You've probably heard stories of newcomers who move to Southern California, buy a house, and later discover to their surprise that their home has a striking view of the mountains. Last year, one of the cleanest on record, east San Gabriel Valley residents couldn't see that far on one of every three days.
Many residents naturally associate haze and a lack of visibility with air pollution.
Even though some pollutants such as ozone and carbon monoxide cannot be seen, when people see haze, some assume they are looking at the effects of industrial and automotive air pollution. However, air quality trends do give us some clues. Morning fog can also contribute to particulate pollution. Emissions of sulfur oxide gases mix with water droplets in air to form sulfate particulate. By afternoon, the droplets have evaporated but the particulates remain in the atmosphere.