Linking social and built environmental factors to the health of public housing residents: a focus group study.

BACKGROUND: Public housing residents have a high risk of chronic disease, which may be related to neighborhood environmental factors. Our objective was to understand how public housing residents perceive that the social and built environments might influence their health and wellbeing. METHODS: We conducted focus groups of residents from a low-income public housing community in Baltimore, MD to assess their perceptions of health and neighborhood attributes, resources, and social structure. Focus groups were audio-recorded and transcribed verbatim. Two investigators independently coded transcripts for thematic content using editing style analysis technique. RESULTS: Twenty-eight residents participated in six focus groups. All were African American and the majority were women. Most had lived in public housing for more than 5 years. We identified four themes: public housing's unhealthy physical environment limits health and wellbeing, the city environment limits opportunities for healthy lifestyle choices, lack of trust in relationships contributes to social isolation, and increased neighborhood social capital could improve wellbeing. CONCLUSIONS: Changes in housing and city policies might lead to improved environmental health conditions for public housing residents. Policymakers and researchers may consider promoting community cohesiveness to attempt to empower residents in facilitating neighborhood change.

A United Nations General Assembly Special Session for mental, neurological, and substance use disorders: the time has come.

Mental, neurological, and substance use (MNS) disorders are leading causes of the global burden of disease and profoundly impact the social and economic well-being of individuals and communities. The majority of people affected by MNS disorders globally do not have access to evidence-based interventions and many experience discrimination and abuses of their human rights. A United Nations General Assembly Special Session (UNGASS) is needed to focus global attention on MNS disorders as a core development issue requiring commitments to improve access to care, promote human rights, and strengthen the evidence on effective prevention and treatment.

Freshwater mussels in an impacted watershed: Influences of pollution from point and non-point sources.

The Grand River watershed in a densely populated region of Ontario supports one of the richest assemblages of freshwater mussels in Canada. However, water quality in this watershed is influenced by urban development, agriculture, and industry. Mussel populations and water chemistry in the lower Grand River and the Boston Creek tributary were evaluated to determine whether point sources of pollution such as discharges of domestic wastewater and industrial effluent, and non-point sources of pollution are affecting mussel distribution and population structure. Semi-quantitative population surveys conducted at 9 study sites identified 20 mussel species, including 3 Species at Risk. Mussel abundance (34-160 mussels/search hour) and species richness indicated that mussel populations in the lower Grand River watershed are continuing to recover from historical lows reported in the 1970s. However, changes in populations at some sites were consistent with altered water chemistry. Most notable was that the three most abundant mussel species in the Boston Creek tributary downstream of a gypsum plant discharge were significantly smaller in length than those upstream of this site. The water chemistry in this habitat was characterized by elevated conductivity (∼2000 µS/cm) and calcium (∼500 mg/L), as well as concentrations of sulfate (∼1000 mg/L) that can be toxic to freshwater mussels. In the Grand River downstream of the confluence with Boston Creek, there tended to be (p > 0.05) fewer mussels (mean 34 ± 20/search h) compared to upstream (mean 67 ± 15/search h) and this corresponded to altered water chemistry, including elevated sulfate (239 mg/L) downstream of the confluence relative to upstream (58 mg/L). These data indicate that chronic exposures to high levels of major ions is likely driving changes to mussel population structure. In addition, the discharges of wash water from a gypsum plant may be impacting sensitive biota in the main stem Grand River well beyond the immediate tributary receiving environment.

Synergistic effects in hydrogen-helium bubbles.

The detrimental effects of hydrogen and helium on structural materials undergoing irradiation are well documented, if not well understood. There is experimental evidence to suggest that a synergistic effect between the two elements exists, which results in increased damage when both are present. This situation is expected in the next generation of fusion and fission reactors, so a fundamental understanding of these synergistic interactions is needed to predict materials performance. We perform atomistic simulations of hydrogen and helium bubbles in body-centered cubic iron to determine the mechanism behind this effect. We first develop an interatomic potential suitable for describing the interactions between hydrogen and helium. Through analysis of the energetics and structure of these bubbles, we explain the observed synergy as a consequence of bubble growth through helium induced loop punching, aided by the presence of hydrogen, instead of as a direct interaction between hydrogen and helium. The hydrogen benefits from an increased area of free surface on which to bind.

Energetics of small hydrogen-vacancy clusters in bcc iron.

Hydrogen may be trapped in voids in iron, leading to undesirable material properties. In this paper, the energetics of small hydrogen-vacancy clusters in body centered cubic iron are investigated. Results from two interatomic potentials are compared. We use molecular dynamics and Monte Carlo methods to find the minimum energy configurations of voids of up to ten vacancies containing up to 50 hydrogen atoms with ratios of hydrogen to vacancy of 10 or less. The formation energies and binding energies of defects to these clusters are calculated. Our results indicate that the hydrogen stabilizes bubbles by causing vacancies to be more tightly bound to clusters, while neighboring irons are less tightly bound. Hydrogen itself becomes less well bound to clusters as the inventory increases. The more physically relevant potential indicates a maximum supported ratio of hydrogen atoms to vacancies of about 4.