Colonization and growth of dehalorespiring biofilms on carbonaceous sorptive amendments.

Removal of polychlorinated biphenyls (PCBs) from contaminated sediments is a priority due to accumulation in the food chain. Recent success with reduction of PCB bioavailability due to adsorption onto activated carbon led to the recognition of in situ treatment as a remediation approach. In this study, reduced bioavailability and subsequent break-down of PCBs in dehalorespiring biofilms was investigated using Dehalobium chlorocoercia DF1. DF1 formed a patchy biofilm ranging in thickness from 3.9 to 6.7 µm (average 4.6 ± 0.87 µm), while the biofilm coverage varied from 5.5% (sand) to 20.2% (activated carbon), indicating a preference for sorptive materials. Quantification of DF1 biofilm bacteria showed 1.2-15.3 × 109 bacteria per gram of material. After 22 days, coal activated carbon, bone biochar, polyoxymethylene, and sand microcosms had dechlorinated 73%, 93%, 100%, and 83%, respectively. These results show that a biofilm-based inoculum for bioaugmentation of PCBs in sediment can be an efficient approach.

Environmental Injustice and Industrial Chicken Farming in Delaware.

Potential disparities in the distribution of poultry CAFOs (confined animal feeding operations) and meat-processing facilities across Delaware were explored with regards to sociodemographic factors including race, ethnicity, and socioeconomic status. We conducted buffer analyses of CAFO host census tracts alongside sociodemographic data in order to explore populations in proximity to the Delaware chicken industry. We conducted a hotspot analysis of CAFOs to find areas with large concentrations of poultry operations and applied zero-inflation regression models to determine if there's a relationship between sociodemographic composition and number of CAFOs/meat- processing facilities in Delaware. Median household income was lower in CAFO host census tracts than all others, and also lower than the state median. A larger percentage of people living in poverty are in poultry CAFO hotspots (15.4 percent) compared to the state average (13.7 percent). Delaware's chicken industry disproportionately burdens low-wealth communities. Delaware policy-makers should employ environmental justice-oriented solutions to best serve impacted populations.

Utilization of the Maryland Environmental Justice Screening Tool: A Bladensburg, Maryland Case Study.

Maryland residents' knowledge of environmental hazards and their health effects is limited, partly due to the absence of tools to map and visualize distribution of risk factors across sociodemographic groups. This study discusses the development of the Maryland EJSCREEN (MD EJSCREEN) tool by the National Center for Smart Growth in partnership with faculty at the University of Maryland School of Public Health. The tool assesses environmental justice risks similarly to the U.S. Environmental Protection Agency's (USEPA) EJSCREEN tool and California's tool, CalEnviroScreen 3.0. We discuss the architecture and functionality of the tool, indicators of importance, and how it compares to USEPA's EJSCREEN and CalEnviroScreen. We demonstrate the use of MD EJSCREEN through a case study on Bladensburg, Maryland, a town in Prince George's County (PG) with several environmental justice concerns including air pollution from traffic and a concrete plant. Comparison reveals that environmental and demographic indicators in MD EJSCREEN most closely resemble those in EPA EJSCREEN, while the scoring is most similar to CalEnviroScreen. Case study results show that Bladensburg has a Prince George's environmental justice score of 0.99, and that National Air Toxics Assessment (NATA) air toxics cancer risk is concentrated in communities of color.