Search results
Results from the WOW.Com Content Network
Many gases have toxic properties, which are often assessed using the LC 50 (median lethal concentration) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits (TLV, TWA/PEL, STEL, or REL) determined by the ACGIH professional association.
The airways and lungs receive continuous first-pass exposure to non-toxic and irritant or toxic gases via inhalation. Irritant gases are those that, on inhalation, dissolve in the water of the respiratory tract mucosa and provoke an inflammatory response, usually from the release of acidic or alkaline radicals.
High CO levels build up in the pulmonary region over several hours, and equilibrate with inhaled CO concentrations. Exposure to carbon monoxide is dangerous because of its toxic, odorless nature. Since the gas takes time to build up in the pulmonary region, an inhaled concentration of 600 ppm would cause a headache and reduce mental capacity ...
Like most toxic gases, the dose inhaled determines the toxicity on the respiratory tract. Occupational exposures constitute the highest risk of toxicity and domestic exposure is uncommon. Prolonged exposure to low concentration of the gas may have lethal effects, as can short-term exposure to high concentrations like chlorine gas poisoning.
The lungs and the remainder of the respiratory tract are exposed to the highest concentration of oxygen in the human body and are therefore the first organs to show chronic toxicity. [28] Pulmonary toxicity occurs only with exposure to partial pressures of oxygen greater than 0.5 bar (50 kPa), corresponding to an oxygen fraction of 50% at ...
The density of the breathing gas is higher at depth, so the effort required to fully inhale and exhale increases, making breathing more difficult and less efficient (high work of breathing). [13] [3] [18] Higher gas density also causes gas mixing within the lung to be less efficient, thus increasing the effective dead space. [4] [5]
Pulmonary toxicity is the medical name for side effects on the lungs. Although most cases of pulmonary toxicity in medicine are due to side effects of medicinal drugs, many cases can be due to side effects of radiation (radiotherapy). Other (non-medical) causes of pulmonary toxicity can be chemical compounds and airborne particulate matter.
Some gases, such as propane and butane gases, are inhaled directly from the canister. Once these solvents or gases are inhaled, the extensive capillary surface of the lungs rapidly absorbs the solvent or gas, and blood levels peak rapidly. The intoxication effects occur so quickly that the effects of inhalation can resemble the intensity of ...