Three systems of the body in which toxicants can enter, how this may occur and an example of a toxicant that can enter the body through each system.
The three common forms of body exposure to toxicants include inhalation, ingestion and skin absorption. Inhalation is the main entry route for most chemicals that are in form of particulates, mists, gases or vapors. Once chemical are inhaled, they are either deposited in the respiratory tract or exhaled. When deposited, damage can take place via direct contact of chemical with tissues or chemical might diffuse into the blood via the blood-lung interface. Upon the lungs or upper respiratory tract tissues contact, chemicals might result to health impacts that range from severe destruction of tissues or simple irritation. Chemicals absorbed into the blood are distributed and circulated to organs which contain high infinity to that specific chemical. Health impacts can then happen in the organs that are sensitive to the toxicant. Some of the inhaled toxicants include ammonia gas, sulfur dioxide, ozone, butadiene, diesel exhaust, acrolein and metal fumes (University of Nebraska Lincoln, 2002).
Skin is another toxicant entry point. Skin contact can result to effects which are comparatively harmless for instant mild dermatitis or redness to more severe impacts that include skin tissues destruction or other devastating conditions. Various chemicals can as well cross the skin barrier to be absorbed into the system of the blood. Once absorbed, they might create systemic destruction to internal organs. Eyes are specifically sensitive to chemicals, such that they can be severely impacted even by a short exposure time, where chemicals are absorbed and transmitted to other body parts resulting to harmful body impacts. Chemicals that enter to the body through contact include metal powders, acids such as sulfuric acid, and ammonia acid among others (University of Nebraska Lincoln, 2002).
Ingestion is another source of chemical entry to human body. This involves chemicals which get into the mouth inadvertently and they are swallowed. These chemicals do not necessarily destroy the gastrointestinal tract specifically unless they are corrosive or irritating. Chemicals which are insoluble in the gastrointestinal tract fluids are usually excreted. Others chemicals which are soluble are absorbed via the gastrointestinal tract lining. They are transmitted to internal organs by the blood where they cause harm. Most of ingested chemical are mostly in powder or liquid form such as acids such as ammonia hydroxide and benzene among others (University of Nebraska Lincoln, 2003).
Processes used by the body to eliminate a Toxicant and an example of a situation where one of these processes might be inhibited and how the inability to eliminate the toxicant might impact the individual.
To be able to maintain health, it is important for the body to be in apposition to handle the toxins and to manage to effectively eliminate them. The human body has secondary and primary routes to eliminate these toxins, which have to be working effectively to as to avoid toxins storage and ensure disease prevention. All basic routes of toxins elimination contain direct entree to outside the body. They are a point of transition between normal processes in the body and excretion. Some of the primary elimination routes include bowels, skin, bladder, menses and breathing. Skin removes body toxins through excretion of sweat. The urinary complex system assist in blood filtering via the kidney as a way of upholding homeostasis and body physiological PH. This system assist in metabolic waste excretion, with main bi-products being nitrogen originating from breakdown of protein and uric acid from metabolism of nucleic acid. These wastes are eliminated through urination. Lungs eliminate carbon dioxide from the body tissues via breathing system. Bowel eliminate toxin from ingested products after useful nutrients are absorbed into the body (Lloyd, 2015).
The secondary elimination routes are used when the basic routes are overloaded by toxins. Secondary toxins elimination routes include sneezing, nasal discharge,, flatulence and gas, coughing, blood or mucus in stool, ear wax, phlegm, tears, leucorrhea and hair. Another major organ used in toxins excretion is the liver. Liver plays different detoxification roles. It filters the blood to eliminate large toxins, get rid of and synthesizes of bile containing cholesterol and other toxins soluble in fat. Other unwanted chemicals are also eliminated by live enzymatic process. This process involves two main processes that include oxidations and conjugation. Oxidation stage involves changing toxic chemical to activated intermediate form which is neutralized later by the next enzyme system. In phase two, other substances such as sulfur, glycine or cysteine molecules are added to the toxic chemical by the liver cells to make them less harmful. This make new toxin water-soluble in order it might then be excreted from the body through water fluids, urine or bile (Cornell College, n.d.).
Factors that can affect the distribution of a toxicant in the body and how manipulation of these factors can increase toxicity.
The distribution of toxicant in the body is determined by a number of factors. Some of these factors include molecular shape and size, solubility at absorption site, level of ionization, and relative lipid solubility of unionized and ionized forms. Although weight of the molecule is essential, it is not as essential as the toxicant lipid solubility with regard to assessment of passive diffusion rate across membranes. The nonpolar substance permeability via a cell membrane is reliant on membrane solubility which can be demonstrated as the drug partition coefficient between membrane phase and aqueous phase and diffusion coefficient or diffusivity that assesses drug molecule mobility in the lipids.
Toxicant can be ionized and unionized form. Generally toxicants have to be in the unionized or uncharged form to be transported across biological membranes through passive diffusion. This is due to the fact that biological membranes are made of lipids which are less permeable to the chemical in ionized form (Baynes & Hodgson, 2004). Toxicity can be increased by adding unionized toxicants. The environment PH can impact toxicants transfer which is ionized by decreasing or increasing the amount of toxicant nonionized form. Toxicant is also influenced by level of toxicants absorption into the blood such that the level absorbed requires being high enough to be able essential impact at the action site in other body areas. Toxicant distribution can also be influenced by a number of complex factors that include tissues perfusion, protein binding, and elimination processes that include biotransformation and excretion. The absorption route also determine on the extent of distribution. Toxins absorbed through various sources can be easily transported to the blood system than when absorbed through a single source. Ingestion and inhalation may provide a faster way of toxicant distribution compared to skin contact due to extensive skin layers. The concentration where high concentration means more molecules to be bombarded may fasten the speed of distribution (Baynes & Hodgson, 2004).