Environmental Toxicology Paper
September 14, 2014
Environmental Toxicology Paper
Environmental toxicology deals with the toxicology of environmental chemicals. This can relate to toxic chemicals found naturally but usually man-made chemicals are predominately studied. The effect of these chemicals on the environment and subsequent ecosystems are of great importance in understanding human impact on our planet. Ecotoxicology is a type of environmental toxicology that deals with the effects of environmental toxins on ecosystems, habitats and the organisms that live in those ecosystems. The wide range of organisms and environmental factors requires ...view middle of the document...
In short, “Toxicodynamics refers to the molecular, biochemical, and physiological effects of toxicants or their metabolites in biological systems.” (Michael A. Trush, 2008, p. 1)
Steps Involved in Toxicokinetics
As mentioned above, there are different stages or steps involved in how the body deals with exposure to toxicants. Absorption, distribution, and elimination are all processes that occur after a toxicant has been exposed to an organism. Toxicants can be absorbed in different ways. Exposure to a toxicant can be absorbed through contact with the skin. When inhaled, toxicants can be absorbed through respiratory exposure. When ingested orally, toxicants may be absorbed as well. As with all toxicants the dose (amount of toxicant exposed to the organism) dictates the amount absorbed and thus the effects of absorption. After absorption occurs the body distributes the toxicant in a variety of ways which will be discussed further on. Eventually elimination of the toxicant will occur. This may take place through excretion and metabolic processes.
Primary Routes of Exposure
Exposure to toxicants may occur through different routes. The three primary routes of exposure are through the skin, respiratory tract and the gastrointestinal tract. Skin is often unprotected by many organisms to include humans and is one of the most common routes for exposure. Many pharmaceutical products are specifically designed to be applied to the skin. Inhalation of toxicants is another common route of exposure. In many cases toxic chemicals go absorbed unnoticed through this route because they are not visible and organisms exposed are unaware that inhalation has taken place. Food and water consumption are the primary ways in which toxicants are exposed through the gastrointestinal tract. Toxicants in food and water can be incredibly important to detect to avoid such exposure.
Pathways of Distribution
After a toxicant is absorbed it travels through linings of the cells of the organ in which it was exposed. For example, if the toxicant was ingested during food consumption it would be exposed and absorbed through the gastrointestinal tract and would then be distributed through the interstitial fluid of the gastrointestinal tract. Interstitial fluid is the fluid surrounding the cells of an organ. In order for a toxicant to be distributed to body cells and tissues it must first penetrate small blood vessels and then the actual cells of the target organ. If a toxicant is able to enter the blood capillaries it can then be distributed throughout the entire body through the cardiovascular circulatory system and may then be able to penetrate cells in any organ of the body. If the toxicant is able to enter the lymphatic system it may then be distributed throughout the lymphatic system of the body.
Four Mechanisms in Moving Toxicants
The four mechanisms involved in moving toxicants across the cell membrane are passive diffusion, filtration, carrier-mediated...