Related Research Articles
Arsenic is a chemical element;it has symbol As and atomic number 33. Arsenic occurs in many minerals,usually in combination with sulfur and metals,but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes,but only the grey form,which has a metallic appearance,is important to industry.
Cadmium is a chemical element;it has symbol Cd and atomic number 48. This soft,silvery-white metal is chemically similar to the two other stable metals in group 12,zinc and mercury. Like zinc,it demonstrates oxidation state +2 in most of its compounds,and like mercury,it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals,in that they do not have partly filled d or f electron shells in the elemental or common oxidation states. The average concentration of cadmium in Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann,both in Germany,as an impurity in zinc carbonate.
Toxicology is a scientific discipline,overlapping with biology,chemistry,pharmacology,and medicine,that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. The relationship between dose and its effects on the exposed organism is of high significance in toxicology. Factors that influence chemical toxicity include the dosage,duration of exposure,route of exposure,species,age,sex,and environment. Toxicologists are experts on poisons and poisoning. There is a movement for evidence-based toxicology as part of the larger movement towards evidence-based practices. Toxicology is currently contributing to the field of cancer research,since some toxins can be used as drugs for killing tumor cells. One prime example of this is ribosome-inactivating proteins,tested in the treatment of leukemia.
A toxic heavy metal is any relatively dense metal or metalloid that is noted for its potential toxicity,especially in environmental contexts. The term has particular application to cadmium,mercury and lead,all of which appear in the World Health Organization's list of 10 chemicals of major public concern. Other examples include manganese,chromium,cobalt,nickel,copper,zinc,silver,antimony and thallium.
Arsenic poisoning is a medical condition that occurs due to elevated levels of arsenic in the body. If arsenic poisoning occurs over a brief period of time,symptoms may include vomiting,abdominal pain,encephalopathy,and watery diarrhea that contains blood. Long-term exposure can result in thickening of the skin,darker skin,abdominal pain,diarrhea,heart disease,numbness,and cancer.
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism,such as an animal,bacterium,or plant,as well as the effect on a substructure of the organism,such as a cell (cytotoxicity) or an organ such as the liver (hepatotoxicity). By extension,the word may be metaphorically used to describe toxic effects on larger and more complex groups,such as the family unit or society at large. Sometimes the word is more or less synonymous with poisoning in everyday usage.
Metallothionein (MT) is a family of cysteine-rich,low molecular weight proteins. They are localized to the membrane of the Golgi apparatus. MTs have the capacity to bind both physiological and xenobiotic heavy metals through the thiol group of its cysteine residues,which represent nearly 30% of its constituent amino acid residues.
Cadmium is a naturally occurring toxic metal with common exposure in industrial workplaces,plant soils,and from smoking. Due to its low permissible exposure in humans,overexposure may occur even in situations where trace quantities of cadmium are found. Cadmium is used extensively in electroplating,although the nature of the operation does not generally lead to overexposure. Cadmium is also found in some industrial paints and may represent a hazard when sprayed. Operations involving removal of cadmium paints by scraping or blasting may pose a significant hazard. The primary use of cadmium is in the manufacturing of NiCd rechargeable batteries. The primary source for cadmium is as a byproduct of refining zinc metal. Exposures to cadmium are addressed in specific standards for the general industry,shipyard employment,the construction industry,and the agricultural industry.
Toxicogenomics is a subdiscipline of pharmacology that deals with the collection,interpretation,and storage of information about gene and protein activity within a particular cell or tissue of an organism in response to exposure to toxic substances. Toxicogenomics combines toxicology with genomics or other high-throughput molecular profiling technologies such as transcriptomics,proteomics and metabolomics. Toxicogenomics endeavors to elucidate the molecular mechanisms evolved in the expression of toxicity,and to derive molecular expression patterns that predict toxicity or the genetic susceptibility to it.
An environmental hazard is a substance,state or event which has the potential to threaten the surrounding natural environment or adversely affect people's health,including pollution and natural disasters such as storms and earthquakes. It can include any single or combination of toxic chemical,biological,or physical agents in the environment,resulting from human activities or natural processes,that may impact the health of exposed subjects,including pollutants such as heavy metals,pesticides,biological contaminants,toxic waste,industrial and home chemicals.
Soil contamination,soil pollution,or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity,agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons,polynuclear aromatic hydrocarbons,solvents,pesticides,lead,and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks,from direct contact with the contaminated soil,vapour from the contaminants,or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks,and require expertise in geology,hydrology,chemistry,computer modelling,and GIS in Environmental Contamination,as well as an appreciation of the history of industrial chemistry.
Nanotoxicology is the study of the toxicity of nanomaterials. Because of quantum size effects and large surface area to volume ratio,nanomaterials have unique properties compared with their larger counterparts that affect their toxicity. Of the possible hazards,inhalation exposure appears to present the most concern,with animal studies showing pulmonary effects such as inflammation,fibrosis,and carcinogenicity for some nanomaterials. Skin contact and ingestion exposure are also a concern.
Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical,biological and physical agents on living organisms. Ecotoxicology is a subdiscipline of environmental toxicology concerned with studying the harmful effects of toxicants at the population and ecosystem levels.
Reproductive toxicity refers to the potential risk from a given chemical,physical or biologic agent to adversely affect both male and female fertility as well as offspring development. Reproductive toxicants may adversely affect sexual function,ovarian failure,fertility as well as causing developmental toxicity in the offspring. Lowered effective fertility related to reproductive toxicity relates to both male and female effects alike and is reflected in decreased sperm counts,semen quality and ovarian failure. Infertility is medically defined as a failure of a couple to conceive over the course of one year of unprotected intercourse. As many as 20% of couples experience infertility. Among men,oligospermia is defined as a paucity of viable spermatozoa in the semen,whereas azoospermia refers to the complete absence of viable spermatozoa in the semen.
In analytical chemistry,biomonitoring is the measurement of the body burden of toxic chemical compounds,elements,or their metabolites,in biological substances. Often,these measurements are done in blood and urine. Biomonitoring is performed in both environmental health,and in occupational safety and health as a means of exposure assessment and workplace health surveillance.
Panos G. Georgopoulos is a Greek scientist working in the field of Environmental Health and specializing in Mathematical Modeling of Environmental and Biological Systems. He is the architect or the MOdeling ENvironment for Total Risk studies (MENTOR) the DOse Response Information and Analysis system (DORIAN),and Prioritization/Ranking of Toxic Exposures with GIS Extension (PRoTEGE),all under continuing development at the Computational Chemodynamics Laboratory of the Environmental and Occupational Health Sciences Institute (EOHSI).
Arsenic biochemistry refers to biochemical processes that can use arsenic or its compounds,such as arsenate. Arsenic is a moderately abundant element in Earth's crust,and although many arsenic compounds are often considered highly toxic to most life,a wide variety of organoarsenic compounds are produced biologically and various organic and inorganic arsenic compounds are metabolized by numerous organisms. This pattern is general for other related elements,including selenium,which can exhibit both beneficial and deleterious effects. Arsenic biochemistry has become topical since many toxic arsenic compounds are found in some aquifers,potentially affecting many millions of people via biochemical processes.
Toxicodynamics,termed pharmacodynamics in pharmacology,describes the dynamic interactions of a toxicant with a biological target and its biological effects. A biological target,also known as the site of action,can be binding proteins,ion channels,DNA,or a variety of other receptors. When a toxicant enters an organism,it can interact with these receptors and produce structural or functional alterations. The mechanism of action of the toxicant,as determined by a toxicant’s chemical properties,will determine what receptors are targeted and the overall toxic effect at the cellular level and organismal level.
The olfactory system is the system related to the sense of smell (olfaction). Many fish activities are dependent on olfaction,such as:mating,discriminating kin,avoiding predators,locating food,contaminant avoidance,imprinting and homing. These activities are referred to as “olfactory-mediated.”Impairment of the olfactory system threatens survival and has been used as an ecologically relevant sub-lethal toxicological endpoint for fish within studies. Olfactory information is received by sensory neurons,like the olfactory nerve,that are in a covered cavity separated from the aquatic environment by mucus. Since they are in almost direct contact with the surrounding environment,these neurons are vulnerable to environmental changes. Fish can detect natural chemical cues in aquatic environments at concentrations as low as parts per billion (ppb) or parts per trillion (ppt).
Occupational toxicology is the application of toxicology to chemical hazards in the workplace. It focuses on substances and conditions that occur in workplaces,where inhalation exposure and dermal exposure are most important,there is often exposure to mixtures of chemicals whose interactions are complex,health effects are influenced or confounded by other environmental and individual factors,and there is a focus on identifying early adverse affects that are more subtle than those presented in clinical medicine.
References
- 1 2 3 "Rollins School of Public Health". sph.emory.eduindex.html.[ permanent dead link ]
- 1 2 "Rotary Club of North Bethesda" (PDF).
- ↑ Fowler, Bruce A. (1983). Biological and Environmental Effects of Arsenic. ISBN 9780444805133.
- 1 2 Fowler, Bruce A. (9 June 2016). Molecular Biological Markers for Toxicology and Risk Assessment. ISBN 9780128095898.
- 1 2 "Current Fellows of ATS – Academy of Toxicological Sciences".
- ↑ National Research Council (US) Committee on Measuring Lead in Critical Populations (1993). "Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations". Read "Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations" at NAP.edu. doi:10.17226/2232. ISBN 978-0-309-04927-6. PMID 25144057 – via nap.nationalacademies.org.
- 1 2 "Bruce A. Fowler". Fulbright.org. January 10, 2018.
- ↑ "Bruce A. Fowler's research works | University of Alaska Fairbanks, Alaska and other places".
- ↑ Nordberg, Gunnar (2007). Handbook on the Toxicology of Metals. ISBN 9780123694133.
- ↑ Fowler, B. A. (December 18, 1998). "Roles of lead-binding proteins in mediating lead bioavailability". Environmental Health Perspectives. 106 Suppl 6 (Suppl 6): 1585–1587. doi:10.1289/ehp.98106s61585. PMC 1533439 . PMID 9860918.
- ↑ Madden, Emily F.; Fowler, Bruce A. (January 1, 2000). "Mechanisms of Nephrotoxicity from Metal Combinations: A Review". Drug and Chemical Toxicology. 23 (1): 1–12. doi:10.1081/DCT-100100098. PMID 10711385. S2CID 23661050 – via Taylor and Francis+NEJM.
- ↑ Fowler, B. A. (1993). "Mechanisms of kidney cell injury from metals". Environmental Health Perspectives. 100: 57–63. doi:10.1289/ehp.9310057. PMC 1519575 . PMID 8354182.
- ↑ Fowler, Bruce A. (April 18, 2012). Luch, Andreas (ed.). "Molecular, Clinical and Environmental Toxicology: Volume 3: Environmental Toxicology". Experientia Supplementum. Springer. 101: 459–470. doi:10.1007/978-3-7643-8340-4_16. PMID 22945579 – via Springer Link.
- ↑ Wang, Gensheng; Fowler, Bruce A. (November 15, 2008). "Roles of biomarkers in evaluating interactions among mixtures of lead, cadmium and arsenic". Toxicology and Applied Pharmacology. 233 (1): 92–99. doi:10.1016/j.taap.2008.01.017. PMID 18325558 – via ScienceDirect.
- ↑ Fowler, Bruce A. (January 1, 2016). "Chapter 8 – Translation of Biomarkers for Human Clinical and Epidemiological Studies". In Fowler, Bruce A. (ed.). Molecular Biological Markers for Toxicology and Risk Assessment. Academic Press. pp. 119–129. doi:10.1016/B978-0-12-809589-8.00008-1. ISBN 9780128095898 – via ScienceDirect.
- ↑ Fowler, B A (April 18, 1987). "Intracellular compartmentation of metals in aquatic organisms: roles in mechanisms of cell injury". Environmental Health Perspectives. 71: 121–128. doi:10.1289/ehp.8771121. PMC 1474359 . PMID 3297654.
- ↑ Fowler, Bruce A. (20 April 2017). Electronic Waste. ISBN 9780128030837.
- ↑ Fowler, Bruce A. (January 1, 2017). "Chapter 2 – Metals, Metallic Compounds, Organic Chemicals, and E-Waste Chemical Mixtures". In Fowler, Bruce A. (ed.). Electronic Waste. Academic Press. pp. 17–31. doi:10.1016/B978-0-12-803083-7.00002-0. ISBN 9780128030837 – via ScienceDirect.
- ↑ Mendez, William; Fowler, Bruce A. (January 1, 2013). "Chapter 12 – Translation of Computational Model Results for Risk Decisions". In Fowler, Bruce A. (ed.). Computational Toxicology. Academic Press. pp. 215–245. doi:10.1016/B978-0-12-396461-8.00014-2. ISBN 9780123964618 – via ScienceDirect.