Use of 15N-depleted artificial compost in bound residue studies

Association of bound residues to soil humic matter may be accomplished by different binding mechanisms such as sequestration in hydrophobic interiors of the organic material or covalent linkage to the organic matter. The structures and chemical environments of compounds can be observed by NMR spectroscopy. We applied 15N-NMR spectroscopy to study the soil-bound residues of 15N-labeled simazine. As the 15N-isotope has a low sensitivity and natural abundance 15N-NMR experiments require long measurement times and often result in low signal-to-noise (S/N) ratios. Therefore, in addition to the use of 15N-labeled simazine, 15N-depleted compost was used to reduce the amount of background signal and enhance the sensitivity. The compost was produced from maize and wheat plants grown on sand with 15N-depleted NH4NO3 as sole nitrogen source. The plants were freeze-dried, ground and mixed with sand for composting. After a composting period of 224 days analysis of the compost revealed a 15N-content of 267 ppm as opposed to a natural abundance of 3650 ppm. Characterization of this artificial compost produced parameter values similar to those of a natural compost. The 13C-NMR-spectra of the humic and fulvic acids during different stages of maturity showed that there was a shift from single-bond functional groups to more complex double-bond and aromatic structures. Experiments with this compost showed an increased signal intensity. The improved sensitivity made it possible to obtain interpretable NMR signals in contrast to experiments with 15N-simazine on native soil where no signals were detectable. The data indicated that the bound residues of simazine are composed of metabolites resulting from N-dealkylation and triazine ring destruction. Silylation of the bound residues showed a very strong binding of the residues to the matrix as only a small fraction could be solubilized.     

Biomonitoring of persistent organochlorine pesticides, PCDD/PCDFs and dioxin-like PCBs in blood of children from South West Germany (Baden-Wuerttemberg) from 1993 to 2003

In the context of a monitoring program, persistent organic pollutants (POPs) were quantified in the blood of 10 year old children at four different demographic regions in Baden-Wuerttemberg, a highly industrialised federal state in South West Germany. DDE, HCB, PCB 138, PCB 153 and PCB 180 were measured in 1996/1997, 1998/1999, 2000/2001 and 2002/2003 in individual samples of about 400 children per year. PCDD/PCDFs and some relevant coplanar PCBs were determined in pooled samples from children in seven cycles from 1993 to 2003. Blood concentrations of the investigated compounds decreased in that time period by a factor of 2-4 with the exception of most PCDFs. The concentrations of POPs in the blood of the children were distinctly lower than the concentrations reported for adults. Breast feeding was associated with about 30% higher median concentrations of DDE, HCB, PCBs and a 30% increase for mean PCDD/PCDF concentrations. Concerning demographic differences, significant lower concentrations of HCB, PCBs and PCDD/PCDFs could be seen in children from Mannheim compared to the region of Aulendorf. About 10-20% higher concentrations were found in boys compared to girls for HCB, indicator PCBs and PCDD/PCDFs. The pattern of non-ortho and mono-ortho PCBs in the blood of children was similar to the pattern reported for mother's milk, and PCB 126 and PCB 156 contributed about 70% to the toxicity of dioxin-like PCBs and about one-third to total TEQ including PCDD/PCDFs.     

Poliovirus and Other Enteroviruses from Environmental Surveillance in Italy, 2009–2015

Within the initiatives for poliomyelitis eradication by WHO, Italy activated an environmental surveillance (ES) in 2005. ES complements clinical Acute Flaccid Paralysis (AFP) surveillance for possible polio cases, detects poliovirus circulation in environmental sewage, and is used to monitor transmission in communities. In addition to polioviruses, the analyses comprised: (i) the monitoring of the presence of non-polio enteroviruses in sewage samples and (ii) the temporal and geographical distribution of the detected viruses. From 2009 to 2015, 2880 sewage samples were collected from eight cities participating in the surveillance. Overall, 1479 samples resulted positive for enteroviruses. No wild-type polioviruses were found, although four Sabin-like polioviruses were detected. The low degree of mutation found in the genomes of these four isolates suggests that these viruses have had a limited circulation in the population. All non-polio enteroviruses belonged to species B and the most frequent serotype was CV-B5, followed by CV-B4, E-11, E-6, E-7, CV-B3, and CV-B2. Variations in the frequency of different serotypes were also observed in different seasons and/or Italian areas. Environmental surveillance in Italy, as part of the ‘WHO global polio eradication program’, is a powerful tool to augment the polio surveillance and to investigate the silent circulation or the re-emergence of enteroviruses in the population.     

Large-Scale Survey of Human Enteroviruses in Wastewater Treatment Plants of a Metropolitan Area of Southern Italy

Human enteroviruses (HEVs) occur in high concentrations in wastewater and can contaminate receiving environmental waters, constituting a major cause of acute waterborne disease worldwide. In this study, we investigated the relative abundance, occurrence, and seasonal distribution of polio and other enteroviruses at three wastewater treatment plants (WWTPs) in Naples, Southern Italy, from January 2010 to December 2014. Influent and effluent samples from the three WWTPs were collected monthly. One hundred and sixty-one of the 731 wastewater samples collected (22.0%) before and after water treatment were CPE positive on RD cells; while no samples were positive on L20B cells from any WWTPs. Among the 140 non-polio enterovirus isolated from inlet sewage, 69.3% were Coxsackieviruses type B and 30.7% were Echoviruses. Among these, CVB3 and CVB5 were most prevalent, followed by CVB4 and Echo6. The twenty-one samples tested after treatment contained 6 CVB4, 5 CVB3, 3 Echo11, and 2 Echo6; while other serotypes were isolated less frequently. Data on viral detection in treated effluents of WWTPs confirmed the potential environmental contamination by HEVs and could be useful to establish standards for policies on wastewater management.     

Comparison of ordinary and lognormal kriging on skewed data of total cadmium in forest soils of Sweden

Spatial statistical analysis of georeferenced data of total cadmium (TCd) in forest soils of Sweden was assumed to providemore advantageous maps than traditional interpolated maps. However, 264 measurements of TCd in O-horizon of forest soils displayed skewed frequency distribution. Since atypicalobservations affect badly the variogram, outliers wereidentified, different data transformations were tested andordinary (OK) and lognormal kriging (LK) scenarios werecompared based on cross-validation. Results were comparedusing overall measures of predictors, e.g. traditionalmean squared prediction error (MSPE), mean of krigingvariances, variance ratio, median of internallystandardised residuals, and assessments of classificationaccuracy, such as percentage of correctly predictedsamples and within-class MSPE.One outlier was identified based on the absolute value of skewness of value differences less or equal to one in data pairs separated at certain lag classes. Mapping categories characterised by percentage of correct classification and within-class MSPE were found to be essential in comparison of kriging results additionally to the overall measures. In comparison of kriging methods, OK predicted high values moreaccurately and LK was more effective to predict low and mediumvalues. Thus, OK was suggested for mapping high concentration of TCd and other pollutants. Percentage of correctly predictedsamples and within-class MSPE were found to be dependent on kriging method, as well as on the number and limits of categories.     

Evaluation of biodegradability of poly(ε-caprolactone)/poly(ethylene terephthalate) blends

The results of an investigation aimed at evaluation of the biodegradability of blends of poly(-caprolactone) (PCL) with poly(ethylene terephthalate) (PET) as the major component are reported. Specimens of the blends, as melt extruded films and/or powders, were submitted to degradation tests under different environmental conditions including full-scale composting, soil burial, bench-scale accelerated aerobic degradation, and exposure to axenic cultures and esterolytic enzymes. Indications have been gained that blending in the melt gives rise to insertion of PCL segments in the PET chain. Copolymers thus attained acted as macromolecular compatibilizers, allowing for a complete miscibility of PCL and PET. The biodegradation detected on the blend samples was, however, well below the values expected from chemical composition and behavior of individual homopolymers under the same environmental conditions. The presence of PET as the major component in PET/PCL blends apparently reduces the propensity of PCL to be degraded, at least in the investigated composition range. The degradation data collected under different environmental conditions indicate that the full-scale composting system is the most efficient among the tested degradation procedures.     

Environmental Racism in the Sunbelt? A Cross-Cultural Analysis

/ Sociologist Robert Bullard challenged the prevailing paradigm of environmentalism as a consensual issue in the United States by developing the concept of environmental racism. As he claims, ethnic minorities have been put "at greater environmental risk" than has the Caucasian majority in most areas of the country. This study of the Tucson metropolitan area examines this proposition by utilizing data from several sources: interviews with elected officials and other opinion leaders, GIS-generated socioeconomic data, articles in the press, and a literature review. We conclude that Bullard's concept has validity for this metropolitan area but that there also exist widely divergent differences of opinion on the subject. We explain why this is so. We further conclude that the allegation of "environmental racism" made by the Hispanic community in the 1980s and 1990s has had a transformative effect on local politics.KEY WORDS: Environment; Racism; Tucson; Garbage dumps; County government; Pollution; Equity; Justice     

Second-trimester diurnal variation of maternal serum alpha-fetoprotein,human chorionic gonadotropin,and unconjugated oestriol: Is it present and does it affect the prediction of a patient's risk for fetal down syndrome?

Both a cross-sectional and a longitudinal study were performed to investigate whether or not the collection time should be taken into consideration when generating a patient's risk for fetal Down syndrome with multiple marker screening. Diurnal variations of third-trimester alpha-fetoprotein (AFP) levels and first-trimester human chorionic gonadotropin (hCG) levels have been previously reported. In addition, large episodic fluctuations of conjugated and unconjugated oestriol (uE3) as well as a diurnal variation have also been reported in the third trimester. If the levels of these analytes routinely fluctuate during the day, they could affect a patient's risk calculation for fetal Down syndrome. The longitudinal study evaluated ten non-diabetic women who underwent sequential sampling for AFP, hCG, and uE3. The cross-sectional study evaluated 1953 patients for these three markers whose time of sampling was recorded between 8·00 a.m. and 5·59 p.m. Using either study design, no significant effect was seen in the median MOM levels of the screening analytes as a function of the time of day.     

Retinal cryptochrome in a migratory passerine bird: a possible transducer for the avian magnetic compass

The currently discussed model of magnetoreception in birds proposes that the direction of the magnetic field is perceived by radical-pair processes in specialized photoreceptors, with cryptochromes suggested as potential candidate molecules mediating magnetic compass information. Behavioral studies have shown that magnetic compass orientation takes place in the eye and requires light from the blue-green part of the spectrum. Cryptochromes are known to absorb in the same spectral range. Because of this we searched for cryptochrome (CRY) in the retina of European robins, Erithacus rubecula, passerine birds that migrate at night. Here, we report three individually expressed cryptochromes, eCRY1a, eCRY1b, and eCRY2. While eCRY1a and eCRY2 are similar to the cryptochromes found in the retina of the domestic chicken, eCRY1b has a unique carboxy (C)-terminal. In light of the radical-pair model, our findings support a potential role of cryptochromes as transducers for the perception of magnetic compass information in birds.