Lungs absorption through

This product is also only available by prescription. The recommended treatment period is up to 24 weeks (McNeil Consumer Products 1997). Using the inhaler by puffing 80 deep inhalations over 20 minutes results in a systemic absorption through the buccal mucosa of 2 mg of nicotine, with maximal nicotine concentrations occurring 15 minutes after the end of inhalation. When the product is used as directed, the patient will likely use 6-16 inhalers per day. This form of NRT is relatively contraindicated in patients with asthma because, although most of the nicotine is absorbed through the buccal mucosa and it is not delivered to the lungs (McNeil Consumer Products 1997), nicotine by inhalation may produce bronchial constriction. 

Wrenn et al. (1981) concluded that the major route of exposure was inhalation. Though intake of thorium through the air may account for less than 1 % of the total intake, absorption through the lungs accounts for approximately 2/3 of the ultimate uptake in the body. This is due primarily to the low gastrointestinal absorption rate (0.02%) in humans (Maletskos et al. 1969 Sullivan et al. 1983). 

Plutonium is not readily absorbed from the animal intestine (65), though on long continued low-level feeding some is taken up (79). There is some absorption through the lungs, and when it enters the body by this path or by injection, it localizes in the bones (64, 65). It is probably more toxic than radium under these conditions (65). It is not actually incorporated into the mineralized matter of the bone as is radium, but seems to concentrate in the cartilaginous portion (24). 

Materials can also reach the liver after skin and lung absorption. If the dose of a drug or poison is large, it may take several passes through the liver in order to be completely metabolized. 

It is clear that to exert a toxic effect a compound must come into contact with the biological system under consideration. It may exert a local effect at the site of administration on initial exposure, but it must penetrate the organism in order to have a systemic effect. The most common means of entry for toxic compounds are via the gastrointestinal tract and the lungs, although in certain circumstances, absorption through the skin may be an important route. Therapeutic agents may also enter the body by other routes such as injection. 

In case of hypothetical homicidal gassings, the sweat produced by the frightened, crowded people and their HCN absorption through skin and lungs will cause similar losses, and in case of the underground morgues of crematorium II and III, additional losses will occur due to the cold and moist walls. 

In addition to absorption through the gastrointestinal tract, ethanol can be absorbed by the alveoli of the lungs. Symptoms of intoxication can be observed from inhalation of air containing more than 1000 ppm ethanol. 

J.K. Piotrowski, Evaluation of exposure of phenol Absorption of phenol vapor in the lungs and through the skin and excretion of phenol in urine. Br. J. Ind. Med. 28 172, 1971. 

This external exposure may not necessarily correlate with internal exposure. The rate of absorption through the skin, the lung or the gastrointestinal tract determines the body burden of the chemical. Measurement of the chemical, its metabolites or products of the interaction of the chemical or its metabolites with cellular macromolecules such as proteins or DNA in body fluids and tissues determines internal exposure . Use of such biomarkers provides exact information on actual internal exposure (target dose) to an agent (Angerer et al. 2007 Boogaard 2007 Needham et al. 2007). When used in experimental studies in animals and humans they allow assessment of the individual and internal exposure as compared to external exposure. 

Fluorocarbon compounds are lipid soluble and, thus, generally well absorbed through the lung. Absorption after ingestion is much lower than after inhalation. Most of the fluorinated hydrocarbons are immediately absorbed. 

Smoked cocaine is absorbed in seconds from the lungs, which results from volatilization of the alkaloid. Peak plasma concentrations occur within a few minutes. Absorption through mucous membranes is initially rapid, then slowed secondary to the vasoconstrictive effects of cocaine. Peak plasma concentrations occur within 1 h after oral ingestion and nasal application. After oral administration, bioavailability is decreased secondary to presystemic hydrolysis in the gastrointestinal tract. 

Chemicals may also be taken up by plants and animals from the environment. Plants can take up pollutants through roots or leaves, while animals can take in pollutants by ingestion of contaminated food or water, absorption through skin or gills, or inhalation into the lungs. Chemicals can be absorbed from the lungs by inhaled vapors or gases, particulate matter (e.g., dust), or aerosols (tiny droplets suspended in the... 

Exposure of mancozeb to humans can occur via absorption through the gastrointestinal tract, absorption through the skin or lungs. Human exposure to mancozeb, similar to maneb, has been calculated for... 

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