Contamination

Contamination is the presence of a constituent, impurity, or some other undesirable element that soils, corrupts, infects, makes unfit, or makes inferior a material, physical body, natural environment, workplace, etc. Contamination is the presence of a constituent, impurity, or some other undesirable element that soils, corrupts, infects, makes unfit, or makes inferior a material, physical body, natural environment, workplace, etc. Within the sciences, the word 'contamination' can take on a variety of subtle differences in meaning, whether the contaminate is a solid or a liquid, as well as the variance of environment the contaminate is found to be in. A contaminate may even be more abstract, as in the case of an unwanted energy source that may interfere with a process. The following represent examples of different types of contamination based on these and other variances. In chemistry, the term 'contamination' usually describes a single constituent, but in specialized fields the term can also mean chemical mixtures, even up to the level of cellular materials. All chemicals contain some level of impurity. Contamination may be recognized or not and may become an issue if the impure chemical is mixed with other chemicals or mixtures and causes additional chemical reactions. The resulting chemical reactions from the presence of an impurity may at times be beneficial, in which case the label 'contaminant' may be replaced with 'reactant' or 'catalyst.' (This may be true even in physical chemistry, where, for example, the introduction of an impurity in an intrinsic semiconductor positively increases conductivity.If the additional reactions are detrimental, other terms are often applied such as 'toxin,' 'poison,' or pollutant, depending on the type of molecule involved. Chemical decontamination of substance can be achieved through decomposition, neutralization, and physical processes, though a clear understanding of the underlying chemistry is required. In environmental chemistry, the term 'contamination' is in some cases virtually equivalent to pollution, where the main interest is the harm done on a large scale to humans, organisms, or environments. An environmental contaminant may be chemical in nature, though it may also be a biological (pathogenic bacteria, virus, invasive species) or physical (energy) agent. Environmental monitoring is one mechanism available to scientists to catch contamination activities early before they become too detrimental. Another type of environmental contaminate can be found in the form of genetically modified organisms (GMOs), specifically when they come in contact with organic agriculture. This sort of contamination can result in the decertification of a farm. This sort of contamination can at times be difficult to control, necessitating mechanisms for compensating farmers where there has been contamination by GMOs. In food chemistry and medicinal chemistry, the term 'contamination' is used to describe harmful intrusions, such as the presence of toxins or pathogens in food or pharmaceutical drugs. In environments where nuclear safety and radiation protection are required, radioactive contamination is a concern. Radioactive substances can appear on surfaces, or within solids, liquids or gases (including the human body), where their presence is unintended or undesirable, and processes can give rise to their presence in such places. Several examples of radioactive contamination include: Note that the term 'radioactive contamination' may have a connotation that is not intended. The term refers only to the presence of radioactivity, and gives no indication itself of the magnitude of the hazard involved. However, radioactivity can be measured as a quantity in a given location or on a surface, or on a unit area of a surface, such as a square meter or centimeter. Like environmental monitoring, radiation monitoring can be employed to catch contamination activities early before they become too detrimental.