The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Curtis D. Klaassen - One of the best experts on this subject based on the ideXlab platform.
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Toxicology of cadmium
Handbook of experimental pharmacology, 1995Co-Authors: Peter L. Goering, Michael P Waalkes, Curtis D. KlaassenAbstract:Cadmium (Cd) is unique among Metals because of its diverse toxic effects, extremely protracted biological half-life (approximately 20–30 years in humans), low rate of excretion from the body, and predominant storage in soft tissues (primarily liver and kidney) rather than bone. The health hazards associated with cadmium exposure became known in the 1940s when FRiberg (1948) reported the occurrence of emphysema and proteinuria in workers exposed to cadmium dust. In the 1960s, cadmium was catapulted into the mainstream of Metal Toxicology research when cadmium was identified as the major etiological factor in itai-itai disease, a condition that afflicted Japanese women exposed to cadmium via their diet which contained cadmium-contaminated rice and water. Cadmium is an extremely toxic element of continuing concern because environmental levels have risen steadily due to continued worldwide anthropogenic mobilization. The mobilization has derived from past and current industrial and agricultural practices.
Peter L. Goering - One of the best experts on this subject based on the ideXlab platform.
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Toxicology of cadmium
Handbook of experimental pharmacology, 1995Co-Authors: Peter L. Goering, Michael P Waalkes, Curtis D. KlaassenAbstract:Cadmium (Cd) is unique among Metals because of its diverse toxic effects, extremely protracted biological half-life (approximately 20–30 years in humans), low rate of excretion from the body, and predominant storage in soft tissues (primarily liver and kidney) rather than bone. The health hazards associated with cadmium exposure became known in the 1940s when FRiberg (1948) reported the occurrence of emphysema and proteinuria in workers exposed to cadmium dust. In the 1960s, cadmium was catapulted into the mainstream of Metal Toxicology research when cadmium was identified as the major etiological factor in itai-itai disease, a condition that afflicted Japanese women exposed to cadmium via their diet which contained cadmium-contaminated rice and water. Cadmium is an extremely toxic element of continuing concern because environmental levels have risen steadily due to continued worldwide anthropogenic mobilization. The mobilization has derived from past and current industrial and agricultural practices.
Kazuo T. Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Exposure, metabolism, and toxicity of rare earths and related compounds.
Environmental Health Perspectives, 1996Co-Authors: Seishiro Hirano, Kazuo T. SuzukiAbstract:For the past three decades, most attention in heavy Metal Toxicology has been paid to cadmium, mercury, lead, chromium, nickel, vanadium, and tin because these Metals widely polluted the environment. However, with the development of new materials in the last decade, the need for toxicological studies on those new materials has been increasing. A group of rare earths (RE) is a good example. Although some RE have been used for superconductors, plastic magnets, and ceramics, few toxicological data are available compared to other heavy Metals described above. Because chemical properties of RE are very similar, it is plausible that their binding affinities to biomolecules, metabolism, and toxicity in the living system are also very similar. In this report, we present an overview of the metabolism and health hazards of RE and related compounds, including our recent studies.
Bruce A. Fowler - One of the best experts on this subject based on the ideXlab platform.
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Interactions and Mixtures in Metal Toxicology
Handbook on the Toxicology of Metals, 2015Co-Authors: Gunnar F. Nordberg, Lars Gerhardsson, Moiz Mumtaz, Patricia Ruiz, Bruce A. FowlerAbstract:Human exposures to Metals, Metalloids, and their compounds frequently occur as mixtures, and hence it is important to consider the joint action of these elements in terms of both mechanisms of acti ...
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Metal Toxicology in Developing Countries
Handbook on the Toxicology of Metals, 2015Co-Authors: Bruce A. Fowler, Candace M. Prusiewicz, Monica NordbergAbstract:Environmental health problems associated with Metals in developing countries are complex and frequently severe. They relate to the mining of mineral deposits in these countries, the smelting of Metal-containing ores, and the secondary smelting of batteries and electronic waste products transported into these countries for recycling. Despite efforts in the international community to promote sustainable development, these activities are frequently conducted in developing countries under conditions of limited health and safety regulation due to the limited resources available to implement environmental and occupational health standards in many developing countries. Poor nutrition and a general lack of food are also contributory factors that exacerbate susceptibility to Metal toxicity. These issues are further compounded by Metal contamination of food crops through the utilization of cadmium-containing phosphate fertilizers, arsenic in irrigation water from contaminated groundwater, and other Metals or chemicals from industrial or municipal wastewater sources. The economies of developing countries are often highly dependent on the mining, smelting, and recycling of Metals, as well as on agricultural products, so tighter regulation of ongoing practices is frequently a secondary concern. This multiplicity of factors combines to create an overall situation that frequently places populations in developing countries at an elevated risk of adverse public health outcomes from Metal exposures. However, it also should be noted that, given the increased globalization of industries and the food supply, Metal contamination of the environment in developing countries with aeolian transport of Metals in the atmosphere, ocean currents, and food may also present potential public health problems to populations in developed countries. For these reasons, the issues discussed in this chapter are generic and global in nature.
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Chapter 8 – Biological Monitoring and Biomarkers
Handbook on the Toxicology of Metals, 2015Co-Authors: Tiina Santonen, Bruce A. Fowler, Antero Aitio, Monica NordbergAbstract:Biological monitoring (BM; synonym, biomonitoring) was developed for the assessment of the health risks from exposure to Metals in the work environment, and the approaches and concepts of biomonitoring are derived from such exposures. At present, biomonitoring is increasingly used to assess exposure from the environment. Biomonitoring and the assessment of external exposure are complementary activities, where external exposure assessments are much more widely applied, especially when the number of chemicals concerned is considered; environmental analysis also offers the distinct advantage of speciation analysis, which is very poorly developed for biomonitoring. Biomonitoring, on the other hand, provides information on exposure from all sources and via all absorption routes, and also considers accumulation of the chemical in the body. Biomonitoring using exposure biomarkers thus considers interindividual differences in absorption, whereas the use of effect biomarkers also considers interindividual differences in susceptibility. Few effect biomarkers, however, have been validated. Biomarkers of susceptibility have so far not been adapted for routine use in Metal Toxicology. The major challenges of biomonitoring are the development of (preferably noninvasive) monitoring methods, which are inexpensive enough to be applied at a frequency that makes possible the meaningful biomonitoring of Metals with a short half-time; the development of exposure biomarker guidance values specific to individual species of different Metals; expansion of the repertoire of validated effect biomarkers; and the validation and application to effect monitoring of the “omic” technologies. Promotion of the scientifically sound use of biomonitoring in chemical risk management, for example as a tool to control the effectiveness of risk management measures, is also one of the today’s challenges.
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Interactions in Metal Toxicology
Handbook on the Toxicology of Metals, 2007Co-Authors: Gunnar F. Nordberg, Lars Gerhardsson, Karin Broberg, Moiz Mumtaz, Patricia Ruiz, Bruce A. FowlerAbstract:Human exposures to Metals and Metalloids such as arsenic frequently occur as mixtures, and hence it is important to consider interactions among these elements in terms of both mechanisms of action ...
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TOXICOLOGICAL HIGHLIGHT Porphyrinurias Induced by Mercury and Other Metals
2001Co-Authors: Bruce A. FowlerAbstract:Biomarkers for toxic agents such as methylmercury are ideally early, chemical-specific biological responses to exposure of a target cell population which can be measured in accessible biological matrices such as blood or urine. Chemical-induced alterations in the heme biosynthetic pathway are among the those biomarkers of chemical exposure/toxic cell injury that have proven themselves both useful and reliable over a number of decades. This pathway, which is essential for life, produces heme, utilized for a host of hemoproteins including hemoglobin, the cytochrome P450 family, and mitochondrial cytochromes. There are a host of biological processes of direct toxicological interest which are dependent upon the heme biosynthetic pathway. The heme pathway is also highly sensitive to inhibition by a number of inorganic agents such as lead, mercury, and arsenicals as well as organic agents such as the chlorinated benzenes and alcohol. There is also a high degree of correlation between excretion of specific porphyrins in the urine and other ultrastructural/biochemical alterations in organelles, such as the mitochondrion, which contain a number of enzymes in the heme biosynthetic pathway (Fowler et al., 1987). This indicates the utility of porphyrinurias in detecting early stages of cell injury. As noted below, Metal-induced disturbances in this pathway have also proven useful for examining the interactions between Metals under mixture exposure conditions (Mahaffey et al., 1981, Conner et al., 1995). Over the years, measurement of lead-induced alterations in this pathway (e.g., blood delta-aminolevulinic acid dehydratase activity and measurement of erythrocyte zinc protoporphyrin) were used in making timely public health screening decisions for both workers and children exposed to lead-containing dust (Piomelli et al., 1987). These measurements have permitted physicians to ascertain that sufficient exposure to lead had occurred to produce a disturbance in an essential biochemical pathway and that a biological threshold had been crossed. The question of variability in individual susceptibility to alterations in the heme pathway by Metals such as lead and mercury, as a function of the biologically active fraction of these Metals, has remained a problem. The paper by Pingree et al. represents a major contribution towards addressing this question for a common organoMetal toxicant (methylmercury) which is of current public health concern. It examines the relationship between biological activity against the renal heme biosynthetic pathway and intracellular biological availability of CH3Hg 1 and Hg as monitored by sodium 2,3-dimercapto1-propanesulfonic acid (DMPS) mobilization from the kidney. The import of these studies in a rodent species is not trivial for humans, since the heme pathway is highly conserved across species, and previous studies (Gonzalez-Ramirez et al., 1995) have shown similar findings with regard to the observed porphyrinuria pattern. Methylmercury-induced porphyrinuria of renal origin was first described in rats (Woods and Fowler, 1977) at dose levels that did not produce signs of neurological dysfunction in this species. Subsequent studies in humans exposed to mercury vapor (Gonzalez-Ramirez et al., 1995) showed similar findings. The study by Pingree and colleagues makes a substantial contribution toward a better understanding of the mechanisms underlying this unique porphyrinuria pattern. It also contributes to the field of Metal Toxicology in several specific areas. First, it defines a relationship between a biological effect (mercury-specific porphyrinuria pattern) and a target tissue dose of this element as measured by the relationship with the DMPS mobilizable fraction. The high degree of statistical correlation between renal mercury burden and porphyrin excretion in the urine indicates that the observed mercury-specific porphyrin excretion pattern may be reliably used as a noninvasive index of the total renal mercury burden. More specifically, the porphyrinuria pattern clarifies this relationship in terms of the biologically active fractions of CH3Hg 1 and Hg as evidenced by the strong statistical relationship between DMPS chelatable fractions and alterations in the observed porphyrinuria. It is also extremely valuable to be aware of the dose-related nature of the porphyrinuria pattern across a wide range of doses, both with regard to the consistency of the For correspondence via fax: (410) 455-6314. E-mail: bfowler@umbc.edu. TOXICOLOGICAL SCIENCES 61, 197–198 (2001) Copyright © 2001 by the Society of Toxicology
Michael P Waalkes - One of the best experts on this subject based on the ideXlab platform.
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Toxicology of cadmium
Handbook of experimental pharmacology, 1995Co-Authors: Peter L. Goering, Michael P Waalkes, Curtis D. KlaassenAbstract:Cadmium (Cd) is unique among Metals because of its diverse toxic effects, extremely protracted biological half-life (approximately 20–30 years in humans), low rate of excretion from the body, and predominant storage in soft tissues (primarily liver and kidney) rather than bone. The health hazards associated with cadmium exposure became known in the 1940s when FRiberg (1948) reported the occurrence of emphysema and proteinuria in workers exposed to cadmium dust. In the 1960s, cadmium was catapulted into the mainstream of Metal Toxicology research when cadmium was identified as the major etiological factor in itai-itai disease, a condition that afflicted Japanese women exposed to cadmium via their diet which contained cadmium-contaminated rice and water. Cadmium is an extremely toxic element of continuing concern because environmental levels have risen steadily due to continued worldwide anthropogenic mobilization. The mobilization has derived from past and current industrial and agricultural practices.