Spatial and temporal analysis of pesticides concentrations in surface water: pesticides atlas

Dutch water boards have a well-established program for monitoring pesticide contamination of surface waters. These monitoring data have been processed into a graphic format accessible online and designed to provide insight into pesticide presence in Dutch surface waters and trends over time: the Pesticides Atlas (http://www.pesticidesatlas.nl). With this tool one can easily get maps of where a pesticide is being measured and where it might possibly constitute an environmental problem over the years. Presently, results of the periods 1997/1998 until 2005/2006 are available at the level of individual active ingredients. At a national level, the percentage of pesticides concentrations that exceed the maximum tolerable risk has declined 30% to 38% over the years 2003/2004 compared with 1997/1998. This means that surface water quality in the Netherlands has improved with respect to pesticides, however there are still many locations at which the measured concentrations exceed the environmental quality standards. The results on linking land use to pesticides concentrations were shown to assist in optimization of monitoring programs. By developing the present Internet tool, many new opportunities for environmental risk assessment and risk management were identified, e.g. optimization of monitoring strategies and communication to policymakers.     

Persistent organochlorine pollutants in human serum of 50-65 years old women in the Flanders Environmental and Health Study (FLEHS). Part 1: Concentrations and regional differences

In 1999, a campaign of the Flemish Ministry of Health, Belgium was set up to assess pollutant concentrations and related health effect biomarkers in humans living in two regions of Flanders. The study was called the 'Flemish Environment and Health Study' (FLEHS). One of the goals was to measure present concentrations of persistent organochlorine pollutants in a Flemish population and to compare values obtained from pooled and individual serum samples. Concentrations of selected organochlorine pesticides, polychlorinated biphenyls (PCB) and polychlorinated dibenzo-p-dioxins (PCDD) and furans (PCDF) were measured by gas chromatography-mass spectrometry. TEQ values were also assessed by Chemical-Activated LUciferase gene eXpression (CALUX) bioassay. The study population consisted of 200 women between 50 and 65 years living in two areas of Flanders, Belgium. Because of the large volumes serum needed for all measurements, the concentrations of organochlorines were measured in 47 pooled serum samples originating from these women. The concentrations of the indicator PCBs (359.8 ng/g fat) and organochlorine pesticides (hexachlorobenzene, p,p'-dichlorodiphenyldichloroethylene, p,p'-dichlorodiphenyl-trichloroethane, lindane and pentachlorophenol), were comparable to those found in other European countries. The concentrations of PCDD/PCDFs showed another picture. With a median value of 48 pg WHO-TEQ/g fat, the women had 2-fold higher levels than a comparable age group from Germany examined in 1996. The mean total WHO-TEQ including PCDD/F, non-ortho and mono-ortho PCBs was 72.7 pg WHO-TEQ/g fat, whereas the CALUX-TEQ mean value was only 35.0 pg TEQ/g fat. In order to assess the pooling procedure, indicator PCBs and CALUX-TEQs were measured in all 200 individuals that were integrated in the pools. The measured values were comparable to the pool results: 390.0 ng/g fat and 41.6 pg TEQ/g fat respectively. It was concluded that pooling of serum samples offers the possibility to measure exposure in the whole study population on a more cost-effective way. However, because of statistical power loss and no possibility of confounder adjustment, pooling is not the most effective way to study regional differences.     

Review of disposal technologies for chromated copper arsenate (CCA) treated wood waste, with detailed analyses of thermochemical conversion processes

Several alternative methods for the disposal of chromated copper arsenate (CCA) treated wood waste have been studied in the literature, and these methods are reviewed and compared in this paper. Alternative disposal methods include: recycling and recovery, chemical extraction, bioremediation, electrodialytic remediation and thermal destruction. Thermochemical conversion processes are evaluated in detail based on experiments with model compounds as well as experimental and modelling work with CCA treated wood. The latter category includes: determination of the percentage of arsenic volatilised during thermal conversion of CCA treated wood, identification of the mechanisms responsible for arsenic release, modelling of high temperature equilibrium chemistry involved when CCA treated wood is burned, overview of options available for arsenic capture, characterisation of ash resulting from (co-)combustion of CCA treated wood, concerns about polychlorinated dibenzo-p-dioxins/furans (PCDD/F) formation. Finally, the most appropriate thermochemical disposal technology is identified on short term (co-incineration) and on long term (low-temperature pyrolysis or high-temperature gasification).     

Diethylaminoethyl-cellulose clean-up of a large volume naphthenic acid extract

The Athabasca oil sands of Alberta, Canada contain an estimated 174 billion barrels of bitumen. During oil sands refining processes, an extraction tailings mixture is produced that has been reported as toxic to aquatic organisms and is therefore collected in settling ponds on site. Investigation into the toxicity of these tailings pond waters has identified naphthenic acids (NAs) and their sodium salts as the major toxic components, and a multi-year study has been initiated to identify the principal toxic components within NA mixtures. Future toxicity studies require a large volume of a NA mixture, however, a well-defined bulk extraction technique is not available. This study investigated the use of a weak anion exchanger, diethylaminoethyl-cellulose (DEAE-cellulose), to remove humic-like material present after collecting the organic acid fraction of oil sands tailings pond water. The NA extraction and clean-up procedure proved to be a fast and efficient method to process large volumes of tailings pond water, providing an extraction efficiency of 41.2%. The resulting concentrated NA solution had a composition that differed somewhat from oil sands fresh tailings, with a reduction in the abundance of lower molecular weight NAs being the most significant difference. This reduction was mainly due to the initial acidification of tailings pond water. The DEAE-cellulose treatment had only a minor effect on the NA concentration, no noticeable effect on the NA fingerprint, and no significant effect on the mixture toxicity towards Vibrio fischeri.     

Within- and among-clutch variation of organohalogenated contaminants in eggs of great tits (Parus major)

In this study we investigated the variation of organohalogenated compounds, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs), within and among clutches of a small insectivorous songbird, the great tit (Parus major), and determined whether egg laying order affects the concentrations of these compounds. PCBs were the major organohalogenated contaminants in the eggs of great tits (mean 4778 ng/g lipid weight), while PBDEs (mean 204 ng/g lipid weight) and DDTs (mean 601 ng/g lipid weight) were found at much lower concentrations. Within-clutch variability of PCBs, PBDEs, and DDTs residues in the egg samples was small (7%, 3%, and 22%, respectively) compared to among-clutch variability (93%, 97%, and 78%, respectively). The small within-clutch variability may be in part related to the small home range of great tits and low spatial heterogeneity of the contaminants. We found no laying order effects on the concentrations of PCBs, PBDEs, and DDTs. Our results show that random egg samples of great tits are suitable as a biomonitoring tool for contamination with persistent organohalogenated pollutants in terrestrial environments.     

Effects of the antidepressant mianserin in zebrafish: molecular markers of endocrine disruption

Due to their environmental occurrence and intrinsic biological activity, human pharmaceuticals have received increasing attention from environmental and health agencies. Of particular, ecotoxicological concern are drugs that affect nervous- and endocrine-systems. Zebrafish genome-wide oligo arrays are used to collect mechanistic information on mianserin-induced changes in gene expression in zebrafish. Gene expression analysis in brain and gonad tissue clearly demonstrated the estrogenic activity of mianserin and its potency to disrupt normal endocrine (estrogenic) signaling, based on induction of molecular biomarkers of estrogenicity (e.g., vitellogenin1 and zona pellucida proteins). The possible mechanism underlying this estrogenic activity of mianserin is disturbance of the Hypothalamo-Pituitary-Gonadal (HPG) axis by direct interference of mianserin with the serotonergic and adrenergic systems in the brain of zebrafish. Taking into account the importance of the HPG-axis, and considering the concept of 'critical window of exposure', our results reveal the importance for more elaborate testing of endocrine disruptive effects of aquatic antidepressants at different lifestages and during longer exposure periods (e.g., life cycle studies). Although there is a low concordance between the gene expression results in this study and previous cDNA microarray hybridizations, the global mechanistic expression patterns are similar in both platforms. This argues in favor of pathway-driven analysis of gene expression results compared to gene-per-gene analysis.     

Diffusion of HTO, 36Cl- and 125I- in Opalinus Clay samples from Mont Terri. Effect of confining pressure

Diffusion coefficients (T=23 +/- 2 degrees C) and accessible porosities for HTO, 36Cl(-) and 125I(-) were measured on Opalinus Clay (OPA) samples from the Mont Terri Underground Rock Laboratory (URL) using the through-diffusion technique. The direction of transport (diffusion) was perpendicular to bedding. Special cells that allowed the application of confining pressure were designed and constructed. The pressures ranged from 1 to 5 MPa, the latter value simulating the overburden at the Mont Terri URL (about 200 m). The test solution used in the experiments was a synthetic version of the Opalinus Clay pore water, which has Na(+) and Cl(-) as the main components (I=0.42 M). The measured values of the effective diffusion coefficients (D(e)) and rock capacity factors (alpha) are: D(e)=1.2-1.5 x 10(-11) m(2) s(-1) and alpha=0.09-0.11 for HTO, D(e)=4.0-5.5 x 10(-12) m(2) s(-1) and alpha=0.05 for 36Cl(-) and D(e)=3.2-4.6 x 10(-12) m(2) s(-1) and alpha=0.07-0.10 for 125I(-). For non-sorbing tracers (HTO, 36Cl) the rock capacity factor alpha is equal to the diffusion-accessible porosity epsilon. The experimental results showed that pressure only had a small effect on the value of the diffusion coefficients. Increasing the pressure from 1 to 5 MPa resulted in a decrease of the diffusion coefficient of approximately 17% for HTO, approximately 28% for 36Cl(-) and approximately 30% for 125I(-). Moreover, the diffusion coefficients for 36Cl(-) and 125I(-) are smaller than for HTO, which is consistent with an effect arising from anion exclusion. The diffusion coefficients of HTO and 125I(-) measured in this study are in good agreement with recent measurements at three other laboratories performed within the framework of a laboratory comparison exercise. The values of the diffusion-accessible porosities show a larger degree of scatter.     

Sonographic detection of central nervous system defects in the first trimester of pregnancy

The fetal central nervous system can already be examined in the first trimester of pregnancy. Acrania, alobar holoprosencephaly, cephaloceles, and spina bifida can confidently be diagnosed at that stage and should actively be looked for in every fetus undergoing first-trimester ultrasound. For some other conditions, such as vermian anomalies and agenesis of the corpus callosum, markers have been identified, but the diagnosis can only be confirmed in the second trimester of gestation. For these conditions, data on sensitivity and more importantly specificity and false positives are lacking, and one should therefore be aware not to falsely reassure or scare expecting parents based on first-trimester findings. This review summarizes the current knowledge of first-trimester neurosonography in the normal and abnormal fetus and gives an overview of which diseases can be diagnosed. © 2016 John Wiley & Sons, Ltd.     

Indoor Air Quality Assessment of Elementary Schools in Curitiba, Brazil

The promotion of good indoor air quality in schools is of particular public concern for two main reasons: (1) school-age children spend at least 30% of their time inside classrooms and (2) indoor air quality in urban areas is substantially influenced by the outdoor pollutants, exposing tenants to potentially toxic substances. Two schools in Curitiba, Brazil, were selected to characterize the gaseous compounds indoor and outdoor of the classrooms. The concentrations of benzene, toluene, ethylbenzene, and the isomers xylenes (BTEX); NO₂; SO₂; O₃; acetic acid (HAc); and formic acid (HFor) were assessed using passive diffusion tubes. BTEX were analyzed by gas chromatography–ion trap mass spectrometry and other collected gasses by ion chromatography. The concentration of NO₂ varied between 9.5 and 23?µg m^?3, whereas SO₂ showed an interval from 0.1 to 4.8?µg m^?3. Within the schools, BTEX concentrations were predominant. Formic and acetic acids inside the classrooms revealed intermediate concentrations of 1.5?µg m^?3 and 1.2?µg m^?3, respectively.