Hyperthermia in oncology and nontoxic integrative treatments
Clifford L. K. Pang, Kaiman Lee in Hyperthermia in Oncology, 2015
Arsenic is an active and widespread heavy metal, with the atomic number 33. In the chemical elements, arsenic is a protean toxic element. Sometimes it seems to occur in the nonmetallic form; this characteristic is called allotropic form. It is usually known from the poison “white arsenic,” with the chemical name of arsenic trioxide. Toxicity of arsenic manifests in many ways; it has contact toxicity, causing inflammation and necrosis of the mucous membranes of the skin, and mostly it causes damages to the viscera, such as heart, liver, kidney, bone marrow, and brain. The human body has no detoxification function for arsenic, which can cause acute and chronic poisoning. Insurmountable environmental pollution provides a good opportunity for the toxicity of arsenic to spread, and consequently the contamination of drinking water has become a serious global problem. Studies show that incidences of cancer, especially gastrointestinal cancer, are significantly increased after the arsenic poisoning of large populations.
Heavy Metals
Dongyou Liu in Handbook of Foodborne Diseases, 2018
Arsenic is a metalloid (showing both metal and nonmetal chemical characteristics) that occurs in both inorganic (less abundant, more toxic) and organic (less toxic, more abundant) forms in the environment. In arsenic biotransformation, harmful inorganic arsenic species (iAs) are converted enzymatically by microorganisms via monomethylarsenic acid (MMA) to dimethylarsenic acid (DMA), which is the end metabolite and the biomarker of chronic arsenic exposure. Upon ingestion and absorption, inorganic arsenic binds to hemoglobin in red blood cells and moves to the liver (in which some inorganic arsenic is converted to organic monomethylarsonic and dimethylarsinic acids), kidneys, heart, lungs, nervous system, gastrointestinal tract, and spleen, as well as placenta. While most inorganic and organic arsenic compounds are excreted by the kidneys, some may remain in keratin-rich tissues (e.g., nails, hair, and skin).
Inorganic Chemical Pollutants
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
Even moderately elevated concentrations of inorganic arsenic (InAs) in drinking water are of major public health concern worldwide.635 In Bangladesh alone, more than 50 million inhabitants are drinking water that contains arsenic above the WHO guideline value of 10 μg/L.636,637 In addition, there is increasing concern about arsenic exposure from food, especially rice products.638 Chronic arsenic exposure is associated with an increased risk of cancer of the skin, lungs, bladder, liver, and possibly kidneys,639 as well as a number of noncarcinogenic effects.635,640,641 The earliest signs of toxicity from chronic exposure to InAs in humans are pigmentation changes and hyperkeratosis, which may proceed to skin cancer.642 Unlike the arsenic-related cancers, which may appear first after two to three decades of exposure, these skin lesions may appear within a few years of exposure.643,644
Cell cycle dysregulation on prenatal and postnatal arsenic exposure in skin of Wistar rat neonates
Published in Xenobiotica, 2023
Navneet Kumar, Astha Mathur, Suresh Kumar Bunker, Placheril J. John
Arsenic (atomic number − 33, relative atomic mass − 74.92) is a metalloid prevalent in earth’s crust as the 20th most common element (IARC Working Group on the Evaluation of Carcinogenic Risks to Humans 2012). It is found in air, water, soil and sediments. Arsenic can exist in oxidation states of −3, 0, +3 and +5; most commonly present as arsenate (+5) in oxygenated environments and as arsenite (+3) in reducing or anaerobic conditions (WHO 2001). Primary arsenic exposure to humans can occur via food and water; other routes may include occupational exposure (industries) and smoking. Contamination of arsenic in drinking water is a major health concern globally, affecting people worldwide (Hunt et al. 2014; Sage et al. 2017). WHO has recommended 10 µg/l (10 ppb) as maximum limit of contamination for arsenic in drinking water (WHO 2011). Groundwater of several countries is reported to have elevated levels of arsenic such as China, Argentina, Chile, United States of America, Mexico, India and Bangladesh (IARC Working Group on the Evaluation of Carcinogenic Risks to Humans 2012; Hunt et al. 2014; Karagas et al. 2015; Bjørklund et al. 2018).
Estimation of total arsenic contamination and exposure in Brazilian rice and infant cereals
Published in Drug and Chemical Toxicology, 2021
Nuryan Fão, Sabrina Nascimento, Alex Huaman de La Cruz, Dionisio Calderon, Rafael Rocha, Tatiana Saint’Pierre, Adriana Gioda, Flavia V. Thiesen, Natália Brucker, Tatiana Emanuelli, Solange Cristina Garcia
Arsenic (As) is a metalloid, occurring naturally in the environment or originating from anthropogenic activities. In food or any other matrix, it can be quantified as total arsenic (tAs) or subdivided into organic (oAs) and inorganic (iAs) forms. Its main inorganic forms are As3+ (trivalent) and As5+ (pentavalent), while the organic forms are monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) (Alexander et al. 2009, Li et al. 2017). This element is one of the main toxic substances present in the Earth’s crust, and since 1997 it has been the number one compound on the priority list of the Agency for Toxic Substances and Disease Registry (ATSDR) of substances that pose the highest potential threat to human health (ATSDR 2018).
Dose-response for assessing the cancer risk of inorganic arsenic in drinking water: the scientific basis for use of a threshold approach
Published in Critical Reviews in Toxicology, 2019
Joyce S. Tsuji, Ellen T. Chang, P. Robinan Gentry, Harvey J. Clewell, Paolo Boffetta, Samuel M. Cohen
Inorganic arsenic is a naturally occurring element present in the earth's crust and occurs in soil and water by various processes. Ultimately, some inorganic arsenic enters into the food chain in both plants and animals (Cullen 2008; Cullen and Reimer 2017). The inorganic form is metabolized by various organisms to a variety of organic metabolites, and thiolation can occur by chemical reaction with hydrogen sulfide. Inorganic arsenic has long been known to be associated with a variety of toxicities, both acute and chronic. Among the chronic effects that have been noted, the earliest and most well-known are the effects on skin, including hyperkeratosis and hypo- and hyperpigmentation, most notably arising on the palms and soles in contrast to similar lesions occurring in sun-exposed areas of the body secondary to ultraviolet radiation (Cullen 2008; Cullen and Reimer 2017). These skin changes are known as either arsenicosis or arseniasis. These benign lesions occurred following ingestion of a variety of solutions that had been developed over time as possible therapies (Fowler's solution, Gay's solution), but an association of these lesions with the evolution of skin cancer was first noted by Jonathan Hutchinson in 1887 (Cullen 2008). He reported five cases of cancer arising from these skin keratoses. These skin changes and skin cancer have been documented following a variety of arsenical therapeutic exposures, including the anti-syphilitic arsenical drugs developed by Ehrlich in the early 20th century.
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