Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. [ 1 ] Pollution can take the form of chemical substances or energy , such as noise, heat or light. Pollutants , the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or nonpoint source pollution . Ancient cultures Air pollution has always accompanied civilizations. Pollution started from prehistoric times when man created the first fires. According to a 1983 article in the journal Science, " soot found on ceilings of prehistoric caves provides ample evidence of the high levels of pollution that was associated with inadequate ventilation of open fires." [ 2 ] Metal forging appears to be a key turning point in the creation of significant air pollution levels outside the home. Core samples of glaciers in Greenland indicate increases in pollution associated wi...