Loss and transformation products of the aromatic antioxidants in MDPE film under long-term exposure to biotic and abiotic conditions

2002 ◽  
Vol 85 (5) ◽  
pp. 974-988 ◽  
Author(s):  
Nadejzda Haider ◽  
Sigbritt Karlsson
Keyword(s):  
Transformation Products ◽  
Abiotic Conditions

The role of abiotic conditions in shaping the long-term patterns of a high-elevation Argentine ant invasion

2005 ◽  
Vol 11 (4) ◽  
pp. 319-331 ◽  
Author(s):  
Paul D. Krushelnycky ◽  
Stephanie M. Joe ◽  
Arthur C. Medeiros ◽  
Curtis C. Daehler ◽  
Lloyd L. Loope
Keyword(s):  
High Elevation ◽  
Argentine Ant ◽  
Abiotic Conditions

scholarly journals Occurrence, Fate, Effects, and Risks of Dexamethasone: Ecological Implications Post-COVID-19

2021 ◽  
Vol 18 (21) ◽  
pp. 11291
Author(s):  
Ndeke Musee ◽  
Lemme Prica Kebaabetswe ◽  
Shepherd Tichapondwa ◽  
Gosaitse Tubatsi ◽  
Ntombikayise Mahaye ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Ecological Integrity ◽  
Transformation Products ◽  
Environmental Matrices ◽  
Ecological Implications ◽  
Recent Outbreak ◽  
Molecular Effects ◽  
Engineered Systems ◽  
Long Term Studies

The recent outbreak of respiratory syndrome-coronavirus-2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), has led to the widespread use of therapeutics, including dexamethasone (DEXA). DEXA, a synthetic glucocorticoid, is among the widely administered drugs used to treat hospitalized COVID-19 patients. The global COVID-19 surge in infections, consequent increasing hospitalizations, and other DEXA applications have raised concerns on eminent adverse ecological implications to aquatic ecosystems. Here, we aim to summarize published studies on DEXA occurrence, fate, and effects on organisms in natural and engineered systems as, pre-COVID, the drug has been identified as an emerging environmental contaminant. The results demonstrated a significant reduction of DEXA in wastewater treatment plants, with a small portion, including its transformation products (TPs), being released into downstream waters. Fish and crustaceans are the most susceptible species to DEXA exposure in the parts-per-billion range, suggesting potential deleterious ecological effects. However, there are data deficits on the implications of DEXA to marine and estuarine systems and wildlife. To improve DEXA management, toxicological outcomes of DEXA and formed TPs should entail long-term studies from whole organisms to molecular effects in actual environmental matrices and at realistic exposure concentrations. This can aid in striking a fine balance of saving human lives and protecting ecological integrity.

Paleoecological and stratigraphic controls on eurypterid Lagerstätten: a model for preservation in the mid-Paleozoic

Paleobiology ◽  
2017 ◽  
Vol 43 (3) ◽  
pp. 383-406 ◽  
Author(s):  
Matthew B. Vrazo ◽  
Carlton E. Brett ◽  
Samuel J. Ciurca
Keyword(s):  
Lower Devonian ◽  
Abiotic Conditions ◽  
Sequence Stratigraphic ◽  
Exceptional Preservation ◽  
Microbial Structures ◽  
Subaerial Exposure ◽  
Stratigraphic Framework ◽  
The World ◽  
Long Term Preservation

AbstractRecent studies of eurypterid paleoecology suggest that formation of eurypterid Lagerstätten in the mid-Paleozoic of Laurentia was controlled by the presence of an ecological–taphonomic window that recurred predictably in nearshore, marginal environments during transgressions. We tested this hypothesis by performing a high-resolution taxonomic, environmental, and stratigraphic survey and quantitative analysis of all Silurian–Lower Devonian eurypterid-bearing intervals in the Appalachian basin, the most prolific region for eurypterid remains in the world. Canonical correspondence analysis of sedimentological and faunal associations revealed a strong lithologic gradient between groupings of eurypterid genera and associated taxa across the basin, and a significant association of eurypterids with microbialites (thrombolites, stromatolites) and evaporitic structures. Field observations confirmed that, stratigraphically, eurypterids in the basin frequently occur above the microbialite structures and beneath evaporites and other indicators of increased salinity or subaerial exposure. Following interpretation of these features within a sequence stratigraphic framework, we present a preservational model in which (1) eurypterids inhabited nearshore settings following freshening conditions concomitant with minor transgressions, (2) their remains were subsequently buried by storms or microbialite sediment baffling, and (3) subsequent long-term preservation of tissues was facilitated by regression and cyclical shallowing-up successions that promoted hypersalinity and anoxia. In the central and southern region of the basin, where microbial structures and evidence for hypersalinity are less common, a similar pattern of cyclical shallowing-upward deposition within eurypterid-bearing units holds. Thus, eurypterid preservation appears to reflect a combination of ecological preferences and abiotic conditions that promoted inhabitation and eventual preservation within the same setting. This study provides the first quantitative support for a sea level–based control on preservation of eurypterids and adds to the growing body of evidence that suggests that analysis of exceptional preservation in the fossil record benefits from interpretation within a sequence stratigraphic framework.

scholarly journals HCH Removal in a Biochar-Amended Biofilter

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3396
Author(s):  
Aday Amirbekov ◽  
Aigerim Mamirova ◽  
Alena Sevcu ◽  
Roman Spanek ◽  
Pavel Hrabak
Keyword(s):  
Transformation Products ◽  
Drainage Water ◽  
Contaminated Sites ◽  
Functional Genes ◽  
High Effectiveness ◽  
Hch Isomers ◽  
Temporary Water ◽  
Treatment Technologies ◽  
Sulfur Oxidizing

This study evaluated the efficiency of two biofilter systems, with and without biochar chambers installed, at degrading and removing HCH and its isomers in natural drainage water. The biochar biofilter proved to be 96% efficient at cleaning HCH and its transformation products from drainage water, a significant improvement over classic biofilter that remove, on average, 68% of HCH. Although iron- and sulfur-oxidizing bacteria, such as Gallionella and Sulfuricurvum, were dominant in the biochar bed outflows, they were absent in sediments, which were rich in Simplicispira, Rhodoluna, Rhodoferax, and Flavobacterium. The presence of functional genes involved in the biodegradation of HCH isomers and their byproducts was confirmed in both systems. The high effectiveness of the biochar biofilter displayed in this study should further encourage the use of biochar in water treatment solutions, e.g., for temporary water purification installations during the construction of other long-term wastewater treatment technologies, or even as final solutions at contaminated sites.

TOXICOLOGICAL AND HYGIENIC ASSESSMENT OF HALOGENATED SILANES AND APPROACHES TO THEIR CONTROL IN THE AIR OF THE WORKING AREA AND HUMAN ENVIRONMENT

2018 ◽  
pp. 49-52
Author(s):  
Kh. Kh. Khamidulina ◽  
A. S. Proskurina ◽  
E. S. Petrova
Keyword(s):  
Main Product ◽  
Transformation Products ◽  
Long Term Effects ◽  
Human Environment

The article presents approaches to the assessment of toxicity, hazard and hygienic regulation and hazard of low stable substances - chlorosilanes: trimethylchlorosilane, trichlorosilane, methyltrichlorosilane. Their toxicity is determined by the main product of the transformation - hydrochloride. The presence of specific and long-term effects is associated with the toxic properties of transformation products. Control of these substances in the air of the working area and in the objects of human environment is recommended to be carried out on the product of transformation - hydrochloride.

Long-term monitoring of plant protection products and their transformation products at karstic springs

2021 ◽  
Author(s):  
Johannes Schorr ◽  
Franziska Jud ◽  
Birgit Beck ◽  
Philipp Longree ◽  
Heinz Singer ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Response Times ◽  
Plant Protection ◽  
Plant Protection Products ◽  
Transformation Products ◽  
Short Term ◽  
Rain Events ◽  
Precipitation Events ◽  
Composite Samples

<p>Karst aquifers are an important water resource for a large part of the world’s population. Because of their natural susceptibility towards contamination, they have to be managed carefully. Human activities such as agriculture, roads or settlements in karst aquifer catchments often lead to the contamination of karstic springs. Due to their special geology, they are at risk of both, long- and short-term contamination. Long-term contamination is due to adsorption of anthropogenic substances in the overlaying soil, the epikarst or rock matrix whereas short-term contamination can be due to spills or precipitation events. Such precipitation events can lead to the mobilization of substances. These are then readily transported to karstic springs where pollutant peaks might be observed. However, current monitoring strategies are not suitable (infrequent, regular sampling intervals) to reveal such peaks. The goal of this study was in a first step, to investigate the contamination level of ten karstic springs (part of NAQUA Swiss National Groundwater Monitoring) in the Swiss Jura, screening for plant protection products (PPP) and transformation products (TP). This was achieved by a monitoring campaign that was conducted from March 2020 until October 2020. Two-week composite samples were collected in addition to the continuous acquisition of electrical conductivity and water level, i.e. spring discharge. Samples were then analyzed by large volume direct injection into a HPLC-HRMS/MS setup using a target list of 130 compounds (105 PPP’s, 25 TP’s).</p><p>Analysis of a first batch of samples of three springs did not reveal many compounds with elevated concentrations (33 detections in 15 samples above 100 ng/L of 3 compounds: chloridazone desphenyl, chloridazone methyl desphenyl, chlorothalonil TP R471811). No PPP’s were observed to be continuously leaching from the catchment and the aquifer in concentrations above 100 ng/L. The detected compounds above 100 ng/L were TP’s which indicates that their parent compounds might be adsorbed to the aquifer matrix or the soil cover, therefore leaching TP’s continuously or pulse like during rain events. In total, 19 compounds were detected above their quantification limits. Of those, 10 PPP’s and 9 TP’s were found. We further evaluated spring responses during rain events based on electrical conductivity and determined response times between 3 and 5.5 hours. Since two-week composite samples cannot reveal short-term concentration dynamics given the fast response times and dilution (both leading to low concentrations in composite samples), we will conduct a sampling campaign with a different strategy in 2021. Therein, in a second step, the goal is to study the pollutant dynamics induced by precipitation events with temporally highly resolved measurements. To achieve this we will install a transportable, liquid chromatography, high resolution mass spectrometer at three selected springs and conduct an automatic sampling and analysis with a high temporal resolution.</p>

scholarly journals A Long-Term Symbiotic Relationship: Recruitment and Fidelity of the Crab Trapezia on Its Coral Host Pocillopora

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 450
Author(s):  
H. M. Canizales-Flores ◽  
A. P. Rodríguez-Troncoso ◽  
F. A. Rodríguez-Zaragoza ◽  
A. L. Cupul-Magaña
Keyword(s):  
Life Cycle ◽  
Coral Host ◽  
Symbiotic Relationship ◽  
Recruitment Process ◽  
Sea Temperature ◽  
Abiotic Conditions ◽  
Coral Colony ◽  
Factors Influencing ◽  
Symbiotic Relation

The symbiotic relationship between the crab Trapezia spp. and pocilloporid corals has been characterized as obligate. Although this relationship is considered common and has been widely registered within the distribution areas of these corals, the initiation of this symbiotic relation and its potential persistence throughout the life cycle of the crustacean is still poorly described. To understand the Trapezia–Pocillopora symbiosis, determining the time and conditions when Trapezia recruits a coral colony and the factors influencing this process are key. Thus, in the present study, healthy, small and unrecruited coral fragments were attached to the substrates (using cable ties) of nearby adult Pocillopora colonies. All fragments were monitored for two years to measure their growth and size at the first evidence of Trapezia crab recruitment, as well as the abundance and permanence of the crabs on the coral fragments. Results showed a relation between the space available (coral volume) and crab recruitment as an increase in substrate complexity is required to provide protection for the crabs and hence maintain the symbiosis, while abiotic conditions such as sea temperature and the distance of the fragments from the adult coral colonies seemingly did not affect the recruitment process. In addition, crabs are able to move between colonies, thus discarding the theory that once recruited, crabs are obligate residents on this specific colony.

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