The Dynamic Relationship between Social Cohesion and Urban Green Space in Diverse Communities: Opportunities and Challenges to Public Health.

Social cohesion is a key factor within social determinants of health and well-being. Urban green spaces can provide environments that potentially facilitate meaningful and positive social interactions that promote social cohesion, equity, human health, and well-being. However, the lack of integration of existing research on social cohesion, urban green spaces, and public health in diverse (e.g., racially and ethnically) communities limits culturally relevant strategies to address health disparities. In this manuscript, we synthesize research on the potential of urban green spaces to promote social cohesion and public health in historically excluded communities. Particularly, we explore the development of social cohesion as it relates to the social environment, built environment, leisure opportunities, green space maintenance, safety, and green gentrification. We highlight key factors and their application to meet opportunities and challenges to social and public health. A conceptual framework is presented to provide an overview and illustrate connections found in the literature.

Physician Training Related to Environmental Hazards near Ash Superfund Sites.

Physicians do not receive formal environmental health training in medical schools. The objectives of this study were to provide health care providers with basic environmental medicine training to better advise, treat or refer patients in the community and to observe any differences in the environmental medicine learning gains pre/post- test assessment. To rectify the problem of the lack of physicians' training related to environmental hazards, we conducted an environmental health workshop which targeted physicians living near Health Zone 1, Superfund ash sites. Fifty health care providers from both St. Vincent Family Medicine and Department of Health, Duval County Health Department (DOH-Duval) participated in a pre-test survey before the training and a post-test survey following the training. We used a non-parametric Wilcoxon Signed-Rank test to compare pre- and post- knowledge of training participants. At the 10% level of significance, the number of incorrect answers significantly declined in the post-training survey compared to the pre-training survey for all participants from both facilities combined (p=0.083). Site-specific analysis show, while a significant difference was found for participants from the St. Vincent's site (p=0.084), the difference for participants from the DOH-Duval site was not significant (p = 0.102), although the number of incorrect answers declined. The training resulted in learning gains for the 50 participants and the evaluations were very positive with 100% of physicians recommending this training to other health care providers. Additionally, training participants gave a high mark for the environmental medicine pocket guide. In 2019, the ash sites are 90% remediated and cleanup is expected to be completed in 2022. There is still a need for additional training for physicians due to other active sites (i.e., Kerr-McGee) in the community. This study highlights the importance of providing environmental hazards training to physicians and the approach by which it could be delivered effectively.

Structural Characteristics of Tree Cover and the Association with Cardiovascular and Respiratory Health in Tampa, FL.

Urban tree cover can provide several ecological and public health benefits. Secondary datasets for Tampa, FL, including sociodemographic variables (e.g., race/ethnicity), health data, and interpolated values for features of tree cover (e.g., percent canopy and leaf area index) were analyzed using correlation and regression. Percent canopy cover and leaf area index were inversely correlated to respiratory and cardiovascular outcomes, yet only leaf area index displayed a significant association with respiratory conditions in the logistic regression model. Percent racial/ethnic minority residents at the block group level was significantly negatively correlated with median income and tree density. Leaf area index was also significantly lower in block groups with more African-American residents. The percentage of African Americans (p = 0.101) and Hispanics (p < 0.001) were positively associated with respiratory outcomes while population density (p < 0.001), percent canopy (p < 0.01), and leaf area index (p < 0.01) were negatively associated. In multivariate models, higher tree density, leaf area index, and median income were significantly negatively associated with respiratory cases. Block groups with a higher proportion of African Americans had a higher odds of displaying respiratory admissions above the median rate. Tree density and median income were also negatively associated with cardiovascular cases. Home ownership and tree condition were significantly positively associated with cardiovascular cases.

Community-Based Participatory Research at Jacksonville Florida Superfund Ash Site: Toxicology Training to Improve the Knowledge of the Lay Community.

Until the late 1960's, Jacksonville, Florida incinerated its solid waste with the resultant ash deposited in landfills or used to fill flood-prone areas. These filled areas were later developed into parks, school sites and residential areas. Lead in soil at these sites was the major toxicant of concern and driver of clean-up actions. During the period of assessment of lead-levels in soil, there were no established lines of communication between the City and residents of affected neighborhoods resulting in mistrust in the community. To address communication issues, a community-based, culturally sensitive Community Environmental Toxicology Curriculum (CETC) and a short video were developed for community stakeholders to inform them of risks, health effects, remediation processes and preventive measures. Pre-and post-tests were developed to measure knowledge gained from the toxicology training. Learning gains averaged 47% and 24% for the community leaders and residents respectively. Most participants strongly agreed that the community toxicology curriculum was a useful tool for promoting awareness of environmental risks in their community and addressing the gap in trust between residents and agencies involved in site remediation.

The use of flow cytometric applications to measure the effects of PAHs on growth, membrane integrity, and relative lipid content of the benthic diatom, Nitzschia brevirostris.

This laboratory study measured the direct effects of three polycyclic aromatic hydrocarbon (PAH) compounds (naphthalene, pyrene, and benzo(a)pyrene) upon cell growth, membrane integrity, and BODIPY-stained lipid fluorescence intensity of the benthic diatom Nitzschia brevirostris using flow cytometry as an analysis tool. Previous field and laboratory studies have reported reductions in algal populations following PAH exposure, but specific, functional responses of the microalgae to these pollutants could not be revealed by cell numbers alone. Using flow-cytometric measurements, we confirmed that maximal cell densities in PAH-exposed diatom cultures were significantly lower compared to controls; however, we also discovered increases in lipids and cells with compromised membranes in PAH-exposed cultures. These results highlight new tools for measuring the direct effects of organic pollutants upon the physiology of taxa comprising microphytobenthic communities important in estuarine food webs.

Characterization of 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine at androgen receptor: mechanistic support for its role in prostate cancer.

2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP) is a dietary mutagenic carcinogen that has been shown not only to induce the formation of DNA adducts, but is capable of inducing tumors in the colon, mammary, and prostate glands. The normal development and maturation of the prostate gland, as well as early progression of prostate cancer, is dependent on androgens acting on the androgen receptor (AR). The actual mechanism by which PhIP interacts with our biological system and its potential interaction at the AR has yet to be fully defined. Here, we describe our work in evaluating the molecular events associated with PhIP-mediated disruption of AR function in LNCaP human prostate cancer cells. We demonstrate, by molecular docking simulation, that PhIP and its metabolite can bind to the ligand-binding domain (LBD). The binding competes with dihydrotestosterone (DHT) in the native AR binding cavity of the receptor. In vitro assays show that PhIP increase AR protein expression in LNCaP cells and alters its responsiveness through PSA protein and mRNA expression. We propose that the mechanism for the tissue-specific carcinogenicity seen in the rat prostate tumors and the presumptive human prostate cancer associated with the consumption of well-done meat may be mediated by this receptor activation. Our results indicate that PhIP may play an important role in modifications of AR function.

A survey of deepwater horizon (DWH) oil-degrading bacteria from the Eastern oyster biome and its surrounding environment.

The deepwater horizon (DWH) accident led to the release of an estimated 794,936,474 L of crude oil into the northern Gulf of Mexico over an 85 day period in 2010, resulting in the contamination of the Gulf of Mexico waters, sediments, permeable beach sands, coastal wetlands, and marine life. This study examines the potential response of the Eastern oyster's microbiome to hydrocarbon contamination and compares it with the bacterial community responses observed from the overlaying water column (WC) and the oyster bed sediments. For this purpose, microcosms seeded with DWH crude oil were established and inoculated separately with oyster tissue (OT), mantle fluid (MF), overlaying WC, and sediments (S) collected from Apalachicola Bay, FL, USA. Shifts in the microbial community structure in the amended microcosms was monitored over a 3-month period using automated ribosomal intergenic spacer region analysis, which showed that the microbiome of the OT and MF were more similar to the sediment communities than those present in the overlaying WC. This pattern remained largely consistent, regardless of the concentration of crude oil or the enrichment period. Additionally, 72 oil-degrading bacteria were isolated from the microcosms containing OT, MF, WC, and S and identified using 16S ribosomal RNA gene sequencing and compared by principal component analysis, which clearly showed that the WC isolates were different to those identified from the sediment. Conversely, the OT and MF isolates clustered together; a strong indication that the oyster microbiome is uniquely structured relative to its surrounding environment. When selected isolates from the OT, MF, WC, and S were assessed for their oil-degrading potential, we found that the DWH oil was biodegraded between 12 and 42%, under the existing conditions.

Immunomodulation in eastern oysters, Crassostrea virginica, exposed to a PAH-contaminated, microphytobenthic diatom.

The trophic transfer of sediment-associated pollutants is a growing concern in shellfish harvesting areas. Previous studies have examined the role of phytoplankton in the transport of organic contaminants to bivalve species, but little information on microphytobenthic communities and their role as contaminant vectors exists. Polycyclic aromatic hydrocarbons (PAHs) are organic compounds formed during natural and industrial processes; they are termed "persistent organic pollutants" because they are only slowly degraded by natural processes. This study examined the transfer of PAH compounds (naphthalene, pyrene, and benzo(a)pyrene) by a microphytobenthic diatom to the eastern oyster, a commercially important shellfish species, to determine if dietary accumulation is a route of contaminant exposure capable of inducing physiological responses. PAH compounds were adsorbed to a diatom culture (Nitzschia brevirostris) in a range of concentrations (5, 125, 625, and 1000 µg L(-1)), and eastern oysters were exposed experimentally to the contaminated diatom cultures to assess possible effects upon oyster hemocytes and selected immune-defense functions. A preliminary experiment was designed to identify individual effects of several PAH compounds (naphthalene, pyrene, and benzo(a)pyrene) on hemocyte viability and phagocytic activity. Results from this experiment revealed that the most-toxic compound, benzo(a)pyrene, at the highest concentration, stimulated an increase in agranular hemocyte counts. A follow-up study examined the effects of benzo(a)pyrene on hemocyte viability, adhesion, phagocytosis, and reactive oxygen species (ROS). These studies showed the ability of this benthic diatom to transport PAHs to the eastern oyster and to cause immunomodulation. Hemocyte responses to dietary PAH exposure included an increase in circulating hemocytes and increased production of reactive oxygen species by these cells.

How cumulative risks warrant a shift in our approach to racial health disparities: the case of lead, stress, and hypertension.

Blacks have persistently higher rates of high blood pressure, or hypertension, compared to whites, resulting in higher health costs and mortality rates. Recent research has shown that social and environmental factors-such as high levels of stress and exposure to lead-may explain racial disparities in hypertension. Based on these findings, we recommend a fundamental shift in approaches to health disparities to focus on these sorts of cumulative risks and health effects. Federal and state agencies and research institutions should develop strategic plans to learn more about these connections and apply the broader findings to policies to reduce health disparities.

Social and Environmental Risk Factors for Hypertension in African Americans.

This study tests the hypothesis that disparities of hypertension risk in African Americans is related to lead exposure, perceptions of racism, and stress, among urban (Roxbury, MA) and rural (Gadsden, FL) communities. Analysis of preliminary data from Phase I reveal 60% in Gadsden and 39% in Roxbury respondents self-reported having hypertension. In Gadsden 80% people did not know if their residence contained lead paint, compared to 45% in Roxbury. In Gadsden County, 58% of respondents reported experiencing racial discrimination in different settings compared with 72% in Roxbury. In regression analyses high cholesterol emerged as a significant predictors of hypertension in Gadsden County (OR=8.29, CI=1.4-49.3), whereas monthly household income (OR=0.15, CI=0.04-0.7) and diabetes (OR=6.06, CI=1.4-26.17) were significant predictors of hypertension in Roxbury after adjusting for other covariates. These preliminary findings set the stage for initiating Phase II (Phase I continues recruitment), that entail biological marker measurements to rigorously test main hypothesis.

Induction of cell death, DNA strand breaks, and cell cycle arrest in DU145 human prostate carcinoma cell line by benzo[a]pyrene and benzo[a]pyrene-7,8-diol-9,10-epoxide.

Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon, is a major environmental pollutant. In this study, the effects of this carcinogen/mutagen and one of its metabolites, benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE), on human prostate carcinoma cell line DU145, were examined. Cell viability, DNA damage, and cell cycle progression were evaluated as toxic end-points. We have shown that B[a]P and BPDE inhibited cell viability following 48 hr of exposure. Furthermore, comet assay analyses revealed that both B[a]P and BPDE induced DNA strand breaks in a concentration-dependent fashion. Flow cytometric analyses showed that about 70% of DU145 cells were arrested by B[a]P at the G1 phase, while about 76% were arrested at G1 phase by BPDE. These data reveal that B[a]P and BPDE are cytotoxic and genotoxic to DU145 prostate cancer cells.