Occurrence and spatial distribution of individual polychlorinated biphenyl congeners in residential soils from East Chicago, southwest Lake Michigan.

We report individual polychlorinated biphenyl congeners and the sum of all congeners (ΣPCB) in residential soils of East Chicago, Indiana. ΣPCB in soils ranged from 20 to 1700 ng/g dry weight (DW), with a geometric mean of 120 ng/g DW. These values are significantly higher than other locations, but similar or lower to locations nearby well-known PCB contamination sites. No PCB spatial distribution pattern was observed. PCB concentrations increase with total organic carbon in the soils and proximity to Indiana Harbor and Ship Canal (IHSC), where sediments are contaminated with PCBs. Most samples are similar in their PCB distribution and Aroclor 1254 yielded the highest similarity to all the samples. A fifth of the samples highly resemble other PCB profiles such as EPA background and Cedar Rapids Iowa soils, and volatilization from Lake Michigan, whereas volatilization from IHSC could not explain the PCBs found in soils. IHSC was expected to be the main source of PCBs in the nearby soils. It is possible that soils are impacted by variety of known and unknown sources, including volatilization from Lake Michigan, resulting in a regional PCB signal. Although PCB concentrations are higher than other locations, samples were below the current US EPA non-cancer residential soil level remediation goal for dioxin TEQ.

Aquifer-Scale Observations of Iron Redox Transformations in Arsenic-Impacted Environments to Predict Future Contamination.

Iron oxides control the mobility of a host of contaminants in aquifer systems, and the microbial reduction of iron oxides in the subsurface is linked to high levels of arsenic in groundwater that affects greater than 150 million people globally. Paired observations of groundwater and solid-phase aquifer composition are critical to understand spatial and temporal trends in contamination and effectively manage changing water resources, yet field-representative mineralogical data are sparse across redox gradients relevant to arsenic contamination. We characterize iron mineralogy using X-ray absorption spectroscopy across a natural gradient of groundwater arsenic contamination in Vietnam. Hierarchical cluster analysis classifies sediments into meaningful groups delineating weathering and redox changes, diagnostic of depositional history, in this first direct characterization of redox transformations in the field. Notably, these groupings reveal a signature of iron minerals undergoing active reduction before the onset of arsenic contamination in groundwater. Pleistocene sediments undergoing postdepositional reduction may be more extensive than previously recognized due to previous misclassification. By upscaling to similar environments in South and Southeast Asia via multinomial logistic regression modeling, we show that active iron reduction, and therefore susceptibility to future arsenic contamination, is more widely distributed in presumably pristine aquifers than anticipated.

Correction: Worldwide increased prevalence of human adenovirus type 3 (HAdV-3) respiratory infections is well correlated with heterogeneous hypervariable regions (HVRs) of hexon.

[This corrects the article DOI: 10.1371/journal.pone.0194516.].

Worldwide increased prevalence of human adenovirus type 3 (HAdV-3) respiratory infections is well correlated with heterogeneous hypervariable regions (HVRs) of hexon.

Human adenovirus type 3 (HAdV-3) respiratory infections occurs worldwide in both children and adults, leading to severe morbidity and mortality, particularly in the paediatric age group and especially in neonates. During HAdV infection, neutralizing antibodies are formed against the epitopes located in the hyper variable regions (HVRs) of the hexon protein. These neutralizing antibodies provide protection against reinfection by viruses of the same type. Therefore it is reasonable to speculate that variations of HAdV-3 in the HVRs could impair the immunity acquired by previous infection with a different strain with variation in its HVRs. HAdV-3 has recently become the major agent of acute respiratory infection worldwide, being responsible for 15% to 87% of all adenoviral respiratory infections. However, despite the increased prevalence of HAdV-3 as respiratory pathogen, the diversity of hexon proteins in circulating strains remains unexplored. This study was designed to explore the variation in HVRs of hexon among globally distributed strains of HAdV-3 as well as to discover possible relationship among them, thus possibly shedding light on the cause for the increased prevalence of HAdV-3. In this study, for the first time we analysed the hexon proteins of all 248 available strains of HAdV-3 from the NCBI database and compared them with those of the HAdV-3 prototype (GB stain). We found that the HVRs of HAdV-3 strains circulating worldwide were highly heterogeneous and have been mutating continuously since -their original isolation. Based on their immense heterogeneity, the strains can be categorized into 25 hexon variants (3Hv-1 to 3Hv-25), 4 of which (3Hv-1 to 3Hv-4) comprises 80% of the strains. This heterogeneity may explain why HAdV-3 has become the most prevalent HAdVs type worldwide. The heterogeneity of hexon proteins also shows that the development of a vaccine against HAdV-3 might be challenging. The data on hexon variants provided here may be useful for the future epidemiological study of HAdV-3 infection.