School of Public Health
Permanent URI for this communityhttp://hdl.handle.net/1903/1633
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
Note: Prior to July 1, 2007, the School of Public Health was named the College of Health & Human Performance.
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Item Cross-Sectional Evaluation of Potential Volatile Organic Compound Exposures Around U.S. Schools(2009) Perodin, Joanne; Sapkota, Amir; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Volatile Organic Compounds (VOCs), characterized by high vapor pressure and low water solubility, exist in gaseous phase at room temperature. Previous studies have suggested exposure to VOCs may be associated with adverse health effects such as asthma exacerbation and in some cases cancer. The major sources of outdoor VOCs include traffic and industrial emissions. Ambient VOCs can react with Nitrogen Oxides (NOx) in the presence of sunlight to form ground level ozone, one of the U.S. Environmental Protection Agency (EPA) Criteria Air Pollutants. This thesis was designed to investigate the potential VOCs exposure among U.S. schoolchildren. Moreover, the influence of various neighborhood factors (urban vs. rural areas, distance from highways, presence/absence of industries) on VOCs concentrations around U.S. Schools was investigated. The findings of this thesis suggest that schools in urban areas, near industries and traffic activity have higher concentrations of VOCs compared to those not possessing such characteristics.Item Environmental influences on physical activity and obesity in African American adolescents-a multilevel perspective(2009) Yan, Fang Alice; Beck, Kenneth; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Background: Prevalence of obesity among adolescents is increasing at an alarming rate. Currently, 34% of all 12-19 year olds are either at risk for overweight or are overweight. Without a comprehensive understanding of the myriad of environmental factors that influence physical activity, we cannot effectively curb the rising rates. Methods: The objective of this study is to evaluate the direct and indirect effects of individual, built, and psychosocial environmental factors on the body mass index (BMI) of African American adolescents, and to assess how the relationships may be mediated by physical activity (PA) levels in an urban setting. A cross-sectional sample of 350 Students (grades 9-12) was drawn from two urban magnet high schools in Baltimore City. The outcome measurements cover a broad array of variables, including BMI, walking behavior, and overall PA. The independent variables are measures of three environments and individual socio-demographic status. The hierarchical linear model analysis was employed. In addition, the mediation analysis was conducted to examine the mediating effect of PA levels. Results: The majority of the sample was African American (69%) and female (58%) with 40% at risk of overweight or overweight. After adjustment for individual socio-demographic factors, living in more hazardous neighborhoods was positively associated with moderate-to-vigorous physical activity (MVPA) and walking for transportation but not with BMI. Densities and proximities of destinations were not associated with BMI. Access to school and museums within 0.25 mile, and grocery stores, retail and shopping, post offices and mix of destinations within 0.5 mile and beyond was positively associated with participation in walking. In addition, densities of fast food restaurants, parks and recreation within 1 mile and 1.5 mile were associated with increased walking. Closer proximity to schools and museums increased both student's MVPA level and their walking trips. Green space coverage within 0.25 mile distance was associated with decreased BMI. In addition, the percentage of green space coverage around homes was not associated with physical activity. Physical activity did not mediate either the destination densities and proximity or the greenness on BMI. Conclusion: The findings support the importance of focusing on places rather than the individuals who live in those places. Increasing the diversity of walkable destinations may contribute to adolescents doing more transport-related walking and achieving recommended levels of physical activity. In general, ecologic approaches to obesity prevention need to focus on urban design and food availability.