Navigation at Sea, History of. The first Western civilization known to have developed the art of navigation at sea were the Phoenicians, about 4,000 years ago (c. 2000 B.C.E. ). Phoenician sailors accomplished navigation by using primitive charts and observations of the Sun and stars to determine directions.
Air pollution risk is a function of the hazard of the pollutant and the exposure to that pollutant. Air pollution exposure can be expressed for an individual, for certain groups (e.g. neighborhoods or children living in a county), or for entire populations.ther examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact.
Some types of air pollution are as follows. Smog: The first type of the air pollution is the smog. It is defined as when the smoke present in the atmosphere after emitting from different sources is combined with the fog present in the air, a mixture formed that is referred to as smog.ypes Of Air Pollution. Air pollution is one of the major problems of the present world. There are so many causes that can pollute the air completely and spread different types of dangerous diseases. On the basis of the different causes of air pollution it can be distinguished into different types.