Search results for "PCB"

Toxicological Profile of Ultrapure 2,2´,3,4,4´,5,5´-Heptachlorbiphenyl (PCB 180) in Adult Rats

2014

PCB 180 is a persistent non-dioxin-like polychlorinated biphenyl (NDL-PCB) abundantly present in food and the environment. Risk characterization of NDL-PCBs is confounded by the presence of highly potent dioxin-like impurities. We used ultrapure PCB 180 to characterize its toxicity profile in a 28-day repeat dose toxicity study in young adult rats extended to cover endocrine and behavioral effects. Using a loading dose/maintenance dose regimen, groups of 5 males and 5 females were given total doses of 0, 3, 10, 30, 100, 300, 1000 or 1700 mg PCB 180/kg body weight by gavage. Dose-responses were analyzed using benchmark dose modeling based on dose and adipose tissue PCB concentrations. Body w…

Survey on the presence of non-dioxine-like PCBs (NDL-PCBs) in loggerhead turtles (Caretta caretta) stranded in south Mediterranean coasts (Sicily, So…

2017

A total of 71 loggerhead turtles (Caretta caretta) stranded along the coasts of Sicily (Southern Italy) were examined for non–dioxine like polychlorinated biphenyl (NDL-PCB) levels in muscle and adipose tissue by a gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) method. The results revealed 6 high-indicator congener (∑6PCBIND) levels in 45% of the loggerhead turtles examined, with mean values of 980.39 ± 2508.39 ng/g wet weight in adipose tissue and 102.53 ± 238.58 ng/g wet weight in muscle tissue. The hexachloro and heptachloro PCB congeners were the most abundant in both the sample types. The highest NDL-PCB levels were reached in an adipose tissue sample of a logg…

Prenatal exposure to PCB-153, p,p'-DDE and birth outcomes in 9000 mother-child pairs: exposure-response relationship and effect modifiers.

2014

Low-level exposure to polychlorinated biphenyl-153 (PCB-153) and dichlorodiphenyldichloroethylene (p-p′-DDE) can impair fetal growth; however, the exposure–response relationship and effect modifiers of such association are not well established. This study is an extension of an earlier European meta-analysis. Our aim was to explore exposure–response relationship between PCB-153 and p-p′-DDE and birth outcomes; to evaluate whether any no exposure–effect level and susceptible subgroups exist; and to assess the role of maternal gestational weight gain (GWG). We used a pooled dataset of 9377 mother–child pairs enrolled in 14 study populations from 11 European birth cohorts. General additive mode…

Theoretical Study of the Charge Transfer Exciton Binding Energy in Semiconductor Materials for Polymer:Fullerene-Based Bulk Heterojunction Solar Cells

2019

Recent efforts and progress in polymer solar cell research have boosted the photovoltaic efficiency of the technology. This efficiency depends not only on the device architecture but also on the material properties. Thus, insight into the design of novel semiconductor materials is vital for the advancement of the field. This paper looks from a theoretical viewpoint into two of the factors for the design of semiconductor materials with applications to bulk heterojunction solar cells: the charge transfer exciton binding energy and the nanoscale arrangement of donor and acceptor molecules in blend systems. Being aware that the exciton dissociation of local excitons in charge transfer states in…

Improved performance in flexible organic solar cells by using copolymeric phase-separation modulators

2018

One of the main problems related to the low performance of the organic solar cells (OSCs), concerns the low mobility of the materials constituting the heterojunction. Indeed, the poor charge transport in the active layer is the principal cause of a competition between separation and recombination of the photogenerated carriers. In this regard, a major obstacle to enhance OSCs efficiency is developing strategies to optimize the exciton dissociation and, consequently, the charge collection at the electrodes. Donor and acceptor systems must be well mixed on the length scale of 5 – 20 nm (exciton diffusion length) to meet the criteria for efficient exciton dissociation. In addition, the network…

Air concentrations of PCBs and OC pesticides using PUF-disks passive air samplers in Sicily Island, Mediterranean Region

2009

Persistent organic pollutants (POPs) are ubiquitous on the planet. Because their physicochemical properties they are persistent and toxic and may become highly accumulated in the food chain. The Stockholm Convention on POPs which is coordinated through the United Nations Environment Program (UNEP) is intended to reduce or eliminate the use, discharges and emissions of these compounds to improve the health of the environment. To assist member countries in assessing the “effectiveness” of their reduction efforts, UNEP Chemicals published a guidance document for the global monitoring of POPs. Of the media that are recommended for monitoring, the atmosphere is especially important because it re…

Changes in eggshell ultrastructure of Falco naumanni and Tyto alba exposed to pesticides and polychlorinated biphenyls (PCBs)

2014

Changes in the quality of eggs of birds exposed to environmental contaminants have been described, but few reports concern eggshell ultrastructure. In this study, infertile or addled Lesser Kestrels (Falco naumanni) and Barn owls (Tyto alba) eggs were collected from the polluted area of Gela plain (Sicily) during 2007, and compared in terms of organophosphate and organochlorine pesticides, and PCBs levels, and eggshell ultrastructure as determined by scanning electron microscopy. Pesticide and PCB residues in eggs were determined by Gas chromatography/ mass spectrometry (GC/MS) [GC Agilent 7890A/MS Agilent 5975C (Agilent technologies) using a DB-5 capillary column in the selected ion monito…

Reliable clinical assessment of stroke patients' postural control and development of physiotherapy in stroke rehabilitation

2007

The main goal of the long-standing clinical research project in the district of East-Savo was to develop an active role in physiotherapy for patients with stroke. A novel assessment instrument, the Postural Control and Balance for Stroke (PCBS) test, was developed side by side with the activating treatment. Present physiotherapy for stroke patients the emphasis is on the physiotherapist’s role, leaving no room for independent participation by the patient. In clinical work there are no systematically used methods either for the evaluation or follow-up of functional capacity, or for balance in stroke patients. This thesis includes reliability and validity studies of the Postural Control and B…

Study on the adsorption of PCBs in alginate Montmorillonite beads by GC-MS analysis

2013

Effect of solid waste landfill organic pollutants on groundwater in three areas of Sicily (Italy) characterized by different vulnerability

2017

The aim of this study was to obtain information on the presence and levels of hazardous organic pollutants in groundwater located close to solid waste landfills. Eighty-two environmental contaminants, including 16 polycyclic aromatic hydrocarbons (PAHs), 20 volatile organic compounds (VOCs), 29 polychlorinated biphenyls (PCBs), 7 dioxins (polychlorinated dibenzo-p-dioxins, PCDDs) and 10 furans (polychlorinated dibenzofurans, PCDFs) were monitored in areas characterised by different geological environments surrounding three municipal solid waste landfills (Palermo, Siculiana and Ragusa) in Sicily (Italy) in three sampling campaigns. The total concentrations of the 16 PAHs were always below t…