Smoking toxic substances produced

TOXIC SUBSTANCES PRODUCED DURING SMOKING, CHARBROILING... 

Human exposure to ethylbenzene occms mainly via inhalation of vapour and/or mist and, to a smaller extent, by dermal contact or ingestion. Ethylbenzene is produced by the incomplete combustion of natural materials, making it a component of smoke from forest fires and cigarettes. It is also a constituent of asphalt and naphtha (Agency for Toxic Substances and Disease Registry, 1997a WHO, 1996a). 

Chemical mortar is a weapon(see under CANNONS) designed to fire shells contg toxic or harassing chemicals, substances producing screening smokes, or incendiaries. These shells are called chemical mortar shells. The term "chemical mortar is somewhat obsolete, because current US mortars are capable of firing, besides expl types of shells, also chem types(Refs 1,2 4)... 

Free radicals arise in the body from normal biochemical reactions and are also produced in the presence of toxic substances from cigarette smoke, polluted air, and other sources. They are quickly deactivated by picking up an electron to form a less-reactive molecule. Thus, the antioxidants are molecules that in one way or another are able to donate an electron to a free radical before it can do any damage. 

While purists would not consider the early use of Greek Fire and gunpowder-based incendiaries as true chemical warfare (CW), these early flame- and smoke-producing techniques have direct (and not-so-direct) connections with the modern use of toxic substances on the battlefield. 

Pyrotechnically generated smokes from grenades or powder clouds may not be acceptable from a safety point of view in certain circumstances for example, where fires may be produced, or in confined spaces with low rates of ventilation where asphyxial effects could develop. In order to reduce such potential hazards, a variety of approaches have been investigated. One of these is the use of highly volatile PCSI materials, which can be projected into enclosed spaces, but no material of sufficiently low toxicity has yet been found which is acceptable. An alternative approach is the use of a PCSI substance dissolved in a volatile solvent, and the mixture projected into the area by means of a pressurized aerosol canister or a frangible missile. This results in the development of an airborne vapor or aerosol of irritant (Ballantyne, 1979). 

Fumes, Smokes, and Dusts Solid particles of various sizes that are suspended in air. The particles may be formed by explosion or mechanical generation or as a by-product of chemical reaction or combustion. Fumes, smokes, and dusts may themselves be toxic or may carry, adsorbed to their surfaces, any of a variety of toxic gaseous substances. As these particles and surfaces collide, adsorbed gases may be liberated and produce local or even systemic toxic injury. 

Smokes and obscurants comprise a category of materials that are not used militarily as direct chemical agents. They may, however, produce toxic injury to the airways. The particulate nature of smokes may lead to a mechanical irritation of the upper and lower airways—therefore inducing bron-chospasm in some hypersensitive individuals (eg, those with asthma). Certain smokes contain chemicals with a degree of tissue reactivity that results in damage to the airways. A discussion of obscurant smokes is followed by a discussion of certain explosion-related (oxides of nitrogen) or pyrolysis-related (perfluoroisobutylene) substances that are important in military practice. 

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