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The tripartite synapse or “neural threesome” refers to the interplay in the synapse between neighbouring neurons, the synaptic cleft, and the surrounding glial cells. Despite extensive research, the effects of glial cells, such as astrocytes, on signal transduction between neurons are not fully understood. The Kirchhoff-Nernst- Planck (KNP) and Extracellular-Membrane-Intracellular (EMI) models constitute a promising framework for modeling these kinds of systems. However, they lack the neurotransmitter-related mechanisms that are necessary to bridge signal transduction across the synaptic cleft. Here, we propose an extension to the KNP-EMI model by a spatio-temporal diffusion-based description of the most prominent neurotransmitter, glutamate, that allows for investigation of the contribution of astrocytes to the functionality of the synapse. We validate our model by showing that the presence of an astrocyte in the domain affects the glutamate flux across the postsynaptic terminal, as observed physiologically. The proposed extension offers a sufficiently simple way of integrating synaptic glutamate dynamics into the KNP-EMI framework. It introduces the relevant interactions between electrical activity and diffusion processes at the tripartite synapse that are necessary to assess how astrocytes might contribute to the functionality of the synapse. This work has implications for future studies involving glial mechanisms and other charged species within the KNP-EMI framework.

Lead in the environment remains a matter of grave concern for public health. Lead has been associated with some traditional medicines and has been linked to cases of lead poisoning. A comprehensive compilation of these reports has not previously been conducted. The objective of this review is to explore how common is lead exposure after traditional medicine use, and which countries, systems and/or products are of most concern when it comes to lead contamination. A systematic search was conducted on PubMed, Ovid and EMBASE for studies published between 2005 and 2020. A grey literature search was conducted. Search terms related to lead and traditional medicine were developed for each database, and there were no limitations on language. Studies were included if they examined elevated lead in humans resulting from the use of traditional medicines reported in case reports, case-series, or observational studies. Of the papers discussing lead exposure, 85 case reports were identified and synthesized for the current review. Several themes were identified in the included studies. Traditional medicine has been used in the many parts of the world, however use is more common in South and Southeast Asian countries. The level of detectable lead in products varied widely by region and product types. Consumers of traditional medicines sought products for a wide variety of symptoms and ailments. The symptoms of lead poisoning from traditional medicine use reflected the typical symptom profile of lead poisoning, highlighting the need for awareness of traditional medicine products as a source of lead exposure. Traditional medicine usage remains an important part of health care in many regions, however there is a risk of lead exposure from several products. Health care practitioners in all regions of the world should be aware of the risk and explore the potential for traditional medicine use for patients presenting with elevated blood lead levels. Countries with a strong traditional medicine culture should explore policies for reducing lead exposure from traditional medicine products. JG, LO and MNBD are staff members of the World Health Organization. The authors alone are responsible for the views expressed in this publication and they do not necessarily represent the decisions, policy, or views of the World Health Organization.

Lead (Pb) pollution and human exposure to Pb, is an important issue for the international community to address being associated with 0.90 million deaths from long-term effects. The Republic of Zambia is a typical mineral resource-rich country, with long-standing mining and smelting activities of metals including Pb in several parts of the country. This narrative review provides a comprehensive overview of previous papers that have assessed human exposure to Pb and related health effects in Zambia. Environmental remediation methods that should be applied locally, ways to reduce Pb exposure of the population, and issues that need to be addressed by various sectors are discussed. Environmental remediation methods using locally available and affordable materials are needed to ensure both sustainable industrial activities and pollution prevention. In the Zambian mining towns, including Kabwe, various research activities have been conducted, including environmental monitoring, human biomonitoring and health impact assessments. The town of Kabwe, which was one of Zambia's largest Pb mining area in the 20th century, continues to have formal and informal Pb-related industries and is known as one of the most polluted areas in the world. For example, despite the World Health Organization asserting that "For an individual with a blood Pb concentration ≥ 5 μg/dL, appropriate action should be taken to terminate exposure", there are reports of blood Pb levels in Kabwe children exceeding 100 μg/dL. While Pb pollution is a global issue, not many places have such continuous and comprehensive research has been conducted, and there is much to be learned from the knowledge accumulated in these areas. Because the high levels of Pb accumulation in humans and the adverse health effects were clarified, we consider that it is important to combine mining activities, which are a key industry, with measures to prevent environmental pollution.

Waste electronic and electrical equipment (e-waste) consists of used and discarded electrical and electronic items ranging from refrigerators to cell phones and printed circuit boards. It is frequently moved from developed countries to developing countries where it is dismantled for valuable metals in informal settings, resulting in significant human exposure to toxic substances. E-waste is a major concern in Africa, with large sites in Ghana and Nigeria where imported e-waste is dismantled under unsafe conditions. However, as in many developing countries, used electronic and electrical devices are imported in large quantities because they are in great demand and are less expensive than new ones. Many of these used products are irreparable and are discarded with other solid waste to local landfills. These items are then often scavenged for the purpose of extracting valuable metals by heating and burning, incubating in acids and other methods. These activities pose significant health risks to workers and residents in communities near recycling sites. E-waste burning and dismantling activities are frequently undertaken at e-waste sites, often in or near homes. As a result, children and people living in the surrounding areas are exposed, even if they are not directly involved in the recycling. While toxic substances are dangerous to individuals at any age, children are more vulnerable as they are going through important developmental processes, and some adverse health impacts may have long-term impacts. We review the e-waste situation in Africa with a focus on threats to children’s health.