Air pollution

Every smoking chimney turns out to be a source of air pollution. Home furnaces tended to burn soft coal incompletely, thus adding unburned carbon particles to the air.

The use of natural gas or oil that have a negligible mineral content is of great help in reducing pollution, but has the disadvantage of rapidly consuming materials which could better be conserved for future generation as raw materials for the manufacture, for example, chemicals and plastics.

It has been found that some chemical processes, such as the manufacture of lime, Portland cement, steel, tend to give off much dust. Lead, bromide and chloride emitted from the exhaust of automobiles which burn lead-containing gasoline produce a lead-chloride-bromide aerosol which is considered to be a common air contaminant in urban areas, it being toxic to people. The chief atmospheric gaseous pollutants originating from the earth’s surface appeared to be oxides of sulphur, oxides of nitrogen, incompletely burned hydrocarbons, and carbon monoxide.

These gases are known to react with energy from sunlight to produce photochemical smog. Smog not only can be highly irritating to eyes and lungs, but it can also cause extensive damage to vegetation.