A novel toxicity fingerprinting method for pollutant identification with lux-marked biosensors

A novel technique is described for the identification and quantification of environmental pollutants based on toxicity fingerprinting with a metabolic lux-marked bacterial biosensor. This method involved characterizing the toxicity-based responses of the biosensor to seven calibration pollutants as acute temporal-dose response fingerprints. An algorithm is described to allow comparisons of responses of an unknown pollutant to be made against the calibration data. This is based on predicting pollutant concentration at each of six different time points over the course of a 5-min assay. If the prediction is consistent between the unknown pollutant and a calibration pollutant at the 95% test level, this is considered to be a positive identification. All seven calibration pollutants could be successfully distinguished from each other with this technique. Environmental samples, individually spiked with single concentrations of pollutants, were compared in this way against the calibration pollutants. An 83% identification success was achieved, with no false positives at the 95% test level. This is a simple and rapid technique that potentially can be applied to monitoring of industrial wastewater or as a screening tool for regulators.

Label-free based quantitative proteomics analysis of primary neonatal porcine Leydig cells exposed to the persistent contaminant 3-methylsulfonyl-DDE

Evidence that persistent environmental pollutants may target the male reproductive system is increasing. The male reproductive system is regulated by secretion of testosterone by testicular Leydig cells, and perturbation of Leydig cell function may have ultimate consequences. 3-Methylsulfonyl-DDE (3-MeSO₂-DDE) is a potent adrenal toxicants formed from the persistent insecticide DDT. Although studies have revealed the endocrine disruptive effect of 3-MeSO₂-DDE, the underlying mechanisms at cellular level in steroidogenic Leydig cells remains to be established. The current study addresses the effect of 3-MeSO₂-DDE on viability, hormone production and proteome response of primary neonatal porcine Leydig cells. The AlamarBlue™ assay was used to evaluate cell viability. Solid phase radioimmunoassay was used to measure concentration of hormones produced by both unstimulated and Luteinizing hormone (LH)-stimulated Leydig cells following 48h exposure. Protein samples from Leydig cells exposed to a non-cytotoxic concentration of 3-MeSO₂-DDE (10μM) were subjected to nano-LC-MS/MS and analyzed on a Q Exactive mass spectrometer and quantified using label-free quantitative algorithm. Gene Ontology (GO) and Ingenuity Pathway Analysis (IPA) were carried out for functional annotation and identification of protein interaction networks. 3-MeSO₂-DDE regulated Leydig cell steroidogenesis differentially depending on cell culture condition. Whereas its effect on testosterone secretion at basal condition was stimulatory, the effect on LH-stimulated cells was inhibitory. From triplicate experiments, a total of 6804 proteins were identified in which the abundance of 86 proteins in unstimulated Leydig cells and 145 proteins in LH-stimulated Leydig cells was found to be significantly regulated in response to 3-MeSO₂-DDE exposure. These proteins not only are the first reported in relation to 3-MeSO₂-DDE exposure, but also display small number of proteins shared between culture conditions, suggesting the action of 3-MeSO₂-DDE on several targeted pathways, including mitochondrial dysfunction, oxidative phosphorylation, EIF2-signaling, and glutathione-mediated detoxification. Further identification and characterization of these proteins and pathways may build our understanding to the molecular basis of 3-MeSO₂-DDE induced endocrine disruption in Leydig cells.

The frequency of Environmental Quality Standard (EQS) exceedance for chlorinated organic pollutants in rivers of the Humber catchments

The southern industrial rivers (Aire, Calder, Don and Trent) feeding the Humber estuary were routinely monitored for a range of chlorinated micro- organic contaminants at least once a week over a 1.5-year period. Environmental Quality Standards (EQSs) for inland waters were set under the European Economic Community for a limited number of problematic contaminants (18). The results of the monitoring program for seven classes of chlorinated pollutants on the EQS list are presented in this study. All compounds were detected frequently with the exception of hexachlorobutadiene (where only one detectable measurement out of 280 individual samples occurred). In general, the rivers fell into two classes with respect to their contamination patterns. The Aire and Calder carried higher concentrations of micro- pollutants than the Don and Trent, with the exception of hexachlorobenzene (HCB). For Σ hexachlorocyclohexane (HCH) isomers (α + γ) and for dieldrin, a number of samples (~ 5%) exceeded their EQS for both the Aire and Calder. Often, ΣHCH concentrations were just below the EQS level. Levels of p,p'- DDT on occasions approached the EQS for these two rivers, but only one sample (out of 140) exceeded the EQS. No compounds exceeded their EQS levels on the Don and Trent. Analysis of the ratio of γ HCH/αHCH indicated that the source of HCH for the Don and Trent catchments was primarily lindane (γHCH) and, to a lesser extent, technical HCH (mixture of HCH isomers, dominated by α HCH), while the source(s) for the Aire and Calder had a much higher contribution from technical HCH.

Use of a batch rotating photocatalytic contactor for the degradation of organic pollutants in wastewater

Aqueous solutions of a chlorinated VOC, 3,4-dichlorobut-1-ene, as well as other pollutants, may be mineralised to carbon dioxide, water and hydrochloric acid using a sealed rotating photocatalytic reactor. The effect of pH, dissolved oxygen concentration, light intensity, pollutant concentration and rotation speed on the degradation rate have been investigated as well as competition kinetics with methanol. This reactor may be optimised to minimise competition effects in mixed solutions. (C) 2001 Elsevier Science B.V. All rights reserved.

Spatial patterns and autocorrelation in the response of microarthropods to soil pollutants: The example of oribatid mites in an abandoned mining and smelting area

Although exogenous factors such as pollutants can act on endogenous drivers (e.g. dispersion) of populations and create spatially autocorrelated distributions, most statistical techniques assume independence of error terms. As there are no studies on metal soil pollutants and microarthropods that explicitly analyse this key issue, we completed a field study of the correlation between Oribatida and metal concentrations in litter, organic matter and soil in an attempt to account for spatial patterns of both metals and mites. The 50-m wide study area had homogenous macroscopic features, steep Pb and Cu gradients and high levels of Zn and Cd. Spatial models failed to detect metal-oribatid relationships because the observed latitudinal and longitudinal gradients in oribatid assemblages were independent of the collinear gradients in the concentration of metals. It is therefore hypothesised that other spatially variable factors (e.g. fungi, reduced macrofauna) affect oribatid assemblages, which may be influenced by metals only indirectly. (C) 2009 Elsevier Ltd. All rights reserved.

Contemporary environmental issues of landfill leachate: assessment & remedies

Landfills are the primary option for waste disposal all over the world. Most of the landfill sites across the world are old and are not engineered to prevent contamination of the underlying soil and groundwater by the toxic leachate. The pollutants from landfill leachate have accumulative and detrimental effect on the ecology and food chains leading to carcinogenic effects, acute toxicity and genotoxicity among human beings. Management of this highly toxic leachate presents a challenging problem to the regulatory authorities who have set specific regulations regarding maximum limits of contaminants in treated leachate prior to disposal into the environment to ensure minimal environmental impact. There are different stages of leachate management such as monitoring of its formation and flow into the environment, identification of hazards associated with it and its treatment prior to disposal into the environment. This review focuses on: (i) leachate composition, (ii) Plume migration, (iii) Contaminant fate, (iv) Leachate plume monitoring techniques, (v) Risk assessment techniques, Hazard rating methods, mathematical modeling, and (vi) Recent innovations in leachate treatment technologies. However, due to seasonal fluctuations in leachate composition, flow rate and leachate volume, the management approaches cannot be stereotyped. Every scenario is unique and the strategy will vary accordingly. This paper lays out the choices for making an educated guess leading to the best management option.

Modelling the fate of persistent organic pollutants (POPs) in the North Sea system

The environmental fate of selected persistent organic pollutants (POPs) in the North Sea system is modelled with a high resolution Fate and Transport Ocean Model (FANTOM) that uses hydrodynamic model output from the Hamburg Shelf Ocean Model (HAMSOM). Large amounts of POPs enter the North Sea from the surrounding highly populated, industrialised and agricultural countries. Major pathways to the North Sea are atmospheric deposition and river inputs, with additional contributions coming from bottom sediments and adjacent seas. The model domain covers the entire North Sea region, extending northward as far as the Shetland Islands, and includes adjacent basins such as the Skagerrak, Kattegat, and the westernmost part of the Baltic Sea. Model resolution (for both models) is 1.5’ latitude x 2.5’ longitude (approximately 3 km horizontal resolution) with 30 vertical levels. The POP model also has 20 sediment layers. Important model processes controlling the fate of POPs in the North Sea system are discussed. Results focus on Lindane gamma- HCH or gamma-hexachlorocyclohexane) and PCB 153.

Assessing the environmental fate of selected polybrominated diphenyl ethers in the region surrounding the Zhuoshui River of Taiwan based on an Equilibrium Constant fugacity model

Polybrominated diphenyl ethers (PBDEs) are a group of flame retardants that have been in use since the 1970s. They are included in the list of hazardous substances known as persistent organic pollutants (POPs) because they are extremely hazardous to the environment and human health. PBDEs have been extensively used in industry and manufacturing in Taiwan, thus its citizens are at high risk of exposure to these chemicals.
An assessment of the environmental fate of these compounds in the Zhuoshui river and Changhua County regions of western Taiwan, and also including the adjacent area of the Taiwan Strait, was conducted for three high risk congeners, BDE-47, -99 and -209, to obtain information regarding the partitioning, advection, transfer and long range transport potential of the PBDEs in order to identify the level of risk posed by the pollutants in this region.
The results indicate that large amounts of PBDEs presently reside in all model compartments – air, soil, water, and sediment – with particularly high levels found in air and especially in sediment. The high levels found in sediment, particularly for BDE-209, are significant, since there is the threat of these pollutants entering the food chain, either directly through benthic feeding, or through resuspension and subsequent feeding in the pelagic region of the water column which is a distinct possibility in the strong currents found within the Taiwan Strait. Another important result is that a substantial portion of emissions leave the model domain directly through advection, particularly for BDE-47 (58%) and BDE-209 (75%), thus posing a risk to adjacent communities.
Model results were generally in reasonable agreement with available measured concentrations. In air, model concentrations are in reasonably good agreement with available measured values. For both BDE-47 and -99, model concentrations are a factor of 2-3 higher and BDE-209 within the range of measured values. In soil, model results are somewhat less than measured values. In sediment, model results are at the high end of measured values.

Endocrine disruptor activity of multiple environmental food chain contaminants

Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/. vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation.Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens (. n= 3), UV filters (. n= 6), phthalates (. n= 4) and a metabolite, pyrethroids (. n= 9) and their metabolites (. n= 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17β-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.

Photocatalytic reactors for environmental remediation: A review

Research in the field of photocatalytic reactors in the past three decades has been an area of extensive and diverse activity with an extensive range of suspended and fixed film photocatalyst configurations being reported. The key considerations for photocatalytic reactors, however, remain the same; effective mass transfer of pollutants to the photocatalyst surface and effective deployments and illumination of the photocatalyst. Photocatalytic reactors have the potential versatility to be applied to the remediation of a range of water and gaseous effluents. Furthermore they have also been applied to the treatment of potable waters. The scale-up of photocatalytic reactors for waste and potable water treatment plants has also been demonstrated. Systems for the reduction of carbon dioxide to fuel products have also been reported. This paper considers the main photocatalytic reactor configurations that have been reported to date. 

The Environmental Fate of polybrominated diphenyl ethers in western Taiwan and coastal waters: evaluation with a fugacity based model

The environmental fate of polybrominated diphenyl ethers (PBDEs), a group of flame retardants that are considered to be persistent organic pollutants (POPs), around the Zhuoshui River and Changhua County regions of Taiwan was assessed. An investigation into emissions, partitioning, and fate of selected PBDEs was conducted based on the equilibrium constant (EQC) fugacity model developed at Trent University, Canada. Emissions for congeners PBDE 47, PBDE 99, and PBDE 209 to air (4.9–92 × 10−3 kg/h), soil (0.91–17.4 × 10−3 kg/h), and water (0.21–4.04 × 10−3 kg/h), were estimated by modifying previous models on PBDE emission rates by considering both industrial and domestic rates. It was found that fugacity modeling can give a reasonable estimation of the behavior, partitioning, and concentrations of PBDE congeners in and around Taiwan. Results indicate that PBDE congeners have a high affinity for partitioning into sediments then soils. As congener number decreases, the PBDEs then partition more readily into air. As the degree of bromination increases, congeners more readily partition to sediments. Sediments may then act as a long-term source of PBDEs which can be released back into the water column due to resuspension during storm events.