Examination of PCDD/F Formation in Thermal Systems Using Simple Mathematical Models
Abstract
1746 13370
Examination of PCDD/F Formation in Thermal Systems Using Simple Mathematical ModelsAbstract
A set of empirical models which accounts for the formation of gas phase polychlorinated dibenzo-p-dioxins and furans (PCDD and PCDF), and solid phase PCDD/F by the de novo mechanism is described.In each case, competing formation and destruction reactions are considered to operate.The effect of the time-temperature history on their formation is then examined.At high temperatures, steady-state is reached in fractions of a second, resulting in the observed low product concentrations.Rapid cooling as found in furnaces [...] 1746 13370 |
Persistent Organic Pollutants in Urban Soils of Central London, England, UK: Measurement and Spatial Modelling of Black Carbon (BC), Petroleum Hydrocarbons (TPH), Polycyclic Aromatic Hydrocarbons (PAH) and Polychlorinated Biphenyls (PCB)by
Abstract
Total organic carbon (TOC), black carbon (BC), total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) were determined in 73 surface (0-2 cm) and subsurface (5-20 cm) soil samples taken from a 142 km2 area in Central London, UK. Soils were assessed to provide a baseline chemistry for site owners, developers, occupiers and regulators involved in understanding the potential risk to human health and the environment. TOC range was 1.75-11.85 % (mean 5.82 %), BC 3.7 [...] 2654 16193 |
Gender-Dependent Effects of Thimerosal on Human Progenitor Neurons: A Potential Link to Regressive AutismAbstract
Regressive Autism [RA] is a subtype of autism spectrum disorder (ASD) that manifests as the loss of previously acquired developmental milestones and skills. Early life dysregulation of neurodevelopment due to exposure to toxic metals has been associated with ASD, but the underlying biological mechanisms by which metals influence neurodevelopment remain unclear. We explored the potential role of thimerosal or ethylmercury on neurite formation and oxytocin receptor (OXTR) modulation in four human-developing neuronal [...] 1595 10492 |
Environmentally Persistent Free Radicals as Sources of POPsAbstract
Environmentally persistent free radicals (EPFRs) are a new class organic pollutant sharing some of the attributes of persistent organic pollutants (POPs). This opinion/short review aims to describe the properties of EPFRs that merit their recognition as an additional and potentially significant source of POPs. EPFRs are ubiquitous in diverse environments because of multiple factors: (1) organic precursors from anthropogenic, biogenic, and other natural emission sources are abundant; multiple mechanisms in PM and so [...] 2029 13353 |
Gender-Dependent Effects of Endocrine Disrupting Chemicals on Retinoic Acid-Related Orphan Receptor Alpha [RORA] and Aromatase Genes on Human Progenitor NeuronsAbstract
Normally we encounter a myriad of chemicals in our daily lives. Endocrine disrupting chemicals [EDCs] are ubiquitous in our environment and upon bodily entry many be stored in adipose tissue and, in pregnant woman, can reach the developing fetal brain, disrupting normal fetal brain development. EDC-induced aberrant levels of sex hormones can alter sexual dimorphism [i.e. degree of feminization or masculinization; sex differences in brain and behavior] and may contribute to the differential susceptibility of males a [...] 1504 10346 |
A Neural Network Evidence of the Nexus Among Air Pollution, Economic Growth, and COVID-19 Deaths in the Hubei Areaby
Abstract
In this study, we used an image neural network model to assess the relationship between economic growth, pollution (PM2.5, PM10, and CO2), and deaths from COVID-19 in the Hubei area (China). Data analysis, neural network analysis, and deep learning experiments were carried out to assess the relationship among COVID-19 deaths, air pollution, and economic growth in China (Hubei province, the epicenter of the COVID-19 pandemic). We collected daily data at a city level from January 20 to July 31, 2020. We used main cit [...] 1580 10741 |
Concentrations of Gaseous Elemental Mercury in the Atmosphere of a Mediterranean Coastal Site in GreeceAbstract
Gaseous elemental mercury (GEM) was monitored in the atmosphere of a coastal site situated in the Northern Aegean Sea of Greece from August 2014 to January 2015. The selected sampling site is seldom impacted by human activities. Thus, it was possible to study the processes involved in natural terrestrial, aquatic, and atmospheric environments. The diurnal and monthly variations in the concentration of GEM as well as the factors influencing these variations were determined. The GEM concentrations were found to be in [...] 1576 10725 |
Challenges in the PFAS Remediation of Soil and Landfill Leachate: A ReviewAbstract
The use of per-and poly-fluoroalkyl substances (PFAS) has resulted in the contamination of different environmental matrices. In EU countries, the sites contaminated with PFAS are usually remediated by excavating the soil and disposing of it in a landfill, as no in-situ or on-site techniques capable of treating large quantities of soil cost-effectively have been developed. Landfilling of PFAS-contaminated soil is one of the sources of PFAS in landfill leachate. In this paper, the physical and chemical treatment meth [...] 5163 38700 |
Initial Validation of a Replicated Field-scale Denitrifying Bioreactor Facility in a Boreal EnvironmentAbstract
Denitrifying bioreactor technology, where a solid carbon source (woodchips) acts as a reactive medium to intercept agricultural tile drainage water, has been successfully used to convert N (NO3-) to di-nitrogen (N2) gas. Four replicated field-scale (24 m long × 3 m wide × 1 m deep), bioreactors were built and operated at the St. John's Research and Development Centre and were successful at removing a notable amount of nitrate (N) from agricultural subsurface drainage water. The objective of this study [...] 1540 10006 |
Evolution of Radar and Lightning Variables in Convective Events in Barcelona and Surroundings for the Period 2006–2020by
Abstract
The Metropolitan Area of Barcelona is a densely populated region in the North-East of the Iberian Peninsula. Infrastructures in this area play a significant role in the economy of this part of Europe. The combination of the Mediterranean Sea and the complex topography is responsible for the occurrence of severe weather events in this location and the surrounding areas. The use of remote sensing data in an hourly resolution allows the identification and characterization of those severe episodes, helping in determini [...] 1683 10739 |
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