John J. Bang

Traffic and Meteorological Impacts on Near-Road Air Quality: Summary of Methods and Trends from the Raleigh Near- Road Study

Abstract A growing number of epidemiological studies conducted worldwide suggest an increase in the occurrence of adverse health effects in populations living, working, or going to school near major roadways. A study was designed to assess traffic emissions impacts on air quality and particle toxicity near a heavily traveled highway. In an attempt to describe the complex mixture of pollutants and atmospheric transport mechanisms affecting pollutant dispersion in this near-highway environment, several real-time and time-integrated sampling devices measured air quality concentrations at multiple distances and heights from the road. Pollutants analyzed included U.S. Environmental Protection Agency (EPA)-regulated gases, particulate matter (coarse, fine, and ultrafine), and air toxics. Pollutant measurements were synchronized with real-time traffic and meteorological monitoring devices to provide continuous and integrated assessments of the variation of near-road air pollutant concentrations and particle toxicity with changing traffic and environmental conditions, as well as distance from the road. Measurement results demonstrated the temporal and spatial impact of traffic emissions on near-road air quality. The distribution of mobile source emitted gas and particulate pollutants under all wind and traffic conditions indicated a higher proportion of elevated concentrations near the road, suggesting elevated exposures for populations spending significant amounts of time in this microenvironment. Diurnal variations in pollutant concentrations also demonstrated the impact of traffic activity and meteorology on near-road air quality. Time-resolved measurements of multiple pollutants demonstrated that traffic emissions produced a complex mixture of criteria and air toxic pollutants in this microenvironment. These results provide a foundation for future assessments of these data to identify the relationship of traffic activity and meteorology on air quality concentrations and population exposures.

Silver Nanoparticle Exposure Induced Mitochondrial Stress, Caspase-3 Activation and Cell Death: Amelioration by Sodium Selenite

Silver nanoparticles (AgNP), one of the most commonly used engineered nanomaterial for biomedical and industrial applications, has shown a toxic potential to our ecosystems and humans. In this study, murine hippocampal neuronal HT22 cells were used to delineate subcellular responses and mechanisms to AgNP by assessing the response levels of caspase-3, mitochondrial oxygen consumption, reactive oxygen species (ROS), and mitochondrial membrane potential in addition to cell viability testing. Selenium, an essential trace element that has been known to carry protecting property from heavy metals, was tested for its ameliorating potential in the cells exposed to AgNP. Results showed that AgNP reduced cell viability. The toxicity was associated with mitochondrial membrane depolarization, increased accumulation of ROS, elevated mitochondrial oxygen consumption, and caspase-3 activation. Treatment with sodium selenite reduced cell death, stabilized mitochondrial membrane potential and oxygen consumption rate, and prevented accumulation of ROS and activation of caspase-3. It is concluded that AgNP induces mitochondrial stress and treatment with selenite is capable of preventing the adverse effects of AgNP on the mitochondria.

Roseomonas rubra sp. nov., isolated from lagoon sediments.

A novel Gram-stain-negative, coccus to oval-shaped, non-motile bacterium, designated strain S5T, was isolated from lagoon sediments collected from North Carolina, USA. Strain S5T was able to grow at 12-45 °C (optima, 30-37 °C) and at pH 6.3-9.0 (optima, 6.5-7.5). No added NaCl was required for growth of strain S5T. Strain S5T was positive for catalase and oxidase activity. C18 : 1ω6c/C18 : 1ω7c, C16 : 1ω6c/C16 : 1ω7c and C16 : 0 were predominant fatty acids with minor amounts of C8 : 0 3-OH, C14 : 0, C16 : 0 3-OH, C18 : 1 2-OH, C14 : 1ω5c, C16 : 1ω5c and C19 : 0 cyclo ω8c. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified glycolipid were major polar lipids. Minor amounts of an unidentified amino lipid and three unidentified lipids were also detected. The G+C content of the genomic DNA was 73.5 mol%. 16S rRNA gene sequence comparisons indicated that strain S5T represents a member of the genus Roseomonas within the family Acetobacteraceae of the class Alphaproteobacteria. Strain S5T had a sequence similarity of 97.80 % with Roseomonas rhizosphaerae YW11T, 97.69 % with Roseomonas aestuarii JC17T and <97 % with other members of the genus Roseomonas. However, strain S5T showed only 45.2±2 and 17±2 % relatedness (based on DNA-DNA hybridization) with R. rhizosphaerae KACC 17225T (=YW11T) and R. aestuarii KCTC 22692T (=JC17T), respectively. Distinct morphological, physiological and genotypic differences from previously described taxa support the classification of strain S5T as a representative of a novel species in the genus Roseomonas, for which the name Roseomonas rubra sp. nov. is proposed. The type strain is S5T (=KEMB 563-468T=JCM 31177T).

Description of Comamonas sediminis sp. nov., isolated from lagoon sediments.

Strain S3T was isolated from lagoon sediments, and appeared as transparent colonies on agar plates, with cells staining Gram-negative. Catalase and oxidase were positive. S3T hydrolyzed starch, casein and tween-20, while urea, chitin, gelatin and tween-80 were not hydrolysed. C18 : 1ω6c/C18 : 1ω7c, C16 : 1ω6c/C16 : 1ω7c,C17 : 0 cyclo and C16 : 0 were the predominant fatty acids with minor amounts of C10 : 0 3-OH, C12 : 0, C14 : 0 and C16 : 0 2-OH. S3T contained diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), and phosphatidylethanolamine (PE) as major polar lipids with minor amounts of unidentified phospholipid (PL) and unidentified lipids (L1-2). Genomic DNA G+C content was 68.3 mol%. 16S rRNA gene sequence comparisons indicated that S3T represents a member of the genus Comamonas in family Comamonadaceae of the class Betaproteobacteria. S3T has a sequence similarity of 98.96 % with Comamonas koreensis YH12T, 97.93 % with Comamonas guangdongensis CY01T and <96.97 % with other members of the genus Comamonas. DNA-DNA hybridization values between S3T and the type strains of the most closely related species were clearly below the 70 % threshold. On the basis of phenotypic, genotypic and phylogenetic analysis, it is proposed that S3T represents a novel species of the genus Comamonas, for which the name Comamonas sediminis sp. nov. is proposed. The type strain is S3T (=KEMB 563-466T =JCM 31169T).

Brevibacterium ammoniilyticum sp. nov., an ammonia-degrading bacterium isolated from sludge of a wastewater treatment plant

A Gram-stain-positive, non-motile, chemo-organotrophic, mesophilic, aerobic bacterium, designated A1(T), was isolated from sludge of a wastewater treatment plant. Strain A1(T) showed good ability to degrade ammonia and grew well on media amended with methanol and ammonia. Strain A1(T) grew with 0-11 % (w/v) NaCl, at 20-42 °C, but not <15 or >45 °C and at pH 6-10 (optimum pH 8.0-9.0). The isolate was catalase-positive and oxidase-negative. The DNA G+C content was 70.7 mol%. A comparative analysis of 16S rRNA gene sequences revealed that strain A1(T) formed a distinct phyletic lineage in the genus Brevibacterium and showed high sequence similarity with Brevibacterium casei NCDO 2048(T) (96.9 %), Brevibacterium celere KMM 3637(T) (96.9 %) and Brevibacterium sanguinis CF63(T) (96.4 %). DNA-DNA hybridization revealed <43 % DNA-DNA relatedness between the isolate and its closest phylogenetic relatives. The affiliation of strain A1(T) with the genus Brevibacterium was supported by the chemotaxonomic data: predominant quinone menaquinone MK-7(H2); polar lipid profile containing diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid; characteristic cell-wall diamino acid meso-diaminopimelic acid; whole-cell sugars galactose, xylose and ribose; absence of mycolic acids; and major fatty acids iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The results of physiological and biochemical tests allowed phenotypic differentiation of strain A1(T) from members of the genus Brevibacterium. On the basis of the results in this study, a novel species, Brevibacterium ammoniilyticum sp. nov., is proposed. The type strain is A1(T) ( = KEMC 41-098(T)  = JCM 17537(T)  = KACC 15558(T)).

The Impact of Social Capital on Environmental Risk Reduction in Moncure

Despite rigorous efforts to understand and resolve environmental justice (EJ) issues, the complexity of the issues associated with many of these EJ communities continues to bring challenges to community residents and environmental researchers. Moncure, NC, located in northern Chatham County, is a rural community proximal to a cluster of several major industries. While the presence of these industries has helped the local residents maintain higher than average household incomes, it has also created environmental concerns (air quality and potential respiratory illness) for the community. In this study, the authors examine the impact of social capital in the form of a community coalition called the Southeastern Chatham Citizens Advisory Council (SCCAC) on the resolution of EJ issues in Moncure. EJ issues in Moncure have been investigated by examining trends in archived data from the U.S. EPA’s Toxic Release Inventory (TRI) and by addressing residents’ pollution concerns, identified in Town Hall meetings, by designing a field monitoring study. Monitoring for the field study was conducted during one week periods in January and June of 2007. Preliminary results from the January sampling was compared with regulatory standard values, TRI data, and with results from a modeling study conducted by NC DENR Division of Air Quality (DAQ). Data indicate that the levels of released pollutants from local industries have been reduced during the overlapping time period when the SECCA has been active in trying to resolve the pollution issues, illustrating the potential impact of social capital on EJ risk reduction.

Water Quality in an Environmental Justice Community in Durham, NC

Environmental Justice Communities are usually minority communities of low socio-economic status with a concern of increased risk from point source pollution not present in other communities. A priority of the U.S. EPA is to empower these communities to advocate for themselves. Toward that end, EPA has entered into a cooperative agreement with the Department of Environmental Earth and Geospatial Sciences at North Carolina Central University, Durham, NC, to perform preliminary community based participatory studies and to establish the infrastructure for long-term interactions with environmental justice communities. In central Durham, housing and commercial properties are intermingled creating a concern for increased pollution and poor water quality in area creeks. To determine if current or past commercial practices impacted creeks, organochlorines (pesticides and polychlorinated biphenyls), polycyclic aromatic hydrocarbons and heavy metals were quantified in water and sediment samples collected during the summer of 2007 from nine creeks located in six parks in the study area. Water quality measurements and contaminant concentrations were compared to regulatory values. To date, few water quality and no contaminant concentrations were above regulatory levels. The results are being shared with members of community organizations at community functions.