Metro Atlanta, already slogging through its smoggiest week this year, is expected to violate federal air quality standards again today.

Forecasters issued an orange alert today for Saturday. Public health officials advise children and people with heart and lung diseases, including asthma, to minimize outdoor activities when smog levels peak in the afternoon and early evening.

As of this afternoon, the region was on track to rack up its fifth consecutive federal violation for ground-level ozone, an ingredient in smog, according to the state Environmental Protection Division's web site (www.air.dnr.state.ga.us/amp/index.php).

On at least three of those days, the region would have violated the old, more lenient standard of 84 parts per billion of ozone. The new standard, in effect since March, is 75 parts per billion.

For more information, go to www.cleanaircampaign.com.