BENZENE TOXICITY AND THE OCCURRENCE OF BENZENE IN THE AMBIENT AIR OF THE HOUSTON AREA

This study was conducted by either literature review or actual field survey. Results are summarized as follows: (1) Long-term occupational exposure of workers to benzene vapor at levels of 3-7 ppm, 2-3 ppm and 1.6 ppm may result in a decreased level of leucocyte alkaline phosphates, an increased incidence of chromosome aberrations and an increased level of ALA in erythrocytes, respectively; (2) Benzene is capable of causing fetotoxic effects in animals at levels as low as 10 ppm by volume; (3) Exposure of animals to or less than 1 ppm benzene vapor may result in leucopenia, an inverse ratio of muscle antagonist chronaxy and a decreased level of ascorbic acid in fetus's and mother's liver as well as whole embryo; (4) Benzene is causally associated with the increased incidence of pancytopenia, including unicytopenia, bicytopenia and aplastic anemia, and chromosome aberrations in occupational exposure population, and at best benzene must also be considered as a leukemogen; (5) Since it can be emitted into the atmosphere from both man-made and natural sources, benzene in some concentrations is present everywhere in the various compartments of the environment; (6) The findings of the emission of benzene from certain natural sources indicate that reducing benzene to a zero-level of exposure is theoretically impossible; (7) The annual average of benzene concentration detected in the Houston ambient air is 2.50 ppb, which is about 2.4 times higher than the nation-wide annual average exposure level and may have been some health implications to the general public; (8) In the Houston area, stationary sources are more important than mobile sources in contributing to benzene in the ambient air. ^

THE NATURAL BACKGROUND GAMMA RADIATION EXPOSURE IN THE METROPOLITAN AREA OF THE VALLEY OF MEXICO

Measurements of the natural background radiation have been made at numerous places throughout the world. Very little work in this field has been done in developing countries. In Mexico the natural radiation to which the population is exposed has not been assessed. This dissertation represents a pioneer study in this environmental area. The radiation exposure which occupants within buildings receive as a result of naturally occurring radionuclides present in construction materials is the principal focus.^ Data were collected between August 1979 and November 1980. Continuous monitoring was done with TLDs placed on site for periods of 3 to 6 months. The instrumentation used for "real-time" measurements was a portable NaI (Tl) scintillation detector. In addition, radiometric measurements were performed on construction materials commonly used in Mexican homes.^ Based on TLD readings taken within 75 dwellings, the typical indoor exposure for a resident of the study area is 9.2 (mu)Rh('-1). The average reading of the 152 indoor scintillometer surveys was 9.5 (mu)Rh('-1), the outdoor reading 7.5 (mu)Rh('-1). Results of one-way and multi-way analyses of the exposure data to determine the effect due to building materials type, geologic subsoil, age of dwelling, and elevation are also presented. The results of 152 indoor scintillometer surveys are described. ^

The Hospital Study of the City of Houston and Harris County

In 1941 the Texas Legislature appropriated $500,000 to the Board of Regents of the University of Texas to establish a cancer research hospital. The M. D. Anderson Foundation offered to match the appropriation with a grant of an equal sum and to provide a permanent site in Houston. In August, 1942 the Board of Regent of the University and the Trustees of the Foundation signed an agreement to embark on this project. This institution was to be the first one in the medical center, which was incorporated in October, 1945. The Board of Trustees of the Texas Medical Center commissioned a hospital survey to: - Define the needed hospital facilities in the area - Outline an integrated program to meet these needs - Define the facilities to be constructed - Prepare general recommendations for efficient progress The Hospital Study included information about population, hospitals, and other health care and education facilities in Houston and Harris County at that time. It included projected health care needs for future populations, education needs, and facility needs. It also included detailed information on needs for chronic illnesses, a school of public health, and nursing education. This study provides valuable information about the general population and the state of medicine in Houston and Harris County in the 1940s. It gives a unique perspective on the anticipated future as civic leaders looked forward in building the city and region. This document is critical to an understanding of the Texas Medical Center, Houston and medicine as they are today. SECTIONS INCLUDE: Abstract The Abstract was a summary of the 400 page document including general information about the survey area, community medical assets, and current and projected medical needs which the Texas Medical Center should meet. The 123 recommendations were both general (e.g., 12. “That in future planning, the present auxiliary department of the larger hospitals be considered inadequate to carry an added teaching research program of any sizable scope.”) and specific (e.g., 22. That 14.3% of the total acute bed requirement be allotted for obstetric care, reflecting a bed requirement of 522 by 1950, increasing to 1,173 by 1970.”) Section I: Survey Area This section basically addressed the first objective of the survey: “define the needed hospital facilities in the area.” Based on the admission statistics of hospitals, Harris County was included in the survey, with the recognition that growth from out-lying regional areas could occur. Population characteristics and vital statistics were included, with future trends discussed. Each of the hospitals in the area and government and private health organizations, such as the City-County Welfare Board, were documented. Statistics on the facilities use and capacity were given. Eighteen recommendations and observations on the survey area were given. Section II: Community Program This section basically addressed the second objective of the survey: “outline an integrated program to meet these needs.” The information from the Survey Area section formed the basis of the plans for development of the Texas Medical Center. In this section, specific needs, such as what medical specialties were needed, the location and general organization of a medical center, and the academic aspects were outlined. Seventy-four recommendations for these plans were provided. Section III: The Texas Medical Center The third and fourth objectives are addressed. The specific facilities were listed and recommendations were made. Section IV: Special Studies: Chronic Illness The five leading causes of death (heart disease, cancer, “apoplexy”, nephritis, and tuberculosis) were identified and statistics for morbidity and mortality provided. Diagnostic, prevention and care needs were discussed. Recommendations on facilities and other solutions were made. Section IV: Special Studies: School of Public Health An overview of the state of schools of public health in the US was provided. Information on the direction and need of this special school was also provided. Recommendations on development and organization of the proposed school were made. Section IV: Special Studies: Needs and Education Facilities for Nurses Nursing education was connected with hospitals, but the changes to academic nursing programs were discussed. The needs for well-trained nurses in an expanded medical environment were anticipated to result in significant increased demands of these professionals. An overview of the current situation in the survey area and recommendations were provided. Appendix A Maps, tables and charts provide background and statistical information for the previous sections. Appendix B Detailed census data for specific areas of the survey area in the report were included. Sketches of each of the fifteen hospitals and five other health institutions showed historical information, accreditations, staff, available facilities (beds, x-ray, etc.), academic capabilities and financial information.

Policy analysis of the Americans with Disabilities Act of 1990 and federal funding concerning barrier-free playgrounds

The Americans with Disabilities Act (ADA) of 1990 was created to prohibit discrimination against disabled persons in our society. The goal of the ADA as a comprehensive civil rights law is to "ensure equal opportunity and complete participation, independent living and economic self-sufficiency" for disabled persons (U.S. Department of Justice, 2008). As part of Title II and III of the ADA, states and local governments are required to provide people with disabilities the same chance to engage in and benefit from all programs and services including recreational facilities and activities as every other citizen. Recreational facilities and related structures must comply with accessibility standards when creating new structures or renovating existing ones. Through a systematic literature review of articles accessed through online databases, articles relating to children with disabilities, their quality of life and their experience gained through play were reviewed, analyzed and synthesized. Additionally, the ADA's Final Rule regarding accessible playgrounds was evaluated through a descriptive analysis which yielded the following five components relating the importance of barrier-free playgrounds to children with disabilities: appropriate dimensions for children, integration of the play area, variety of activity and stimulation, availability of accessible play structures to communities, and financial feasibility. These components were used as evaluation criteria to investigate the degree to which the ADA's Final Rule document met these criteria. An evaluation of two federal funding sources, the Urban Parks and Recreation Renewal Program (UPARR) and the Land and Water Conservation Fund (LWCF), was also conducted which revealed three components relating the two programs' ability to support the realization of the ADA's Final Rule which included: current budget for the program, ability of local communities to attain funds, and level of ADA compliance required to receive funding. Majority of the evaluation of the Final Rule concluded it be adequate in development of barrier-free playgrounds although there are some portions of the guidelines that would benefit from further elucidation. Both funding programs were concluded to not adequately support the development of barrier-free playgrounds and therefore it was recommended that their funding be re-instated or increased as necessary. ^

Objective assessment of the built environment and its relationship to physical activity and obesity

The role of physical activity in the promotion of individual and population health has been well documented in research and policy publications. Significant research activities have produced compelling evidence for the support of the positive association between physical activity and improved health. Despite the knowledge about these public health benefits of physical activity, over half of US adults do not engage in physical activity at levels consistent with public health recommendations. Just as physical inactivity is of significant public health concern in the US, the prevalence of obesity (and its attendant co-morbidities) is also increasing among US adults.^ Research suggests racial and ethnic disparities relevant to physical inactivity and obesity in the US. Various studies have shown more favorable outcomes among non-Hispanic whites when compared to other minority groups as far as physical activity and obesity are concerned. The health disparity issue is especially important because Mexican-Americans who are the fastest growing segment of the US population are disproportionately affected by physical inactivity and obesity by a significant margin (when compared to non-Hispanic whites), so addressing the physical inactivity and obesity issues in this group is of significant public health concern. ^ Although the evidence for health benefits of physical activity is substantial, various research questions remain on the potential motivators for engaging in physical activity. One area of emerging interest is the potential role that the built environment may play in facilitating or inhibiting physical activity.^ In this study, based on an ongoing research project of the Department of Epidemiology at the University of Texas M. D. Anderson Cancer Center, we examined the built environment, measured objectively through the use of geographical information systems (GIS), and its association with physical activity and obesity among a cohort of Mexican- Americans living in Harris County, Texas. The overall study hypothesis was that residing in dense and highly connected neighborhoods with mixed land-use is associated with residents’ increased participation in physical activity and lowered prevalence of obesity. We completed the following specific aims: (1) to generate a land-use profile of the study area and create a “walkability index” measure for each block group within the study area; (2) to compare the level of engagement in physical activity between study participants that reside in high walkability index block groups and those from low walkability block groups; (3) to compare the prevalence of obesity between study participants that reside in high walkability index block groups and those from low walkability block groups. ^ We successfully created the walkability index as a form of objective measure of the built environment for portions of Harris County, Texas. We used a variety of spatial and non-spatial dataset to generate the so called walkability index. We are not aware of previous scholastic work of this kind (construction of walkability index) in the Houston area. Our findings from the assessment of relationships among walkability index, physical activity and obesity suggest the following, that: (1) that attempts to convert people to being walkers through health promotion activities may be much easier in high-walkability neighborhoods, and very hard in low-walkability neighborhoods. Therefore, health promotion activities to get people to be active may require supportive environment, walkable in this case, and may not succeed otherwise; and (2) Overall, among individuals with less education, those in the high walkability index areas may be less obese (extreme) than those in the low walkability area. To the extent that this association can be substantiated, we – public health practitioners, urban designers, and policy experts – we may need to start thinking about ways to “retrofit” existing urban forms to conform to more walkable neighborhoods. Also, in this population especially, there may be the need to focus special attention on those with lower educational attainment.^