Mercury Toxicity

Environmental mercury (Hg) exposure is still a significant problem with many facets that have serious effects on ecosystems and human health. This chapter explores the complex problem of Hg exposure, looking at its numerous mechanisms, historical context, and toxicological ramifications. Mercury exposure pathways for plants, animals, and humans are extensively investigated to shed insight on how this deadly metal might enter and affect living creatures. The historical viewpoint reveals key occurrences of Hg poisoning and their effects on public consciousness, illuminating the progression of Hg use from ancient civilizations to the current era. The conversion of Hg into methylmercury, its impact on plants, animals, and humans, and its ecological effects on wildlife and aquatic ecosystems are highlighted in the section on toxicological implications. At-risk populations include vulnerable populations like newborns, pregnant people, and indigenous tribes. The chapter also covers the difficulties in monitoring and mitigation efforts due to the permanence of Hg, its global sources, and biomagnification. The section on the regulatory framework and guidelines evaluates national and international rules and agreements aimed at reducing Hg pollution, but it also recognizes the difficulties in their implementation and enforcement. The use of emission controls, the reduction of product Hg, and secure waste disposal are all considered mitigation and remedial measures. The chapter finishes by providing perspectives on the outlook for the future and recommendations, highlighting the necessity for ongoing research, public education, and international cooperation to successfully address the ongoing challenge of environmental Hg exposure.

Mercury (Hg) contamination of food is one of the global threats to human health, as food is the most significant Hg exposure pathway for humans. The pervasive problem of Hg contamination in our food supply chain deserves a thorough investigation of its sources, pathways, health dangers, and legislative options. The numerous aspects of Hg contamination in our foods are thoroughly explored in this chapter. Mercury enters the food from various sources, and the chapter reveals the complex routes by which Hg gets into a variety of food products through a comprehensive investigation of both natural and man-made sources, highlighting the significance of understanding these entry points. In addition, in-depth food classifications based on Hg concentration are also provided, including those for processed foods, meats, seafood, terrestrial produce, and nutritional supplements. The chapter helps readers make informed dietary decisions, which is important in particular for vulnerable populations by eliminating items with high Hg content. In tandem with risk assessment, the chapter underscores the importance of monitoring and regulation in mitigating Hg-related hazards. It delves into regulatory frameworks designed to manage and curb Hg contamination, emphasizing the need for consistent surveillance and compliance. As Hg contamination continues to pose a global challenge, this chapter serves as an indispensable resource for readers to unravel the complexities of the presence of Hg in our food and proactively addressing the associated risks.

Mercury contamination of water resources is a growing environmental concern due to its detrimental and bioaccumulative effects on ecosystems and human health. The present assessment highlights the comprehensive bibliometric review of research trends concerning mercury contamination in water resources. The study carried out by analyzing a vast array of scientific literature with an aim to identify key research themes, prominent authors, highly cited publications, and other emerging trends in the field. The bibliometric analysis methodology involves data mining from the robust Web of Science database and applying relevant metrics. The study revealed a substantial increase in research output on mercury contamination in water resources over the past few decades highlighting significant global research recognition on mercury contamination of water resources. Moreover, the highly cited publications in this area indicate seminal studies that have shaped the understanding of mercury contamination water resources. These publications have facilitated foundation for subsequent research and have influenced policy-making and decisions makers in addressing mercury pollution. This study provides a comprehensive overview of the research landscape on mercury contamination in water resources, offering valuable insights into the existing knowledge gaps and future directions for addressing this critical environmental issue.

Mercury, which has been used since ancient times can also cause severe threats to human health and the environment. It exists in various forms (like metallic, inorganic, and organic), and each carries its own health burden. Its ability to be transported long distances is an environmental threat that can affect far-away ecosystems and wildlife. Notable mercury-related incidents such as Minamata, Iraq, Grassy Narrows, Kodaikanal, and others shook the world. In addition, its widespread industrial use poses a high risk of exposure. Major threats posed in healthcare are artisanal and small-scale gold mining (ASGM), scientific applications, and electrical industries. Mercury enters the human body both through inhalation and/or ingestion, inducing a range of detrimental cellular changes. It binds with the sulfhydryl and selenohydryl groups on albumin present in the plasma, disrupting receptors, and intracellular signals. It induces the production of free radicals and alters cellular redox potential. Additionally, it can disrupt cellular signaling pathways, involved in cell growth, differentiation, and apoptosis. Its permeability across the blood–brain barrier makes it severely neurotoxic, especially CH₃-Hg (methylation mainly caused by microbes) binds to thiol-containing molecules like cysteine to form CH₃-Hg-Cys and readily crosses the blood–brain barrier, damages the cerebellum and visual cortex. Mercury can induce post-translational changes affecting protein biosynthesis. Besides, the digestive, respiratory, muscular, and renal systems are also affected. Mercury produces oxidative stress, triggers autoimmunity and damages DNA, mitochondria, and lipid membranes. Its disposition in the CNS suggests its potential role in the pathogenesis of multiple sclerosis, Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and glial tumors. Several methods for controlling mercury pollution exist but the use of nano-adsorbents and bioremediation are most common. As a holistic approach, phasing out mercury use, replacing it with suitable substitutes, proper waste disposal, continuous monitoring and evaluation, and enforcing strict legislation seems to be a practical option. WHO and the national governments have provided the restrictions and permissible limits for mercury use. Worth mentioning is the implementation of the Minamata Convention to control and reduce global mercury emissions and releases.

Mercury is a highly hazardous heavy metal that has no recognised biological use in the human body. It exists in three forms viz. Elemental mercury, Organic mercury and Inorganic mercury. All these three forms have been proven to have hazardous impact on living community. It has the capacity to accumulate in the various tissues of body and increases its concentration when moves up from lower to higher trophic level. Living beings are potentially in danger due to the development of industrial technology, the widespread and uncontrolled use of synthetic chemicals like herbicides, fertilisers, insecticides and fungicides, as well as industrial effluents. Coal-fired thermal power plants serve as the principal source of mercury poisoning fall to the ground from the air and then wash into a water body. Organisms of aquatic biota are easily exposed to and ingest mercury deposits in the tissues especially in gonads, liver, kidney and gills. Long-term mercury exposure damages the nervous system and causes tremors, spasms and memory loss, hallucinations, severe sadness, and increased excitability, delirium and personality alterations. Alterations in the histopathology and cytology are the initial indications of stress upon mercury toxicity. Several histological aberrations have been observed on the cellular level. The current study provides an understanding of the systematic adverse effects of mercury content on the neurological and cytological features of plants, animals and humans. Additionally, it highlights the significance of cytology and neurology as a tool for a more accurate assessment of mercury in toxicity control programmes. The molecular mechanism behind the toxico-kinetics of mercuric toxicity in living organisms requires more investigation in order to develop detoxifying techniques that will enhance general health.

Mercury (Hg) is a grave environmental pollutant that poses a major global threat to human life. It is one of the ten “chemicals of concern” according to the World Health Organisation. Protection of the environment and human health from the releases of mercury and its compounds by anthropogenic activities is key for the sustainability of the biosphere. The Minamata Convention on mercury for ensuring sustainable production and consumption patterns is a significant component of achieving Sustainable Development Goal 12 (SDG 12). An adsorption technique biochar has been applied to remove Hg from polluted and wastewaters using biochar produced from different biowastes. Mercury pollution in water is associated with toxicity to the environment and living organisms. This book chapter critically evaluates the chemical behaviour of mercury, environmental occurrence and sources, mechanism, and toxicity. The chapter also examines the application of biowaste biochar techniques for mercury removal via adsorption, factors influencing mercury adsorption, the role of biochar in Hg remediation technologies, water treatment technologies, innovative approaches for the treatment of mercury, regeneration and economic challenges of biowaste-derived adsorbents, management of post-adsorption materials, green economy framework, and challenges and future research directions. A significant aspect of the book chapter is on the use of biowaste biochar (green chemistry approach) to transform mercury and its compounds into less hazardous forms. With a green technological approach using biowaste biochar can transform mercury and its compounds into less hazardous forms to guarantee mercury absence in the environment and water systems.

The prevalence of heavy metals in bodies of water is connected to an increase in the quantity of industry and people. This has major implications for the well-being of humans and the environment. Because of the exceptionally toxic nature of mercury, mercury pollution is one of the major environmental challenges. This book chapter discusses the adsorptive properties of various components of biomass for the elimination of ions of heavy metals from an aqueous medium. There are many functional groups present in the biomass. The pollutant absorption capacity of biomass changes due to the ionization of functional groups with pH variation, based on the type of adsorbate and adsorbent. Because of the availability of a high number of exposed active sites, small particle size provides a large surface area for the adsorption of contaminants from the aqueous medium, whereas temperature variation modifies the thermal characteristics of biomass as well as their adsorption capacity. This article examines current developments in the creation of an environmentally acceptable and economically feasible method for treating wastewater from the textile industry utilizing absorbents made from algal biomass. The method used microalgal biochar to biosorb away heavy metals and organic contaminants (dyes) from textile effluents. This review shows light on the process of removal of mercuric ions from wastewater using different types of biomass. Also, it focuses on the challenges faced during good adsorptive removal of heavy metals.

Mercury (Hg) jeopardizes ecological balance and public health globally owing to its cytotoxicity, indegradability, coexistence in different chemical forms, uneven distribution, mobility, and long-lasting in the atmosphere. Therefore, the endeavors for feasible, economic, systematic, easily available, and sustainable approaches can be customized, which are conclusively enduring. Bioremediation, particularly microbial remediation means, as a greener and cheaper strategy has piqued the interest of biotechnologists and ecologists to mitigate Hg risk. By the virtue of versatile physiological performance, microorganism either prokaryotic or eukaryotic in planktonic or in the sessile-biofilm state, solitary or in consortium, indigenously occurred or intendedly introduced as GMO under aerobic or anaerobic circumstances and even extremophiles, have the ability to detoxify Hg and transform its phase to less-toxic valence through various metabolic scenarios like biosorption, bioprecipitation, bioleaching, bioaccumulation, and biovolatilization. Importantly, all previous mechanisms were catalyzed by different enzymatic systems including mercuric reductase and organomercurial lyase. However, their recruitment in in situ or ex situ technologies also implemented sensibly. Interestingly, the combined remediation technology boosted microbial-remediating efficiency and potentiality, especially upon hybridizing microbes with novel biosorbents such as carbon-based material, polymer, and nanoparticles. All preceding aspects were addressed in detail inclusively in this chapter to compensate the gap among knowledge, lab-scale practice, and field-scale application for alleviating Hg-toxicity.

The potential toxicity of environmental mercury in various environmental spheres is well documented. The environment faces the problem of bioaccumulated mercury as a result of anthropogenic activity. Numerous removal/remediation methods, including modern developments, have been covered in this article. Mercury moves around in the environment and enters the food chain, having an impact on the biota of many different ecosystems as well as human health. One of the main factors that affect our environment and cause concern is the MeHg generation. In the current article, the redox chemistry of environmental mercury is also covered because it sheds light on bioavailability and enhances remedial measures for mercury pollution. Significant advancements in the ability to access mercury pollution have been developed over time. Numerous remediation techniques, including soil washing, membrane filtration, phytoremediation, and bacterial remediation, have been suggested based on the environmental cycling and interactions at various layers of ecosystems. Additionally, graphene-based membranes’ contribution to mercury remediation has also been listed.

Mercury is considered one of the toxic pollutants that are present in the environment through natural or anthropogenic additions. Mercury in elemental, inorganic, and organic forms poses a serious risk to the environment and living organisms. The increase in mercury concentration due to the cyclic movement through soil–air–water interactions for several years results in poisoning depending on its chemical form and exposure. Apart from inorganic mercury, methylmercury is quite toxic as it accumulates in the food chain through biomagnification, which later causes health hazards. Biochar is a carbonaceous material that is produced due to the thermal dissociation of plant and animal material under a low oxygen supply. Recent studies have mostly focused on the extensive application of biochar as a soil ameliorant, adsorbent, and many other applications. However, Hg-contaminated soils and their remediation were studied well, but the sediment and aqueous solution studies were limited. This chapter brings out detailed information about biochar preparation and its physicochemical and biological characteristics. The different mechanisms of biochar preparation for mercury remediation have been clearly discussed. It has also highlighted the modifications of biochar for better mercury remediation. Finally, we have discussed reusing and recycling biochar after mercury reclamation.

With the global increase in urbanization and industrialization, the threat to natural ecosystems and biodiversity in the form of pollution is imminent. Universally, one of the major categories of pollutants that we face today is the presence of heavy metals in the environment. Mercury, in particular, is a highly toxic heavy metal capable of showcasing bioaccumulation, persistence, and biomagnification capabilities. It is also responsible for numerous health hazards in human beings and animals. To curb the problem of mercury poisoning in living organisms, several conventional remediation techniques have been tried and tested for the removal of mercury. Some of these conventional methods are not that accurate in remediating mercury, so using nano adsorbents can show a promising future. Nano-sized adsorbent materials have been widely studied in remediation procedures. Numerous studies in nanotechnology have revealed the effectiveness of nano adsorbents composed of polymers, zeolite, carbon, metals, or even those with magnetic properties in remediation or pollutant removal procedures. The effectiveness of these adsorbents can be applied to remove mercury from different environments based on their functionality. These nano adsorbents are sustainable, reusable, efficient, and cost-effective when it comes to conventional mercury remediation techniques. The major challenges in the use of nano adsorbents may involve issues in large-scale production and application, toxicity, or even pollution if not handled appropriately. This chapter describes the synthesis, applications, challenges, and future scope of various nano adsorbents in the context of mercury remediation or removal techniques from different environments.

The indent of industrialization and its development has led to an increase in the levels of pollutants that are released into the environment. Most of these pollutants are toxic and highly dangerous, deteriorating the air, water, and land. One such dangerous and highly toxic pollutant is mercury, a heavy metal that can pollute water sources for a long time due to its persistence and bioaccumulation. The toxic effects of mercury have been well documented due to its impact on human health and ecosystem. Though mercury does exist in its natural form in the environment, its toxicity is negligible; due to the release of mercury contaminants from anthropogenic sources, the concentration of mercury toxicity in the environment has increased tremendously. One such anthropogenic source is wastewater, from which mercury gets released into the environment in high amounts. So, this chapter discusses the importance of effective treatment techniques for remediating mercury-contaminated wastewater by physical, biological, and chemical methods. The latest research on adsorption and filtration techniques have been discussed that could prove to be effective alternatives to conventional wastewater treatment practices. Synthesis and mechanisms of various types of biosorbents, nanosorbents, membrane filter techniques, and adsorbents have been described along with their potential future and challenges that need to be overcome to perform as an effective, efficient, and biocompatible wastewater treatment technique.

Mercury (Hg) finds the 80th position in the periodic table and exists in its various physical and chemical states. It is a heavy metal and serves as a global pollutant. It is emitted into the environment from both natural and anthropogenic sources, accumulating in ecosystems and having a negative impact on plants, animals, and people. The fact that this material is harmful and polluting is what causes widespread concern. The brain, central nervous system, and other organs sustain serious damage as a result of its potent neurotoxic effects. From its initial state, mercury goes through substantial changes, changing its chemical forms, traveling across the environment, and eventually settling in soil and sediment deposits. Once it contaminates the soil it is not easy to remove or detoxify. Hg remediation can be achieved by many conventional techniques which include physical, chemical, and combination of both methods. The conventional methods are costly and not enough to detoxify Hg completely as well as time-consuming. On the other hand, the bioremediation of mercury which includes microbial bioremediation and phytoremediation are eye-catching methods used worldwide with potential recovery and detoxification. The bioremediation methods are eco-friendly, cost-effective, and also recognized by environmental regulatory authorities. This chapter emphasizes the Hg toxicity, sources of Hg pollution, and recent developments in the bioremediation of mercury.

The main source of contamination to the environment by mercury occurs when it is discharged into the water or soil by industries, and it can be converted by microorganisms present in the environment into a more toxic organic compound, which is rapidly absorbed by different aquatic organisms, and through the food chain, it can accumulate in different living beings and environments. The heavy metal mercury compounds can be harmful for living organisms, accumulating in the kidneys and brain, causing damage to the nervous system. Because it accumulates in the body, high levels of exposure to this metal cause severe health problems. Here, we analyzed the biosorption of mercury by ten fungal biomasses isolated from a place with a high flow of heavy-duty vehicles. The fungal biomasses more efficient in the removal of the metal were: Purpureocillium lilacinum, Mucor sp., Aspergillus flavus, Penicillium sp., and Aspergillus terreus, with removal percentages of 100%, 100%, 100%, 97%, and 93%, respectively, at a pH of 5.5, 28 °C, and 24 h of incubation, and under the analyzed conditions. The use of different natural biomasses can be a great alternative to try to eliminate the different pollutants produced by different human and industrial activities. Too, we studied the optimal conditions of removal of this metal by P. lilacinum.