Multimedia emissions inventory of polychlorinated biphenyls for the U.S. Great Lakes states

Polychlorinated biphenyls (PCBs) were banned in the United States in 1979, and since then a significant decline in their release to the environment has been observed. This decline has now reached a plateau. Several new regulatory programs have been put in place to further reduce PCB emissions/releases. However, our ability to measure the effectiveness of these regulatory/voluntary programs and to support regional fate/transport and source/receptor modeling efforts depend on reliable emission information. In this study, we attempt to improve the emission inventory for PCBs by compiling and analyzing the multimedia total PCB emission/release data reported for the U.S Great Lakes states for each year from 1990 to 2000. Although Toxic Release Inventory (TRI), National Emissions Inventory (NEI), Great Lakes Regional Air Toxic Emissions Inventory (GLRATEI), and Integrated Atmospheric Deposition Network (IADN) data formed the basis of estimating air emissions, we used the TRI, National Response Center (NRC), and PCB transformer inventory data to estimate PCB releases to land. We used the Permit Compliance System and NRC data to obtain estimates of PCB discharges to water systems in the Great Lakes states. The Remedial Action Plans for each area of concern were the primary source for estimating PCB loads of dredged sediments. On the basis of the NEI, IADN, and GLRATEI data, the total air emissions within the decade were approximately 126 t. The regionwide discharges to water systems and releases to land in the form of landfills and accidental spills in 1990-2000 were estimated as approximately 170 and 3225 t, respectively. We estimated that approximately 1.3 million t of PCB-contaminated sediment were removed or targeted for removal in five lakes of the U.S. portion of the Great Lakes basin. We stress that these estimates were based on reported amounts and the unreported PCB releases/emissions could result in significantly higher estimates.     

Investigation of the blood biochemical status of gas station workers

The aim of this study was to examine occupation-associated effects on blood cytokine and immunoglobulin g (IgG) levels, antioxidant enzyme activities (SOD, GSHPx, and catalase), nitrite and nitrate levels, and malondialdehyde (MDA) concentrations in gas station workers (GSWs). Trace elements (Cu, Zn, and Pb) in serum, and the amount of hemoglobin in erythrocytes were also determined. Forty male GSWs and 30 male controls were included in the study. No significant difference was observed between the hemoglobin levels of GSWs and those in controls. Proinflammatory cytokine levels, such as tumor necrosis factor-α and interleukin-8 were significantly increased in GSWs’ sera. Interleukin-1β and interleukin-6 were below the detection limit of the assay in both the groups. Cytokine receptor interleukin 2R concentration and IgG levels were also significantly increased. Approximately, two-fold increase in nitrite and nitrate concentrations was found in GSWs’ sera. Erythrocyte antioxidant enzyme levels were significantly lower in GSWs’ blood. MDA concentration, a measure of lipid peroxidation, was found to be significantly elevated. Zn levels were significantly decreased, whereas Cu and Pb levels were increased in GSWs’ sera. Smoking was not found to be a major confounder for the association between exposure and blood parameters.     

Insights into the Viscoelastic Peculiarities of Cyanobacterial Extracellular Polymeric Substance (EPS)

Journal of Polymers and the Environment - Extracellular polymeric substances (EPSs) can be defined as renewable, high molecular weight polymeric materials produced by bacteria and microorganisms....