Air Quality Alerts Issued Across 11 States

Air quality alerts are in effect across at least 11 states, prompting health officials to advise residents to stay indoors and limit outdoor activity. The National Weather Service said alerts cover New Jersey, New York, Connecticut, Massachusetts, Rhode Island, New Hampshire, Maine, Pennsylvania, Delaware, and Maryland, along with parts of Southern California.

Alerts remain in effect from Tuesday morning through Tuesday evening.

Ground-level ozone is the main pollutant in the Northeast. The National Weather Service stated that vehicle and industrial emissions react with sunlight to form ozone, and hot, sunny conditions accelerate the process. High-pressure systems can trap pollutants and allow ozone levels to rise.

Major metropolitan areas including New York City, Long Island, northern New Jersey, and Philadelphia are under alert.

Southern California, wildfire smoke is affecting air quality in Los Angeles and Orange Counties. The Sandy Fire near Simi Valley is producing smoke that winds are carrying into populated coastal areas. Health officials said smoke can reach unhealthy levels for sensitive groups and contains fine particles that penetrate deep into the lungs.

Air pollution can irritate lungs and airways, trigger asthma attacks, and worsen heart and lung disease. The American Lung Association reported that over 129 million Americans were exposed to unhealthy ozone levels in recent years.