(Portland, OR) -- An Air Quality Advisory is in effect for Portland, Vancouver, Salem, Albany and Corvallis through this afternoon due to smoggy conditions. Authorities say smog levels will reach levels that could be unhealthy for sensitive groups, including children, pregnant women, older adults and people with heart disease or respiratory conditions. Those people should limit outdoor activity. You can help reduce smog by limiting driving, wait to use gas powered yard equipment and refuel vehicles when it's cooler.