Did he really bring the war home with him? – Authors' reply

Clinics in Laboratory Medicine, 2006

Heavy metals are natural components of the earth's crust and as such are the oldest toxins known to humans, having been used for thousands of years. Potential exposures to heavy metals include natural sources (eg, groundwater, metal ores), industrial processes, commercial products, folk remedies, and contaminated food and herbal products. Virtually all heavy metals are toxic in sufficient quantities. Several, however, are of particular interest because of their concentrations in the environment (lead, mercury, and arsenic) or their use in criminal poisonings (arsenic and thallium). Entering our bodies by way of food, drinking water, and air, metals produce toxicity by forming complexes with cellular compounds containing sulfur, oxygen, or nitrogen. The complexes inactivate enzyme systems or modify critical protein structures leading to cellular dysfunction and death. The most commonly involved organ systems include central nervous, gastrointestinal (GI), cardiovascular, hematopoietic, renal, and peripheral nervous systems. The nature and severity of toxicity vary with the heavy metal involved, its exposure level, chemical and valance states (inorganic versus organic), mode of exposure (acute versus chronic), and the age of the individual. Children, with their developing nervous systems, are particularly vulnerable to heavy metal intoxication (especially lead) and deserve special consideration. This article presents an overview of the aforementioned heavy metals with emphasis on clinical presentation and pathophysiology.

Journal of Evolution of Medical and Dental Sciences

In this case report we discuss a patient with neurological manifestations thought to be a case of hepatic encephalopathy. With no improvement in symptoms despite treatment, it created a diagnostic dilemma. Eventually, toxicological investigations were done which revealed that heavy metal poisoning could be the possible culprit. Encephalopathy is characterised by impaired mental state as a result of a diffuse brain dysfunction or other psychiatric condition that induces unconsciousness, typically followed by diffuse electroencephalogram (EEG) anomalies. Both primary neurological and systemic disorders are root causes of encephalopathy. Encephalopathy results from several causes such as liver failure or liver cancer, metabolic abnormalities, anoxic encephalopathy, infections, exposure to harmful compounds such as lithium paint, synthetic contaminants (toxins), inflammations (systemic lupus erythematous, sarcoidosis), drug induced, demyelination (e.g., multiple sclerosis), degenerative...

Journal of Toxicology and Environmental Health Sciences, 2019

As a side effect of industrialization, some diseases have developed only recently, becoming a challenge for the medical specialists both in research and medical treatment fields. Among these, the poisoning with heavy metals occupies a certain category that must retain attention, due to since the effects of this kind of poisoning are very serious effects if these injuries poisonings are not properly recognized and treated. Most common heavy metals that are involved in poisonings are Mercury, Cadmium, Lead and Arsenic. They are capable of inducing a wide range of pathologies, including neoplasms with cerebral localization. In order to illustrate the link between the poisonings with heavy metals and neoplasms, we present a case of a 19 years old patient, who was diagnosed both with germinoma, which is a malignant tumor of the median brain structures, and mercury poisoning. Since germinoma and mercury poisoning are rare conditions, it is very hard to obtain enough data for a statistically significant study. However, the case study which encompasses the poisoning with heavy metals and germinoma supports the idea of performing proper screenings in the event of individuals being diagnosed with mercury poisoning, especially when they can turn out to be potentially treatable.

The Journal of Emergency Medicine, 2007

Pure inorganic heavy metal ingestions for suicidal intent are a rare occurrence. Most case reports on this subject focus on the serious neurological, hepatic, or renal side effects. We describe two cases of significant heavy metal poisonings (arsenic trioxide and mercuric chloride) that were successfully managed with aggressive decontamination and combined chelation therapy. Both chemicals were obtained in pure powder form through the Internet.

Pakistan journal of pharmaceutical sciences, 2015

People relate the neural disorders with either inheritance or psychological violence but there might be some other reasons responsible for the ailment of people that do not have such a background. The present study explains the chronic effect of heavy toxic metals on nervous system. During experimentation, rabbits used as laboratory animals, were given test metals in their diet. Concentration of metals given to them in the diet was less than their tolerable dietary intake. Behavioral changes were observed during experimentation. Periodic increase in the metal concentration was seen in the blood sample of rabbits. They were slaughtered after a period of eight months of slow poisoning. Histological examination of brain tissues was performed. The brain samples were analyzed by Atomic absorption spectroscopy and Inductively Coupled Plasma Mass Spectrometry to find the retention of heavy metals in mammalian brain. Concentration of lead, mercury and cadmium in the blood samples of occupat...

Handbook on the Toxicology of Metals, 2007

Metal poisoning may or may not be apparent from the clinical features induced. The exposure pattern in terms of time, concentration, and route of exposure is a determinant of clinical effect. Short-term high-and long-term low-level exposure by ingestion is seen more often in the domestic environment and by inhalation more often occupational in origin. Acute and chronic clinical effects of metal toxicity may involve the gastrointestinal, respiratory, cardiovascular, renal, hemopoietic, and central nervous systems.

Biodiversity International Journal, 2020

Numerous debates exist as to the precise definition of the term "heavy metal" and which elements appropriately fit into such. Several authors rationalized the definition on atomic weight; others, based on specific gravity of greater than 4.0, or more than 5.0 while a few based it on chemical behaviour. Regardless of one's choice of classification, heavy metal toxicity is a rare diagnosis. However, if undetected or inefficiently managed, heavy metal exposure can lead to remarkably disability and death. This paper gives a succinct and systematic review on the emission, absorption, metabolism and excretion of selected heavy metals. It also delves into their biotoxic effects on the human wellbeing and the ecosystem in general with the mechanisms of their actions. It concludes with the various therapeutic options and management plans for different heavy metal poisoning. This review posits that though heavy metal poisoning could be clinically diagnosed and medically treated, the most appropriate measure is to avoid heavy metal contamination and its subsequent human exposure and toxicity. Thus exposure monitoring and possible intervention for minimizing marginal exposure of humans to heavy metals in the surrounding may be a giant stride towards prevention. National and international synergy is pivot for designing right measures for the prevention of heavy metal toxicity.

Journal of Occupational Health, 2000

Coordination Chemistry Reviews, 2018

Past poisoning epidemics have revealed that the chronic exposure to exceedingly small daily doses of toxic metal and metalloid species can-over time-severely affect human health. Today, several potentially toxic metals and metalloids have been accurately quantified in the bloodstream of the average population, but the interpretation of these from a public health point of view remains problematic. Conversely, the biomolecular origin for a multitude of grievous human diseases remains unknown. Supported by recent epidemiological evidence, these seemingly unrelated facts suggest that human exposure to the aforementioned pollutants may be linked to the etiology of more adverse health effects than we currently know. Based on the interaction of toxic metal and metalloid species with essential trace elements, plasma and erythrocytes in the bloodstream, we have previously argued that a better understanding of these bioinorganic chemistry processes are destined to provide important new insight into their mechanisms of chronic toxicity. This perspective provides an update on recent advances to better understand these bioinorganic processes and attempts to integrate these findings with the whole organism in order to establish connections with the etiology of human diseases. Based on the recent observation of the arsenite-induced perturbation of the whole-body distribution of selenite in mammals and the mercuration of hemoglobin in erythrocyte cytosol it is argued that bioinorganic processes in the bloodstream critically determine which metal and/or non-metal containing species will impinge on the toxicological target organ(s). Accordingly, the bioinorganic chemistry that unfolds in the bloodstream represents a critical bottleneck in terms of linking the exposure of humans to toxic metal species with the etiology of diseases. Furthermore, a better understanding of the blood-based detoxification of environmentally abundant toxic metal species is of direct practical use to develop palliative treatments to ameliorate the adverse effect that toxic metal species exert on certain human populations.