SAN FRANCISCO (CBS SF) — The Bay Area Air Quality Management District has issued another Spare the Air alert for Wednesday because of unhealthy levels of smog expected in the region.

It is the second-straight day the alert has been issued and ninth time overall this summer season, according to the air district.

A persistent high-pressure system over the Bay Area will lead to triple-digit temperatures and light winds in many areas, causing an unhealthy buildup of smog particularly in the East and South Bay.

Excessive amounts of smog, or ozone, can cause throat irritation, congestion and other medical problems, particularly for seniors, children and those with respiratory and heart conditions, according to the air district.

The district is encouraging Bay Area residents to do their part by finding alternatives to driving alone, such as carpooling or taking public transit.

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