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Toxics, Volume 2, Issue 2 (June 2014), Pages 92-363

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Research

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Open AccessArticle Exposure to BPA in Children—Media-Based and Biomonitoring-Based Approaches
Toxics 2014, 2(2), 134-157; doi:10.3390/toxics2020134
Received: 25 February 2014 / Revised: 27 March 2014 / Accepted: 3 April 2014 / Published: 17 April 2014
Cited by 2 | PDF Full-text (940 KB) | HTML Full-text | XML Full-text
Abstract
Bisphenol A (BPA) is used in numerous industrial and consumer product applications resulting in ubiquitous exposure. Children’s exposure is of particular concern because of evidence of developmental effects. Childhood exposure is estimated for different age groups in two ways. The “forward” approach uses
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Bisphenol A (BPA) is used in numerous industrial and consumer product applications resulting in ubiquitous exposure. Children’s exposure is of particular concern because of evidence of developmental effects. Childhood exposure is estimated for different age groups in two ways. The “forward” approach uses information on BPA concentrations in food and other environmental media (air, water, etc.) combined with average contact rates for each medium. The “backward” approach relies on urinary biomonitoring, extrapolating backward to the intake which would have led to the observed biomarker level. The forward analysis shows that BPA intakes are dominated by canned food consumption, and that intakes are higher for younger ages. Mean intake estimates ranged from ~125 ng/kg-day for 1 year-olds to ~73 ng/kg-day among 16–20 years olds. Biomonitoring-based intakes show the same trend of lower intakes for older children, with an estimate of 121 (median) to 153 (mean) ng/kg-day for 2–6 years, compared with 33 (median) to 53–66 (mean) ng/kg-day for 16–20 years. Infant intakes were estimated to range from ~46 to 137 ng/kg-day. Recognizing uncertainties and limitations, this analysis suggests that the “forward” and “backward” methods provide comparable results and identify canned foods as a potentially important source of BPA exposure for children. Full article
Open AccessArticle Association of Human Mortality with Air Pollution of Hong Kong
Toxics 2014, 2(2), 158-164; doi:10.3390/toxics2020158
Received: 11 February 2014 / Revised: 30 April 2014 / Accepted: 4 May 2014 / Published: 9 May 2014
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Abstract
In this study, we attempted to investigate the general statistical association of air pollution with the cardiovascular and respiratory mortality of the elderly in Hong Kong. Based on six years of measurements including the major air pollutant concentrations (PM10, SO2
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In this study, we attempted to investigate the general statistical association of air pollution with the cardiovascular and respiratory mortality of the elderly in Hong Kong. Based on six years of measurements including the major air pollutant concentrations (PM10, SO2, NO, NO2, O3, CO), ambient temperature, and mortality (respiratory, cardiovascular) between 2005 and 2010, correlation analysis was carried out in annual, monthly and weekly time scales. From an annual perspective, it was found that the air pollution species may pose a constant effect on the respiratory and the cardiovascular mortality during the studied period since the elderly mortality rates and the air pollution annual concentrations show obvious constant trends. From a monthly time scale, it was found that NO2 and CO have high positive cross correlation with the respiratory mortality of the following 1 to 2 months. In addition, PM10 and CO also have similar delayed influence on the cardiovascular mortality. Among these four pollutants, only CO was found to exhibit high statistical association in the weekly time scale and it is most related to the cardiovascular mortality of the week after next. Therefore, it was concluded that the effect of air pollution on the elderly mortality of Hong Kong should be cumulative. This study implies that the establishment of weekly or monthly air quality indices is necessary for health implications. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
Open AccessArticle Human and Veterinary Antibiotics Used in Portugal—A Ranking for Ecosurveillance
Toxics 2014, 2(2), 188-225; doi:10.3390/toxics2020188
Received: 5 March 2014 / Revised: 23 April 2014 / Accepted: 13 May 2014 / Published: 23 May 2014
Cited by 6 | PDF Full-text (779 KB) | HTML Full-text | XML Full-text
Abstract
Antibiotics represent a pharmacotherapeutic group widely used in both human and veterinary medicine for which ecosurveillance has been continually recommended. It is urgent to rank the antibiotics and highlight those that may pose potential risk to the environment, a key step for the
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Antibiotics represent a pharmacotherapeutic group widely used in both human and veterinary medicine for which ecosurveillance has been continually recommended. It is urgent to rank the antibiotics and highlight those that may pose potential risk to the environment, a key step for the risk management. The absence of this type of contributions applied to the Portuguese reality supported the idea of compiling the data presented herein. With such purpose the most recent and representative data is used to draw a comparative contribution of each antimicrobial classes according to their intended use, i.e., in human versus veterinary medicine. The aim was to assess: (1) the amount and patterns of antimicrobials usage between human and animals; (2) the qualitative comparison between the antimicrobial classes used in each practice (human and veterinary) or specific use; (3) the potential to enter the environment, metabolism, mode of action and environmental occurrences. This manuscript will, thus, identify priorities for the environmental risk assessment, considering the ranking of the antimicrobials by their usage and potential environmental exposure. Ultimately, this study will serve as a basis for future monitoring programs, guiding the policy of regulatory agencies. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
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Open AccessArticle Effects of Lead and Cadmium on Brain Endothelial Cell Survival, Monolayer Permeability, and Crucial Oxidative Stress Markers in an in Vitro Model of the Blood-Brain Barrier
Toxics 2014, 2(2), 258-275; doi:10.3390/toxics2020258
Received: 2 April 2014 / Revised: 26 May 2014 / Accepted: 29 May 2014 / Published: 5 June 2014
Cited by 4 | PDF Full-text (706 KB) | HTML Full-text | XML Full-text
Abstract
Oxidative stress, which is the loss of balance between antioxidant defense and oxidant production in the cells, is implicated in the molecular mechanism of heavy metal-induced neurotoxicity. Given the key role of lead (Pb) and cadmium (Cd) in inducing oxidative stress, we investigated
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Oxidative stress, which is the loss of balance between antioxidant defense and oxidant production in the cells, is implicated in the molecular mechanism of heavy metal-induced neurotoxicity. Given the key role of lead (Pb) and cadmium (Cd) in inducing oxidative stress, we investigated their role in disrupting the integrity and function of immortalized human brain microvascular endothelial cells (hCMEC/D3). To study this, hCMEC/D3 cells were exposed to control media or to media containing different concentrations of Pb or Cd. Those exposed to Pb or Cd showed significantly higher oxidative stress than the untreated group, as indicated by cell viability, reactive oxygen species (ROS), glutathione (GSH) levels, and catalase enzyme activity. Pb also induced oxidative stress-related disruption of the hCMEC/D3 cell monolayer, as measured by trans-endothelial electrical resistance (TEER), the dextran permeability assay, and the level of tight junction protein, zona occluden protein (ZO-2). However, no significant disruption in the integrity of the endothelial monolayer was seen with cadmium at the concentrations used. Taken together, these results show that Pb and Cd induce cell death and dysfunction in hCMEC/D3 cells and, in the case of Pb, barrier disruption. This suggests blood brain barrier (BBB) dysfunction as a contributing mechanism in Pb and Cd neurotoxicities. Full article
(This article belongs to the collection Heavy Metals Toxicology)
Open AccessArticle Water-Air Volatilization Factors to Determine Volatile Organic Compound (VOC) Reference Levels in Water
Toxics 2014, 2(2), 276-290; doi:10.3390/toxics2020276
Received: 3 April 2014 / Revised: 30 May 2014 / Accepted: 3 June 2014 / Published: 11 June 2014
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Abstract
The goal of this work is the modeling and calculation of volatilization factors (VFs) from water to air for volatile organic compounds (VOCs) in order to perform human health risk-based reference levels (RLs) for the safe use of water. The VF models have
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The goal of this work is the modeling and calculation of volatilization factors (VFs) from water to air for volatile organic compounds (VOCs) in order to perform human health risk-based reference levels (RLs) for the safe use of water. The VF models have been developed starting from the overall mass-transfer coefficients (Koverall) concept from air to water for two interaction geometries (flat surface and spherical droplets) in indoor and outdoor scenarios. For a case study with five groups of risk scenarios and thirty VOCs, theoretical VFs have been calculated by using the developed models. Results showed that Koverall values for flat and spherical surface geometries were close to the mass transfer coefficient for water (KL) when Henry’s law constant (KH) was high. In the case of spherical drop geometry, the fraction of volatilization (fV) was asymptotical when increasing KH with fV values also limited due to Koverall. VFs for flat surfaces were calculated from the emission flux of VOCs, and results showed values close to 1000KH for the most conservative indoor scenarios and almost constant values for outdoor scenarios. VFs for spherical geometry in indoor scenarios followed also constant VFs and were far from 1000KH. The highest calculated VF values corresponded to the E2A, E2B, E3A and E5A scenarios and were compared with experimental and real results in order to check the goodness of flat and sphere geometry models. Results showed an overestimation of calculated values for the E2A and E2B scenarios and an underestimation for the E3A and E5A scenarios. In both cases, most of the calculated VFs were from 0.1- to 10-times higher than experimental/real values. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
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Open AccessArticle Using Statistical and Probabilistic Methods to Evaluate Health Risk Assessment: A Case Study
Toxics 2014, 2(2), 291-306; doi:10.3390/toxics2020291
Received: 4 March 2014 / Revised: 22 April 2014 / Accepted: 8 May 2014 / Published: 11 June 2014
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Abstract
The toxic chemical and heavy metals within wastewater can cause serious adverse impacts on human health. Health risk assessment (HRA) is an effective tool for supporting decision-making and corrective actions in water quality management. HRA can also help people understand the water quality
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The toxic chemical and heavy metals within wastewater can cause serious adverse impacts on human health. Health risk assessment (HRA) is an effective tool for supporting decision-making and corrective actions in water quality management. HRA can also help people understand the water quality and quantify the adverse effects of pollutants on human health. Due to the imprecision of data, measurement error and limited available information, uncertainty is inevitable in the HRA process. The purpose of this study is to integrate statistical and probabilistic methods to deal with censored and limited numbers of input data to improve the reliability of the non-cancer HRA of dermal contact exposure to contaminated river water by considering uncertainty. A case study in the Kelligrews River in St. John’s, Canada, was conducted to demonstrate the feasibility and capacity of the proposed approach. Five heavy metals were selected to evaluate the risk level, including arsenic, molybdenum, zinc, uranium and manganese. The results showed that the probability of the total hazard index of dermal exposure exceeding 1 is very low, and there is no obvious evidence of risk in the study area. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
Open AccessArticle Comparison of Selected Methods for Individual Decontamination of Chemical Warfare Agents
Toxics 2014, 2(2), 307-326; doi:10.3390/toxics2020307
Received: 25 March 2014 / Revised: 20 May 2014 / Accepted: 3 June 2014 / Published: 13 June 2014
Cited by 1 | PDF Full-text (1039 KB) | HTML Full-text | XML Full-text
Abstract
This study addresses the individual decontamination of chemical warfare agents (CWA) and other hazardous substances. The individual decontamination applies to contaminated body surfaces, protective clothing and objects immediately after contamination, performed individually or by mutual assistance using prescribed or improvised devices. The article
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This study addresses the individual decontamination of chemical warfare agents (CWA) and other hazardous substances. The individual decontamination applies to contaminated body surfaces, protective clothing and objects immediately after contamination, performed individually or by mutual assistance using prescribed or improvised devices. The article evaluates the importance of individual decontamination, security level for Fire and Rescue Service Units of the Czech Republic (FRS CR) and demonstrates some of the devices. The decontamination efficiency of selected methods (sorbent, glove and sponge, two-chamber foam device and wiping with alcohol) was evaluated for protective clothing and painted steel plate contaminated with O-ethyl-S-(diisopropylaminoethyl)-methylthiophosphonate (VX), sulfur mustard, o-cresol and acrylonitrile. The methods were assessed from an economic point of view and with regard to specific user parameters, such as the decontamination of surfaces or materials with poor accessibility and vertical surfaces, the need for a water rinse as well as toxic waste and its disposal. Full article
Open AccessArticle Environmental Risk Communication through Qualitative Risk Assessment
Toxics 2014, 2(2), 346-363; doi:10.3390/toxics2020346
Received: 21 February 2014 / Revised: 13 May 2014 / Accepted: 29 May 2014 / Published: 19 June 2014
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Abstract
Environmental analysts are often hampered in communicating the risks of environmental contaminants due to the myriad of regulatory requirements that are applicable. The use of a qualitative, risk-based control banding strategy for assessment and control of potential environmental contaminants provides a standardized approach
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Environmental analysts are often hampered in communicating the risks of environmental contaminants due to the myriad of regulatory requirements that are applicable. The use of a qualitative, risk-based control banding strategy for assessment and control of potential environmental contaminants provides a standardized approach to improve risk communication. Presented is a model that provides an effective means for determining standardized responses and controls for common environmental issues based on the level of risk. The model is designed for integration within an occupational health and safety management system to provide a multidisciplinary environmental and occupational risk management approach. This environmental model, which utilizes multidisciplinary control banding strategies for delineating risk, complements the existing Risk Level Based Management System, a proven method in a highly regulated facility for occupational health and safety. A simplified environmental risk matrix is presented that is stratified over four risk levels. Examples of qualitative environmental control banding strategies are presented as they apply to United States regulations for construction, research activities, facility maintenance, and spill remediation that affect air, water, soil, and waste disposal. This approach offers a standardized risk communication language for multidisciplinary issues that will improve communications within and between environmental health and safety professionals, workers, and management. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)

Review

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Open AccessReview Assessment of Health Risk in Human Populations Due to Chlorpyrifos
Toxics 2014, 2(2), 92-114; doi:10.3390/toxics2020092
Received: 20 November 2013 / Revised: 28 January 2014 / Accepted: 18 March 2014 / Published: 3 April 2014
Cited by 2 | PDF Full-text (1177 KB) | HTML Full-text | XML Full-text
Abstract
A wide ranging survey was carried out of the available data from ten different countries on human exposure to chlorpyrifos, in many different occupational and nonoccupational settings. Low levels of chlorpyrifos residues were found to be widely distributed in the global human population,
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A wide ranging survey was carried out of the available data from ten different countries on human exposure to chlorpyrifos, in many different occupational and nonoccupational settings. Low levels of chlorpyrifos residues were found to be widely distributed in the global human population, but most of these do not constitute a public health risk, as evaluated using the U.S. Environmental Protection Agency (USEPA) Guidelines. For example, the general populations in USA, Germany and Italy had detectable residue levels well below the guidelines. However, high levels of health risk were apparent in a specific group of pregnant mothers in the USA, at median exposure with a HQ0.50 of 26.6, suggesting that most of this population group was affected. Also the high exposure group (5% most exposed) with occupationally exposed manufacturing workers in the USA had a HQ0.95 of 2.6 to 42.0, and pest control applicators in Australia and the USA both had a HQ0.95 of 5.2. Some farmers in Sri Lanka and Vietnam had a high level of risk after spraying applications, having a HQ0.95 of 2.2 and 19.5 respectively at the high exposure level. These results suggest that there is a possibility of adverse health effects in specific population groups in many different settings throughout the world. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
Open AccessReview Evaluation of Glycol Ether as an Alternative to Perchloroethylene in Dry Cleaning
Toxics 2014, 2(2), 115-133; doi:10.3390/toxics2020115
Received: 3 January 2014 / Revised: 25 February 2014 / Accepted: 18 March 2014 / Published: 3 April 2014
Cited by 1 | PDF Full-text (542 KB) | HTML Full-text | XML Full-text
Abstract
Perchloroethylene (PCE) is a highly utilized solvent in the dry cleaning industry because of its cleaning effectiveness and relatively low cost to consumers. According to the 2006 U.S. Census, approximately 28,000 dry cleaning operations used PCE as their principal cleaning agent. Widespread use
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Perchloroethylene (PCE) is a highly utilized solvent in the dry cleaning industry because of its cleaning effectiveness and relatively low cost to consumers. According to the 2006 U.S. Census, approximately 28,000 dry cleaning operations used PCE as their principal cleaning agent. Widespread use of PCE is problematic because of its adverse impacts on human health and environmental quality. As PCE use is curtailed, effective alternatives must be analyzed for their toxicity and impacts to human health and the environment. Potential alternatives to PCE in dry cleaning include dipropylene glycol n-butyl ether (DPnB) and dipropylene glycol tert-butyl ether (DPtB), both promising to pose a relatively smaller risk. To evaluate these two alternatives to PCE, we established and scored performance criteria, including chemical toxicity, employee and customer exposure levels, impacts on the general population, costs of each system, and cleaning efficacy. The scores received for PCE were 5, 5, 3, 5, 3, and 3, respectively, and DPnB and DPtB scored 3, 1, 2, 2, 4, and 4, respectively. An aggregate sum of the performance criteria yielded a favorably low score of “16” for both DPnB and DPtB compared to “24” for PCE. We conclude that DPnB and DPtB are preferable dry cleaning agents, exhibiting reduced human toxicity and a lesser adverse impact on human health and the environment compared to PCE, with comparable capital investments, and moderately higher annual operating costs. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
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Open AccessReview Delayed Behavioral Effects of Early Life Toxicant Exposures in Aquatic Biota
Toxics 2014, 2(2), 165-187; doi:10.3390/toxics2020165
Received: 24 February 2014 / Revised: 12 May 2014 / Accepted: 13 May 2014 / Published: 20 May 2014
Cited by 9 | PDF Full-text (632 KB) | HTML Full-text | XML Full-text
Abstract
Behavioral development occurs together with the development of the nervous system. Studies on mammals indicate that exposures to some chemicals during embryonic development at concentrations that do not produce anatomical malformations may nevertheless produce behavioral deficits later in life, an example of delayed
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Behavioral development occurs together with the development of the nervous system. Studies on mammals indicate that exposures to some chemicals during embryonic development at concentrations that do not produce anatomical malformations may nevertheless produce behavioral deficits later in life, an example of delayed effects. There have been reports of delayed effects in aquatic organisms. Delayed behavioral effects of mercury, chlorinated and other pesticides, polycyclic aromatic hydrocarbons (PAHs), and some synthetic hormones in the environment have been reported in fishes and invertebrates; in some cases behavioral effects are manifested years after the exposure. Another type of delayed behavioral effect results from exposure of mature females before fertilization (maternal exposure). Even when embryos and larvae are reared in clean water, offspring may manifest abnormal behaviors following maternal exposure. The reported behavioral changes are generally deleterious and compromise the fitness of the animal in its natural environment. Delayed effects and their impacts on fitness are not considered in standard short-term embryo bioassays, which will therefore underestimate neurotoxicity. The literature in the field is scattered and has not been reviewed. The objective of this paper is to review and synthesize what is known about delayed behavioral effects in aquatic biota. Full article
(This article belongs to the Special Issue Developmental Neurotoxicology)
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Open AccessReview Overview of the Current State-of-the-Art for Bioaccumulation Models in Marine Mammals
Toxics 2014, 2(2), 226-246; doi:10.3390/toxics2020226
Received: 16 April 2014 / Revised: 19 May 2014 / Accepted: 20 May 2014 / Published: 27 May 2014
Cited by 1 | PDF Full-text (486 KB) | HTML Full-text | XML Full-text
Abstract
Information regarding the (toxico)kinetics of a chemical in organisms can be integrated in mathematical equations thereby creating bioaccumulation models. Such models can reconstruct previous exposure scenarios, provide a framework for current exposures and predict future situations. As such, they are gaining in popularity
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Information regarding the (toxico)kinetics of a chemical in organisms can be integrated in mathematical equations thereby creating bioaccumulation models. Such models can reconstruct previous exposure scenarios, provide a framework for current exposures and predict future situations. As such, they are gaining in popularity for risk assessment purposes. Since marine mammals are protected, the modeling process is different and more difficult to complete than for typical model organisms, such as rodents. This review will therefore discuss the currently available models for marine mammals, address statistical issues and knowledge gaps, highlight future perspectives and provide general do’s and don’ts. Full article
(This article belongs to the Special Issue Risk Assessment of Environmental Contaminants)
Open AccessReview The Equipment of Czech Firefighters for the Detection and Field Analyses of Chemical Warfare Agents
Toxics 2014, 2(2), 247-257; doi:10.3390/toxics2020247
Received: 25 March 2014 / Revised: 19 May 2014 / Accepted: 26 May 2014 / Published: 30 May 2014
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Abstract
This paper describes the requirements for the devices of detection, chemical reconnaissance and field analyses of chemical warfare agents (CWA) and divides them into simple devices of detection, universal detectors, selective analyzers, multi-component analyzers and mobile laboratories. It also describes the devices of
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This paper describes the requirements for the devices of detection, chemical reconnaissance and field analyses of chemical warfare agents (CWA) and divides them into simple devices of detection, universal detectors, selective analyzers, multi-component analyzers and mobile laboratories. It also describes the devices of detection available within the Fire and Rescue Service of the Czech Republic (FRS CR) and compares them with some prospective trends of further development. Full article
Open AccessReview Abnormal Copper Homeostasis: Mechanisms and Roles in Neurodegeneration
Toxics 2014, 2(2), 327-345; doi:10.3390/toxics2020327
Received: 6 May 2014 / Revised: 4 June 2014 / Accepted: 5 June 2014 / Published: 18 June 2014
Cited by 4 | PDF Full-text (975 KB) | HTML Full-text | XML Full-text
Abstract
As a cofactor of proteins and enzymes involved in critical molecular pathways in mammals and low eukaryotes, copper is a transition metal essential for life. The intra-cellular and extra-cellular metabolism of copper is under tight control, in order to maintain free copper concentrations
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As a cofactor of proteins and enzymes involved in critical molecular pathways in mammals and low eukaryotes, copper is a transition metal essential for life. The intra-cellular and extra-cellular metabolism of copper is under tight control, in order to maintain free copper concentrations at very low levels. Copper is a critical element for major neuronal functions, and the central nervous system is a major target of disorders of copper metabolism. Both the accumulation of copper and copper deficiency are associated with brain dysfunction. The redox capacities of free copper, its ability to trigger the production of reactive oxygen species and the close relationships with the regulation of iron and zinc are remarkable features. Major advances in our understanding of the relationships between copper, neuronal functions and neurodegeneration have occurred these last two decades. The metabolism of copper and the current knowledge on the consequences of copper dysregulation on brain disorders are reviewed, with a focus on neurodegenerative diseases, such as Wilson’s disease, Alzheimer’s disease and Parkinson’s disease. In vitro studies, in vivo experiments and evidence from clinical observations of the neurotoxic effects of copper provide the basis for future therapies targeting copper homeostasis. Full article
(This article belongs to the collection Heavy Metals Toxicology)

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