Influence of meteorological factors on air pollution
Answers
The term "air pollution" is used so commonly that you may not think definitions are necessary. But the issue is more complicated than it first appears.
Ask most people to define air pollution, and their first response is to describe smog, the smelly stuff that turns the air brown or gray and hovers over urban centers like Los Angeles, Mexico City, and Beijing. Even here, though, definitions vary. Some sources define smog as the presence of unnatural levels of ground-level ozone, while other sources say things like "fog mixed with smoke." A more modern and precise definition is "a photochemical haze caused by the action of solar ultraviolet radiation on atmosphere polluted with hydrocarbons and oxides of nitrogen especially from automobile exhaust."
Officially, air pollution can be defined as the presence of harmful substances in the air, either particulates or microscopic biologic molecules, that pose health hazards to living organisms, such as people, animals or plants. Air pollution comes in many forms and may include a number of different pollutants and toxins in various combinations.
Air pollution is far more than a nuisance or inconvenience. According to a 2014 World Health Organization report, air pollution in 2014 caused the deaths of around 7 million people worldwide.