Health risk of bathing in Southern California coastal waters

Bathers exposed to microbiological contamination in coastal waters have an excess risk of gastrointestinal and respiratory illness. The disease burden associated with this risk may be considerable in Southern California, where 50 million annual beach visitors recreate in coastal waters that receive billions of gallons of polluted discharges from nearby urban areas. The goal of this study was to estimate the risk and disease burden of gastrointestinal and respiratory illness from bathing in the coastal waters of Southern California and to identify areas and periods of especially high risk. For 2000 – 2004, gastrointestinal and respiratory illness rates were estimated with a simulation model that utilized water quality, beach attendance, and bathing rate data, along with three published dose-response relationships. An estimated 689,000 to 4,003,000 episodes of gastrointestinal illness and 693,000 episodes of respiratory illness occurred each year at Southern California beaches during the study period. The majority of illnesses (57% – 80%) occurred during the summer season. A relatively small proportion of beaches (12 of 67) accounted for half of all illnesses. Only small fluctuations in the annual health burden were observed. Coastal water contamination is a serious health risk for bathers at Southern California beaches. Although coastal waters are more contaminated during the winter, most contamination related illnesses occur during the summer months due to large seasonal increases in bathing populations. California's marine water contact standards may be inadequate to protect the health of bathers

Access to Eye Care Before and After Vision Loss: A Qualitative Study Investigating Eye Care Among Persons Who Have Become Blind

Navigating access to eye care requires that patients recognize the need for screening and care, employ limited financial and social resources, manage complex health insurance policies, and access specialty clinical care. We investigated the experience of patients through the progression of vision loss to blindness, utilizing qualitative methods. We conducted structured telephone interviews with 28 persons with blindness throughout Oregon. Utilizing closed and open-ended questions, we explored patient experience on the events preceding avoidable blindness. Coding for emergent themes was conducted independently by two researchers using a constant comparative method. Participants described important barriers to accessing eye care: at the systems level, lack of access to providers and treatment; at the community level, available social support and services; and at the individual level, readiness to act and trust in providers. These findings suggest that important barriers to accessing preventive eye care, early diagnosis and treatment, vocational rehabilitation, and social services often occur at multiple levels. Access to eye care should be prioritized in efforts to reduce preventable visual impairment

Influence of Variable Precipitation on Coastal Water Quality in Southern California

Objectives: To examine the consequences of changing precipitation levels on southern California's recreational coastal water quality, and compare the responses of watersheds with differing levels of urban development. Methods: The geo-temporal relationship for six years (2000-2005) of precipitation levels, discharge rates for the ten primary waterways, and coastal water bacteria concentrations at seventy-eight southern California beaches were examined. Results: Precipitation levels, river-creek discharge rates, and coastal water bacteria concentrations were significantly correlated (p < 0.01) for all ten watersheds investigated. Water bacteria concentrations significantly increased with higher levels of precipitation across 95% of the seventy-eight beaches investigated. A heavily developed watershed had significantly higher median bacteria concentrations (186 cfu) in the adjoining coastal waters compared to an undeveloped watershed (10 cfu) of similar size. Conclusions: Precipitation and ensuing runoff strongly control the rate of polluted water delivered to most beaches in southern California. Variable precipitation generates a greater response in coastal water bacteria concentrations in developed watersheds compared to undeveloped areas. Projected declines in regional precipitation as a consequence of climate change may result in less contaminated water delivered to coastal waters, thus decreasing risk of water associated illnesses during winter months. Water Environ. Res., 83, 2121 (2011)

Structural and magnetic ordering in Pr_0.65(Ca_ySr_1-y)_0.35MnO₃: Quantum critical point versus phase segregation scenarios

The phase diagram of Pr0.65(CaySr1-y)0.35MnO3, 0.6 <= y <= 0.8, has been determined by neutron diffraction, magnetization and electrical conductivity measurements in order to investigate the nature of the transition between ferromagnetic metallic and charge-ordered insulating states near y=0.75. Two possible scenarios for this transition have been proposed: a "quantum critical point"-like feature, near which an associated charge-disordered paramagnetic phase is present, or a phase coexistence region. We demonstrate that the latter case is true, phase segregation occurring on a mesoscopic/macroscopic length-scale (several hundred Angstroms to several microns). Our results show that no significant amount of the charge-disordered paramagnetic phase is present at low temperatures. Our data also indicate that the charge-ordered insulator to ferromagnetic metal phase boundary is temperature as well as composition-dependent.Comment: Submitted to Phys. Rev.