Other Atmospheric Pollutants


  1. Volatile organic compounds, e.g. Polycyclic aromatic hydrocarbons (PAH?s)

    Because of their widespread use in fuels hydrocarbons predominate among organic atmospheric pollution. Unsaturated compounds such as PAH's are generally the result of the incomplete burning process. Being unsaturated these compounds are often more reactive and are associated with the formation of "photochemical" smog. Many compounds exhibit a carcinogenic ability.

  2. Inorganic Fluorine & Chlorine compounds

    Fluorine, hydrogen fluoride and other volatile fluorides are produced during the manufacture of Aluminium and phosphate fertilisers where they are found in the minerals from which these are mined. Hydrogen fluoride gas is dangerously toxic, irritating to body tissues and at the parts per thousand level may be fatal. Exposure to fluorides can cause fluorosis. Plants are particularly susceptible to the effects of gaseous fluorides. Chlorine was the first poisonous gas deployed in the 1st World War. It is used as a manufacturing chemical in the plastics industry and in water treatment. Incineration of chlorinated plastics releases hydrogen chloride, which rapidly dissolves in water vapour as hydrochloric acid.

  3. Organic oxides

    Such as ethylene and propylene oxide, used as intermediaries in the chemical industry and also as a fumigant and sterilant. Although only a limited potential to enter the environment these are known mutagen* and carcinogens.

  4. Organohalides (carbon based compounds containing fluorine, chlorine, bromine or iodine)

    These are widely used in industry, e.g. Di-chloromethane used in paint stripper, as a blowing agent in urethane polymer manufacture, Dichlorodifluoromethane used as a refrigerant, Vinyl chloride used in manufacture of pipe, hose and other PVC products. Poly chlorinated Bi-phenyls used as heat transfer and hydraulic fluids.

    Many of these compounds are known to have carcinogenic, mutagenic and teratogenic* properties and as they are generally difficult to break down build up in the food chain and in the environment.

  5. Organo nitrogen compounds, e.g. aniline

    Contaminants in this category include amines, amides, nitriles, nitro compounds, or heterocyclic nitrogen. Amines have a rotten fish odour an obvious reason why air contamination by this group is undesirable. Aniline, pyridine and naphthalenes are used in the manufacture of dyes, amides, photographic chemicals, drugs, pesticides, pigments, and curing agents. This group is of particular concern in the workplace as well as the general atmosphere as they are among some of the few chemicals whose carcinogenic behavior has been based on observations of humans.

* (Mutagen: alters DNA to produce inheritable traits, can therefore cause birth defects).
* (Teratogen: Materials classed as teratogenic, can kill the embryo or fetus or cause other damaging changes that can result in metal retardation, deformed organs or other birth defects. In males damage may occur to sperm chromosomes.)