July’s scorching heat wave created a “blanket of smog” from California to Maine, with the number of unhealthy days up from last year in 38 states, according to data compiled by a watchdog group.

Today, however, the word refers to the type of smog that forms in large cities, such as Los Angeles. Because this type of smog forms when chemical reactions take place in the presence of sunlight, it ...

WASHINGTON - About 170 million Americans now live in areas that the federal government says are too smoggy to be healthy, the U.S. Environmental Protection Agency will announce today. That's 60 ...

Every morning, when you step outside in the garden, you always wonder to see a soft white mist or a thick yellow haze in your garden. But do you ever realise that what you are seeing outside is this ...

Sunny skies and sizzling temperatures are coming Sacramento’s way — but the summer weather also brings the dangers of smog looming across the capital region. The haze is more than a blemish on the ...

The U.S. Environmental Protection Agency on Thursday adopted a stricter health standard for ozone, a lung-damaging component of smog. Here are some answers about the new rule: How stringent is the new ...