philosophy / Department of Human Nutrition / Edgar Chambers IV / Food consumption continues to be an area of focus for nutrition, health, and consumer research. Eating adequate amounts of fruits and vegetables, appropriate levels of dairy products, increasing whole grains, and switching to lean meat and fish all are associated with managing weight and reducing the risk of chronic diseases including cancer, diabetes, hypertension, and cardiovascular disease. Research has shown that food consumption rates vary across segments of the U.S. population depending on several socio-demographics including race/ethnicity, gender, and age. The purpose of this research was to examine consumption of various foods including fruits and vegetables, dairy products, selected types of grain and starchy vegetable foods, and meat and legume products based on race and ethnicity, age, and gender using 24-hour recall dietary data from survey years 2003-2006 of the National Health and Nutrition Examination Survey (NHANES) conducted by the Centers for Disease Control and the United States Department of Agriculture. The 2003-2006 NHANES 24-hour dietary recall data, known as What We Eat In America, were used for analysis of food consumption. Two non-consecutive days of 24-hour dietary recall and demographic information were analyzed to assess consumption patterns of participants who: 1) were at least two years of age, 2) had complete and satisfactory dietary recall data, and 3) were members of a selected racial/ethnic group. The sample size was 17, 885 males and females: 4,994 African Americans (non-Hispanic); 7,525 Whites (non- Hispanic); and 5,366 Hispanics (Mexican American and other Hispanics). Individual Foods Files (IFF), containing foods coded for each individual, were accessed via the NHANES website to use for the consumption comparison analysis. There were food files for each of the two recall days of each survey year, 2003-2004 and 2005-2006. These findings indicate that there are racial/ethnic, age, and gender differences in the consumption of various foods. Fruits, vegetables, and dairy products were only consumed by 70-80% of the sample populations. Only 18-42% of the respondents reported eating whole grain breads, legumes, nuts, and seeds. However, meat and meat product consumption was reported by more than 75% of the sample. African Americans consumed fewer fruits, vegetables, whole grains, and dairy products compared to Whites and Hispanics. African Americans had a tendency to consume culturally relevant items such as greens, sweet potatoes, grits, and chicken. Children consumed more French fries, frankfurters, peanut butter, macaroni and cheese, and hamburgers than adults. Consumption rates among males and females depended on race/ethnicity. However, within a racial/ethnic group, gender consumption differences were minimal. This research demonstrates that the types of foods eaten for all groups of food products vary by racial and ethnic population, and age or gender subgroups. African Americans' fruit and vegetable consumption trends are distinct in many cases. This research serves as a current baseline for future research exploring the relationship of dietary intake and race and ethnicity. Given that African Americans have higher incidences of chronic diseases, there is a need to continue to develop culturally sensitive dietary counseling and intervention programs. Furthermore, this study highlights areas of opportunities to expand research involving African Americans from a sensory, business and promotional perspective capitalizing on the diversity of food habits.

Polychlorinated Biphenyls (PCBs) are a group of 209 ‘man-made’ chlorinated organic compounds that were widely used in the 20th century for a variety of industrial uses. PCBs were first commercially produced in the 1929 and were manufactured until the 1980s when their use was phased out due to environmental and human health risks. However, due to their widespread use and persistence they are ubiquitous in the environment and remain a contaminant of concern. The structural properties that determine the persistence of PCBs in humans were therefore elucidated by statistical analysis of data from the National Health and Nutrition Examination Survey (NHANES). PCBs with chlorine bonding in the 2,5-and 2,3,6- positions (and 2- in di- and tri-chlorinated congeners) were rapidly biotransformed and so can be classed as episodic congeners whereas PCBs with chlorine bonding in the 2,3,4-, 2,4,5-, 3,4,5-, and 2,3,4,5- positions were more resistant to biotransformation and can therefore be classed as steady state congeners. A fundamental requirement of using PCB signatures for environmental fingerprinting is an effective analytical method capable of producing high resolution signatures from biological samples. An extraction and clean-up method was developed that was successfully applied to different biological matrices (blood and tissues). A two dimensional gas chromatography with time of flight mass spectrometry (GCxGC-ToFMS) method was designed and optimised to provide a congener specific method capable of identifying 200 out of the 209 PCBs, with detection limits in human serum in the range of 1 to 10 ng g-1 lipid. The extraction and detection methods were used to determine the source of PCB contamination and age date exposure in workers at a transformer dismantling plant. A total of 84 different PCB congeners were identified in the sera of 30 workers with concentrations of the 7 indicator PCBs ranging from 1.2 - 39 μg g-1 lipid. Analysis of PCB signatures was able to distinguish recent from prolonged exposure and also identified an additional source of inhalation exposure in a subgroup of workers. Analysis of 12 different tissue types obtained from the common guillemot (Uria aalge) suggested a high degree of perpetuation between the PCB signature in different tissue types. This shows that comparative assessments can be undertaken between animals using different tissue types and that small (1 g) samples of blood can be used as a non-lethal sampling technique. The regional provenance of 25 wrecked Leach’s storm petrels (Oceanodroma leucorhoa) was also determined using PCB signatures. Results from GCxGC-ToFMS analysis revealed distinctively different PCB signatures in birds from Canada and Europe. The findings reported in this thesis enhance our understanding of PCB signatures in the environment and show how they can be used effectively to age date and identify the source of exposure in humans and animals.

Introduction: Asthma is a common debilitating disease of the airways that afflicts an estimated 300 million worldwide, causing reduction in physical activity, lost school/work days, and even death. There are many known and suspected risk factors of asthma; however, there is much controversy over prior and current cigarette smoking. Approximately 25% of the United States population currently smokes, with a quarter of these being asthma patients. Another 22 to 43 percent of asthmatics are ex-smokers. Objectives: (1) To estimate the prevalence for lifetime asthma in the adult US population; (2) to determine prevalence odds ratios (POR) of lifetime asthma based on questionnaire (smoking status, tobacco consumption) after adjustment of potential confounding variables; (3) to determine POR of lifetime asthma based on laboratory values (serum cotinine); and (4) to assess the validity of self-reported measures (smoking status and tobacco consumption) using serum cotinine as the gold standard.Methods: The National Health and Nutrition Examination Survey (NHANES) 1999-2002 is a proportional cross-sectional sample that uses weights to be representative. Crude odds ratios were obtained through univariate analysis; multiple logistic regression analysis was used to obtain adjusted odds ratios of asthma. Interactions for age, gender, and race/ethnicity were explored. Validity measures included sensitivity and specificity tests for self-reported smoking and non-parametric correlation of tobacco consumption with serum cotinine levels.Results: The overall prevalence of lifetime asthma among n=10,252 adults was 11.56% (95%CI 10.45-12.66). Analyses were stratified by race/ethnicity due to significant interaction. After adjusting for age, gender, body mass index, and family history of asthma, ex-smoking non-Hispanic Whites, non-Hispanic Blacks, and other races had odds ratios of 1.57 (95%CI 1.26-1.97), 1.52 (95%CI 1.01-2.27), and 1.97 (95%CI 1.01-3.83), respectively, relative to never smokers within their respective race/ethnic groups. Sample persons with a family history of asthma and increasing body mass index were significant predictors for lifetime asthma among all race/ethnic groups. Based on laboratory values, non-Hispanic White respondents with serum cotinine levels of 0.011 to Discussion: Self-reported smoking and tobacco consumption are valid measures of tobacco use. The present study found no significant relationship between current smoking and lifetime asthma. Despite the limited findings, asthmatic smokers make up a distinct, difficult-to-treat subgroup for which future treatment research should address.

Drinking groundwater is the primary way humans accumulate arsenic. Chronic exposure to inorganic arsenic (iAs) (over decades) has been shown to be associated with multiple health effects at low levels (5-10 ppb) including: cancer, elevated blood pressure and cardiovascular disease, skin lesions, renal failure, and peripheral neuropathy. Using hypertension (or high blood pressure) as a surrogate marker for cardiovascular disease, we examined the effect of iAs alone and in a mixture with other metals using a cross-sectional study of adults in United States (National Health and Examination Survey, NHANES, 2005-2010) adjusting for covariates: urinary creatinine level (mg/dL), poverty index ratio (PIR, measure of socioeconomic status, 1 to 5), age, smoking (yes/no), alcohol usage, gender, non-Hispanic Black, and overweight (BMI>=25). A logistic regression model suggests that a one-unit increase in log of inorganic arsenic increases the odds of hypertension by a factor of 1.093 (95% Confidence Interval=0.935, 1.277) adjusted for these covariates , which indicates that there was not significant evidence to claim that inorganic arsenic is a risk factor for hypertension. Biomonitoring data provides evidence that humans are not only exposed to inorganic arsenic but also to mixtures of chemicals including inorganic arsenic, total mercury, cadmium, and lead. We tested for a mixture effect of these four environmental chemicals using weighted quantile sum (WQS) regression, which takes into account the correlation among the chemicals and with the outcome. For one-unit increase in the weighted sum, the adjusted odds of developing hypertension increases by a factor of 1.027 (95% CI=0.882,1.196), which is also not significant after taking into account the same covariates. The insignificant finding may be due to the low inorganic arsenic concentration (8-620 μg /L) in US drinking water, compared to those in countries like Bangladesh where the concentrations are much higher. Literature provides conflicting evidence of the association of inorganic arsenic and hypertension in low/moderate regions; future studies, especially a large cohort study, are needed to confirm if inorganic arsenic alone or with other metals is associated with hypertension in the United States.

Objective: The purpose of this study was to determine the extent to which the presence of social support correlates with attempts at weight loss in the past 12 months, attempts not to gain weight in the past 12 months, and participants’ satisfaction with their weight status. Methods: We used a cross-sectional study design using data collected by the 2003-2004 and 2005-2006 National Health and Nutrition Examination Surveys (NHANES) (CDC). For this study we included males and females, of multiple ethnicities, and a range of ages from 40 to 70 + years. Participants with missing data on height and weight were not included in the study. The final sample consisted of 3,982 participants. We defined social support using three domains: affiliation with religious organizations, relationships of trust, and social participation (Irwin J, et al., 2008). Weight loss attempts, weight maintenance attempts, and satisfaction were defined based on self-report. Analysis: We analyzed different classifications of social support in relation to three separate weight loss variables. The measure of association was an odds ratio. Logistic regression models provided odds ratios adjusted for potential confounders. All analyses were conducted in SUDAAN version 10 (RTI, Research Triangle Park, NC) to account for the complex survey design. Conclusion: Social support was not associated with weight loss variables. Various reasons for these results could include the age of the participants or the lack of questioning into the intensity of the social support being received.

Purpose: The substantial impact of indoor air quality and environmental hazards in the home on one’s health has long been recognized in the field of public health. This cross-sectional study investigates the risk between home based hazards, specifically lead, and respiratory health in children. The objective of this study is to examine the extent to which children testing positive for blood lead exposure are at an increased risk for having poor respiratory health. Methods: A nationally representative sample of 977 children ages 1- 6 years was obtained from the 2005-2006 National Health and Nutrition Examination Survey (NHANES). Information from the demographic, blood lead level, and respiratory health questionnaire databases were combined to assess the impact of lead exposure on respiratory health. Blood lead exposure (BLL) was assessed at the following cut-off values: 1, 2, 3, 4, 5 and 10ug/dL. Respiratory health status was dichotomized as good and poor respiratory health based on the study participant’s answers to the questionnaire. Logistic regression was used to determine the relationship between blood lead levels and respiratory health status while controlling for the following potential confounders: race, age, sex, and annual family income. Results: This study was unable to establish a relationship between lead exposure and poor respiratory health in children ages 1-6 years, and the lack of relationship held for increasing levels of lead exposure. However, this study did reveal the significant impact of low level lead exposure in children with approximately 77% exposed at BLL ≥ 1ug/dL and 39% at BLL ≥ 2ug/dL. It is important to note that this is only a snapshot of the amount of lead exposure within this population; it is very likely that the levels fluctuate. Conclusion: While the percentage of study population decreases as the lead exposure increases, it is still alarming at the number of children exposed to low levels of lead. A large and growing body of literature documents the adverse health effects associated with low levels of lead exposure in children. This finding further supports the need for continuing research in examining the true impact of low level lead exposure and in determining a threshold dose level. In addition, a stronger study with a larger sample size and a more clearly defined respiratory health variable would allow for the relationship to be more closely examined before a definitive “no association” result can be made.