The air looks pretty clean to me. Whats the problem?
While some air pollution is visible along skylines as a haze or yellowish fog, many critical components of air pollution are clear. The Environmental Protection Agency (EPA) has identified pollutants, many of them invisible, which contribute to ground-level ozone (smog) and to negative health effects. The air may appear to be clean even though invisible pollutants in it present a danger to public health.
